[GT4LIFE]

I’ll just post up some component numbers and odds and ends before I forget everything before it is finally finish.

1. Stainless steel ⅜″ exhaust flange cut from the file above (every bit of room is critical. I would not go ½″) Edit: I would go with ¾ mild steel and just have it planed to what ever thickness you want after the fact.
2. Treadstone Performance 304 stainless cast T3 merge collector (buy it off Ebay for a significant savings vs buying it direct).
3. Nine 1 ½″ long schedule 10 stainless 304 steel 90 degree pieces
4. Five total 1 ½″ short schedule 10 stainless steel 304 90 degree pieces
   (two of the five are cut down significantly from two separate short 90)
5. One 1 ½″ by one foot straight schedule 10 stainless steel 304 (used every last bit of it; absolutely no room to mess up on the straight).
6. One strip of 1″ by ⅛″ straight mild steel bar to connect both flanges at start.
7. One 38 mm wastegate block of flange
8. One custom built T3 to IHI RBH5 adapter bracket; mild steel.
9. T3 gasket flange (comes in packet of two)

After test fit I’ll post up some measurements to locate merge collector in position with manifold exhaust flange. Rough it .80″ towards passenger side, and bottom of merge coll front edge is roughly even with lower exhaust manifold holes at center. The merge collector flange itself is at a 10 to 15 degree angle raising up as it goes toward the front of the car.

[91 ragtop]

Have you gotten this welded up yet ?


Ken.........

[GT4LIFE]

Have you gotten this welded up yet ?


Ken.........

Nope. Instead of spending the long weekend off on the car I ended up spending it on the house with a 1/2 kitchen remodel that occurred just by adding a new frig. Water, electrical, cabinets, paint. If only they would of done this stuff with a $100 install. Maybe it is worth it because now for the first time in my life I have a working ice maker. The good news is I have 19 work days left, and one of the first things I will do is test fit the manifold and have it welded up.

[GT4LIFE]

It is back from the welders. It looks good. I was a little disappointed that he didn't back purge with argon. There is no sugar crystal on the inside of the header that I can see. He said that it didn't need to be back purged because it was thick enough material. However, the o2 housing downpipe does have a little bit, but still not much because that was thinner material. I do have to fix the flange tab on the header; the one that goes around the longer stud on the top driverside. It bowed out almost 1/8". I will strap it down to the parts head that I have (questionable on its usability) and hit that tab with some heat and torque down the two nuts as I apply heat, and then let it cool down. I was already planning on having all the flanges belt sanded flat, but that tab would force me to take off an 1/8" minimum. I'll post up some images soon.

[GT4LIFE]

After being welded:

[GT4LIFE]

Flanges are finally planed. It cost an arm and a leg to have them correctly planed. I’ll post up some pictures of the flanges. They are truly flat which is important. The exhaust manifold lost a little over 1/16″. The ⅜″ is now a little over a ¼″.

[GT4LIFE]

Finished Manifold + O2 Housing/Downpipe:










Things to remember if I do another one update:

1. Mild steel exhaust manifold flange ⅝ to ¾″
2. Use Schedule 10 1.5″ stainless for most of the runners except use schedule 20 or 30 for first section of runner that welds to manifold. This will make the first part of the runner a lot closer to the engine exhaust port diameters. I had to grind the flange to try to port match. You will still need to port match from schedule 20 to schedule 10, but that is way easier to do before tack welding.
3. Way easier to just buy a small t3 flanged turbo then make adapter plate.

Port matched flange:

[Sea Bass]

Beautiful work!

[GT4LIFE]

I just wanted to follow up with some additional suggestions after driving with the manifold and turbo setup for ½ a year.

I still need to take the manifold back off to wrap.

The 1.5″ schedule 10 really opens up the 52 mm turbo with a 76 A/R turbine ratio in 5th gear above 5000 rpms. I pulls like a beast off the end my speedometer gauge. However, I’m not sure if it really needs the 1.5″ runners since the the turbine A/R actually needs to be slight smaller maybe a .63 A/R or even a .48 A/R (for daily driver). There are not much options with the IHI RHB5200 turbo I’m using, but I’m thinking to the next turbo. I’m really looking at the Turbonetics T3 50 and buying it with the .48 turbine A/R and also picking up there .63 A/R turbine casing. This turbo does have a slightly larger than 52 mm turbine inducer. In connection to this I think that if I did it over I could get away with 1.25″ schedule 10 with an outside diameter of 1.66″ and an inside diameter of 1.44″. This would lighten the entire manifold (up 2 lbs) and make the cutting and bends a lot easier. I also think that this would port match easier with the engine exhaust outlet diameter. I believe off memory that the exhaust outlets on the g13b are exactly 1.5″ this would make it a small step down really of only .03″ (1.5-1.44= .06/2 = .03″). That is really an insignificant port change. The ports on the flange could be cut to 1.44″ and port matched to the 1.5″. Right now with schedule 10 1.5″ the outside diameter is 1.9 with an inside diameter of 1.682″. This creates a step up from 1.5 to 1682 of .182″/2 = .091″ which is a significant change. I port matched it with the thickness of the flange as best I could. The down side to using 1.25 schedule 10 would be that the cast merge collector I used is 1.5″. This would require using a reducer in reverse 1.25 back to 1.5″. The other good thing would be that the materials will be slightly cheaper.

[Instant_shine]

Nice work man!