pyro719

iTrader: (5)

I'm trying to tune my car with tunercats and it seems like the more fuel I give the car the more power it makes. Its running 13.5/1 afr @ wot what a good afr to shoot for for max power on my car?

moehorsepower

iTrader: (3)

First off how do you know you are making more power? guessing? On a Dyno, Street, If on a non loaded Dyno, I would richen it up a tad, If on the street, keep adjusting until your MPH starts to diminish...I have had cars make max power at 12.9 and a few up as far as 13.3 A/F....

wrd1972

iTrader: (12)

12.9 - 13.3 for NA for most.

Formula350

iTrader: (3)

Whether or not this is ACTUALLY true, or even carries over to our cars, but a cheap "ricer" mod I was going to do to my DD Corolla was labeled "adjustable A/F". I feel like a douche even posting this because I know that it is literally a 'hack', but I'm hoping the info might at least hold true. Anyways you put a potentiometer inline with IAT and while idling, adjust it till the RPM rises, then as it starts to drop back it off till it's at it's highest. That is apparently the 'sweet' spot. Now if that holds true and you can at least gauge the A/F R off that, then would you be able to adjust what ever settings you're tinkering with in the tune that relates to A/F R till the RPMs rise to their peak?

If not, disregard this This hack is for the older (up to 91) 4AFE 'Yota I4 16v cars, so the PCM vehicles may be too smart for it.

pyro719

iTrader: (5)

Im tuning with a wideband. I guess I should just wait and tune at the track or dyno

Shon Herron

iTrader: (25)

just had one of the tuned cars I did on the dyno.
street showed WB readings in the 12.8-13.1 range.
Dyno's WB showed 12 the whole run and made 328ish, leaned it out to 13.0 the next run, it picked up 5 and made 333, TQ was about the same from what I recall.

It is what it is.....

xx_ED_xx

iTrader: (17)

Supposedly boosted applications have a different A/F then NA etc. I have always been told 12.8 - 13.1 NA boosted closer to 11.8 - 12.1. And dyno tuning A/F wont be the same as Driving it on the street

ss.slp.ls1

iTrader: (36)

That is a very old hack indeed and should never be done to a modern vehicle.

Shon Herron

iTrader: (25)

agree! too bad the room of people do not understand it...."lean it out!"
it doesnt need it....points to the graph....OK....See....didnt pick up anything, now we have to go back to the street and see what the WB shows...

Formula350

iTrader: (3)

lol is mine "modern" (2 years newer than my 91 Crapolla) then? I still run the archaic ECM

myltwon

iTrader: (1)

there is no real perfect air-fuel ratio like stated, every car is different

my car actually picked up some power with going with a richer fuel ratio on my cc503 setup

buffman

iTrader: (9)

I was told by bryan herter he likes 12.8-13.1ish on the street AFR tuning. He said you'd see 12.5 on a dyno ends up slightly leaner on the street near 13.0

GIZMO

iTrader: (8)

There is no perfect answer to this question. I agree with the 12.8 to 13.1 range for N/A. The only thing that I will add is that these cars perform better at different A/F ratios depending on what gear you are in (and acceleration rate). It takes a bunch of logging and ET slips to figure out the "sweet spot". DA also becomes a factor.

phirepower

iTrader: (2)

Wow very interesting

buffman

iTrader: (9)

There are also very few places that good AFR runs can be made. I like to try and log mine up to around 110 mph..

ss.slp.ls1

iTrader: (36)

I hit 130-160 mph twice a day. Once on the way to work, and once on the way back, no joke. Either on the 133 or the 5fwy.

WH97Z

every motors is different. take it to the dyno and see what it likes. there are general numbers to shoot for but some motors like to be a little leaner and others a little fat. good luck

robsquikz28

iTrader: (246)

its all about test and tune and RE tune

Ed Wright

iTrader: (1)

That is correct. Also what you are using for fuel. With VP C11 mine likes 12.5 to 12.8, with VP C12 it likes 13.0 to 13.3. With Sunoco 110, it likes 13,3 to 13.5. Wide bands won't even read the same with all fuel. That is why you have to find what your car likes on the fuel you are using. There is no magic number.

When I first tried VP C11, my wide band suddenly showed 13.8-1, but with the injector pulse width versus RPM being the same, and power out-put being the same, the actual air/fuel ratio could not have really been different.
Evidently it's the makeup of the fuel causing a different reaction from the sensor. They do what the name implies, senses oxygen content, then the software makes a calcuation as to the air/fuel rato. It's not perfect like a lot of people want to make it. It is just a point of reference. You have to actually test to find what your vehicle likes. The MPH on your time slip is the answer.

ryle

iTrader: (19)

SRJ
Dude, that's awesome!