okay ,hello again.i see alot of discussion on turbo charging and other forced air setups.people are pushing the LS for forced,and i agree.if your intake is under pressure, you dont need to have a staged intake.because the pressure is ensuring a complete cylinder fill.if you run a forced setup ,like a Vtech, i believe the stage system will act as a restrictor plate making less.the second stage has a increased plenum area(compared to an ls plemun area) that will make more power up on the top end.any enrichment of the a/f can be compensated for through fuel pressure.hey look this is it in nutshell.extensive Tunning and alot of custom work could cause argeuments.OK, no oppionions,no my friend knows this guy,has anybody actually turboed their vtech car?what problems have you encountered?if you disagree with the above please explain in detail?im no stranger in the shop.

thanks
mark

 

If you put the exact same turbo setup and ran the exact same boost level on stock LS and stock GSR motors, the GSR would make more power.

The more aggressive cam profile that VTEC uses for high RPM helps any motor, regardless of whether it's normally aspirated or running forced induction. The GSR cylinder head also flows much better numbers, and the high compression ratio produces more power (it won't detonate as long as there's proper tuning).

 

yes your right the cams are more aggressive.and its not really it in a nutshell!! there is much to debate.does anyone have flow bench #s for a GSR and the LS heads?and stock LS/GSR cam specs?the higher gsr compresion would mean you would not be able to run as much boost,and less total ignition timming! what about the staged plenum?its my understanding correct?

 

Sure you in theory you could run more boost with the lower compression ratio, but the LS motor also takes more boost to make the same power as a GSR motor.

I guess if you really want to debate cam specs and flow numbers that might be sort of interesting, but I'll just stick to dynos.

GSR @ 7 psi (red line)


LS @ 7 psi


The Drag and Rev Hard kits use nearly identical T3/TO4E turbos.

Why would you want to run more boost on an LS motor when all that does is create more heat and more stress, when the GSR motor will make more power?

The stock internals are only good up to power levels approaching 300 hp at the wheels anyway, and then you're talking built motors where once again the VTEC motor is going to be at an advantage.

 

How could you even understand that first post?!

Good dynos...thats about what youre looking at. And headwork on LS turbo setups can yeild some VERY impressive results. A buddy was making 252/228 @ 8PSI with his stock B18B w/good headwork.

The 2stage manifold does exactly what it does for NA...increases midrange. Take the 2stage out and youll see a midrange loss and peak gain.

 

What kind of headwork are we talking about here?

I have an 00LS with a rev hard kit that I put on a little over a month ago. As I have been taking it easy until I can get it tuned, I've been researching stuff like this and am just wondering what all he did, and what you would consider to be a good headwork route.

Thanks.

 

just open the head up. port and polish, 3 angle valve job, port match the intake and exhaust. these are your main methods. if you wanna run with a b18c then you have to put the same compression into your motor. 9.0 compression on 8 psi will prob make like 195 to 200 whp. but that compression up to 9.5 and youve got like 220 to 240 whp on 8 psi with good tuning. compression makes the whole difference. im building slightly for turbo and i am using forged pistons with a cr of 9.5 measured in a b18c. measured in a b18b it will be 9.4. those two tenths will make atleast a 15 to 20 hp difference. building a fast motor is like putting a puzzle together, if you dont build it right you will know it.