Hey Guys,

I went to the dyno with two bimmer friends today to get some baseline runs before I look into buying HFC's and a exhaust. I also changed out my coupe mid-pipe for an 05/06 sedan midpipe earlier in the day.

Since I have a 5AT, all of the runs were in third gear and from about 55mph. On my first runs, the car was 193whp and 201whp. This seemed completely wrong to me because thats way lower than stock output. Also, the graph was very wavy. The tech fiddled with the connection to the RPM signal, or whatever it was, and on the next two runs the car went:

EDIT: Bad spark plugs brought down HP. Made 229whp, 219wtq with recently installed OEM platinum plugs (spacer, 05/06 mid-pipe).

221whp 214wtq
223whp 215wtq

I was content with these results, but the graph was still wavy, and no amount of smoothing was going to fix it. i have 75k miles, but I was hoping for 230whp and 220wtq with the spacer.

I am wondering if a better connection to the RPM signal would have given me some extra hp since fiddling around to get a better connection resulted in a 22whp gain over the ridiculously low readings I was getting.

Has anyone else had issues with a wavy dyno plot? Also, does finding a better connection smooth out the waviness and give you more power?

Here are some pics from the day.








The green 95 540i is a 6 speed, but has 182k miles and low compression in two cylinders. Regardless, he still put down 227whp and 242wtq.

The E30 has an M50 swap from a 92 525i, and it's VERY clean. Unfortunately, he only put down 161whp and 146wtq.

Any feedback on the RPM signal and why my whp is down a little?


Thanks for the help!

 

No feedback, but your comments on YouTube got me...

"next time do you want me to ask the DOT to install brighter highway lights so you can see the race better?"

It was horrible footage since you can't see jack however...but thanks for posting! =)

It'll be nice to see post-mod numbers as well.

How much did they charge you for the runs?

 

Plese stop making duplicate threads on the same topic.

 

Thanks man, and they charged me $60 for up to 5 runs.

My internet froze, so I clicked resent the info after changing the title, sorry.