George3

Let's say we have a 3.2 engine and want to build it up for the track with more horse power. Something that will give us a lot of horsepower, but yet be reliable for longevity and not be a ticking time bomb.

This would be for an exclusively track-only car.

What suggestions would you recommend?

Thanks

Ed Hughes

How much do you want to spend?

Building a 3.2 decently is not an inexpensive proposition. Adding goodies puts it even higher.

George3

Very good question.

First of all, I've never owned an older 911, but they really get around the track pretty well, particularly in the corners because of the lighter weight.

I'm looking for a mid-term hold car, maybe a couple years. Regarding the dollars, I'm not familiar with what this sort of work involves and costs, but let's say at least middle to middle-upper build, and then go from there.

Ed Hughes

I spent close to $10K rebuilding my engine without cutting corners, and doing some stuff like completely rebuilt heads racing valve springs, Ti retainers, ARP rod bolts, reground cams, and a lot of machine shop inspection. I didn't replace the pistons or cylinders, as they spec'd out OK, but there was some material removed from the jugs to counter a bit of taper at the end. That saved me $3500. I wasn't really looking to build to a budget, but I took advantage of re-using the P's and C's. I did the work myself, save the machining, so there's a couple of thousand more I saved.

I did the work myself, so there were some savings there, but I wasn't really lo

Steve Weiner-Rennsport Systems

Thats precisely what I ask all of my clients,....

There are many things one does for more power combined with increased durability but its really one's budget that frames what you will ultimately do.

84_Carrera

Ok, so I'll bite... assuming the longevity issues is removed from the equation (ie, we know it'll be reliable power...) what does $10k buy me on a build, power-wise? $12.5K? $15k? $17.5k? $20k? At what point $$-wise does a build stop being able to make power without sacrificing considerable longevity?

With other engines I've built, I've known that $X dollars gets me these cams, porting here, overbore for increased displacement, powerband gets moved here; want more, you're looking at dropping compression & adding forced induction, which is $Y more for moderate boost, $Z more for higher boost levels because the injectors, rail, pump, pressure regulator need to be upgraded & you'll get %A increase in power, %B increase in tq, but sacrifice @C reliability, & have to you ^D fuel, etc.

3.2L-vintage 911 engines are unknown in this regard to me, most folks dropping $15k into a hop-up will look to a 964/993 3.6L. But if you're tracking & want to keep weight down & stay in a class, I can see where folks would care about modifying their own engine...

Just curious.

George3

+1 ^
Well, said. . . about how much power would you expect to extract per $1000 spent, in a nutshell?

spence88mph

It's really one of those how long is a piece of string question, there are so many ways to modify the 3.2, you can go the NA route get some more power with more compression and porting, MAP or MAF, cams and exhaust which would get you around 260hp, increase displacement, 3.4, 3.5, 3.6 to it closer to 300 and above. Or go forced induction for 300 to 700hp.

I think a good choice would be a 300hp 3.5 (It's somewhere in the 911 engine rebuild book), I calculated about 16K when I added up the parts a while ago to do that provided you can do the work yourself.

vanwyk4257

I have a friend with a 3.4 twinplug running supercup cams, B&B headers, M&K muffler and running somewhere between 9.5 to 10.5 (I don't recall) compression. This is in a full street carrera coupe, and the acceleration is fierce. I don't know what it cost to build because he did a lot of it himself, but it's a very solid engine, and I may do the same some day if/when mine requires a rebuild.

KRA993tt

If you do a search on the pelican parts board you may get a lot of good info. The 911 engine rebuild and 911 tech board have lots of 3.2 rebuilds discussed. Lots of different configurations and options for you.

strudel

We built a 3.4 twin plug race motor on the conservative side. Since my wife and I both drive, we wanted a motor with some decent engine life. Basically a 3.4 (Mahle 10.5/1), stock heads, twin plugs, 50 pmo's, headers. Power is 325 f.w.h.p. Should be refreshed about every 60 hrs. This set up would be around $20K. If you go efi, I would add another $4-5K+ including set up. I delivered the motor to the builder, and re-installed it.

The real question is, is this a track, d.e. car or are you going to race in a particular class? Though I always fine someone to race with, I'm not competitive in my GT3 class. For a GT3 race motor I think your more around the $30K + range, at least 350+ h.p. and the motor will need to be refreshed every 20-25 hrs.
As you start exceeding 300 h.p. the trans will also need to be beefed up, this can add up to another $4K +.

I went with 50 pmo's to keep the expense down, and easier set up. I would have preferred an EFI.

'73S coupe
'75 carrera rs look race car w/3.4
'79 930/dp935 w/3.5 twin plug
'68 v.w. crewcab w/3.2, 46 pmo's, crankfire, 5 sp, & more

KeithC2Turto

One thought:

A well set up stock motor w race exaust and Chiped for race fuel can make 250-270 FWHP.

If you blow one up, sell it as a core and plug in another used motor.

Spend the savings on the suspention, lightening the car, track fees, and driving schools.

KeithC2Turto

PS, need more, could put a close ratio gear set in the transmission.

Thanks for letting me play.

George3

This is not a track car that will be raced.
This is strictly for D.E.

Jay Gratton

What year 911 will this be going? I would probably get a 3.6 and call it the day with that.