04ctsvfl

iTrader: (4)

For some reason my car on the dyno today was reading an afr of around 10. It puffed some black smoke midway through the run and then a tad of white at the end. Im assuming this is very bad. When I fix this will I make more power?

I was still able to put a car length racing from a 60ish roll in 3rd to about 90......on a 08 c63 amg immediately after the dyno....somehow it doesnt all equate.

Could there be anything wrong with my motor if I have been running this rich for a while? I havent hooked up the spray yet so dont worry about that part.... what should my a/f be at and how much more power do you think Ill make?
Thanks

Mike454SS

iTrader: (4)

If the engine is NA (based on your signature, I think it is), you want to get that AFR more into the 12.5-13.0 range. You will most likely make more power. I've gone as lean as 13.2 in search of power on some engines but that requires a lot of care and attention in the tune to really be perfect, staying a bit richer than that number (12.8ish) is much better for most people...it might leave a few (very few) horsepower on the table, but it's less risky.

If you're going to spray a dry shot, then the tune will need some more work to be safe, but if the nitrous will be a wet shot, you can keep the NA tune in a normal NA range, and setup the fuel jet on the nitrous to keep the nitrous afr correct seperately.

98Camarod

iTrader: (43)

What doesn't add up is that after the dyno you thought something was wrong with the car and yet you still raced

Definitely need to lean it out though either way

Fatbum

iTrader: (1)

I wouldn't go over 12.8 A/F ratio.

Your tune could be total garbage. Do you have someone who can download it from your vehicle and post it up?

The dark smoke is most definitely a rich condition, the white can be any amount of things.

See if you can have someone look at your tune first before jumping to any conclusions though.

04ctsvfl

iTrader: (4)

is there more tendency to foul spark plugs? or o2 sensors?

Doc

iTrader: (9)

Ever get those exhaust leaks fixed?

Eagle02

iTrader: (20)

Yes and yes, but if you pull the plugs and they look OK I'd say you probably haven't hurt your O2s. If you had it tuned for spray, perhaps the tuner made it way fat to make it more "safe" on the juice? Pretty common as far as I can tell.

-Eagle

04ctsvfl

iTrader: (4)

I did Doc, thankyou. It was actually a spark plug that was loose, and I was losing compression out of the clyinder. And thats why I think maybe the tune that was spot on (afr wise) when the compression was being lost, is why it is so rich now that I have the motor put together right....does this make sense at all? Im trying to figure out how the tune a year ago had a perfect afr, and now I fix a leak, and **** goes to hell. I would for certain come to you guys if I still lived in North Florida, I just dont have the time or funds to justify the trip up there to get this settled. Are you all coming to PBIR for any events in the next few months?

But now theres a whole new issue.