I went to the dyno today... got a few pulls for a rough baseline.
2001 E55 30k miles, stock.
262 hp @ 6000
271 ft_lbs @ 4500
Did the pulls in 2nd gear. ~73 °F ambient temp
Torque converter was slipping... wasn't able to get anything below 3900 rpm. Has anyone else run into that issue? What did you do to remedy it? How do these numbers look?
Torque converter is not slipping. You cannot go WOT till roughly 3700 in our cars, and theres no way to put it into a true dyno mode so you are just going to have to get used to 3800-6000 rpm dynos. Also did you disable ESP? if so that may be why you were having issues, if so those results are completely useless. Also what altitude are you at and what type of dyno was it. All are important factors.
Torque converter is not slipping. You cannot go WOT till roughly 3700 in our cars, and theres no way to put it into a true dyno mode so you are just going to have to get used to 3800-6000 rpm dynos. Also did you disable ESP? if so that may be why you were having issues, if so those results are completely useless. Also what altitude are you at and what type of dyno was it. All are important factors.
You say the torque converter is not slipping... How would you explain the graph?
My explanation: At WOT in 2nd, the revs jumped up and then the torque converter didn't lock until 3900...
Did you disconnect ESP 100% or just hit the ESP off button (b/c that doesn't count). For a mustang dyno those numbers are not that bad. most mustang dynos of our cars stock have come back between 272-282, yours just may be a lower then average car. All my dyno runs were done from about 3800-6000, you have to slowly ease into the throttle. Also 2nd gear numbers will always be lower. you need to do runs in 4th gear for true HP numbers. Go back and demand they redyno your car for doing it improperly. I've never heard dyno operator dynoing a car in 2nd gear so thats huge mistake. Also this time tell them to clean up your graph and change the x & y axis scale (320HP max on y-axis and 3000-6000 rpm on X-axis), whoever dynoed your car REALLY didn't know what he/she was doing.
Quote:
Originally Posted by jeff.bisonett
You say the torque converter is not slipping... How would you explain the graph?
My explanation: At WOT in 2nd, the revs jumped up and then the torque converter didn't lock until 3900...
Of course ESP was disabled.
165ft above sea level and it's a mustang dyno.
Last edited by omeyhomey : 06-25-2007 at 02:39 AM.
so you're saying that 4th gear will gain me the 10-20 hp that other cars have seen? Will that let me start at ~ 3k rpms?
Of course ESP was hard disabled. It would not let the car run without being disabled.
The dyno operator is the owner of the shop and has dynoed 1000's of cars. This was the first mercedes. He has not seen much difference between which gear was used.... as long as I do it the same every time it shouldn't matter. He also did give me a graph from 3000-6000. I posted this one because I wanted to know about the slipping torque converter... I suppose it's possible that the tires slipped?
Thanks for all your input. I will try again in 4th gear on the next dyno day.
It's not so much "gaining" real horsepower, but it is a more accurate gear ratio in 4th so you will get a more true value. By easing on the gas you will prevent the safety systems from freaking out and pulling timing and fuel. Both of which will cause you power as well.
well, assuming 18% drive train loss, a stock 350hp car should put down around 287hp and 328ft/lb. Has anyone an accurate E55 drive train loss value? The HP seems close but the torque figure is way off. That could just be the fact he was in second instead of fourth so there was some gearing variances in play.
so you're saying that 4th gear will gain me the 10-20 hp that other cars have seen? Will that let me start at ~ 3k rpms?
Of course ESP was hard disabled. It would not let the car run without being disabled.
The dyno operator is the owner of the shop and has dynoed 1000's of cars. This was the first mercedes. He has not seen much difference between which gear was used.... as long as I do it the same every time it shouldn't matter. He also did give me a graph from 3000-6000. I posted this one because I wanted to know about the slipping torque converter... I suppose it's possible that the tires slipped?
Thanks for all your input. I will try again in 4th gear on the next dyno day.
Yes there is a substantial difference between 2nd & 4th gear. No you cannot start at 3000rpm, 3700rpm is pretty much the gut off and you have to gradually floor the pedal and once you get past 3700 you should be able to give it 95% then around 3900-4000 100% (theres no way around this unfortunately). i highly doubt its torque converter, probably just dyno error
stock dyno results 
Linear Mode
