LN 32

I've posted this previously elsewhere, but thought I'd add it here as well...

We put the car in 'W' mode and turned off ESP. Three runs were completed on my 2002 AMG SLK32 with approximately 1200 miles on the odometer. The tests were run on a 2001 model Mustang Eddy Current 4 wheel dyno. Here are the results using conversion factors of 123% and 121%, respectively (more on parasitic loss below):

First set are based on 123% wheel to crank conversion (aka parasitic loss):
<b>
Run#1 352 ftlbs 355 hp
Run#2 351 ftlbs 359 hp
Run#3 347 ftlbs 353 hp </b>

Second set of numbers are based on 121% conversion factor:
<b>
Run#1 346 ftlbs 350 hp
Run#2 345 ftlbs 353 hp
Run#3 342 ftlbs 347 hp </B>

<i>How we determined the parasitic loss conversion factor (wheel output to crank output):</i>

The 123% factor is a number that falls almost directly into the middle of % conversion factor (high 127% and low 118%) normally applied to a Mustang Eddy-Current Dyno and the 121% conversion factor was developed by dividing dyno wheel hp into manufactured stated hp output for each run and then averaging the results.
<i>
Averaging results of all runs for each conversion factor: </i>

Now averaging hp and torque for all runs for each conversion factor, the average for 123% is <b>350 ftlbs and 356 hp </b>and the average for 121% is <b>344 ftlbs and 350 hp</B>. Manufacturer stated ratings are 332 ftlbs and 349 hp.

In all three runs max toque was reached at approximately 4500 rpm and hp at 5750 rpm.

Since I haven't gotten around to scanning the dyno sheets, photos of the monitor showing the output at the wheels are located at here. (Note: This is not crank hp (i.e., hp at the crank with accessories) or torque, but rather wheel hp and torque, shown prior to application of any conversion factor. Crank hp is what is advertised by manufacturers.)

Vic55

What does using the "W" mode do for you instead of the "S" mode. I know what is does in regards to daily driving- starting in 2nd gear instead of first but does it give you more peak HP or peak torque??

LN 32

Putting it in 'W' mode does only what you stated (i.e., start in 2nd gear). It does nothing to affect peak horsepower or torque.

Don

You might mention that the W-mode also changes the shift point thresholds. In fact, the reason you used the W-mode was to help prevent downshifts during the dyno test.

speeder

Hello--
I'm going for a test drive in a 2002 SLK32AMG tomorrow & would appreciate any feedback on potential problems with the electric roof, engine, supercharger, etc. Does anyone know of a dealer with a competitive price in the Orange County, CA area?
Thanks,
Bob

jswedberg

Maybe I'm a little slow - you said your numbers were rear-wheel horsepower? Or does the parasitic-loss conversion make it "equivalent" to crank HP?



Do your numbers mean that the MB figures are on the mark, more or less?

Or

Does that mean that Mercedes is EXTREMELY conservative on their (crank) horsepower figures?

LN 32

Mercedes' numbers seem very close to the mark to me.... maybe slightly conservative, but well within the normal variation.

newsguy

Hey, just wonder how your test drive ever turned out and what you ended up getting, I'm in your same boat!

cvayala

Finally!! I thank you for posting those pics, I got my 32 used with RennTech mods, I also received a dyno sheet showing about 330 hp at the wheels, I needed something to compare it with. Thanks again.