Thread: air/fuel and engine management

What air fuel ratio you running at WOT? My ve is coming in monday for the wifes p10, and need some tuning advise. I want a rt2 but doesnt look like its gonna happen soon. Other people seem to be having luck with safc, so leaning toward that direction. What you think?

I tuned for 13.0 @ wot on stock cams. Nistune here

anywhere from 12.8's to 13.3's is good for n/a

how much power r u making

The motor isn't on the car yet. Just got a hold of calum ecu will be 3 weeks. Thanks for the info. All I could fined was tuning for boost. Quick ser how's that nitrous feel? Plan on putting some spray on after the car is up and runnin

After a 100 pulls of plying with the a/f, mine makes the most power everytime at 13.5:1. Thats on a 200hp/149tq ve.

Similar to what others have said, I like 12.8:1 at WOT for N/A tunes.

That tells me either your timing is too advanced, and/or the wideband data was off (likely by half a point).

Just sayin'.

That pretty intresting that you say that, because I need to have my ecu burned as its running a base tune. I got a chipped ecu that requires Moates equipment to edit and reburn, and though the a/f's are a nice flat line, it was recomended that I fine tune the base map ecu for timming. I need to do that badly. Ive been running 13.8:1 for the past few months and just turned it to 13.5 last week when I rented the dyno again. So you are saying if it makes more power running that lean, then the timing is too advanced?

Yah. You want the flame front to hit the top of the piston at the right time (and also with as much speed as possible). A leaner mixture burns slower. So what you're doing is you're slowing down the flame front by leaning it out so that it hits the top of the piston at the correct time. You're compensating for a spark that's happening too soon. If you'd just retard the timing instead (and add fuel), you'd get the flame front to hit the top of the piston later (as desired) and the mixture would be richer so the flame front will be moving faster, so you should make more power.

Add some fuel and pull some timing.


Then again, it could be that the wideband data is wrong. I never trust a dyno's wideband, especially if it's a tailpipe sniffer. I only trust a sensor plumped directly into the exhaust shortly after the turbine exit. If it's the dyno's sensor, I want to compare it to a know good one first.