92 Black GT
- Thread starter GT4LIFE
- Start date
More pictures of the wheel setup including spacers, volt rays dura lug nuts, and volt rays valve stem (gunmetal).
Blox Sport 60.1 to 73.1 5 mm wheel spacers with a custom bevel and an addiional two holes drilled in a 10x114.3 to go on our 4x114.3.
ARP Wheel Stud 100-7708 12x1.5 mm x 63.5 mm cut to 54 mm
The ARP wheel studs have a great knurl diameter (12.509 mm) to fit our 12.38 mm diameter holes width ( you can use a 1/2" drill bit perfectly). It also has a great knurl length of 8 mm with a 1 mm space under the head to fit our 9.5 mm hub thickness.
These our the 12 x 1.25 mm ones I returned.
The wheels are 15 x 6.5 4x114.3 45 offset with 195 R50 BF Goodridge G Force Sport Comp 2 tires on them at 10 lbs a piece.
Blox Sport 60.1 to 73.1 5 mm wheel spacers with a custom bevel and an addiional two holes drilled in a 10x114.3 to go on our 4x114.3.
ARP Wheel Stud 100-7708 12x1.5 mm x 63.5 mm cut to 54 mm
The ARP wheel studs have a great knurl diameter (12.509 mm) to fit our 12.38 mm diameter holes width ( you can use a 1/2" drill bit perfectly). It also has a great knurl length of 8 mm with a 1 mm space under the head to fit our 9.5 mm hub thickness.
These our the 12 x 1.25 mm ones I returned.
The wheels are 15 x 6.5 4x114.3 45 offset with 195 R50 BF Goodridge G Force Sport Comp 2 tires on them at 10 lbs a piece.
Teeth said:
Thanks. I got them for a good price. After all the work I am going to have to move them out a little bit more. I will have to go with a 7 mm or 10 mm spacer same company. I'm rubbing I'm pretty sure on the inside when I'm putting lateral force on hard cornering. 10 mm will bring me down to 35 mm offset and restore my scrub radius to how it was before. The exact offset on the wheels is 43.6 ish mm giving me a 33.6 offset. The tires grip like crazy going around a corner, but I do think I can notice the difference on a straight away where I think the scrub radius is probably close to being 0. Will I won't settle for the rub and don't want to waste money moving it 2 mm. I will have to measure how much 5 mm will put them out. If I'm lucky they won't be noticeable. With the H&R sport springs I don't think I'm going to rub on the fenders above.
It's a hard suggestion to make to someone that is rocking some wheels like that, but there's really nothing wrong with the cheapo aluminum wheel spacers. They aren't as pretty I suppose, but it's not like you can see them when the wheels are on--$20 and problem fixed...
Also, if you didn't know already, the track is different front and rear anyway, so there's no reason to space out the rear wheels other than how it looks (and IMO 10mm is not a huge difference visually) and you'll get more neutral or rear-biased handling if you don't.
Also, if you didn't know already, the track is different front and rear anyway, so there's no reason to space out the rear wheels other than how it looks (and IMO 10mm is not a huge difference visually) and you'll get more neutral or rear-biased handling if you don't.
Teeth said:
It is not rubbing from wheel turn but body flex/wheel movement up and down only in the rear. The spacing on the inside was pretty tight between tire and inside well. The front spacer would be fore getting less neutral or rear-biased handling and the rear to remove the rub. I'll spend the money to buy the hub centric ones. I noticed a much smoother rider at over 85 mph. However, It is hard to say if it is from the new wheel/tires and or the hubcentric spacers or combinations of them. Either way I don't think I could settle at this point. I figured the track was probably different, but never measured it. Thank you for the advice.
I'm just going to grab some text from my site on Geometroforum.com since it is at risk of going down. A lot of this will probably be out of order and need to be sorted. I just don't want to lose some of my thoughts on some of this stuff.
Images of what comes with the Goodridge Brake Lines:
Looking at these Dynapro Wilwood calipers:
https://www.summitracing.com/parts/wil-120-7376
and these Honda brackets:
11" rotor Honda kit bracket (250-8642)
https://www.ebay.com/itm/162881834996
12.19" rotor Honda kit bracket (1250-6289)
https://www.summitracing.com/parts/wil-250-6289?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-wilwood-disc-brakes&gclid=EAIaIQobChMI-Jqw-M_z2QIViFp-Ch3bJgJSEAQYASABEgKgGvD_BwE
Note!:These Honda brackets will not work on the Dynapro Wilwood calipers above. They need to use the Forged Dynalite Internal caliper 120-13839. Further information below on these calipers.
and these rotors: 285 mm diameter, 51 mm height, 64.1 mm bore
?, 21/19 mm thickness, 4 x114.3
https://www.ebay.com/itm/182889427424
I know that the Dynapro calipers have been used on other GT(i) builds, and further research has shown that those Honda brackets will not work with the Dynapro calipers. Additionally, I'm not 100% certain of the Rover 800 rotors either. The rotors fit the specs for the stock gt hubs, but their is still a chance of a clearance issue overall. Tomorrow I will get the inside diameter of my 15" wheels and go from their with the measurements of the brackets, calipers, and rotors. In the end it will come down to buying the calipers, and buying the rotors, and buying one of the brackets to test fit. Some of of this is information is from Redlinegti and some info on Teamswift. I also am trying to get a dxf file for a custom bracket made for the gt(i), but so far no luck. I know that the calipers will fit up to a 12.19" rotor and as small as 10.75", and the width of the rotor is in range also.
I will also have to buy something like these to convert the brake lines:
https://www.summitracing.com/parts/wil-220-0628
These ones will not work sense they are not 10mm x 1.0 threads.
There is additional talk about having to upgrade the master cylinder (increasing master cylinder diameter will decrease clamping force) to increase overall braking, but there is also talk that is not really true. Other conversations about upgrading just the brake booster and leaving the master cylinder alone. I'll try to do some test stops before and after to provides some real data. Tomorrow I'll throw on the the brake lines and freshen up the stock brakes and then do the testing. Hopefully this won't turn into a huge waste of money. I don't want something that just looks pretty. I wan't something that will cut down the 60 to 0 times. From video coverage on the 89 GTi from the release the 60 to 0 brake testing averaged 125 feet. The goal would be to get this under 100 feet.
Keeping my notes on this together: The 11.22"/ 285 mm disc will easily fit. I need to precisely measure everything with a mock up on my spare hub and see where everything actually sits. I thought earlier that the 12.10"/ 309.6 mm would fit, but looking more closely at how far out the caliper is from the disc (1.92") it will not fit these rims. I would need 13.62"/ 345.928 mm with 6.77"/ 172 mm radius from center to the outside of the caliper. It would have been sweet if the 12.10" fit, but the 285 mm disc is still 35 mm wider in diameter than stock.
Technically, it might be possible to choose a hat with a much larger offset say 2" and that would tentatively pull the caliper away from the front of the wheel and the inside diameter of the wheel is much larger at that point going from the smallest diameter of a 13.25" to around 13.75". There is only 19 mm/ 0.75" of clearance from the back side of the stock disc to the hub brake flange. Any larger offset than 1.41" will leave you with clearance issues for the bolt head to go. I think Wilwood does sell bolt kits that have less thick hex heads for this purpose (1.41" - 0.866" = 0.544"; 0.75 - 0.544 = 0.206", hex head would have to be less than this which might not be possible). In order to go larger than 1.41" you would have to have an inside hub clearance greater than 8.5". This would also put the bracket on the other side of the hub brake flange which would not be ideal, but I have seen examples of this done. Any larger offset than 1.036" and the bracket will have to go on the other side of the brake hub flange if your bracket width is .50". For reference the stock hub brake flange is only 13 mm/ 0.512" thick.
There are
Spec images:
Specific Measurement to my TE37 6.5 15" Wheels with 45 offset
(These measurement will be different from wheel to wheel, but I would aim for combined wheel offset of 35 mm)
Right now I have 1.54" from the tire mount to the brake disc (0.866"/22 mm offset +0.28"/7 mm face + 0.39"/10 mm I need to check and make sure that I have the clearance going out from the mount to fit the 1.93" total distance from disc. I only need .39" and .84 of the 1.93" goes into 1.25" radius 90 degree bend. . I have 0.50" past the wheel mount pad and only 13.25" at the pad diameter giving me a radius clearance of 6.625". The additional clearance was measured from the most narrow spot where the back of the wheel arms join the wheel side wall. If I take the measurement at .75" out I have approximately 19 mm of additional clearance. I believe the caliper bend radius will allow clearance out to the 19 mm. This additional clearance will greatly help. That hat (170-6996) I would have to use would be only 1.37" from disc surface with the 10 mm wheel spacer. 1.93 - 1.37 = 0.56". This would not fit (0.08" is the clearance needed for all parts). Wilwood does have another hat (170-10650) that would push it out to 1.09 (.83 offset + 0.26 face) + 10 mm = 1.484". 1.93" - 1.484 = 0.446. 0.446 + .080 =0.526 (I would have to see if I can get these in blanks since they are the wrong bolt pattern). The clearance would just work. With the first hat (170-6996) I would have to go with 15 mm spacers to make it work. 0.73 offset + 0.25 face + 0.59/15 mm spacer = 1.57". The hat (170-6996) combination will decrease my wheel offset by .76 mm. The hat (170-10650) combination will increase my wheel offset by 0.056"/ 1.44 mm. The third option would be the one piece Honda Acura Rover 800 rotors listed above. The offset and face thickness is not known, but the hat height is 51 mm. 51 mm - .81"/20.57 mm thickness = 30.43 mm + 10 mm spacer = 40.43 mm/ 1.59". This would decrease wheel offset by 0.05/ 1.27 mm. Mental note: decreasing wheel offset will push the wheel further out.
The stock offset is 0.866"/ 22 mm. Offset is distance between outside edge of disc and to the bottom edge of hat. It does not include the thickness of the face of the rotor. The stock front GT(i) rotors have a listed hat height of 50 mm (21 mm disc thickness + 22 mm offset + 7 mm for rotor face thickness). The rotors I measured have a 19 mm thick edge with a total hat height of 48 mm.
Wow I can spend hours trying to find the right rotors, hats, calipers, caliper brackets. Not only do I have to worry about clearance, but I have to calculate out total wheel offset. I'm think now that I will go with the hats because of the weight savings, diameter options for rotors, and other rotor options.
The verdict:
1. Almost every measurement is wheel specific. 15" is the minimum access for wheel disc size above 260 mm ish.
2. The disc thickness should remain at .81". You would not want to go higher which would just add weight, and lower would not dissipate heat correctly.
3. The stock rotor offset is 0.866"/22 mm (distance from hub mount/bottom of rotor face to the edge of front of disc). The offset should not exceed this amount and should not be too much less than this amount. If it exceeds this amount the thickness of the caliper bracket will have to decrease which is not ideal. If it is less you will have to use a larger wheel spacer in order to make clearance between the caliper and the wheel. Again I would aim to keep the wheel offset at 35 mm. You can put the bracket on the other side of the hub brake flange.
4. Caliper wheel clearance needs to be accounted for both outside edge and front back facing of wheel. The hat offset and thickness of face of rotor need to be added together when determine this clearance. Hat height is not the same thing as offset. Hat height is distance from back of disc/bottom of disc to top of facing. The stock hat height is roughly 50 mm (measured height was 48 mm (19 mm disc + 22 mm offset + 7 mm face). Disc will vary in thickness. For the Billet Dynapro 4 piston Wilwood Calipers there are 5 different bore sizes with a disc width of .81 (ones listed have dust boot and can come in red or black); add "RD" for red:
1.25" = 120-7374
1.38" = 120-7376
1.50" = 120-7327
1.62" = 120-7378
1.75" = 120-7380
I believe each one of these has a 1.93"/49 mm caliper width from disc to outer facing of caliper. Most of these calipers have a 1.25" radius cut on the outer edge of the caliper that will help with clearance.
5. The one piece rotor GD263 for Honda Legend Rover 800 that I listed should indeed work. It will add unsprung weight. However, the nice thing about this part is that the center bore is still 64.1 ish mm which is the same for the stock center bore. This means that the rotor will fit nicely to the hub without relying just on the two screws to fasten it down. The wheel center bore is 60.1, but the disc bore is 64.1. This was listed wrong on other sites. Additionally the width is .81, the diameter 285 mm, the hat height is 51 mm (1 mm more than the stock height), and the bolt pattern 4x114.3. I am not 100% on the inside diameter clearance which needs to be more than 5.25", but it should be. The 1 mm helps a lot with the caliper clearance and allow me to keep my 10 mm spacer.
6. The 11" Honda bracket may fit if I went with the caliper from the 11" Honda kit (140-8695) or 12.19" Honda kit (140-6163). The caliper is the same for both kits (120-13839) Forged Dynalite Internal. It has a 5.25 center mount that matches the bracket. I know that the kits are from a year and make of Honda that should be a direct fit caliper for the 89 to 94 gt(i) hub. You have to look closely at the dimensions and compare the caliper differences. It is a 1.38 bore size, 3.6lbs, no dust boot, different pads, and will require a greater radial clearance amounts on disc sizes over 11". The pad doesn't fit flush with the caliper edge like the calipers above. The 6x6.25 hats from the kit will not fit around our wheel hubs. You would have to custom make a hat to fit the 11" 2 piece rotors from the kit (I believe it is possible to lathe the 0.076" off to get clearance). You could also find a one piece rotor in the 260 mm range. The Forged Dynalite calipers would require a 16" wheel to clear 11.75" rotor. Side not these calipers can be used up to a 13" rotor.
The Dynapro radial calipers listed above in section 4 have a 5.98" mount center and not a 5.25" mount center. The Dynapro radial calipers above have a different mount system entirely so the Honda brackets above are not going to work with these calipers. They require the use of mounting bracket (250-6309) which comes with the calipers. They mount center for this bracket is 3.5" which needs to have a second bracket to get it to roughly our 5.5" mount center on our hubs. (Edit: this bracket will not work either). The advantage of the Dynapro calipers is the simple better brake pad mount system and that they should fit with 11.75 rotor under a 15" wheel. Here is a good section to include the difference between lug mounts and radial mounts. The radial mounts allow you two planes of adjustments to fit the caliper over the brake rotors. The lug mounts only give you one plane of adjustments with spacer/washers.
6. 2 Piece rotor and hat requires even more calculations. For starters none of the 6 x 6.25 hats list on Wilwood's catlog will fit due to the inside wheel hub clearance being less than 5.25. However, Summitracing hat 171-8975 that I received has a inside hub clearance of 5.6". If you want disc that are 10.75 or 11" this would work. If you want larger disc it leaves you with 8 x 7.00 hats which again would eliminate the 11" Honda kit. The 12" Honda kit has too small of an offset which would require a larger wheel spacer not to mention the bolt pattern would be wrong. The Wilwood hat 170-6996 will work with my wheels with a 15 mm spacer. There is a chance this will work with only my 10 mm spacer. This is a 8 x 7.00 hat with an inside wheel hub clearance of 5.90", center bore diameter of 2.72"/69 mm, 4x4.5 bolt patter, and weight of 1.6lbs . This hat has an offset of 0.73", and a face thickness of 0.25". The total distance from disc would be 0.98" and add a 15 mm/0.59" wheel spacer = 1.57". This should clear. I will have to design a bracket to work with this. No luck on getting the dxf file. The other option is to go with the 171-8976 hat which is a blank 8 x 7.00 hat with a center registration that is small enough to mill to 64 mm. The offset is 1.22" with a face of 0.26. The offset difference will more than likely force me to put the bracket on the other side of the hub brake mount. This does weight 2.2 lbs which is still not bad. This would solve any clearance issues and it is cheaper to buy, but will cost you to drill out the bolt pattern.
The 8 x 7.00 opens up a lot of 2 piece rotor options. My wheel clearance should allow me to have a 11.75" rotor. There are a bunch of options: plain, slotted,
Braking System Notes: Interesting to note that you only use two of the four pistons when calculating effective caliper piston area.
Additionally, I had not even thought to calculate in pedal ratio which I will need to measure. Does anyone know the pedal leverage ratio? I will have to run the numbers now and compare front leverage ratios with rear ratio and than calculate in line pressure. I will figure out all the numbers for the stock setup and then compare them with what happen when I change the front caliper bore size. This will at least allow me a glimpse of what I am messing with. Than I will have to find some formula for how disc diameter, thickness, and pad surface area will effect brake bias. I don't want to throw out the front rear bias to much. I know some people have messed with the proportioning valve to compensate and counter clamping force. If I can increase the clamping force a little in the front that will be okay.
The proportioning valve should only adjust the rear, and leaves pressure and leverage ratio on the front alone. Does anyone know what % of decrease the proportion valve does for the rear? I know I read somewhere on here. I also think it is different between a GT(i) and other models. I think T3ragtop talked about being able to adjust it in one of his threads. If I increase the front clamping force and if the proportioning valve is adjustable I can decrease the resistance in the proportioning valve slightly to offset the change.
Transmission is in, but I broke a water temperature sensor. I thought I could switch it out with the sensor from the 89 engine, but it is smaller then this one. I'll have to pick one up in town tomorrow. I still have some work ahead of me getting everything else back together.
I went ahead and took the radiator out so I could put on the sporty blue hoses. I like the look of them. I also switch out the distributor 'O' ring, and finally installing the right radiator mount. I'm not sure if the correct one is an auto or manual radiator. Either way I have the right one that is ground down and painted.
t3ragtop
Apr 12 2018, 03:07 PM
the brakes on a gt are already at a level where you really should be running good stainless braided brake hoses.
another thing to consider is that upgrading the gt brakes also pushes the limit on the master cylinder with its relatively small bore. massive multiple pot calipers require much more juice.
the reason for the stainless braided hoses is that when you stomp the pedal, the rubber brake hoses swell up with increased pressure. braking power is reduced when the hoses balloon up making the pedal feel and braking control like mush when you really need the brakes.
jardamuth at turbine tech was fond of using the larger bore brake masters from other suzuki models when he mounted larger calipers.
keep in mind that the brake proportioning valves on the sf413 chassis has an adjusting screw accessible by removing the stamped steel cap on top. all the proportioning valves for the various models of the sf413 production use the same basic valve body. they have differing part numbers that reflect the factory adjustment for pressure so that means that you can use any valve for custom pressure calibration.
when i converted my red twincam vert to 4 wheel discs borrowed from a gt, i still had to tweak the gt proportioning valve as the vert has a different weight distribution, hence different braking dynamics. that was even more pronounced on my turbo3 vert as there is a big difference in weight between the twincam and the turbo3. the weight of the twincam mill causes the vert's nose to dive more and as weight transfers to the front wheels, the ass end comes up higher taking more weight off the rear tires.
the turbo3 braking dynamics are affected less as the g10t is only a small bit heavier than the g10 that it came equipped with. the rear brakes lock up much quicker on that car.
again, the additional braking control that is gained by using the braided brake hoses is more than noticeable. you can feel things in the pedal and modulate the brakes right at the edge of locking them up, something that is impossible when using the factory rubber brake lines.
I was looking for your post on the adjustment part of the proportioning valve. Do you remember if it is just a turn mechanism? I will take a look at my spare proportioning valve.
I am already running BF Goodridge stainless steel brake lines. I could feel the difference when I changed them out, and not to mention they look a hell of a lot better.
I have never heard of the stop valve, but the idea makes sense. However, I am hesitant to give up the mechanical emergency brakes. I looked at the little guys that you mount in addition to a normal caliper, but the bracket design to accommodate that caliper and the other caliper seemed like more than I wanted to figure out. On the Wilwood Combo Parking Brake Caliper I will have to purchase some adapter to connect the cable. I am hoping that doesn't get to complicated either.
As far as the weight transfer I realized how helpful lowering the car can be. Technically speaking the best part of lowering a car that is almost never capitalized is adjusting the proportioning valve to give a little bit more pressure back to the rear brakes since less weight is transferring forward. My car is only lowered 1.4", but I'll take it.
The problem with increasing the size of the piston(s) of the master cylinder is that it will decrease the clamping force at every caliper. This is why on redlinegti that someone recommended not increasing the master cylinder, but instead switching out the brake booster for one that generates more force. The other thing that can be changed is the pedal leverage arm ratio. Both the pedal levrage arm ratio and the brake booster will increase the amount of force added to the equation without change the clamping force.
Example: Master cylinder 1"= surface area of 1x1x.785= .785 inches squared
Stock Maser cylinder .8125" = surface are of .8125 x .8125x .785= 0.518 inches squared.
Take the calipers that I'm buy 120-7380
Total surface area= 4.8 inches squared.
4.8 divided by .785 =6.1:1 x say foot pressure of 100lbs = 611 lbs per square inch of clamping pressure.
4.8 divided by 0.518 = 9.3:1 x say foot pressure of 100lbs= 930 lbs per square inch of clamping pressure.
611/930=34% decrease in clamping force. This would put the car almost right back to where the car starts with the same clamping force as the stock set up.
With a true dual master cylinder you would have the larger master cylinder for rear and a smaller master cylinder for the front, and you would not need a proportioning valve.
Without doing anything it will require further length of travel of the brake pedal to get the needed force to move the larger calipers. Hence why someone described the setup as a longer pedal feel.
Stock power brake booster has a diaphragm diamter of 6.60". I need to compare this with the Vitara brake booster. The 1999 to 2005 Grand Vitara has a brake booster diaphragm of 8.79". The 2006 to 2012 Grand Vitara has a diaphragm of 10.67". It looks to have the same mounts, but I would have to compare them first hand. I'm guessing the diameter of the 10.67 one would be to big for the space, but again I have no idea.
I called Wilwood today to see if they had some of the parts for the brakes as a kit to help cut the cost down. Nope! I also let them know about the error in their catalog. I figured that single error probably cost a lot of sales. I will check down the road to see if they change their catalog. Before I forget the rear brake calipers that I want have choices between 13, 6, and nothing on the end of their part number this refers to the clocking of the caliper bracket that it comes with. 13=1:00, 6= 6:00, and nothing is 10 to 11:00. It is adjustable anyways this is what it comes set as.
No real update other than I got the shims, bolts, and nuts in. The 12mm shims were wrong so I'm sending them back. I realized that Summit had changed the inside bore dimension back to 5.10 for the 6x6.25 hats that I ordered for the rear. I quickly ordered another one thinking maybe they were changing the actual size. I had spoken with a Wilwood rep before Summit had changed the size listing, and he said he was going to look into it. I got the second one in and instantly I measured both of the hats. The verdict is that the outer inside diameter is 5.6", but the inner inside is 5.10 before the 90 radius cut. It looks like the outer ends of the radius are flat for about and 1/8" at the edges of the diameter of inner inside diamter. If you add 0.125 x2 for both sides of the diameter + 5.10 it should clear with a 5.35". I will not know 100% until I have the center bore diameter lathed and I can drop in a rear spindle onto the hat. If worse comes to worse I can have something like a 1/16" lathed off the true inside diameter to make them work.
I fully switched over the fronts yesterday, but didn't have anyone on hand to help me bleed the brakes. The first time through for anything ends up taking extra time. I realized that my brackets technically need 1 mm more off the main mounting surface. It is close enough to run with it, but I think I'm going to have a 2nd set fabricated with all the little changes made. I will also have the 2nd set anodized.
I ended up shaving two corner edges of the two middle hex socket bolts for additional clearance. This gave me my .08 clearance between the inner wheel and the caliper. Loosing the 1 mm will give me just a little bit more clearance which I will feel more comfortable with.
The brake lines with the adapters work, but boy do I hate having to use unnecessary fittings. I did find a way to use the original 1/8-27 npt fitting to 3/8-24, but I hesitant to use them because the surface for the crush washer is not ideal. However, they are cheap and they remove the additional fitting. You have to drill out the inside bottom of the inverted flare, and have a 10mm x1.00 finishing tap. I currently don't have a camera to take pictures which means it will be a bit before I post up some new images to go with.
Online and a already uploaded image:
These ones will work, but you can see how thin the edge is on the female end. This would be the surface for the crush washer. You would also need to shave down the banjo bolt around 1/2" so it will bottom out.
I did finish the FreeCad designing of the rear brake caliper mount.
This turned out to be harder than the front. However, once you figure out how to use the program it is much easier. I will make all the dxf files available when I am done done. This is again for the Dynapro Low Profile Lug Mount with 11" rotors for the rear with a two piece hat with a .77 offset. I will have to double check the clearance, but a small two bolt rear mount side bracket should be possible to attach a small mechanical parking e-brake. The mount is symmetrical and works for both sides.
I figured out what the problem with bleeding was. It was just me being stupid. There is an inner and an outer bleed valve. You put a 7/16 box wrench around the larger fitting, and use a small 1/4 on the inner fitting. It was design to be super easy to bleed, but apparently it was so easy that it confused me. Anyways bleeding is done, and the brakes feel about right. I will have to wait for some better weather to test again. I caught a couple people looking at the front brake set up already. I think it just surprises people since they are on such a small car.
I changed my mind again; I still want the mechanical cables. I think the spacing will work if I build my own base plate to mount both from. The parking brake will be horizontal and the hydraulic hand brake will be vertical. The placement should allow me to almost set one on top of the other without direct interference.
The list for finishing the brakes:
1. Test just the finished fronts.
2. Purchase Suzuki Vitara Brake Booster.
3. Install booster, and test again.
4. Wait for 10% off for Summit again (maybe).
5. Purchase rear caliper sets. (Dynapro Low Profile Lugmounts, and Spot Parking/Emergency calipers)
6. Purchase rear 11" discs.
7. Make final changes to FreeCad file with actual parts on hand to measure some undisclosed geometry.
8. Design small spot caliper bracket.
9. Have brackets cut.
10. Install.
11. Purchase Hydraulic dual handbrake.
12. Build solid lines with correct fittings.
13. Double flare the stock lines in the middle.
14. Build base plaste.
15. Install.
16. Remove and anodize everything.
I have an engine rebuild which will happen before the hydraulic hand brake, but I will eventually get to everything.
Images of what comes with the Goodridge Brake Lines:
Looking at these Dynapro Wilwood calipers:
https://www.summitracing.com/parts/wil-120-7376
and these Honda brackets:
11" rotor Honda kit bracket (250-8642)
https://www.ebay.com/itm/162881834996
12.19" rotor Honda kit bracket (1250-6289)
https://www.summitracing.com/parts/wil-250-6289?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-wilwood-disc-brakes&gclid=EAIaIQobChMI-Jqw-M_z2QIViFp-Ch3bJgJSEAQYASABEgKgGvD_BwE
Note!:These Honda brackets will not work on the Dynapro Wilwood calipers above. They need to use the Forged Dynalite Internal caliper 120-13839. Further information below on these calipers.
and these rotors: 285 mm diameter, 51 mm height, 64.1 mm bore
?, 21/19 mm thickness, 4 x114.3
https://www.ebay.com/itm/182889427424
I know that the Dynapro calipers have been used on other GT(i) builds, and further research has shown that those Honda brackets will not work with the Dynapro calipers. Additionally, I'm not 100% certain of the Rover 800 rotors either. The rotors fit the specs for the stock gt hubs, but their is still a chance of a clearance issue overall. Tomorrow I will get the inside diameter of my 15" wheels and go from their with the measurements of the brackets, calipers, and rotors. In the end it will come down to buying the calipers, and buying the rotors, and buying one of the brackets to test fit. Some of of this is information is from Redlinegti and some info on Teamswift. I also am trying to get a dxf file for a custom bracket made for the gt(i), but so far no luck. I know that the calipers will fit up to a 12.19" rotor and as small as 10.75", and the width of the rotor is in range also.
I will also have to buy something like these to convert the brake lines:
https://www.summitracing.com/parts/wil-220-0628
These ones will not work sense they are not 10mm x 1.0 threads.
There is additional talk about having to upgrade the master cylinder (increasing master cylinder diameter will decrease clamping force) to increase overall braking, but there is also talk that is not really true. Other conversations about upgrading just the brake booster and leaving the master cylinder alone. I'll try to do some test stops before and after to provides some real data. Tomorrow I'll throw on the the brake lines and freshen up the stock brakes and then do the testing. Hopefully this won't turn into a huge waste of money. I don't want something that just looks pretty. I wan't something that will cut down the 60 to 0 times. From video coverage on the 89 GTi from the release the 60 to 0 brake testing averaged 125 feet. The goal would be to get this under 100 feet.
Keeping my notes on this together: The 11.22"/ 285 mm disc will easily fit. I need to precisely measure everything with a mock up on my spare hub and see where everything actually sits. I thought earlier that the 12.10"/ 309.6 mm would fit, but looking more closely at how far out the caliper is from the disc (1.92") it will not fit these rims. I would need 13.62"/ 345.928 mm with 6.77"/ 172 mm radius from center to the outside of the caliper. It would have been sweet if the 12.10" fit, but the 285 mm disc is still 35 mm wider in diameter than stock.
Technically, it might be possible to choose a hat with a much larger offset say 2" and that would tentatively pull the caliper away from the front of the wheel and the inside diameter of the wheel is much larger at that point going from the smallest diameter of a 13.25" to around 13.75". There is only 19 mm/ 0.75" of clearance from the back side of the stock disc to the hub brake flange. Any larger offset than 1.41" will leave you with clearance issues for the bolt head to go. I think Wilwood does sell bolt kits that have less thick hex heads for this purpose (1.41" - 0.866" = 0.544"; 0.75 - 0.544 = 0.206", hex head would have to be less than this which might not be possible). In order to go larger than 1.41" you would have to have an inside hub clearance greater than 8.5". This would also put the bracket on the other side of the hub brake flange which would not be ideal, but I have seen examples of this done. Any larger offset than 1.036" and the bracket will have to go on the other side of the brake hub flange if your bracket width is .50". For reference the stock hub brake flange is only 13 mm/ 0.512" thick.
There are
Spec images:
Specific Measurement to my TE37 6.5 15" Wheels with 45 offset
(These measurement will be different from wheel to wheel, but I would aim for combined wheel offset of 35 mm)
Right now I have 1.54" from the tire mount to the brake disc (0.866"/22 mm offset +0.28"/7 mm face + 0.39"/10 mm I need to check and make sure that I have the clearance going out from the mount to fit the 1.93" total distance from disc. I only need .39" and .84 of the 1.93" goes into 1.25" radius 90 degree bend. . I have 0.50" past the wheel mount pad and only 13.25" at the pad diameter giving me a radius clearance of 6.625". The additional clearance was measured from the most narrow spot where the back of the wheel arms join the wheel side wall. If I take the measurement at .75" out I have approximately 19 mm of additional clearance. I believe the caliper bend radius will allow clearance out to the 19 mm. This additional clearance will greatly help. That hat (170-6996) I would have to use would be only 1.37" from disc surface with the 10 mm wheel spacer. 1.93 - 1.37 = 0.56". This would not fit (0.08" is the clearance needed for all parts). Wilwood does have another hat (170-10650) that would push it out to 1.09 (.83 offset + 0.26 face) + 10 mm = 1.484". 1.93" - 1.484 = 0.446. 0.446 + .080 =0.526 (I would have to see if I can get these in blanks since they are the wrong bolt pattern). The clearance would just work. With the first hat (170-6996) I would have to go with 15 mm spacers to make it work. 0.73 offset + 0.25 face + 0.59/15 mm spacer = 1.57". The hat (170-6996) combination will decrease my wheel offset by .76 mm. The hat (170-10650) combination will increase my wheel offset by 0.056"/ 1.44 mm. The third option would be the one piece Honda Acura Rover 800 rotors listed above. The offset and face thickness is not known, but the hat height is 51 mm. 51 mm - .81"/20.57 mm thickness = 30.43 mm + 10 mm spacer = 40.43 mm/ 1.59". This would decrease wheel offset by 0.05/ 1.27 mm. Mental note: decreasing wheel offset will push the wheel further out.
The stock offset is 0.866"/ 22 mm. Offset is distance between outside edge of disc and to the bottom edge of hat. It does not include the thickness of the face of the rotor. The stock front GT(i) rotors have a listed hat height of 50 mm (21 mm disc thickness + 22 mm offset + 7 mm for rotor face thickness). The rotors I measured have a 19 mm thick edge with a total hat height of 48 mm.
Wow I can spend hours trying to find the right rotors, hats, calipers, caliper brackets. Not only do I have to worry about clearance, but I have to calculate out total wheel offset. I'm think now that I will go with the hats because of the weight savings, diameter options for rotors, and other rotor options.
The verdict:
1. Almost every measurement is wheel specific. 15" is the minimum access for wheel disc size above 260 mm ish.
2. The disc thickness should remain at .81". You would not want to go higher which would just add weight, and lower would not dissipate heat correctly.
3. The stock rotor offset is 0.866"/22 mm (distance from hub mount/bottom of rotor face to the edge of front of disc). The offset should not exceed this amount and should not be too much less than this amount. If it exceeds this amount the thickness of the caliper bracket will have to decrease which is not ideal. If it is less you will have to use a larger wheel spacer in order to make clearance between the caliper and the wheel. Again I would aim to keep the wheel offset at 35 mm. You can put the bracket on the other side of the hub brake flange.
4. Caliper wheel clearance needs to be accounted for both outside edge and front back facing of wheel. The hat offset and thickness of face of rotor need to be added together when determine this clearance. Hat height is not the same thing as offset. Hat height is distance from back of disc/bottom of disc to top of facing. The stock hat height is roughly 50 mm (measured height was 48 mm (19 mm disc + 22 mm offset + 7 mm face). Disc will vary in thickness. For the Billet Dynapro 4 piston Wilwood Calipers there are 5 different bore sizes with a disc width of .81 (ones listed have dust boot and can come in red or black); add "RD" for red:
1.25" = 120-7374
1.38" = 120-7376
1.50" = 120-7327
1.62" = 120-7378
1.75" = 120-7380
I believe each one of these has a 1.93"/49 mm caliper width from disc to outer facing of caliper. Most of these calipers have a 1.25" radius cut on the outer edge of the caliper that will help with clearance.
5. The one piece rotor GD263 for Honda Legend Rover 800 that I listed should indeed work. It will add unsprung weight. However, the nice thing about this part is that the center bore is still 64.1 ish mm which is the same for the stock center bore. This means that the rotor will fit nicely to the hub without relying just on the two screws to fasten it down. The wheel center bore is 60.1, but the disc bore is 64.1. This was listed wrong on other sites. Additionally the width is .81, the diameter 285 mm, the hat height is 51 mm (1 mm more than the stock height), and the bolt pattern 4x114.3. I am not 100% on the inside diameter clearance which needs to be more than 5.25", but it should be. The 1 mm helps a lot with the caliper clearance and allow me to keep my 10 mm spacer.
6. The 11" Honda bracket may fit if I went with the caliper from the 11" Honda kit (140-8695) or 12.19" Honda kit (140-6163). The caliper is the same for both kits (120-13839) Forged Dynalite Internal. It has a 5.25 center mount that matches the bracket. I know that the kits are from a year and make of Honda that should be a direct fit caliper for the 89 to 94 gt(i) hub. You have to look closely at the dimensions and compare the caliper differences. It is a 1.38 bore size, 3.6lbs, no dust boot, different pads, and will require a greater radial clearance amounts on disc sizes over 11". The pad doesn't fit flush with the caliper edge like the calipers above. The 6x6.25 hats from the kit will not fit around our wheel hubs. You would have to custom make a hat to fit the 11" 2 piece rotors from the kit (I believe it is possible to lathe the 0.076" off to get clearance). You could also find a one piece rotor in the 260 mm range. The Forged Dynalite calipers would require a 16" wheel to clear 11.75" rotor. Side not these calipers can be used up to a 13" rotor.
The Dynapro radial calipers listed above in section 4 have a 5.98" mount center and not a 5.25" mount center. The Dynapro radial calipers above have a different mount system entirely so the Honda brackets above are not going to work with these calipers. They require the use of mounting bracket (250-6309) which comes with the calipers. They mount center for this bracket is 3.5" which needs to have a second bracket to get it to roughly our 5.5" mount center on our hubs. (Edit: this bracket will not work either). The advantage of the Dynapro calipers is the simple better brake pad mount system and that they should fit with 11.75 rotor under a 15" wheel. Here is a good section to include the difference between lug mounts and radial mounts. The radial mounts allow you two planes of adjustments to fit the caliper over the brake rotors. The lug mounts only give you one plane of adjustments with spacer/washers.
6. 2 Piece rotor and hat requires even more calculations. For starters none of the 6 x 6.25 hats list on Wilwood's catlog will fit due to the inside wheel hub clearance being less than 5.25. However, Summitracing hat 171-8975 that I received has a inside hub clearance of 5.6". If you want disc that are 10.75 or 11" this would work. If you want larger disc it leaves you with 8 x 7.00 hats which again would eliminate the 11" Honda kit. The 12" Honda kit has too small of an offset which would require a larger wheel spacer not to mention the bolt pattern would be wrong. The Wilwood hat 170-6996 will work with my wheels with a 15 mm spacer. There is a chance this will work with only my 10 mm spacer. This is a 8 x 7.00 hat with an inside wheel hub clearance of 5.90", center bore diameter of 2.72"/69 mm, 4x4.5 bolt patter, and weight of 1.6lbs . This hat has an offset of 0.73", and a face thickness of 0.25". The total distance from disc would be 0.98" and add a 15 mm/0.59" wheel spacer = 1.57". This should clear. I will have to design a bracket to work with this. No luck on getting the dxf file. The other option is to go with the 171-8976 hat which is a blank 8 x 7.00 hat with a center registration that is small enough to mill to 64 mm. The offset is 1.22" with a face of 0.26. The offset difference will more than likely force me to put the bracket on the other side of the hub brake mount. This does weight 2.2 lbs which is still not bad. This would solve any clearance issues and it is cheaper to buy, but will cost you to drill out the bolt pattern.
The 8 x 7.00 opens up a lot of 2 piece rotor options. My wheel clearance should allow me to have a 11.75" rotor. There are a bunch of options: plain, slotted,
Braking System Notes: Interesting to note that you only use two of the four pistons when calculating effective caliper piston area.
Additionally, I had not even thought to calculate in pedal ratio which I will need to measure. Does anyone know the pedal leverage ratio? I will have to run the numbers now and compare front leverage ratios with rear ratio and than calculate in line pressure. I will figure out all the numbers for the stock setup and then compare them with what happen when I change the front caliper bore size. This will at least allow me a glimpse of what I am messing with. Than I will have to find some formula for how disc diameter, thickness, and pad surface area will effect brake bias. I don't want to throw out the front rear bias to much. I know some people have messed with the proportioning valve to compensate and counter clamping force. If I can increase the clamping force a little in the front that will be okay.
The proportioning valve should only adjust the rear, and leaves pressure and leverage ratio on the front alone. Does anyone know what % of decrease the proportion valve does for the rear? I know I read somewhere on here. I also think it is different between a GT(i) and other models. I think T3ragtop talked about being able to adjust it in one of his threads. If I increase the front clamping force and if the proportioning valve is adjustable I can decrease the resistance in the proportioning valve slightly to offset the change.
Transmission is in, but I broke a water temperature sensor. I thought I could switch it out with the sensor from the 89 engine, but it is smaller then this one. I'll have to pick one up in town tomorrow. I still have some work ahead of me getting everything else back together.
I went ahead and took the radiator out so I could put on the sporty blue hoses. I like the look of them. I also switch out the distributor 'O' ring, and finally installing the right radiator mount. I'm not sure if the correct one is an auto or manual radiator. Either way I have the right one that is ground down and painted.
t3ragtop
Apr 12 2018, 03:07 PM
the brakes on a gt are already at a level where you really should be running good stainless braided brake hoses.
another thing to consider is that upgrading the gt brakes also pushes the limit on the master cylinder with its relatively small bore. massive multiple pot calipers require much more juice.
the reason for the stainless braided hoses is that when you stomp the pedal, the rubber brake hoses swell up with increased pressure. braking power is reduced when the hoses balloon up making the pedal feel and braking control like mush when you really need the brakes.
jardamuth at turbine tech was fond of using the larger bore brake masters from other suzuki models when he mounted larger calipers.
keep in mind that the brake proportioning valves on the sf413 chassis has an adjusting screw accessible by removing the stamped steel cap on top. all the proportioning valves for the various models of the sf413 production use the same basic valve body. they have differing part numbers that reflect the factory adjustment for pressure so that means that you can use any valve for custom pressure calibration.
when i converted my red twincam vert to 4 wheel discs borrowed from a gt, i still had to tweak the gt proportioning valve as the vert has a different weight distribution, hence different braking dynamics. that was even more pronounced on my turbo3 vert as there is a big difference in weight between the twincam and the turbo3. the weight of the twincam mill causes the vert's nose to dive more and as weight transfers to the front wheels, the ass end comes up higher taking more weight off the rear tires.
the turbo3 braking dynamics are affected less as the g10t is only a small bit heavier than the g10 that it came equipped with. the rear brakes lock up much quicker on that car.
again, the additional braking control that is gained by using the braided brake hoses is more than noticeable. you can feel things in the pedal and modulate the brakes right at the edge of locking them up, something that is impossible when using the factory rubber brake lines.
I was looking for your post on the adjustment part of the proportioning valve. Do you remember if it is just a turn mechanism? I will take a look at my spare proportioning valve.
I am already running BF Goodridge stainless steel brake lines. I could feel the difference when I changed them out, and not to mention they look a hell of a lot better.
I have never heard of the stop valve, but the idea makes sense. However, I am hesitant to give up the mechanical emergency brakes. I looked at the little guys that you mount in addition to a normal caliper, but the bracket design to accommodate that caliper and the other caliper seemed like more than I wanted to figure out. On the Wilwood Combo Parking Brake Caliper I will have to purchase some adapter to connect the cable. I am hoping that doesn't get to complicated either.
As far as the weight transfer I realized how helpful lowering the car can be. Technically speaking the best part of lowering a car that is almost never capitalized is adjusting the proportioning valve to give a little bit more pressure back to the rear brakes since less weight is transferring forward. My car is only lowered 1.4", but I'll take it.
The problem with increasing the size of the piston(s) of the master cylinder is that it will decrease the clamping force at every caliper. This is why on redlinegti that someone recommended not increasing the master cylinder, but instead switching out the brake booster for one that generates more force. The other thing that can be changed is the pedal leverage arm ratio. Both the pedal levrage arm ratio and the brake booster will increase the amount of force added to the equation without change the clamping force.
Example: Master cylinder 1"= surface area of 1x1x.785= .785 inches squared
Stock Maser cylinder .8125" = surface are of .8125 x .8125x .785= 0.518 inches squared.
Take the calipers that I'm buy 120-7380
Total surface area= 4.8 inches squared.
4.8 divided by .785 =6.1:1 x say foot pressure of 100lbs = 611 lbs per square inch of clamping pressure.
4.8 divided by 0.518 = 9.3:1 x say foot pressure of 100lbs= 930 lbs per square inch of clamping pressure.
611/930=34% decrease in clamping force. This would put the car almost right back to where the car starts with the same clamping force as the stock set up.
With a true dual master cylinder you would have the larger master cylinder for rear and a smaller master cylinder for the front, and you would not need a proportioning valve.
Without doing anything it will require further length of travel of the brake pedal to get the needed force to move the larger calipers. Hence why someone described the setup as a longer pedal feel.
Stock power brake booster has a diaphragm diamter of 6.60". I need to compare this with the Vitara brake booster. The 1999 to 2005 Grand Vitara has a brake booster diaphragm of 8.79". The 2006 to 2012 Grand Vitara has a diaphragm of 10.67". It looks to have the same mounts, but I would have to compare them first hand. I'm guessing the diameter of the 10.67 one would be to big for the space, but again I have no idea.
I called Wilwood today to see if they had some of the parts for the brakes as a kit to help cut the cost down. Nope! I also let them know about the error in their catalog. I figured that single error probably cost a lot of sales. I will check down the road to see if they change their catalog. Before I forget the rear brake calipers that I want have choices between 13, 6, and nothing on the end of their part number this refers to the clocking of the caliper bracket that it comes with. 13=1:00, 6= 6:00, and nothing is 10 to 11:00. It is adjustable anyways this is what it comes set as.
No real update other than I got the shims, bolts, and nuts in. The 12mm shims were wrong so I'm sending them back. I realized that Summit had changed the inside bore dimension back to 5.10 for the 6x6.25 hats that I ordered for the rear. I quickly ordered another one thinking maybe they were changing the actual size. I had spoken with a Wilwood rep before Summit had changed the size listing, and he said he was going to look into it. I got the second one in and instantly I measured both of the hats. The verdict is that the outer inside diameter is 5.6", but the inner inside is 5.10 before the 90 radius cut. It looks like the outer ends of the radius are flat for about and 1/8" at the edges of the diameter of inner inside diamter. If you add 0.125 x2 for both sides of the diameter + 5.10 it should clear with a 5.35". I will not know 100% until I have the center bore diameter lathed and I can drop in a rear spindle onto the hat. If worse comes to worse I can have something like a 1/16" lathed off the true inside diameter to make them work.
I fully switched over the fronts yesterday, but didn't have anyone on hand to help me bleed the brakes. The first time through for anything ends up taking extra time. I realized that my brackets technically need 1 mm more off the main mounting surface. It is close enough to run with it, but I think I'm going to have a 2nd set fabricated with all the little changes made. I will also have the 2nd set anodized.
I ended up shaving two corner edges of the two middle hex socket bolts for additional clearance. This gave me my .08 clearance between the inner wheel and the caliper. Loosing the 1 mm will give me just a little bit more clearance which I will feel more comfortable with.
The brake lines with the adapters work, but boy do I hate having to use unnecessary fittings. I did find a way to use the original 1/8-27 npt fitting to 3/8-24, but I hesitant to use them because the surface for the crush washer is not ideal. However, they are cheap and they remove the additional fitting. You have to drill out the inside bottom of the inverted flare, and have a 10mm x1.00 finishing tap. I currently don't have a camera to take pictures which means it will be a bit before I post up some new images to go with.
Online and a already uploaded image:
These ones will work, but you can see how thin the edge is on the female end. This would be the surface for the crush washer. You would also need to shave down the banjo bolt around 1/2" so it will bottom out.
I did finish the FreeCad designing of the rear brake caliper mount.
This turned out to be harder than the front. However, once you figure out how to use the program it is much easier. I will make all the dxf files available when I am done done. This is again for the Dynapro Low Profile Lug Mount with 11" rotors for the rear with a two piece hat with a .77 offset. I will have to double check the clearance, but a small two bolt rear mount side bracket should be possible to attach a small mechanical parking e-brake. The mount is symmetrical and works for both sides.
I figured out what the problem with bleeding was. It was just me being stupid. There is an inner and an outer bleed valve. You put a 7/16 box wrench around the larger fitting, and use a small 1/4 on the inner fitting. It was design to be super easy to bleed, but apparently it was so easy that it confused me. Anyways bleeding is done, and the brakes feel about right. I will have to wait for some better weather to test again. I caught a couple people looking at the front brake set up already. I think it just surprises people since they are on such a small car.
I changed my mind again; I still want the mechanical cables. I think the spacing will work if I build my own base plate to mount both from. The parking brake will be horizontal and the hydraulic hand brake will be vertical. The placement should allow me to almost set one on top of the other without direct interference.
The list for finishing the brakes:
1. Test just the finished fronts.
2. Purchase Suzuki Vitara Brake Booster.
3. Install booster, and test again.
4. Wait for 10% off for Summit again (maybe).
5. Purchase rear caliper sets. (Dynapro Low Profile Lugmounts, and Spot Parking/Emergency calipers)
6. Purchase rear 11" discs.
7. Make final changes to FreeCad file with actual parts on hand to measure some undisclosed geometry.
8. Design small spot caliper bracket.
9. Have brackets cut.
10. Install.
11. Purchase Hydraulic dual handbrake.
12. Build solid lines with correct fittings.
13. Double flare the stock lines in the middle.
14. Build base plaste.
15. Install.
16. Remove and anodize everything.
I have an engine rebuild which will happen before the hydraulic hand brake, but I will eventually get to everything.
This thread is just full of intense awesomeness! Keep up the good work man. It’s a bummer about GMF. This is just not a good year for the forums!
I have all the parts for the rear brakes, but my machinist went on a well deserved vacation. I hoping by the end of the month I will get the rear brackets made. At that point I can move onto the emergency brake components. In the meantime I am about to buy the rest of the component parts for my stainless steel turbo manifold. I am contemplating between schedule 10 and schedule 40 1 1/2" pipe. I will build a jig, and just spot the component together and have a welder take care of the rest. I'm am buying a 4 to 1 collector that already has a t3 turbo flange on it. I will buy an adapter for now to match up to the RBH5vj11 turbo I have on hand. In the long run I would really like a slightly larger turbo with a twin scroll design.
Still waiting on the brake parts, and since all I have time for is work I can wait. However, as above I'm starting to purchase parts for the turbo system (long over due) and am looking at a few different contenders. Remember this car is my daily driver, and I'm not looking to go over 200 whp. One of the contenders is a Turbonetics T3 50 ball bearing unit. I have ran the top end cfm numbers on the compressor chart at 216 cfm.
(79.3 x 6500 rpm x 0.5 x 1.01)/1728 = 150 cfm
With different chip or standalone: (79.3 x 8500 rpm x 0.5 x 1.01) / 1728 =197 cfm
I ran the numbers again at 8500 which is where I imagine I don't want to run past all that often irregardless of how well I have the engine rebuilt. I did bump the volumetric efficiency for what I think a different cam grind would provide.
(79.3 x 8500 x 0.5 x 1.11 % / 1728 = 216 cfm ) this would be the high side of what I would run a compressor map for matching a turbo. 216 cfm is just under 18 lbs per minute.
The fit on the compressor map is quite nice.
Turbonetics:
T3-50 CAST part # 20268T compressor: inducer: 1.674" (42.5mm) exducer: 2.367" (60mm) 3" 2.00" 20374-3 T3
It uses an F1-49 turbine which has an exducer of 1.929" (49 mm). The inducer is 2.320" (58.9mm) 69 Trim
There are multiple A/R for the turbine .48, .63, .65, and .85
Anyone running this unit?
Anyone know if this unit comes water-cooled? I'll try calling them tomorrow.
Anyone have some feedback between running a .48 or .63 turbine housing?
Anyone have a recommendation for another turbo?
Any other feedback would be welcome.
I do have a IHI RBH5 vj11 Mazda/Ford turbo on hand, but I don't really want to run it.
(79.3 x 6500 rpm x 0.5 x 1.01)/1728 = 150 cfm
With different chip or standalone: (79.3 x 8500 rpm x 0.5 x 1.01) / 1728 =197 cfm
I ran the numbers again at 8500 which is where I imagine I don't want to run past all that often irregardless of how well I have the engine rebuilt. I did bump the volumetric efficiency for what I think a different cam grind would provide.
(79.3 x 8500 x 0.5 x 1.11 % / 1728 = 216 cfm ) this would be the high side of what I would run a compressor map for matching a turbo. 216 cfm is just under 18 lbs per minute.
The fit on the compressor map is quite nice.
Turbonetics:
T3-50 CAST part # 20268T compressor: inducer: 1.674" (42.5mm) exducer: 2.367" (60mm) 3" 2.00" 20374-3 T3
It uses an F1-49 turbine which has an exducer of 1.929" (49 mm). The inducer is 2.320" (58.9mm) 69 Trim
There are multiple A/R for the turbine .48, .63, .65, and .85
Anyone running this unit?
Anyone know if this unit comes water-cooled? I'll try calling them tomorrow.
Anyone have some feedback between running a .48 or .63 turbine housing?
Anyone have a recommendation for another turbo?
Any other feedback would be welcome.
I do have a IHI RBH5 vj11 Mazda/Ford turbo on hand, but I don't really want to run it.
t3ragtop
Moderator
In practice, the RHB 5 turbo works really well for a medium pressure system.
If you price the Turbonetics why not get a quote from our old benefactor, jess Tremblay (Jardamuth) at Turboms.ca ?
If you price the Turbonetics why not get a quote from our old benefactor, jess Tremblay (Jardamuth) at Turboms.ca ?
Sure why not.t3ragtop said:In practice, the RHB 5 turbo works really well for a medium pressure system.
I ran the compressor map for it and it is a nice fit. However, I would probably want to rebuild it just be safe. I have rebuilt one before. At that point I'm $300 in and time is money. I'm sure it would run for a while just fine, but the rear end seals tend to go and leak oil throughout the system. I don't really want to match that flange to the manifold and would prefer a t3 flange which gives me options down the road.
If you price the Turbonetics why not get a quote from our old benefactor, jess Tremblay (Jardamuth) at Turboms.ca ?
I crunched out on FreeCad today a file to cut out flanges to go from a vj11 to a t3 flange. This will be in the form of a dxf file. I'm not sure why this was never made before since most Probe or Mx-6 owners would benefit from this. There was a flange that was close online, but the measurements would not have worked. This will be 1/2" thick. There may be some obstacles with the bolts. You will need button 10.9 8mm x 1.25 or grind down some 12.9 zinc plated 8mm x1.25 socket cap screws x 1" (x4). I will leave the flange drilled but unthreaded, but most t3 flanges are 10 mm x 1.5. The inner will need to be ground to adjust to the t3 since I couldn't get it right on the program. The 8mm heads will recess up into the flange and you simply screw in 10mm studs that stick out from the other set of holes. I will be using this to go from a t3 merge collector with external wastgate hole to the vj11. This way I won't have to cut anything off or weld things again. It is also cheaper to buy the cast t merge collector than have someone weld it up.
91 ragtop
New member
Where did you get that collector from ?
Ken............
Ken............
91 ragtop said:
That collector is available from Threadstoneperformance.com. It is over $100, but time is money, and I would have to spend over that just to have someone weld it up as nice. The design is also nice in the fact that it is so short and it has the external wastegate port. I will simply put a plug over that for now leaving it a super nice option for later.