Dynoed really low... - The Unofficial BMW M5 Messageboard (m5board.com)

jrhaile · 9th June 2008, 06:41

So last year about this time I dynoed at 330rwhp and very similiar torque with my stock mufflers...

I went and dynoed yesterday after I had thought my car was running up to par with my "new" Magnaflow Cans. My highest was 316rwhp and 308rwtq with other pulls being around the 303rwhp

. I've recently spent A LOT of money on the car replacing CPS', O2's, VGCs, Spark Plugs and coil boots, cleaning the air filters and oil seperators. Cleaning the oil seperator from the butt-dyno perspective seemed to honestly help out a lot. The only thing I have not changed is the MAF sensors. Obviously this is what I'm going to do next but I'm curious if this doesn't help, what next? For the time being, I just cleaned my MAFs and I'm going to go for a test drive in a few minutes to see if I notice anything different.

The only other thing I can think of is clogged original 120k cats?

What confuses me is it seemed like my car is running on all 400 horses again after I cleaned the oil seperator's and since I was able to keep right with a brand new E92 M3, I figured I'd be dynoing in the 330-340rwhp range.

Any thoughts on this are more then welcome...

Kelleyo · 9th June 2008, 14:51

Was it the same dyno both times? If not, that could explain the difference.

jrhaile · 9th June 2008, 19:08

Not the same dyno but both the same dynojet model...

I cleaned my MAFs last night and there is a noticable improvement with the car. 30hp/tq? Not sure... I'll see if I can pop in to my local dyno and make a couple of quick pulls today..

gsfent · 9th June 2008, 20:22

Quote:

Originally Posted by jrhaile

Not the same dyno but both the same dynojet model...

I cleaned my MAFs last night and there is a noticable improvement with the car. 30hp/tq? Not sure... I'll see if I can pop in to my local dyno and make a couple of quick pulls today..

Different dynos, expect different results, even if same type. For example, the first one may have corrected for temp and humidity, the second may not (just an example). The only thing dynos are really good for is a before and after comparison.

If you think the car is not up to snuff, run the dynamic MAF test. If all is good, I would say you are fine, even if the Magnaflows lost a couple of hp (it can happen) or gained a couple. Most butt dynos aren't that highly calibrated!!!
Regards,
Jerry

E55AMG2 · 9th June 2008, 21:56

Quote:

Originally Posted by jrhaile

Not the same dyno but both the same dynojet model...

I cleaned my MAFs last night and there is a noticable improvement with the car. 30hp/tq? Not sure... I'll see if I can pop in to my local dyno and make a couple of quick pulls today..

check the altitude/baro pressure settings in the runfile...thats prob where the difference lies.

jrhaile · 10th June 2008, 02:55

Quote:

Originally Posted by E55AMG2

check the altitude/baro pressure settings in the runfile...thats prob where the difference lies.

Altitude where I dynoed on Saturday was near or at Sealevel in the Seattle/Kirkland area. Where I dynoed previously is around 2000ft in elevation.

jrhaile · 10th June 2008, 02:58

Also is there a condensed version of the steps on how to test your mafs?

E55AMG2 · 10th June 2008, 04:13

Quote:

Originally Posted by jrhaile

Altitude where I dynoed on Saturday was near or at Sealevel in the Seattle/Kirkland area. Where I dynoed previously is around 2000ft in elevation.

While that may be, you still need to see the altitude the dyno stack had been calibrated to...its pretty easy to get the runfiles from the dyno operator and view them with winpep7 (free from dynojet)