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View Full Version : Max HP at stock PSI?



Whorse
01-05-2006, 11:14 PM
I'm curious what the most HP/LB-FT numbers that can be acheived without increasing the boost (12psi/14spike) is on these cars (Without going extremely expensive of course).

I don't really feel like upgrading too much in my engine if I don't have to, and more than anything I'm curious.

Going from stock, my thoughts would be new wires at 8mm, new plugs gapped and indexed, relocated starter, new intercooler, 52mm TB, ported head, 2.5"/3" (depending on cost) exhaust (need a Cat here for emissions), advanced timing, and new ECU.

I would like to see 200hp without any extra boost. Is this possible?

Clay
01-06-2006, 12:00 AM
My first 87 GLHS with only the stage 2 LM (14.7 PSI) and 2.5" exhaust put down 200 HP to the wheels. Thats ~250 HP at the crank.

Thats a pretty good number for "stock" boost.

Whorse
01-06-2006, 12:02 AM
I'm not sure that there are any cals for the VNT as good as the Stage 2. I know that TU has a good one, but will it improve that much?

GLHNSLHT2
01-06-2006, 09:56 PM
good luck

thx138
01-07-2006, 04:56 PM
Not sure about the hp, but the best I could do with the stock vnt was mid 14's (14.5/6 if I remember right) on street tires (2.30 short time) in my g-body. It would spike to 14/15 and then settle back to 13/14 with no cat.

moparzrule
01-07-2006, 05:12 PM
With a VNT I don't know...but with the mods in my sig I put down 234 WHP at 14 PSI boost.
200 WHP from a VNT at 12-14 PSI would be tough, but doable with a ported head, ported exhaust manifold, and 2.5'' catless exhaust. I wouldn't go 3'' if you never plan on upgrading the turbo, there's no point. Do you have an actual sniffer test for the emissions? Here we just have a visible inspection so I gutted my cat and shoved a pipe through it!
The intercooler upgrade is pretty much mandatory. Another little trick for a few ponies would be an underdrive pulley, although now that I look at your sig you're not gonna want to do that LOL.
Oh, the 52mm throttle body will only hurt your performance at that HP level...it's only necessary at 300+ WHP. I never even bothered with it on my 300 WHP setup because I heard that it hurts your fuel economy pretty badly.

CLAY, 200 WHP isn't even close to 250 at the crank....230 tops, especially in an L body they have shorter axles which is more efficient in getting the power to the wheels.

Whorse
01-07-2006, 08:19 PM
Yeah I don't think I want an underdrive pully. If anything I'd want a larger alternator which would suck some power.

Has anyone ever used a Vortex/Helix intake? I've read about these for some other vehicles. Basically the same concept as a gun barrel, where there walls of the intake pipes and throttle body are scored in a spiral pattern and when the air is forced through it, creates a vortex which moves faster and more densly than straight flow.

moparzrule
01-07-2006, 11:14 PM
Has anyone ever used a Vortex/Helix intake? I've read about these for some other vehicles. Basically the same concept as a gun barrel, where there walls of the intake pipes and throttle body are scored in a spiral pattern and when the air is forced through it, creates a vortex which moves faster and more densly than straight flow.

This is a turbo application, that does not apply. There's no point!

Whorse
01-14-2006, 07:16 PM
Why wouldn't it make a difference? The air is still going the same way, just at a higher pressure, and unlike oil, air has a very low viscocity so it won't bond to the walls, which should make it subject to manipulation by galleys or channelling of the intake walls.

GLHNSLHT2
01-14-2006, 08:42 PM
Hehehe The turbo already does it for you :) I wouldn't put it downstream either as it could blow apart and go right into the intake :) You see them on F1 cars? Nope. In fact in Cart cars they plunge mill the intake ports to create ridges and straighten the air out so it goes into the ports faster.