ROSCOEP5

I want to get at least 350 hp from my engine. What are some mods I can do to achieve this. I also want to increase midrange power and top end, are there any suggestions.

vader86

That power goal is pushing the limits of the stock intake, Id do away with it altogether. Its far too restrictive for our engine.

Id try the Superram and Accel 219 cam and 1.6RR, with some Hooker longtube headers and a good catback exhaust. It will get you 350 easily. Both the SR and 219 cam can be ordered from lingenfelter.com or you might find them on ebay cheaper.

You could also try the modded TPI setup, I dont care for it myself but Vic89 and Joe90 have gotten the most from the stock intake. Basically what you do here is buy one of the aftermarket base manifolds (superram base or TPiS Bigmouth) and some AS & M runners and port the plenum and port match everything. Add a cam like the Accel 211 or ZZ9 and some 1.6rr and you could probably get good power.

If you have a 6speed, you could think about the TPiS Miniram (tpis.com) and one of their cams. It makes great midrange and top end, but can be a bit of a dog on the low end, depending on cam choice, so you might need gears. (and a higher stall TC if you have an automatic)

GusBustamanteJr

you wont make 350 without heads...

MrNuke

Simple.
Supercharger or NOS.

Jim85IROC

Properly ported L98 heads can support 400hp. ZZ4s make 350 horsepower with bone-stock L98 heads. It's definately possible.

GusBustamanteJr

Yes, true, but it will cost almost as much as a new set of AFRs to properly do a full CNC port job. I had mine ported by one of the best head guys in town, and it looked like a CNC job, cost $600. I have the SR and 219 and everything else you can throw at it.....not near 350 RWHP. More near to 300.
You can get good heads for $1300, even some Edelbrocks for $900. I would go that route next time. 350 RWHP is hard and expensive to reach

grapeknutz

A set of AFR's and a mini ram probably will do the trick, and for good measure a slightly hot cam :smash:

scorp508

His D-Ports should be fine for that.

1991Z07

The stock-style TPI is good for up to about 425 HP. Your D-ports will work fine with some CNC work done to them (I recommend CNC Cylinder heads....very nice work http://www.cncheads.com/ ).

There are those who say to get aftermarket heads, but personally I like the stealthy look....



AFR's or such show that you've radically changed something, while CNC ported stock heads don't.

I've got more information on my web site...just follow the link in the signature.


[Modified by Joe90, 9:58 AM 2/26/2003]

scorp508

With forced induction maybe.

Jim85IROC

I think (hope) that he was referring just to the heads. There's no way from here to eternity that you can get 425 hp with the stock runners & base in a n/a configuration.

1991Z07

I think I see the confusion now....I said the stock-STYLE intake, not the stock intake itself.

I'm there with no forced induction or NOS...and yes I was referring to heads & intake. AS&M runners, Accel base (polished off the casting flash in the runners...no porting) and 220 CFM heads...if you pay attention to the details you can get there.

The numbers in my signature were pre-siamesed base. The 3rd Gen guys have good empirical data showing a 20-25 HP increase from siamesed bases. Add 20 HP to the 397 there and I am close. A little more tuning and then we'll take it back to the dyno for another pull.

If I had time and wasn't working on the 427 SBC, I might have tried a S/R and tuned it to see what I could have gained from that. But then again, I LIKE someone looking under the hood at an event and just seeing those stock-looking runners and underestimating what I have :D

I'm thinking about showing up in Bowling Green this year for the event....depends on my commitments with work if I can take a week off to go. I can't say the drags will be stellar since I don't do very much of that, but the autocrosses will be fun.


[Modified by Joe90, 11:06 AM 2/26/2003]

GusBustamanteJr

326 rwhp is not near 425 dude!!

scorp508

Keep in mind your engine is already modified. You may get 20hp on a stock car, but not when you have already improved many of the stock downfalls.

1991Z07

Using Lingenfelters figures of a 17-18% drivetrain loss for a ZF6 C4 (I used 18% as a worst-case)....

326.4 HP = .82 x N

326.4 = N
.82

398 HP = N

My sig figures were base on 326 HP...I left off the extra .4 and actually rounded it down.

So unless my algebra is wrong, I should have approximately 398 HP at the flywheel. Of course, there are lots of variables and we could go round & round about it, but I took Lingenfelter at face value. They have engine dynoed motors and installed them into cars to chassis dyno them, and know what the differences were. They use this as a "standard" ZF drivetrain loss.

And ROSCOEP5 was asking about which I take as flywheel horsepower...not rear-wheel horsepower.

AND...If you add 20 RWHP to my original runs it looks like this:

346.4 HP = .82 x N

346.4 = N
.82

422.3 HP = N

Which is.....
[Modified by Joe90, 11:58 AM 2/26/2003]

1991Z07

Actually Scorp, they took that into account when they did the tests.

They incrementally changed runners, plenum, base, heads, THEN siamesed the base and dynoed after every step. The siamesed base yielded 20 HP after everything else was already done.

What was significant is it raised the HP/TQ curves up by about 900 RPM as well. The SOTP from mine right now is they are right on the money. Mine now pulls HARD to 6k RPM. After that it falls off, how much we'll see when I take it back to the dyno.

Ken Lanham

Joe,
What are the specs on the Corvette Challenge cheater cam?

GusBustamanteJr

Duder,

With all the debate about FWHP on the forum, I thought we were all going to use only RWHP!!!

In that case, 425 is easy!!!

I think anyone making 300 to the rear wheels is really kickin butt and has done some serious and well planned mods. I thought it would be easy to get there, but i soon learned it is not. Still hoping to get there once I get rid of all this stupid Knock Retard, and get a final tune. Getting to 300-350 on motor alone is going to cost about $3K unless you get some cheap parts and do all the work yourself. To get more than that, I would think you have 3 options:

Stroker
NOS
Turbo\Blower

Either way add another $3k to the mix, unless you go with NOS, which is about $1200-$1500 for a GOOD setup.

I am old school, where we think NOS is cheating.....I am slowly starting to accept it though, by force! I hope to go the stroker route. Maybe throw in a turbo or blower when I get bored with that!!! AHHHHHH I hate the FORUM!!!!!!!

A Time spent on FORUM=MORE MONEY FROM MY WALLET TO THE AFTERMARKET MANUFACTURES POCKET!!! X N hours of tinkering in the garage / 3x wife complaining - Ax3 to fix or change what I broke or found broken during N = CA-CHING$$$

1991Z07

Duration @ .50:
225 int.
229 exh.

Lobe Separation 113 deg
Lobe Centers 109 deg.

Lift w/1.6 RR
.555 int.
.556 exh.

This is the cam Morrison used for the Challenge series. I got it from him personally.... P/N X2221-2271-13

Comes from Cam Motion in Baton Rouge LA. Last info I had on them was 292 Dallas Dr. (225) 926-6110.

Ken Lanham

Wow, thats interesting. Even bigger than than the LPE 219 cam that people like to use on the SuperRam cars. I would have thought it a bit too much for a long runner TPI setup.

How does the car idle? Is the cam detectable at all from the sound?

-Ken