I have a single T76 right now but I can get a GT35 and was thinking getting another one on my 6.2 L9H since with this T76 and a GT45 I start getting bad knock once I push it much past 10 lbs. Looking at the drivers side header on the passenger side but flipped pointed up it looks good and clears the valve cover and coils good, but the biggest problem is the steering shaft and having to figure out how to get the exhaust output out of the turbine under the truck:





Looking at the passenger side manifold it looks more promising. I can't fully seat it in its place unless I cut the flange off which I plan on probably doing to make a pie cut bend or either weld on my own flange or maybe V-band it (but I hate v-bands but given the space constraints they probably make the most sense). There is definitely more room to run the turbine output exhaust and try to get it by the steering shaft. I guess maybe the brake lines could move but that seems like it would be a pita getting into that or maybe trying to re-bend them or maybe replacing them with a flexible braided steel line section. Another thing is I guess I can find aftermarket plug wire with 90 degree bends that I think would help them fit better with the manifolds flipped up I hope. I think I would probably use 2.5 in pipe on the turbine outlets and looks like it might fit by the steering shaft. I am just wondering if anyone has ever been able to accomplish anything like this since I haven't found any proof, I know the production kits I think rotate the turbo and also use fabricated shorty headers which I want to use the stock manifolds because I have a bunch I need to do something with and plus they are very good at damping noises unlike stainless headers:

 

Some one here did it before but I don't remember who. I think it was a GMT800 truck
I had Smoke Shows last truck and I believe he used GTO manifolds to do it.

EDIT: I stand corrected. V2 CTS-V Manifolds

 

 

V2 CTS-V manis

 

Thanks, the CTSV manifolds look like they would be perfect to put the turbo in the right place.

However the delusional ebay prices don't look as good haha. They are almost as much as the GM list price which makes no sense to me but I guess when you're bidding against the world it might make more sense.

Did you end up cutting them manifolds and putting your own flanges on? And did you put extra pipe on it to locate the turbo? I am thinking maybe trying to pie cut schedule 40 which would be thicker than just regular exhaust tube and I feel like it would be easier to weld without blowing through and the pie cuts should give me tighter turns to get where I need to. Did you have issues with plug wire routing? Or anything else burning/getting to hot from the manifolds being upside down?

 

Also forgot to ask, it looks like you had to extend the factory wire harness? The ones that comes from the ECM connectors? Or were you able to just reroute them behind the brake booster?

 

I know he re routed the harness. Not sure if anything was extended. The Coil packs were mounted down low on the shock stud.

They were mounted on the top of the shock's with an extra nut. I Used the longest Spark Plug cables they had at the Auto parts store when I had to replace them. I think they were listed as 12-14 inches total length. Due the variation in Coil packs from the factory they usually have 2 different size available.


He did not cut the flange off the manifolds he re-used the OE style flange and added pipe up to the turbo. I might have a picture of 1 of the pipes when it was apart.

 

If you look close to the Center of the valve cover to the back of the turbo you can see the pipe fabbed up to it, It's wrapped in heat wrap.

Maybe he has some of the build pictures he can share.

 

Found his old build thread on that truck.

https://www.performancetrucks.net/fo...rience-544437/

One of his older trucks he used different Twin Turbskies but same CTS-V Exhaust manifolds.

https://www.performancetrucks.net/fo...511097/page13/

 

Thanks for finding all that. It's good to know it can be done. As far as I know I think the main difference between the GMT800 and 900 would be the 4wd trucks still had recirculating ball steering so the steering shaft I think is a little different, but I think most everything else is about the same layout besides the coil springs on the 900 which I think leaves a little less room.

I used to bash twin setups just because I thought people were just doing it because it was cool to have 2 turbos. But then you realize just how much turbo you really need especially with 6.2 liters of displacement. And not only do you get a more symmetrical look, to me the exhaust routing would be as simple or more simpler I think than doing a single and having to have a stupid crossover pipe since with twins I can technically should be able to route the exhaust from the turbo back 100% just like stock and use the stock cats. Right now with my single I just have the secondary single big cat and although it sounds about like stock with the stock muffler and resonator and piping, I can tell the tuning of the resonator is off a little and having the cheap Chinese supposed 304 stainless crossover with no cat on it makes a lot of crappy broken and beat up work van noise.