I went to a local dyno earlier today to check my AF with the 3" maf and found I was running flat 15:1, so after leaving I hooked up a VAFC I was given and set it up then went ahead and added 15% fuel from 3k-6600. Can anybody guesstimate if I'm adding enough fuel to be in the safe range? My guess was that 15% technically should put me back to 13 or so, but I'm very new to using an AF controller.

I can't really afford to hit the dyno again or get a wideband, I'm trying to just ghetto tune it to a safe AF until I can do one of those things.

 

Its hard to say without a wideband or dyno read out. I mean i am adding 23% and im at 12.5 but i am also boosted and running a 4 inch maf. So without some other device i.e wideband or dyno readout there is no way of knowing.

 

Yeah, it is too hard to say. I'd actually take the 3" MAF off until a proper tune with a dyno or WB can be done. Not sure that it's worth the risk running so lean or trying to adjust AFR blind.

 

richer is better than leaner................hard to tune without a wideband tho

 

vs

This man does not mince his words...

 

People that have no way of immediately and correctly adjusting the AFR post-larger MAF housing have no business installing it, IMO.





hard delete > me

 

Thanks for info. I messed around with the fuel and if i added 20% it actually bogged a bit, so I backed it down to 13% and I'm going to leave it at that until I can get a wideband reading.

 

man i was at about the same as you and once i had everything hooked up i took out about 8-10% along 2800-redline and right now i'm at 13.4 to 12.8 at redline but like everyone said its hard to tune without dyno or wideband.....

 

What were you at before taking out 8-10%?

 

10.6-10.8 at WOT above 3500rpm......rich as hell ahahh

 

Ahh so that's why adding 15% had me running so rich. I moved it back until the car didn't smoke/feel sluggish in the higher RPMs then took out a little more and I'm at 5% fuel added across the board.

I figured if I was going to have to ghetto tune, I could tune from pig rich to something reasonable for safety's sake.

 

wide band or retune asap

or take the maf off..

 

If you run too rich its just as bad as running lean. Get a wideband. Ebay has them for 254 shipped an AEM uego. Install tune and have a nice day.

 

if you run too rich you might use up extra fuel
if you run to lean, you might use up extra engines.

Rich is always better than lean.

 

well rich can cause it's own problems, but definately not as QUICKLY as lean haha...

Anyway, I hit the dyno yesterday with the headers/ypipe + this 3" maf/intake piping and I had a couple of spikes in the powerband up to 14.3 or so, but otherwise it was all in the 13s and 12s.... so this mod didn't really lean it up as bad as I thought, it was probably that gay wideband that turbotune used.

 

Rich is not better than lean. Right is better. You can ruin a engine rich also sir.

 

14:2 at idle and usually in the 15s at wot. Although the car DOESNT run hot or feel sluggish at all. Im currently looking for a leak some where in the exhaust and have a walboro on stand by.
Personally i wouldnt try and tune a car without a wideband, could potentially go bad very easily.

 

you're richer than most @ idle, and lean as hell when WOT.

 

^^^ i know man , its really getting annoying. The car runs like a champ tho. Untill this all happened youd never guess the a/f was so off by driving it.