Fun Dyno Comparisons: 3.2 vs 3.4 vs 964

[Steve W]

It's been a while but I though it be fun to post some dyno chart comparisons of different stock and lightly modified 911s and their build specs to show what is possible with some of the most common mods.

Below is a 3.2 to 3.4 conversion compared to a 964. The 964 in red is basically stock except for a muffler bypass and chip tuned on the dyno for an additional 20 hp, from 237 to 255 hp at the wheels. The 3.4 in blue doesn't make as much torque as the 3.6, but makes about the same peak hp at 255 rwhp. The 3.4 is built with the standard Mahle 98mm 3.4 p/cs measuring about 9.9 to 10.0 CR, with Dougherty Racing 993 Super Sport cams, a rebored throttle body, ExtrudeHoned manifolds, the stock air flow meter with an open airbox cover, stock heat exchangers with a Fabspeed premuffler and a Dansk Sport muffler. Both conservatively tuned for 91 octane fuel.



And below is the same two cars as above, but with my stock 86 3.2 overlaid. I removed the torque graphs for better visual clarity. Dark blue is my 86 all stock, and in green is after a chip remap. The engine and exhaust is completely stock, including cat and OE muffler, except with a modified cone air filter setup.

[Peter M]

Interesting Steve, thanks for posting.

Was the 3.4 twin plugged as well?

[slow&rusty]

Good info

[Mr. Merk]

Originally Posted by Peter M

Interesting Steve, thanks for posting.

Was the 3.4 twin plugged as well?

Don't think it was, I wish it had headers on it though! I bet the factory exhaust configuration is really choking that build!

[Steve W]

Originally Posted by Peter M

Interesting Steve, thanks for posting.

Was the 3.4 twin plugged as well?

No, single plug. The Mahle 98 3.4s have a Max Mortiz asymmetrical wedge dome which cups the compressed mixture towards the single plug. You can't twin plug those properly because the second plug will be shrouded when the piston is at the top. Twin plugging require a symmetrical dome such as you see on the 964s and 993s.

Originally Posted by Mr. Merk

Don't think it was, I wish it had headers on it though! I bet the factory exhaust configuration is really choking that build!

The stock exhaust setup is actually very good. When header systems are installed on 3.2s and 964s, there's no real noticeable power difference vs the stock exhaust setup with a cat or muffler bypass. And the inner diameter of the 964 heat exchangers are basically the same as the 3.2s.

The power is actually pretty good. These are SAE corrected numbers, not STD which typically inflates everything. If you take the rear wheel hp number at 255, and conservatively figure a 11% transmission loss, 255/0.89 = 287 hp at the flywheel. Or if figuring a 15% transmission loss 255/0.85 = 300 hp at the motor.

[Bill Verburg]

Originally Posted by Steve W

It's been a while but I though it be fun to post some dyno chart comparisons of different stock and lightly modified 911s and their build specs to show what is possible with some of the most common mods.

Below is a 3.2 to 3.4 conversion compared to a 964. The 964 in red is basically stock except for a muffler bypass and chip tuned on the dyno for an additional 20 hp, from 237 to 255 hp at the wheels. The 3.4 in blue doesn't make as much torque as the 3.6, but makes about the same peak hp at 255 rwhp. The 3.4 is built with the standard Mahle 98mm 3.4 p/cs measuring about 9.9 to 10.0 CR, with Dougherty Racing 993 Super Sport cams, a rebored throttle body, ExtrudeHoned manifolds, the stock air flow meter with an open airbox cover, stock heat exchangers with a Fabspeed premuffler and a Dansk Sport muffler. Both conservatively tuned for 91 octane fuel.



And below is the same two cars as above, but with my stock 86 3.2 overlaid. I removed the torque graphs for better visual clarity. Dark blue is my 86 all stock, and in green is after a chip remap. The engine and exhaust is completely stock, including cat and OE muffler, except with a modified cone air filter setup.

the 993SS cams are excellent for 964/993, especially so w/ headers on the 964s, we so ~300hp for a 964 w/ 993s and headers +chip

993 sees similar or a little better but doesn't need the headers

on my 993 3.6 is my '76 I run headers, 993RS hydraulic cams , chip and see just short of 300 at the rear wheels

[3literpwr]

I still need one of these for my 10.3:1 (Max Mortz), 3.4 with 20/21 cams.

[Jeff Alton]

Thanks for posting Steve. By the way, the latest chip you sent us for the Strosek 964 engine build worked perfect.

Cheers

[Steve W]

Originally Posted by Bill Verburg

on my 993 3.6 is my '76 I run headers, 993RS hydraulic cams , chip and see just short of 300 at the rear wheels

300 at the rear wheels or at the motor? At the rear wheels would be amazing! Do you know what kind of dyno that was on?

Originally Posted by Jeff Alton

Thanks for posting Steve. By the way, the latest chip you sent us for the Strosek 964 engine build worked perfect.

Cheers

Great to hear Jeff! With the 993SS cams used, that's useful feedback!

[Peter M]

Steve,
Thanks for the ignition configuration clarification.

So in a nutshell, to give the same rwHP and given the displacement and ignition disadvantages we have a 3.4 with its modified inlet manifold and 993SS cams having a volumetric efficiency somewhere between 5 to 10% higher than the 3.6 engine.

Is that how you read it too Steve? That's an extraordinary improvement!

I find it surprising that the owner of the 3.4 didn't go twin plug given the proven advantages. It's not as though they were scrimping on costs looking at the other modifications!

[winders]

Originally Posted by Steve W

300 at the rear wheels or at the motor? At the rear wheels would be amazing! Do you know what kind of dyno that was on?

300 HP at the rear wheels of a 3.6 with headers, cams, and a chip is hard to believe indeed....at least from an reasonably accurate chassis dyno anyway.

[Steve W]

Originally Posted by Peter M

So in a nutshell, to give the same rwHP and given the displacement and ignition disadvantages we have a 3.4 with its modified inlet manifold and 993SS cams having a volumetric efficiency somewhere between 5 to 10% higher than the 3.6 engine.

Is that how you read it too Steve? That's an extraordinary improvement!

I'm sure the cams have much to do with the shift in the VE. You can put similar cams in the 3.6 and get similar results.

Originally Posted by winders

300 HP at the rear wheels of a 3.6 with headers, cams, and a chip is hard to believe indeed....at least from an reasonably accurate chassis dyno anyway.

I never said it was unbelievable, just amazing. Not exactly 300 rear wheel hp, but pretty close. This is a 95 993 3.6 motor rebuilt by Downtown L.A's Porsche master tech, his personal track car, all stock including OE p/cs, except with some Elgin cams, headers with an open exhaust, and tuned to run on race fuel. Conservatively figuring a 11% transmission loss, it works out to 330+ hp at the motor:

https://www.facebook.com/watch/?v=973195809420153

[Bill Verburg]

Dynapak dyno @ rear wheel hub
283hp@6750
233lb-ft@5500

[winders]

I was talking about street cars with street exhaust and unleaded pump gas. Bill's numbers in the post just above this one is the max I would expect.

[Bill Verburg]

same day as mine another 993 3.6, headers, ss cams, chip pulled in the 290s, but I don't have that complete data set

additionally, the clutch/ flywheel package seems to make a big difference

my 3.6 has a 915 w/ Sachs aluminum sport clutch and builds revs like crazy compared to similar motors using various lighter than stock but still heavier 993 /G50 setups

I've also seen street 993 3.6s w/ various hotter cams, ITBs and Motronic pull into the 300s

best air cooled I've seen is a buddies Rothsport 4.0 which pulls into the 400s

all it takes is cubic dollars

[Steve W]

Very nice! Jeff does build some trick motors. Below in red is another '95 3.6 Motronic chip tuned for Dave B at TRE about 10 years ago. This one is 305 at the wheels on a Dynojet SAE corrected (340-350 hp at the motor). It's a track car with headers.


In comparison in blue is another 3.2 to 3.4 conversion (3.35L technically). After dyno tuning, it has cams, a trick set of headers, running the stock 3.2 intake, stock air flow meter with cone filter. 278 SAE corrected (315-325 at the motor).



Just off the dyno, the motor below also makes over 400 hp on a Superflow engine dyno on pump gas. Although very Singeresque, it not for a Singer but built by the same guys who build their motors.

[winders]

Here is a 3.6L race engine:

This dyno is the one used by NASA and PCA to verify HP numbers. Note that numbers are SAE corrected. HP loss with a 915 drivetrain and the wheel/tire combination is at least 15%.

[Bill Verburg]

Originally Posted by Steve W

Very nice! Jeff does build some trick motors. Below in red is another '95 3.6 Motronic chip tuned for Dave B at TRE about 10 years ago. This one is 305 at the wheels on a Dynojet SAE corrected (340-350 hp at the motor). It's a track car with headers.


In comparison in blue is another 3.2 to 3.4 conversion (3.35L technically). After dyno tuning, it has cams, a trick set of headers, running the stock 3.2 intake, stock air flow meter with cone filter. 278 SAE corrected (315-325 at the motor).



Just off the dyno, the motor below also makes over 400 hp on a Superflow engine dyno on pump gas. Although very Singeresque, it not for a Singer but built by the same guys who build their motors.

Who did the valved GT3 muffler setup? I'm still trying to piece that together for mine

Here's the rear wheel torque for several 993 engine cars we've seen here, I like the torque data because you can do so much more useful stuff w/ them



for instance here are the acceleration curves for my '76 w/ both of my motors
I like the 3.6 for general all around daily street use better than the 3.8

[Steve W]

The VRAM does all a lot more midrange torque between 3200 to 4200 vs the previous dual resonance intake. They also seem to have better power extension and less fall off out to 7000 rpm. Jae Lee of Mirage along Randy Aase and myself tested this on AASCO's Superflow engine dyno, on a 95 3.8 with complete intake swaps and it's around +30 ft lbs.

The valved setup is likely done in house. You can see it's just a set of Fabspeed headers modified with V-band clamps to a GT3 muffler. Domestically, Fabspeed, Soul,and TPC racing makes valved side bypass pipes, though you may or may not be able to mod and mate them up to your B&B headers. If you want to fab them yourself, I think you can source the Porsche spec valves from Fabspeed. Overseas, afaik, M&M and Cargraphic made them too.

[Bill Verburg]

Originally Posted by Steve W

The VRAM does all a lot more midrange torque between 3200 to 4200 vs the previous dual resonance intake. They also seem to have better power extension and less fall off out to 7000 rpm. Jae Lee of Mirage along Randy Aase and myself tested this on AASCO's Superflow engine dyno, on a 95 3.8 with complete intake swaps and it's around +30 ft lbs.

The valved setup is likely done in house. You can see it's just a set of Fabspeed headers modified with V-band clamps to a GT3 muffler. Domestically, Fabspeed, Soul,and TPC racing makes valved side bypass pipes, though you may or may not be able to mod and mate them up to your B&B headers. If you want to fab them yourself, I think you can source the Porsche spec valves from Fabspeed. Overseas, afaik, M&M and Cargraphic made them too.

Thanks

I've been talking to Joe about a new set of headers, will inquire about the GT3 adaption

I've got the Ti Gt3 muffler in my garage