3.4 - like to hear HP/TQ output of your engine

[Craig 930 RS]

To all those who have a 3.4 - with Motronic or carbs - I'd like to hear what HP/TQ measurements you achieved with your modded motor.....and a few notes about what you did to get the good #s!

(I will have one built soon)

Craig

[ttweed]

To get the good numbers, Craig, you go to a dyno that reads generously! I thought everyone knew that...

Seriously, though, my carb'd 3.4 pulled 280HP @ 6800 RPM and 240 ft.lbs. at 5000 RPM at the rear wheels on a Dyno Dynamics machine at Huntley Racing, running an open exhaust. It has the Mahle Sport 10.3:1 P/Cs, WebCam 171e grind, PMO 50s, Carillo rods and Aase springs.


I have had it on a DynoJet several times since with a Quiet Horsepower muffler setup and haven't registered more than 260 RWHP. A friend of mine had the same 20HP difference on his Boxster between the same two machines.

YMMV,
TT

[rdane]

Tom is your engine twin plugged?

[Craig 930 RS]

Tom you have a PM ;-)

THANKS for the info!
-Craig

[ttweed]

Originally posted by rdane
Tom is your engine twin plugged?

No, single-plug only, w/ Euro SC distributor, recurved. I run a 97 octane race gas blend in it.

[squirrelman]

ok I give, I'm a newb and I havent heard of the 3.4 engine before. What is it from, or what is it made out of?

[jpnovak]

Typically a 3.4 is made from a 3.2 Carrera case, crank, rods with 98mm pistons.

These same 98mm pistons can make a 3.2 out of a 3.0. This is called a short stroke 3.2.

Jamie

[squirrelman]

Thanks for the info. Sorry to go a little off topic but what does a conversion like this usually cost to turn the 3.2 to a 3.4?

[ttweed]

Originally posted by squirrelman
what does a conversion like this usually cost to turn the 3.2 to a 3.4?

Squirrelman-
That is a very open-ended question, and must be qualified with a second one- "how fast do you want to go?"

The P/C set from Mahle alone is around $3K. To simply gain 200cc in displacement, it is obviously not a real cost effective mod for a 3.2, unless you are rebuilding and buying new P/Cs anyway. If you increase the compression ratio, you can gain a little more. If you change the induction system so you can run a wilder cam, then you can start seeing some serious gains, but you are talking about "Cubic Dollars" by this time.

If you bought all the parts for my engine and put it together yourself, it would cost you about $8000, given that you had a 3.2 case and crank already. To have someone else build it for you, you would be looking at around $12-13K. If you had another few CDs to throw at it, you could twin plug it, do a little head work and go with EFI- individual throttle bodies and aftermarket EMS. Most of the 3.4 GT club racers are making 340-370HP with that kind of setup, but the costs are over $20K by then.

Whenever I see the ads at Jegs for a 350HP Chevy crate motor for $3000 I silently start to weep.

TT