Ddnspider's- Project Wrong-Way- Rear Mount Turbo Thread
I'm going to pressure test the cold side but I'm thinking it must be a hotside leak big enough to prevent good pressure.
https://www.jegs.com/i/Dynomax/289/88028/10002/-1
Pretty nice kit even though the welds sucked lol.
I’m thinking if I ever did a rear mount, I’d run 2.5 to the middle of the car. Step down to 2.25 after that. Actually would be 3” collector off the headers, then after a for or so, neck down to the 2.5. I dunno, I’m my mind I think it would keep velocities and volume up.
On The Tree
Joined: Apr 2017
Posts: 115
Likes: 6
my c5z is ceramic coated manifolds, 2.5" off each to a 3" ypipe then steps down to 2.25 to the t4 flange 75mm turbine that is ceramic coated as well. all the piping is wrapped. the cold side is 2" 78mm billet wheel. should light really fast. I went 3" to 2.5 cause i might have bigger motor and 800rw+ 700rw now is the goal. car is almost done
I WOULD NEVER DO HEADERS!!!
my c5z is ceramic coated manifolds, 2.5" off each to a 3" ypipe then steps down to 2.25 to the t4 flange 75mm turbine that is ceramic coated as well. all the piping is wrapped. the cold side is 2" 78mm billet wheel. should light really fast. I went 3" to 2.5 cause i might have bigger motor and 800rw+ 700rw now is the goal. car is almost done
my c5z is ceramic coated manifolds, 2.5" off each to a 3" ypipe then steps down to 2.25 to the t4 flange 75mm turbine that is ceramic coated as well. all the piping is wrapped. the cold side is 2" 78mm billet wheel. should light really fast. I went 3" to 2.5 cause i might have bigger motor and 800rw+ 700rw now is the goal. car is almost done
I disagree. I’m my opinion, the freer flowing headers will benefit. Why? Think about how air flows and what it does. Step down a couple times after the headers to keep the velocity up and you are jamming all that air into a pipe that’s progressively getting smaller. In my mind, you’d have better flow and velocity. As exhaust gases travel down the pipe, they cool off, contracting and slowing down. As it slows down, the reduction in pipe size will speed the velocity back up. Causing better spool and flow. Have I tried this? No. But I’m certain it’ll work. Choking stuff down right out the head does not seem like a good idea. I think the reason you are having this mentality of not using them is because on most turbo setups, the norm is manifolds. Yea, but we do manifolds because headers are too long. Won’t fit that way. High end setups use headers. It’s much more work to build headers AND if they aren’t built to withstand the heat and weight of a turbo (could use a support) then they won’t Last long. An engine is still an air pump with a turbo. And more flow the better. I could be wrong but my brain is saying I’m not.
https://ls1tech.com/forums/forced-in...urbo-saga.html
Don't forget that most high end setups use headers because A) they need to face forward and B) they're fitting a monster turbo.
On The Tree
Joined: Apr 2017
Posts: 115
Likes: 6
I disagree. I’m my opinion, the freer flowing headers will benefit. Why? Think about how air flows and what it does. Step down a couple times after the headers to keep the velocity up and you are jamming all that air into a pipe that’s progressively getting smaller. In my mind, you’d have better flow and velocity. As exhaust gases travel down the pipe, they cool off, contracting and slowing down. As it slows down, the reduction in pipe size will speed the velocity back up. Causing better spool and flow. Have I tried this? No. But I’m certain it’ll work. Choking stuff down right out the head does not seem like a good idea. I think the reason you are having this mentality of not using them is because on most turbo setups, the norm is manifolds. Yea, but we do manifolds because headers are too long. Won’t fit that way. High end setups use headers. It’s much more work to build headers AND if they aren’t built to withstand the heat and weight of a turbo (could use a support) then they won’t Last long. An engine is still an air pump with a turbo. And more flow the better. I could be wrong but my brain is saying I’m not.
I was in your camp until I read:
https://ls1tech.com/forums/forced-in...urbo-saga.html
Don't forget that most high end setups use headers because A) they need to face forward and B) they're fitting a monster turbo.
https://ls1tech.com/forums/forced-in...urbo-saga.html
Don't forget that most high end setups use headers because A) they need to face forward and B) they're fitting a monster turbo.
. After some discussion and further research we decided that it was the lack of heat in the exhaust causing us issues. He tried the experiment first on his car. He had a completely stock exhaust setup that spooled well to 12psi on a stock engine and a T70 .81 p-trim turbo. He swapped out to Jet hot long tubes. The result was amazingly disappointing. With no other changes besides the long tubes, the car
would barely build 5psi of boost and took seconds to even achieve that. He then pulled the exhaust system and headers off the car and wrapped it in header wrap. The result was fantastic, it spooled as well as it did on the stock uninsulated exhaust. Seeing how well this worked I decided to have him fabricate an entire new exhaust system for me. The exhaust is made out of 2.5" OD from the manifolds to the turbo and then insulated with fiberglass header wrap to just over the rear axle (we ran out). The end result of this was much much faster spooling and I could now achieve 20psi of boost with the waste gate still opening. I now had to leave on 5-6psi of boost because
it spooled so much faster it would blow the tires off if I left higher. It would also build 10psi of boost in 2.5 seconds now when using the transbrake, a huge improvement.
would barely build 5psi of boost and took seconds to even achieve that. He then pulled the exhaust system and headers off the car and wrapped it in header wrap. The result was fantastic, it spooled as well as it did on the stock uninsulated exhaust. Seeing how well this worked I decided to have him fabricate an entire new exhaust system for me. The exhaust is made out of 2.5" OD from the manifolds to the turbo and then insulated with fiberglass header wrap to just over the rear axle (we ran out). The end result of this was much much faster spooling and I could now achieve 20psi of boost with the waste gate still opening. I now had to leave on 5-6psi of boost because
it spooled so much faster it would blow the tires off if I left higher. It would also build 10psi of boost in 2.5 seconds now when using the transbrake, a huge improvement.
Yea but if you read the part where he said he pulled it all off and wrapped it. Didn’t specify wrapping headers or manifolds. Then he does mention manifolds AFTER he rebuilt the whole exhaust. I assumed he wrapped the headers. Then put manifolds on. But I guess not.
I think he had stockers throughout his saga. His installer was the one who swapped headers for stockers. Do a search on here. Lots of info on headers vs manifolds.
Fwiw cast iron is a much better insulator vs steel or steel with air gap wrapped furry ribbon of itchy death.
Swaintech has the best coating for that and wont cause premature rusting etc like wrap.
Bottlenecking exhaust farther down the path only inhibits not helps.
Swaintech has the best coating for that and wont cause premature rusting etc like wrap.
Bottlenecking exhaust farther down the path only inhibits not helps.
Yup. Headers flat out dissipate too much heat vs stock manifolds. You need more heat=more pressure to spin the turbine wheel. I think the Ohio Boys are a good reference of what stock manifolds are capable of.
I knew zombie had another thread with headers but couldn't find it.
https://ls1tech.com/forums/forced-in...ts-inside.html
I knew zombie had another thread with headers but couldn't find it.
https://ls1tech.com/forums/forced-in...ts-inside.html
Not to insult your intelligence and you've probably already checked, but just because it happened to me, I'll ask (regarding no boost) are you sure your 'fire ring' is in place on your wastegate? I had a similar result to yours but it was because I found the fire ring still in the box after doing some testing. Once in place, I got all the boost back.
Not to insult your intelligence and you've probably already checked, but just because it happened to me, I'll ask (regarding no boost) are you sure your 'fire ring' is in place on your wastegate? I had a similar result to yours but it was because I found the fire ring still in the box after doing some testing. Once in place, I got all the boost back.
post 253 he mentions that it’s fine.
Can’t help on no boost. One thing to add on the exhaust. You can buy the intermediate over axle pipe from walker for like 35$ new for a 4th gen with a v6. It should hook up right where your pipe ends and go over axle. It’s 2.25 or 2.5 but significantly smaller than v8.