Building out a happy 3.2L or 3.4L

[KNIGHTRACE]

I would just do gears and leave the 8:31 alone, the same gearing can be accomplished and it is much stronger. William Knight

[thethrill]

Great advice knightrace. Btw if you want to go fast (Ricky bobby style) have knightrace build you a turbo motor!

Now back to reality. Making horsepower on a n/a motor is expensive and typically there are a lot of comprimises - drivability reliability service w replacement parts a/c etc.

Since you are on a budget loosing weight is free horsepower. With a street driven car you can loose at least 300 pounds and still have a car that's streetable. A 300 lbs loss is the equivalent to an extra 30-40 horsepower. The car will handle better brake better less wear and tear on the transaxle, etc.

In short if you do a mild rebuild in the 3.2 (cams chip exhaust) and a few upgrades for durability like rod bolts and studs - and loose 300 or so lbs you will have a beast of a car and have the reliability of a stock car and have $$$ left over.

[jager911]

Originally Posted by thethrill

Great advice knightrace. Btw if you want to go fast (Ricky bobby style) have knightrace build you a turbo motor!

Now back to reality. Making horsepower on a n/a motor is expensive and typically there are a lot of comprimises - drivability reliability service w replacement parts a/c etc.

Since you are on a budget loosing weight is free horsepower. With a street driven car you can loose at least 300 pounds and still have a car that's streetable. A 300 lbs loss is the equivalent to an extra 30-40 horsepower. The car will handle better brake better less wear and tear on the transaxle, etc.

In short if you do a mild rebuild in the 3.2 (cams chip exhaust) and a few upgrades for durability like rod bolts and studs - and loose 300 or so lbs you will have a beast of a car and have the reliability of a stock car and have $$$ left over.

That is exactly my plan, rebuild with 40hp seems doable and get the car down to fighting weight of 2200lbs. Bumpers and wing were already replaced. I want the car to be streetable so I will not be stripping the interior.

[jager911]

Originally Posted by gumba

I went with a mild 3.4 for our street legal race car (longevity). Mahle 9.5, stock heads, g80 cams, 50pmo, twin plug, 1 5/8 headers, custom exhaust, 325 chp on the Jerry Woods dyno. 100 octane for the track, and 93 (California) on the street.
Previously we ran a 3.2 with sw chip, SSI's and sport muffler. With that set up the best bang for the buck was swapping out the 8:31 for a 7:31 in the '84 trans. If felt like we picked up 20 h.p. at the bottom end.

That sounds like the happy motor I'd like to have but not for $10k, it's probably $15-$16k with the PMOs and twin plug.
I already have a 7:31, outpulls higher hp cars up to 100.

[gumba]

If all your after is 40 h.p. 46mm pmo's, SSI's and a good sport muffler will get you very close +/- (according to Bruce Anderson's book) without doing anything else. You might get more if you went to headers.

[jager911]

Originally Posted by gumba

If all your after is 40 h.p. 46mm pmo's, SSI's and a good sport muffler will get you very close +/- (according to Bruce Anderson's book) without doing anything else. You might get more if you went to headers.

PMOs are ~$4k, not in my budget and I don't like messing with carbs.
I probably already have +20hp as I have headers, megaphones and a custom tune (according to Steve Wong's dyno charts). I need ~30hp more so I figure from my tired 30yr old motor, I can do a slightly modded build, either 10.3:1 Euro Ps&Cs, cams or 3.4L and with good exhaust and tune, I should get 250-260 easily. My buddy who did this got 261 hp after dyno tuning by Behe, he started at 225 before tuning, picked up 35hp on the dyno. I want to do this for single-plug Motronic motor to keep the costs down, my labor is free.

[gumba]

Unless your going to a race motor, I don't see the advantage of 10:1 p&c's, based on the h.p. your after. I would think you'll need to run at least 100 octane race gas, and needing to twin plug. The reason I mentioned my 3.4 was I'm using 9.5:1 p&c's, using race gas at the track and pump for the street, and getting 325 c.h.p.
It would also seem that sticking to the motronic is still going to limit your h.p. regardless of the internal mods. I ran 46 pmo's on my internally stock 3.2 for the past 6 yrs with no issues. I suggested going to pmo's because it would free up some more h.p. without going into the motor. Not to mention you'll never know what you'll run across when you do go into the motor.

[jager911]

Originally Posted by gumba

Unless your going to a race motor, I don't see the advantage of 10:1 p&c's, based on the h.p. your after. I would think you'll need to run at least 100 octane race gas, and needing to twin plug. The reason I mentioned my 3.4 was I'm using 9.5:1 p&c's, using race gas at the track and pump for the street, and getting 325 c.h.p.
It would also seem that sticking to the motronic is still going to limit your h.p. regardless of the internal mods. I ran 46 pmo's on my internally stock 3.2 for the past 6 yrs with no issues. I suggested going to pmo's because it would free up some more h.p. without going into the motor. Not to mention you'll never know what you'll run across when you do go into the motor.

Although, I don't technically "race" as in a racing class, for all intents and purposes, my 911 is driven the same way as a race car, every shift at close to redline. I'm running with 7 different car clubs in the Instructor classes where we run nose to tail. I'm hanging with GT3s on slower courses and pass the slower guys, I want to keep up with the fast guys. I spoke to Steve Weiner. You can build a streetable track motor without going twin-plug, the limit is about 10.3:1. I had a prior "happy" 3L motor based on a Carrera 3.0 with 10.5:1, it ran fine on 93 octane, single plug. I wanted to rebuild my 3.2L anyway, not just to chase hp and figured it's the time to do some sensible cost-effective upgrades like hi-comp Ps&Cs and cams. Done properly, it should last the rest of my driving career before I hang up the gloves. Anyway, what do I know, taking in all the feedback. If I got a great deal on PMOs, I could change my mind, 325hp would keep me happy chasing down GT3s. Listening to you, maybe I should do a leakdown on my motor and if good, instead of Ps&Cs, do a top-end and go the PMO route.

[Jgordon]

I had a good time with a 3.4 build - I did not do it myself, but it came out to under $10 grand all in. I had over-revved and dinged an exhaust valve, and she needed the valve guides done anyway, so marginally I was out even less cash.

Ended up with Mahle 10:1s, 964 cams, and the obligatory SW chip.

Plus, the purist in me likes the fact that a 3.4 is more of a reversible mod than selling your engine and replacing with a 3.6. I STILL haven't done my final dial-in on the dyno, because a) I ran out of money and b) I've been screwing with the exhaust ever since. I need to bite the bullet, ask Ben at M&K to build me a slightly less raucous muffler, then finalize it.

Fresh off the build, with the restrictive stock muffler AND CAT, she was pulling 208 at the wheels, so 245 or so at the crank. If I ran it now, I'd probably be over 250, and with a proper chip, hopefully closer to 260.

Pelican sucks:
You all suck

Good to know:
3.2 to 3.4 - what else?

First dyno run:
First Dyno Run on the 3.4

[jager911]

Originally Posted by Jgordon

I had a good time with a 3.4 build - I did not do it myself, but it came out to under $10 grand all in. I had over-revved and dinged an exhaust valve, and she needed the valve guides done anyway, so marginally I was out even less cash.

Ended up with Mahle 10:1s, 964 cams, and the obligatory SW chip.

Plus, the purist in me likes the fact that a 3.4 is more of a reversible mod than selling your engine and replacing with a 3.6. I STILL haven't done my final dial-in on the dyno, because a) I ran out of money and b) I've been screwing with the exhaust ever since. I need to bite the bullet, ask Ben at M&K to build me a slightly less raucous muffler, then finalize it.

Fresh off the build, with the restrictive stock muffler AND CAT, she was pulling 208 at the wheels, so 245 or so at the crank. If I ran it now, I'd probably be over 250, and with a proper chip, hopefully closer to 260.

Pelican sucks:
You all suck

Good to know:
3.2 to 3.4 - what else?

First dyno run:
First Dyno Run on the 3.4

.
Sounds like it was worth it. Thanks for the links, when I did a search, those did not show up.