Increasing HP 3.2: just clarification on the matters.

RarelyL8 or Superman said something about it being not too difficult to get a 3.2 up to 260 HP....how???
Warren often mentions changing the cam to S-cams? What's up with this, and why don't they just come stock?
Dual exhaust headers are also a solution, but since I want a heater, that's out.

Then someone asks Warren about a new crank...I assume to increase the displacement....how would that work? You'd have to tear the whole engine down, and would that be risky to emissions passing?




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Kurt B
1984 911 Carrera Cabriolet
75 914 1.8

I was noticing in my Porsche Family Tree book last night that for the first year or two, the 3.2 was rated higher horsepower than the later years. It seems to me that the initial hp rating was 230 or so.

I keep hearing about "mass ir flow" units which I notice are not cheap. I also hear about just popping in a chip. I'd have to consult my Bruce Book for more detailed information, but I believe 260 is achievable without engine removal. Am I all wet?

We poor 3 liter drivers are stuck with about 210, maybe 220 hp unless we remove and disassemble the motor.

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'83 SC

3 liter engines respond well to exhaust mods, the most common being SSI's and a performance muffler. You do retain heat with this setup. 3.2's also respond well but the heat is a bit more difficult to get, you need to fabricate some ductwork. To do the ssi mod you give up your cats which may be a legal issue, depending on local.
The "S" cams are incompatible with CIS or the older DME induction because of the strong pulses in the intake tracts due to the longer duration of the valve events. The "S" cams can be made to work in larger displacement DME applications if the flapper type air measures is changed to a hot wire type. This is because the larger displacement minimizes the pulse effect and the fact that the hot wires are less affected by the pulses. "S" cams also work well with carburators like the Webers or PMS products.
High compression pistons are another path to power, however, without the highest quality fuels detonation becomes an issue without twin plugging and or antiknock controls ala 3.6 engines DME controls

The '84 -86 euro 911 Carrera's were rated at 231 hp due to higher compression and more agressive DME controls. They also came with transmission coolers for the Al. case 915. Only a few N.A. cars, mostly from Texas were so equipped with trans coolers

Kurt, The simplest things you need to do, are a chip, exhaust(w/heat), and a K&N powerflow cone setup. That should add around 30-40 HP. The "big bore" throttle bodies dont do much unless you upgrade all the fuel/spark components along with it.(like crank fire or programmable fuel) Even if you increase air going in, your O2 sensor is going to send a signal to the brain, and try to maintain a 14.7:1 ratio.
Marc

On a 3.2 engine, it has been shown that an aftermarket cone filter does nothing for the power of the car. I believe it was Anderson himself who ran a 3.2 without an air cleaner on a dyno and noted a less than one HP gain. On the 964 3.6 engine the intake was changed and will benefit from an aftermarket intake.

Putting an SSI exhaust on a 3.2 will net you perhaps 25 hp with a chip. That's $30/hp if you pay $800! Expensive.

S cams won't work on the 3.2 I've heard, for the reasons Bill outlined. The S cams were came with driveability problems too, I understand.

Lastly the Euro 3.2s were indeed rated at 231hp due to their higher compression - which you'd have to change the pistons for.

Darnit, Porsche just made a reliable, powerful engine, and left us with no cheap way to upgrade 'em!

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Mark Szabo
1986 911 Targa 3.2
1987 Escort 5-speed 1.9
The 911 Gallery

You said the S word. Smog. That is a big restriction when it comes to making power. None of it is cheap. You might consider forced induction of some type - many of these systems are smog approved. They also deliver bigger numbers than pistons, cams, carbs, headwork, etc. for a similar price. Of course the payback (most likely) is reduced engine life.

OH BOY!,First let everyone know that im not a porsche expert,but tru my own reserch;
Kurt if you can get 260 HP out of a 3.2 without going into the engine PLEASE let me know we will go on business,i can tell you that as we all know i installed a turbocharged in my 3.2 and is good for 276HP at 5500 rpm at the wheels just to give you a idea,if smog is the problem which i used to have,you can install a chip,a J pipe ,air cleaner and a nice exhaust, that will give you a little juice, at the time of the smog inspection just re install the factory staff,last time i just install the cat and everything else stay in place and she pass ,of course it depends who you ask theres a lot of modifications on the market but for the money is just a waste.just my opinion.
Regards Juan
www.geocities.com/titos88911/MY911.HTML

Keep in mind, I already have a chip, bursch muffler, k&n cone...so if I did get any cheap HP, I would already have it (cheap meaning, those 3 cost me 700$ total). Yes, my 0-60 times have dropped, but I guess it's time to hit a dyno and just find out where I am NOW.


Juan...I'm investigating your efforts...I feel OK about getting 260, and maybe 276 HP out of a 3.2, but anymore seems to imply engine burn out. You're the guinea pig on this one! Let's hope your engine continues to kick ass.



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Kurt B
1984 911 Carrera Cabriolet
75 914 1.8

In Bruce A's 911 Performance Handbook he claims 265hp from a 3.2 with just a switch to Webers and headers. Probably not street legal in most of the country and no heater, but shows the possibilities.

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Jeff Parker
72t

Kurt-
I have recently measured 217 dyno'd HP to the rear wheels (approx. 255-260 at the flywheel) with my recently rebuilt US 3.2L Porsche engine. It was built in strict adherence to SCCA Solo2 ASP class rules, so no knife edged crank, boatailing, race valve springs, non-stock cams or pistons/cylinders. It is completely stock inside except for the following: balanced, ARP fasteners, minimal port polish. On the outside the following changes were made: intake manifold extrude-honed, enlarged throttle body, 993 MAF sensor, K&N cone filter, 944 turbo injectors, Motec programmable injection and ignition, SSI, Flowmaster exhaust. I think this is close to the best you can hope for in a stock US 3.2L with bolt on products. If you were to go to a 993 vario-ram intake or individual throttle bodies you might get 15-20 more HP max. So, I would guess about 275 is max. Now if I could just legally change my cam and install Euro P&Cs!

Randy
72 911s

Kurt-
I have recently measured 217 dyno'd HP to the rear wheels (approx. 255-260 HP at the flywheel) with my recently rebuilt US 3.2L Porsche engine. It was built in strict adherence to SCCA Solo2 ASP class rules, so no knife-edged crank, boatailing, race valve springs, non-stock cams or pistons/cylinders. It is completely stock inside except for the following: balanced, ARP fasteners, minimal port polish. On the outside the following changes were made: intake manifold extrude-honed, enlarged throttle body, 993 MAF sensor, K&N cone filter, 944 turbo injectors, Motec programmable injection and ignition, SSI, Flowmaster exhaust. I think this is close to the best you can hope for in a stock US 3.2L with bolt on products. If you were to go to a 993 vario-ram intake or individual throttle bodies you might get 15-20 more HP max. So, I would guess about 275 is max. Now if I could just legally change my cam and install Euro P&Cs!

Randy
72 911s

260 hp can be reached with a EURO 3.2 engine, but it's expensive no matter how you go about it. I don't think a chip will give more than 10-15 hp realistically. That would bring power up to 241-246 hp. Then you can replace the pre muffler and main muffler with "sport items", but I don't think you will gain much from this. Maybe 10 hp if you're lucky. However changing the mufflers, the chip AND the airmass meter SHOULD (don't know for sure) take power up to app. 260 hp on a euro engine.

I put a K&N HighFlow intake on my euro 3.2, but kept the stock airmass meter (cost reasons). I must admit that I feel no difference in power, torque or acceleration. A friend of mine put a similar K&N intake in his car a gained 6 hp at the wheels. He couldn't feel a difference either. Maybe it's because we have so much hp already that we will not notice a few more?

I installed 964 cam grinds when I rebuild my 3.2, These work very well with the hotwire mass airflow I am using. Together with a chip I have a definate seat of the pants improvement over stock especially over 4000 rpm. The new motor positively screams to 7000rpm whereas before, power used to literally disappear at 5600 rpms. Dont know about HP but it feels as fast as my old modified (16psi) 944 turbo (yes, don't forget the 911 is lighter!). Next mods for me are headers / muffler, should pep it up a little.

I think on USA compression 3.2's with headers, sport muffler, decent chip, mass air, and 964 cams you can expect some where in the 250hp range. Andersons book describes a test of a 3.2 with all the aforementioned mods apart form the cams which put out 247hp. The cams would probably add 8-10hp. Wilder cams may add peak power but would detract from the drivability of a street car with steet gears. My car makes an extrememly broad power band with 964 cams and the extra breathing at high RPMs, complimented by the mass air give it a beautifull top end screamer personallity without compromising low end tractability significantly. I want to get in on dyno soon to back these figures up.

Hey rattlsnak, email some info about your crankfire system please!

Sorry about the double post - I think the site had a hiccup! I thought I would add a few more observations that I've made after researching this topic over the past couple of years. While subjective, they may be helpful to anyone else contemplating the challenge of "adding" HP to a stock US 3.2L.

Let's say a stock US 3.2L is rated at about 215 HP. My experience with adding a chip and a test bypass pipe on a stock 3.2 was a little more top end pull and added throttle response with some increased smoothness overall - I would guess this added about 10-15 HP overall. The potential problem with an aftermarket chip is that the redline cut-out may exceed 6800 RPM - a definite recipe for disaster in a 3.2 with stock rod bolts. Adding SSI or headers and a sport muffler may gain you an additional 15 HP over the test pipe - so now we are up to about 240 HP. To add more power and throttle response you need to spend considerably more time and money. You could enlarge the throttle body and switch to a MAF sensor, or what is known as a "hot wire" air flow sensor. This will improve air flow and throttle response, but without finding a way to add more fuel it will not, in many's opinion, give you the increased torque/HP results that warrant the cost. So essentially you end up with two choices: 1) Weber/PMO carbs with crankfire ignition or 2)some kind of electronic fuel and ignition management system mapped to whatever intake/injection system your budget allows. The second choice is the ultimate: if sophisticated (like Motec), it will give you more adjustability than carbs and ultimately (after ALOT of fine tuning) better driveability. If you step up to individual throttle bodies, the throttle response and HP will also be greater than with carbs. Of course, now you have spent upwards of $10,000 on bolt-ons for a stock 3.2L, not including labor! You could of course transfer much of this to your next engine.

Alot of what I did to my car was a result of a rulebook. If I wanted 275 HP in a 911 and didn't need to satisfy any rules, I would put a 3.6 in! However, at the end of the day, I think MFI, carbs, or individual throttle bodies with a Motec-type system will deliver the ultimate in throttle response - which is to me what driving these cars is all about.

Randy

Randy,

That doesn't sound very 'stock' to me, but I guess you meant 'stock longblock' ... not stock engine!

It also sounds like a $6K or more set of modifications to get 40-50 hp ... ???

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Warren Hall
1973 911S Targa

Warren-

Like I initially said in my first post, "stock inside" and in my second post "bolt ons for a stock 3.2L". As you noted, the engine proper: case, crank, rods, pistons, cylinders, heads (the longblock) is all stock US 3.2. The rest has been bolted on to the outside, and, as detailed in my posts, is not stock (but interestingly most are Porsche parts from other engines). You're right, this search for a more HP and throttle response is expensive (more like 10K with labor)! But as you know, a competitive advantage is worth it for the truly serious, and lots of torque and throttle response in an early car makes throttle-steering on a closed course mighty addictive!

Best regards,
Randy