Thread: VE-T twin scroll setup

Pulled the manifold off today to discover some things. The exhaust manifold gasket had a leak on cyl #4. The gasket fell apart in my hands. Good thing the new one is MLS.

The wastegate gasket was also leaking, prior to the valve. It had burned a hole right through the ATP supplied lead gasket. Left a hole about 1/16" thick and 3/4" long right before the valve. This will throw out some of the results from this twin scroll test though. Since the new manifold should be leak free, the data will be skewed a little bit. I am honest, so I figured I would let everyone know before I post a graph that shows unrealistic gains in spool. Leaks FTL.

Anyone know what kind of difference these leaks pre-turbo would do to spool and response? I am really anxious to see what happens with the new manifold, especially with all the leaks fixed. I just hope someone can learn something from the data put out there so that the results are complete garbage.

Part of me wonders how responsive this turgo is going to get, and what kind of torque increase I can expect. Any thoughts?

having the leaking gaskets may not kill spool as much as you thought. A lot of times those gaskets burn out because of excessively high backpressure in the manifold to where the exhaust gasses will find any weak seal and begin to leak.

because of the design of the log manifold and its lack of design for fluid flow, i doubt that those leaks will affect the spool that much. sure it might get slightly better by fixing those leaks, but the twin scroll is still gonna kill it in power and spool.

I think you can clear 200whp by 4000rpm with the right parts and cams and cam switching point. here is a DET setup with some good parts and tuning and tweaked cam timing. Makes 200whp by 3800rpm

That's good to know. If I do break the 200whp mark by 3800rpm, then that is only 300rpm quicker than the log manifold. But it is a bigger ex housing anyway.

I will take pics of the big leaks today. I don't think they really hurt spool that much, but the turbo has gotten more and more unresponsive over the past 9 months. Boost onset used to happen at 4000rpm, now it is closer to 5000rpm.

Just Wow. This looks cool.

I've got to see if I can get a hookup for a new CHRA for this GT30R. Seems like flying debris through the turbine makes for some disasterous results. Not sure when this happened, but it had to be a while ago. Regardless of this damage, and the resulting balance issues, the turbo still spooled up pretty good and made good power. But this was prob the leading culprit in the diminished response of this turbo that was noticed almost a year ago.

Oh dear good luck sourcing a new CHRA, I hope they don't charge you your left nut for it!

They will. A new one is around $950 or so. I may have someone who can help me out though. It is real crap they don't offer a core exchange for such an expensive unit. I bought this turbo new a few years ago for $1100 bucks, but the price has skyrocketed for this turbo since then.

I think it is dumb that they charge so much for a turbo when I know they mark it up by hundreds of dollars. I do know someone who may be able to get the CHRA for a cheaper price, but I don't know how much. I will keep you guys posted though. This project must continue, regardless of cost. I have already spent too much on this turbine housing and manifold to change setups for something different.

I thought of this as a chance to upgrade, but what would I upgrade to? There isn't another turbo that is as responsive as this that will make 500whp, and there isn't a point in getting a GT35R (with more lag) when my MAF will only support 550whp or so. Also, injectors and fuel pump will only support that much too.

I have the capability of having a 500whp monster of a car, but I don't really want to push it to an extreme that will make the car a trailor queen. Otherwise I have a GT4088 that I could use

Picks of the leaks:











Just a cool pic.