Thread: Think I went with too big of a turbo...

I haven't got that far yet, I have a few turbos laying around that i could use during break in, (few gtir T28s, GT2560R, t25's) But of course ill get something bigger.

Im not rushing things, I only just got hold of a very VERY cheap VE head, so right now im tearing down the DET bottom end for rebuild

I made 288whp at 13psi on my ve with a t25 and a 2 1/2 exhaust. Just saying.

T25, is far too small for what i want - I would want power throughout the rev-range.

I have had my fun with T25/t28's with my AWD Det - Time to play with other things.

VET cams where/are still on the table. They are just hard to come by. But it seems like VE would still not appreciate the restrictive log. I can understand on why too. With such a good flowing head, the exhaust manifold is the killer. Thus I think even with VET cams I will see some heat/timing issues.

I'm curious on what it makes now too, and how far I could get it power wise, but I honestly don't even want to bother wasting the time on it anymore. I'm going to start buying supplies for building my manifold.

Protech makes a manifold like this and SE-Rawkus made over 500whp on his. Problem is it requires some modification to the downpipe still, and the price is a little out of my price range (~$850 shipped).




Once I get my mig I will build everything from scratch, including the downpipe and lead pipe. Then sell the current manifold and try to get some money back .



The VET exhaust manifold flows better then even the GTi-R one right? Cams would definitely help out by reducing reversion, but contaminated flow would still be a concern.



That's the kind of car response I'm looking for. Neck hurting torque, but knowing our transmissions and axles I would have to keep the torque down.

Thanks for the input on the GTiR manifolds, sounds like they might be an upgrade, but ultimately still don't flow well enough.



Jeeez, I thought T25's topped out a lot earlier?

Nope, Damian made 327whp on a t25 on his VE-T. Also I forgot who was the other forum member that made over 300whp on his t25 and ran mid 12's on his DE-T T25, screename was blkse-r or something like that. Lance also made over 300whp and over 300ft lbs of torque on his DET with a t25.

Dang, the most anyone here has made is about 280whp with a GT2560r. It was maxxed. But they are supposed to be good around 300.

I do agree that running a log and VET cams does limit the VVL a bit. Having just the intake kick on isn't as fun as having both cams switching and all hell breaking loose. So it doesn't make the best use of the head flow.

And even now, I am tubular with 1.6L cams, I still don't feel like the VVL is used to its full potential. Still could use better exhaust flow. Top end power is still pretty limited and within 30whp of my VET/Log setup. And I still feel like there is more left on the table with just getting the parts to work together.

I think the 2.0 cams would work better for what the setup has now, but on low boost the 1.6 cams perform better. Once I go over 20psi, the 2.0 cams seemed to work better. And I think this all comes down to flow, and overlap. The 1.6 cams work better on low boost, when backpressure is relatively low. But once the backpressure spikes with boost, it looses the top end quite a bit.

I have always wondered how a large cam would work with a small-ish turbo with a big exhaust housing. Like my GT30 with a 1.06 open housing. I think that it would perform really well on high boost, but noone dares try it. With such a free-flowing cam, free-flowing turbine housing, and small turbo, you would think that it would still have to spool faster than a .63 GT35r. Less rotational inertia. But when it hits, it is going to hit really hard, really fast.

In that case I might go with SR16VE cams after I get a manifold then too. I feel like they might be a little slow NA wise, but boost would help them feel better.




That's some very impressive numbers. Regular journaled bearing T25's?

Yeah. Blkse-r clicked off a 12.1 quarter mile pass on dr's. It's on the old forum.

Those numbers would be understandable on a +t especially on a ve+t. VE's make good numbers without the turbo haha.

300hp on a DET is a bit hard to believe tho. I ran 13-15psi on my T25 on my AWD det and there was no way i was even near that. (Nismo injectors, cams n62)

I do have access to some turbos that have 1.06 a/r - Maybe i should see if i can get my hands on a cheap one and give it a try.

AWD will obviously give you way less horses.

I am striving for 325-350 on my T28 setup. It's going to be maxxed out, but I hope I can hit it