c32kompressor

my local shop had a dyno day today. to make a long story short, i dynoed 330.2whp stock last year on the same dyno. (even at the same event and had the same dyno tech.)this year my car wouldnt stay in gear though?? it kept down shifting under load. my numbers today were 298.6 whp. but my a/f ratio started around 12, dropped to 10.8 and went back up to mid 11's. could my a/f be tweaked? i dont see why i would make less hp with a tune?

jturkel

same gasoline? same temperature/conditions?

c32kompressor

SAme gas, but a little hotter day

gt4awd

Not really the cars fault. It will downshift if you go WOT too soon...

c32kompressor

true.

Zeebrock

A dyno is just a tool not an instrument, it can barely be relied upon from run to run for accurate HP numbers. Come back a week later and +/- 10hp would be quite normal. Comparing your results from a year ago is like expecting the weather on the day to be the same as last year. It just isn't going to happen.

loungn14

ding!

DrewZ9266

a 32whp is a decent difference. Any other changes to the car since the last dyno? Did it feel faster when you got the tune? Weather conditions/etc/etc of course come into play. Something very small (maint. wise) could make it vary.

mikekuriger

it could be time to get the fuel injectors cleaned and balanced

JUAN CASAUS

Or buy some new injectors. I changed mine out and there was a noticeable difference in throttle response and performance. I have an extra set of new injectors if you're interested.

loungn14

did you get a good dyno run in without downshift?

chris.bachman

My guess...they've changed some settings on the dyno.

Velociabstract

My guess is that the IAT's surpassed 115º on the dyno this time. (Guess how I know)

Les

francoisisp

PM sent

c32AMG-DTM

330 whp as a stock baseline is pretty ridiculously high... but the importance is the relative difference (delta) between runs pre and post modification(s).

Was the only thing changed the tune, and you went from 330 whp to 299 whp?

Doesn't sound right... that's a big difference. I'm sure Jerry/Jake will get you sorted.

c32kompressor

No. it kept downshifting every run.

mikekuriger

did you use dyno mode? my car won't downshift in dyno mode.

c32kompressor

I put it in dyno mode. Even tried doing it twice. It went in dyno mode, but kept downshifting