Dyno Results In! E28 535is Euro M6 Motor...

[Cacatfish]

I finally got my car to the dyno today, and it was some of the best money I've spent.

My first run was 223WHP and 216WTQ with AFR right around 14+ to 1 up to redline. Way too lean (!!) and some definite detonation (damn crap CA gas!!).

I loosened the AFM spring 3 clicks for the second run and got 228WHP at 5200 rpms before the tech shut it down as it looked like the AFR was still a bit lean at around 13.3 to 1.

Three more clicks on the AFM got me to 241WHP at 6600 rpm and 229WTQ at 5300 rpm. Also picked up torque all the way through the range (about 10 lbs).

I am now going pretty fat at redline (about 11.5 to 1) but I'll go with that for now, and may set it back one click . Mostly reading 12 to 13.5 to 1 through the range.

Im sure glad I discovered the lean condition before the rude melted piston awakening!!

With 16% drivetrain loss, this puts me right at the stock spec for M88 at 286HP at the motor. Motor is stock with 100k miles on it, came out of a Euro spec M635csi.

All numbers are Dynojet SAE corrected. Uncorrected, I was at 252whp and 239WTQ.

Guess my fuel mileage will take a little hit from this! Oh Well!! :)

[bähnstormer]

that is awesome! any graphs though?

[Cacatfish]

I will try to scan it tonight at my mom's place, I dont have a scanner....

[E34nication]

nice... that should be alot of fun.

[KarlSpackler]

wow nice numbers!!

[jimmyz2]

Congrat's and way to go.Keep pushing the envelope. :buttrock

[Cacatfish]

Thanks everybody, here is a pic of the chart:

The first run is the red and the third run is the blue...
The tech attributed the breakup in the red to detonation..(yikes!), though I think it could have been the wheels slipping on the rollers (it was wet out)

You can see how rich the AF gets on the third run near redline (11.2 to 1) but no more pinging!

[stuntride]

what did u adjust on the AFM to change ur air-fuel ratio?

[Cacatfish]

what did u adjust on the AFM to change ur air-fuel ratio?

If you pull off the plastic square top that sits near where the plug attatches, you will see the wound up spring and circular potentiometer for the air flow meter. If you loosen up the little clip, you can rotate the round toothed wheel one way or the other to loosen or tighten the spring, which will call for more or less fuel for a given air flow.

In this case, counter-clockwise loosens the spring, and thus richens the mixture (potentiometer moves further for given force on the flapper door).

Just remember to keep track of your original starting place on the wheel with some kind of mark, or you can have trouble getting back to baseline

I love old tech! :D ...

[Hypr5]

How do you know when your too rich or too lean without a meter?

[stuntride]

unless u kno cars good enough to smell the dif then u cant kno, he got to do it strapped down to a dyno. think i might have to make a trip to the dyno pretty soon

[Mblaster]

Dang...those are some nice numbers :D

[Cacatfish]

How do you know when your too rich or too lean without a meter?

Yes, like stuntride says, I was fortunate to be able to jimmy with it between runs and then see where my A/Fs were. Otherwise it would be a bit of a gamble. You can get a general idea from looking at plugs and exhaust tips, but it sure is nice to have the full readout in front of you!