Joe Anstett

Over the holidays (and routine maintenance) I had my 1986 951 dyno-tuned and I'm very pleased with the results - up 20 horsepower and 40 lb-ft, and both curves moved left 500-1000 RPM sooner (meaning the power comes sooner/lower down). I'll post the graph as soon as my scanner cooperates.

Power mods are:
- B&B Tri-Flow headers
- FabSpeed exhaust w/o cat
- Lindsey Boost Enhancer
- Old stock-mapping chips

Coming in, the car made:
251 whp @ 5500 RPM
237 lb-ft @ 5000 RPM

After tuning:
269 whp @ 5400 RPM
277 lb-ft @ 4400 RPM

which, assuming a 16% transmission loss (M5 tranny) should put it roughly at 320 bhp and 330 ft-lb at the flywheel.

Apparently the car used to be running rich (it runs great now, much smoother under acceleration), and it also had a very weird harmonic balance issue on the dyno that would cause it to shudder at certain rpms (yet it is fine on the road).

I'm pleased with the results, especially the big gain in torque and now knowing my peak torque is slightly higher than peak horsepower (I always like to have the two close and prefer higher torque). The added volume under the torque curve is impressive, as you'll see when I post the chart.

So, what do you think? Good results? I'm curious to know other people's results, both in stock form and modded to roughly the same degree as mine.

Thanks to the crew at PowerTech in Rockaway, NJ.



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1986 Porsche 944 Turbo
2000 Pontiac Trans Am
2002 Jeep Liberty Sport

Keithr726

Very nice, but 330bhp seems a bid high to guesstimate. What are those headers good for HP wise?

hosrom_951

What boost level?

Joe Anstett

Added dyno graph.

It's headers + fabspeed exhaust with a test pipe (no cat).

Running slightly higher than original stock boost, IIRC 1.1-1.2 bar which is about 12-14 psi?

The spikes at the peak are due to some weird harmonics issue my car had with the dyno (curiously it's fine during road testing). It would start shaking the dyno violently at those points.

JrodNJ

Hi Guys. I'm new to the forums (but not new to the Porsche World in a general sense). I was directed to this post by my friend Scott. Joe, I believe this Porsche belonged to my brother Pete. I had an opportunity to buy it about 8 years ago and didn't and have always regretted it. I hope it's been reliable for you and it sure seems to pack one hell of a punch between 4000 and 5000 rpm now!!!

Do you have any other threads/photos of the car?

Jared

Techno Duck

1.1 bar is about 16psi.. 1.2 is around 17.5psi

944CS

something is not right with your car based on those graphs

JrodNJ

If you're referring to the graph over 5000 rpm I assume that's where the OP ran into issues with harmonic balances?

special tool

what kind of wastegate do you have?

944CS

what is the LBE set at - that could be causing pressure spikes, which is why the graph is all over the place

also, when you say 'tuning', what exactly did they do? any re programming of DME or KLR chips?

Joe Anstett

Could be the LBE, although Powertech said they didn't see any harmonic issues off of the Dyno. I'll take off the LBE and readjust.

I haven't touched the wastegate.

Yes, it was a custom set of chips.

Jared, I have plenty of pictures (including Lime Rock and Pocono). I should have them online somewhere, let me find them...

944CS

you must find out what the boost curve is of your new chips...in the mean time adjust your LBE down to about 6 psi - do you know how to do this?

Joe Anstett

^ Yeah, number of thread turnss, etc. I should still have the instructions. Worst case I can remove the LBE and test.

Jared and Pete are interested in pics...

Here's pictures from the first cleanup.
http://rides.webshots.com/album/91214516WhNaJZ
http://rides.webshots.com/album/91226289dwSHqw

Track pics:
Lime Rock: http://rides.webshots.com/album/214364468OHEwTJ
Pocono: http://rides.webshots.com/album/329573930Zlisyn

A.Wayne

Very interesting cardiogram , where are the dyno sheets