Stock M5 rainy day dyno results

multiowner · 28th October 2006, 20:26

Getting ready to do the rear differentials so I decided to get the beast dyno'ed. Found a great shop in Staten Island. Ripp Modifications. Two regular guys, Ross and Perry. Have alot of knowledge between them. New Dynamics Dynamometer can do both rear and all wheel drive.

Was able to do 2 runs, before trans got yellow cog and had to cool down,

1st run cold 419.8 whp w/ 319 ftlb torque

2nd run hot 432.4 whp w/ 329 ftllb torque

Very happy with results, car completely stock with charcoal filters removed.
Was in 4th gear 500 w dcs off ( programed w/ m button) will scan and post Monday with air chart.

darren_dallas · 28th October 2006, 20:31

Multiowner,

I've not seen too many dyno sheets on the M5 (have been looking for some myself) so I appreciate you sharing your results.

I am concerned though at how low the rwhp numbers turned out. Rwtq numbers seem like they may be in line with what to expect, but 319 and 332 rwhp are low. Are you sure you don't mean 419 and 432? That would be more appropriate.

Thank you,

Darren

chrisn · 28th October 2006, 20:35

Umm, did you swap the "4" for a "3" in those numbers?

Should be around 420-425 RWHP with filters out

Sprocket · 28th October 2006, 20:35

If you go back and do your runs in 6th gear (1:1 drive ratio) you will see about 100 hp improvement at the wheels. The car should be making about 410-450 rwhp.

Wolverine · 28th October 2006, 21:34

Actually, you're much better off doing the runs with the new differential. You should be able to run the car in 6th gear (1:1) without exceeding the maximum speed of the dyno.

With the existing differential, the HP peak of the M5 at 7750 rpm in 6th gear is at a speed of 165 mph. This is above the max speed of most dynos. However, if you use the 3.91 differential, 7750 in 6th gear occurs at 152 mph. Most dynos can go up to 150, so you'll get a much more accurate run in 6th gear with the new differential.

JamesInLV · 28th October 2006, 22:11

Quote:

Originally Posted by multiowner

Was able to do 2 runs, before trans got yellow cog and had to cool down,

1st run cold 319.8 whp w/ 319 ftlb torque

2nd run hot 332.4 whp w/ 329 ftllb torque

.

Like was said otherwise, those WHP numbers should be 419 and 432, or perhaps they were drastically reduced by running in 4th gear (not likely). My dyno run, w/out charcoal filters was 431.2hp and 317.5 ftlb of torque. That 329 ftlb number sounds great, but it was also done in 4th gear. Stock, your dyno run should be done in 5th gear, since you can't run 6th gear to redline without hitting the speed limiter. To run a decent before & after, you should do a dyno run in 5th gear once you get the new differential, and then do another run in 6th gear (as said, that's the closest 1:1 ratio) to get the most accurate dyno numbers on your car to take away with you. I know dyno time costs money, so whatever you do will be great.