help me design my sbc single front mount turbo system
#11
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Today I found out there are two local welders that can weld stainless. I knew the one could tig weld aluminum and is damn good at it but was unaware he works with stainless. The other one I've known forever but didn't know he had a tig welder but knew he was able.
I'm not against stepping up to any size of anything. Thats why I'm asking before I go and buy anything. Schedule 40 butt weld 90s are available in 3 inch, that being 3 inch ID and 3 1/2 inch OD. That should be plenty beefy to support a turbo. So lets say I made the passengers side with a 1/2 inch thick header flange, stainless 1 1/2 inch (1 5/8 ID) schedule 40 primaries and a stainless 3 inch (3 inch ID) schedule 40 log with a T6 flange. That would mean the crossover would also need to be made from 3 inch (OD on exhaust pipe) stainless with possibly a flex joint in the middle like KB posted above. If I use 304 stainless on everything hot side including the down pipe is there any reason why I can't heat wrap everything? From the down pipe back I will use aluminized steel 4 inch as I've already got the MBRP muffler and tailpipe.
I'm getting some mixed opinions on the waste gate location. If I build my own header which I am and tilt it out towards the fenderwell to make clearance between the turbo and AC compressor this will also make room for the waste gate too right at the very end of the system just before the curve up to the turbo flange. Then I could easily route it back to the down pipe and keep the thing quiet.
I'm not against stepping up to any size of anything. Thats why I'm asking before I go and buy anything. Schedule 40 butt weld 90s are available in 3 inch, that being 3 inch ID and 3 1/2 inch OD. That should be plenty beefy to support a turbo. So lets say I made the passengers side with a 1/2 inch thick header flange, stainless 1 1/2 inch (1 5/8 ID) schedule 40 primaries and a stainless 3 inch (3 inch ID) schedule 40 log with a T6 flange. That would mean the crossover would also need to be made from 3 inch (OD on exhaust pipe) stainless with possibly a flex joint in the middle like KB posted above. If I use 304 stainless on everything hot side including the down pipe is there any reason why I can't heat wrap everything? From the down pipe back I will use aluminized steel 4 inch as I've already got the MBRP muffler and tailpipe.
I'm getting some mixed opinions on the waste gate location. If I build my own header which I am and tilt it out towards the fenderwell to make clearance between the turbo and AC compressor this will also make room for the waste gate too right at the very end of the system just before the curve up to the turbo flange. Then I could easily route it back to the down pipe and keep the thing quiet.
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You will need a flex joint in the crossover, you can get them in stainless and it will take alot of streas away from your welds and out of the system. You will also be able to wrap everything without worry. How big are you willing to go on the gate? Pretty much all of trick and kb's systems have the gate in the crossover, and most people only run a 38mm gate without problems. Sure, having it right next to the flange is a bit more optimal but you would never notice any difference with a large enough gate. Having them up high is really the only option on a twin kit.
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Use 2 1/2'' pipe for the log, you don't need 3" at all. I've only ever built two 3" pipe logs and they where for big boost, 400+ci 91mm T6 turbo builds. 2 1/2" tube crossover is plenty. Between me and Trick I'm sure the are over a 100 turbo kits out there with WG in the crossover. I've only ever had a problem with 2 and boost creep, and one turned out to be a bad diaphragm in the WG.
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Use 2 1/2'' pipe for the log, you don't need 3" at all. I've only ever built two 3" pipe logs and they where for big boost, 400+ci 91mm T6 turbo builds. 2 1/2" tube crossover is plenty. Between me and Trick I'm sure the are over a 100 turbo kits out there with WG in the crossover. I've only ever had a problem with 2 and boost creep, and one turned out to be a bad diaphragm in the WG.
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Just looked at the runners I use on manifolds. OD is a gnats *** under 2.00. You might need adapter plates if your SBC heads are standard port config.
The middle runners being side by side not sure if you have enough room to get to the bolts once runners are in stalled. Something to look at..
Last edited by TrickTurbo; 01-03-2012 at 04:35 PM.
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I'm trying to find more info on the Dart Pro 1 aluminum heads to see if the exhaust ports are in the stock location or if they are spread apart in the middle. If not its going to be tight but I think 3/8" twelve point headed bolts will still fit.
TrickPerformanceProducts, that sounds just like 1 1/2 inch schedule 40. Its listed as 1.90 inches, so a C hair less than 2 inches.
My thought on going three inches on the log is that you've got the exhaust from 4 cylinders feeding into the log and then adding 4 more on top of that and maybe there is a chance it would become restrictive? Then again the more I think about it when you break it down no two cylinders ever fire at the same time so the exhaust is being introduced into the system on a cylinder by cylinder basis hence the reason to keep the pipe size a little smaller around 2 1/2 inches to keep the velocity high. Would you still recommend going with a T6 flange turbo and a big exhaust housing on a 2 1/2 inch crossover and log system?
If I go with the Dart Little M block 400 ci. block which I'm certain I am, I know I will want to push it. I'm already planning on running dual Bosch 044s with a half inch fuel feed line and so on. I feel the fuel system will be up to the task. 1200 sounds like a nice number. I just don't want to go to all this work and have the system be too small.
TrickPerformanceProducts, that sounds just like 1 1/2 inch schedule 40. Its listed as 1.90 inches, so a C hair less than 2 inches.
My thought on going three inches on the log is that you've got the exhaust from 4 cylinders feeding into the log and then adding 4 more on top of that and maybe there is a chance it would become restrictive? Then again the more I think about it when you break it down no two cylinders ever fire at the same time so the exhaust is being introduced into the system on a cylinder by cylinder basis hence the reason to keep the pipe size a little smaller around 2 1/2 inches to keep the velocity high. Would you still recommend going with a T6 flange turbo and a big exhaust housing on a 2 1/2 inch crossover and log system?
If I go with the Dart Little M block 400 ci. block which I'm certain I am, I know I will want to push it. I'm already planning on running dual Bosch 044s with a half inch fuel feed line and so on. I feel the fuel system will be up to the task. 1200 sounds like a nice number. I just don't want to go to all this work and have the system be too small.
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I found pictures of it that looked like they were but I hadn't found anything in writing until now. Thanks.
And to answer the question from an earlier post I was told I need a 44mm waste gate.
And to answer the question from an earlier post I was told I need a 44mm waste gate.
Last edited by oldred95; 01-03-2012 at 09:30 PM.