Can you get to 400 without turbo or super-charger

MightyBobo

I think it goes without saying, the sky is practically the limit when you add giggle juice, so why even bother mentioning it?

Cams isn't going to happen in this car - only on the exhaust side. The only way to get the valves to open up more would be either a LOT of money into the intake VVEL system, or simply tuning the valves to be open more and more often. Its going to be VERY complicated either way, and a tuners nightmare at first Im sure.



And problem is, he wont be making more than 90WHP to hit 400 WHP than stock...on a dynojet dyno (generally recognized as the most inaccurate...), they're putting down what, about 280ish to the wheels stock? He'll need 120WHP more. That translates to approx 140+ CRANK horsepower more. You think full boltons will do that? Because when an LSX based motor - something with a LOT more displacement and room to grow - can pick up 140 crank horsepower from boltons, well, god damn. It all slows down very fast after the "big" boltons, IE headers-back exhaust.

Crash

AH! So that's how the VVEL works! I was wondering how they were doing it. Makes sense to use an screw-style actuator setup. They're very reliable so long as the motor doesn't burn out.

I'm 100% positive that someone will come up with a baseline configuration for tuning the VVEL and tuners can just use that as a starting point.

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2002 Corvette Z06 - Totaled
2003 Corvette Z06 50th Anniversary

MightyBobo

Talk to the HONDATA guys...or, maybe the guys forced to use it . According to my friend, i-VTEC is KINDA similar, and only the HONDATA guys have figured it out lol. So you pay out of your *** for the tuning solution

Crash

^^^ That will change fast as snot. LS2's were cracked in about 3 weeks followed by a billion other tuners shortly after.

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2002 Corvette Z06 - Totaled
2003 Corvette Z06 50th Anniversary

MightyBobo

Yeah, but their premise was very similar to that of the LS1. Not very hard to figure out at all. And besides, its push rod power here - very simple.

This motor is considerably more difficult to tune with, assuming you're tuning for anything OTHER than WOT more than likely.

Crash

Yeah. I know what you mean.

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2002 Corvette Z06 - Totaled
2003 Corvette Z06 50th Anniversary

welderz

I won't say it's impossible but it's highly unlikely. The vq37vhr is putting out almost 90 horsepower per liter stock. LS motors don't come anywhere near that from the factory therefore they have more room to easily add horsepower. This is the biggest limiting factor in modifying the 370z for n/a. The vq35 is hard to even get to 300rwhp with full boltons and cams. The vq37hr has a definite advantage with vvel but no one knows yet what it's capable of I'm very optomistic about it. I don't know yet but I think 340rwhp is the limit with full boltons and a tune. High compression pistons won't give too much of a return considering your starting at 11-1 compression ratio and you will need race gas and engine longevity will be drastically cut. The heads already flow extremely well so a port and polish will help but results won't be drastic. If your shooting for 400rwhp n/a it's going to be very expensive and your engine won't last the life of the vehicle. I know you want to go n/a but FI is the better way to go. Many 350z's have been running for several years with superchargers and turbochargers putting down 400rwhp on the stock block. And the vq37vhr has been torn down and inspected by several shops and it has a proven stronger bottom end so I think it might even last the life of the vehicle at 400rwhp on the stock block. The cosworth engine is a bad benchmark to go by that's a race engine that would cost a lot to reproduce. Just so you know I'm a member over at my 350z so I have some background in the vq motors.

Q_USAF

The more information I see, the more I think that 400 is unattainable without going turbo or using a supercharger.

Q_USAF

I'm thinking mid-range numbers like 330 to 350 now.. Am I off base. I'm shooting for just bolt-on's.

RCZ

I havent read the whole thread, but based on recent findings, I think 400NAHP is a dream on this car. I think we should aim for 300-320 at best.

Crash

Agreed. (That is until someone figures out how to tune the VVEL 100%)

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2002 Corvette Z06 - Totaled
2003 Corvette Z06 50th Anniversary

drisko

My initial performance goal is 370hp at the flywheel, which should equate to about 315whp. I know this is easily possible with JUST high-flow cats, cat-back exhaust, and Cobb AccessPort Stage 2. The AP Stage 2 out for the G37 with this setup claims about 11% gain (about 38hp), so I expect the Z will have similar #s.

Adding an intake to this setup with a Stage 2+ tune would more than likely result in another 10-15hp gain, which brings flywheel horsepower close to 400 at the flywheel, but not quite. I think getting 400 even at the flywheel will be tough to do, but maybe with a plenum spacer, pullies, and some other stuff it will be possible. Now, 400whp, that is a whole other story. I honestly don't know if it's possible at all naturally aspirated without doing some major work.

Crash

I REALLY doubt that those mods gives you 40HP more at the crank...

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2002 Corvette Z06 - Totaled
2003 Corvette Z06 50th Anniversary

KingDavid

I'm pretty sure no one even dared to think that I/H/E with a tuned AP would net anywhere near 90 whp above stock either. Never know until it's tested and tried...I'd like to see the outcome.

welderz

I haven't been on the g37 forums so I personally don't know but I don't trust that 90 horsepower gain. They were most likely taken on different days considering that headers were installed. That brings up a ton of variables between the 2 dyno runs.