First Dyno Run on the 3.4 - Page 2

Jgordon · 07-19-2005, 04:40 PM

Ralph, the car feels pretty damn good. Great engine note, really screams above 4500, and this is with the stock exhaust. It seems a LOT louder than it did before. That and there seems to be a lot more power, and the power seems much smoother. the whole engine just feels tighter, it's hard to describe. I am just starting a job, so I haven't really gotten a chance to have fun yet. I'm hoping that this saturday provides an opportunity.

I would have liked to have done some dyno runs, but the reason this whole thing started was an overrev. So I didn't really get the chance to see what she was putting out prior to the surgery. If she hadn't needed the valve guides and the new valves, I never would have dived into this particular pool to begin with.

Between engine loosening, AFR tuning, moving to a lighter weight synthetic oil and an exhaust system, I'm hoping I can squeeze another ~20 hp out of it. That would make me very happy. I'll definitely update you when I get a chance to wring her out a little.

Carrera3.5L · Carrera3.5L's Garage

Quote:

Originally posted by Jgordon
Ralph, the car feels pretty damn good. Great engine note, really screams above 4500, and this is with the stock exhaust. It seems a LOT louder than it did before. That and there seems to be a lot more power, and the power seems much smoother. the whole engine just feels tighter, it's hard to describe. I am just starting a job, so I haven't really gotten a chance to have fun yet. I'm hoping that this saturday provides an opportunity.

I would have liked to have done some dyno runs, but the reason this whole thing started was an overrev. So I didn't really get the chance to see what she was putting out prior to the surgery. If she hadn't needed the valve guides and the new valves, I never would have dived into this particular pool to begin with.

Between engine loosening, AFR tuning, moving to a lighter weight synthetic oil and an exhaust system, I'm hoping I can squeeze another ~20 hp out of it. That would make me very happy. I'll definitely update you when I get a chance to wring her out a little.

Very nice! Glad to hear that it worked out for you and you had a minimum of downtime. Yes, you'll find some more power with a less restrictive exhaust and the AFR optimized and the added displacement should make the motor smoother up the rpm range compared to a 3.2L that does very little until 4,000 rpm IMO.

Getting back from NYC and NJ yesterday, how the heck do you guys deal with the oppressive humidity on a daily basis? It's brutal.

Ralph

Jgordon · 07-20-2005, 07:45 AM

the great 911 air conditioning.

Steve W · Steve W's Garage

Dynapacks dyno more conservatively than Dynojets, so don't try and make a direct comparison. One clue was when Rick Deman swapped in a stock DME during the runs got around 185 hp, a number that would be considered low even for a bone stock 3.2. Perhaps it's the Dynojets that are optimistic. With a better exhaust, you should develop more power. Looking at your current fuel mapping, I can tell the potential is there. I spoke with Rick yesterday, and he wants the AFRs programmed around 13.5:1, so we'll see how it dynos.

JeremyD · JeremyD's Garage

Quote:

Originally posted by 89911
I did use higher compression Mahles which are key (listening Jeremy? )

Did you (I mean your mechanic) test the compression ratio? Didn't Ralph have a bunch of problems with the compression ratio on his motor with the higher CR "Mahles"...

DG624 · 07-20-2005, 11:22 AM

It seems that the 3.4 may not be worth the extra money for pistons unless the entire piston/rod combination is lightened and stronger. Also can polishing the cylinders to reduce friction make improvements? It seems that just .2 L can't make that much difference. Improving the flow, CR and efficiency should be much more important. This is good information although I can't afford to rebuild mine now. I have thought of a twin plug change but if I stay with 3.2 will the CR change to 10:1 be too much?