Dinan 540-S3 Dyno Results - The Unofficial BMW M5 Messageboard (m5board.com)

540-S3 · 31st May 2007, 23:51

I had my 1997 S/C 540 dyno'd yesterday at West Coast Viper today. Dinan claims 414hp at the crank, so I was expecting around 364 at the wheels. The tech said he thought it would be closer to 330. We were both surprised by the results at 400hp and 358tq at the wheels or 448hp(?) at the crank. Either their results are skewed or a previous owner made some mods that I was unaware of. This car was actually Steve's R&D car. Could he have made some changes that he made only to his car? Maybe someone changed out a pulley. Anyway your comments are welcome.

DRM · 1st June 2007, 07:46

Have you checked S/C boost pressure?? 'Think it's supposed to be about 6psi. 'Suspect ol' Stevo might have had it set a "bit" higher. LOL

aw/ir02smg · 1st June 2007, 07:54

540-s3,

hey- if that is accurate, i'd be jumping up and down!! that is some scary numbers your car is putting down. ever take it to the 1/8 or 1/4 mile tracks?

for a while, i was going to get a couple more dynos done, but it seems rather difficult and inconsistent. i find that the shop i went to - was having difficulty doing it on my auto tranny....

i've since taken the 1.8 mile track as my measuring stick. not to mention the element of fun for $20!!!

the next time i head down to aga, maybe both you and dan can get a chance for a little impromptu get together...

540-S3 · 1st June 2007, 17:10

I just did some rolling runs with MfiveLeo last night. He has velocity stacks and cat back exhaust. It seems we were pretty evenly matched depending on what RPM range we started at. If I could get in my power band I would win and visa-verse. That being said I find it hard to believe that the readings above are correct. It would seem that I would have a big horsepower advantage over him. Can his 3:15 gear ratio and his other mods make up the difference in hp? Not sure. What do you guys think?

aw/ir02smg · 1st June 2007, 18:46

forgot to mention - mine dynoed at 327 rwhp back one really hot 100 degree day last year. so the 330 figure is more like it. however, you having a 6 speed vs my power-draining auto tranny will also have some difference.

as you said, if the figures were remotely true, you would have an insane advantage!

not sure his mods would account for THAT much increase in hp...