I just got a wideband and im ready to tune my PowerFC. Im running an intake, and full 3" exhaust.

I'm planning to put the PowerFC and AFC display in line and video tape them as I drive. With the Power FC in maptrace mode I figure I should be able to tune pretty easily. (datalogit in near future)

My question. What kind of AFRs should I be looking for?
not only under boost but light load too???

also under light boost less than 5psi what AFR should I target?

my max boost is 13PSI

Im hoping some of you that know first hand will speak up here.

 

from what i have read, you shooting for low 11's or mid 10's on the wideband (lower # is more rich=good). also you might also want to tune it a little more rich due to the extra load when on the streets. im not sure if this is AFR or what. if you find out, let me know

 

Well from what I have learned. 11.3-11.6 is pretty good under load.

under load is easy. what Im not sure of and have found very little info on is light load situations.

What should I look for crusing on flat at 65 MPH...
How about revving the engine to wind it up under light acceleration (low to no boost - high RPM)?

anyone care to get this rolling with some personal observations?

anyone know what a factory stock AFR looks like? I figure that woule be a start but on the rich side.

 

It would be better and easier to read the results if you
have the commander display only RPM and KNOCK LEVEL.

Make only one run with map trace to determine which P rows you are using as these will remain constant for the boost you are running no matter what the fuel or timing is or how many runs you make.

Go read my UEGO testing posts. The AFR will lag a little behind actual rpms by a few hundred.

 

well I couldn't get a hold of a video camera the could see the LED display in the daylight. I will have one today though. I had a friend sit there and watch things just for a base to make sure nothing alarming was in there.
I read your UEGO posts. They are pretty good/helpful.

my new problem is boost Ill do a search before throwing it to the fire.

 

today I got my boost resolved (couldn't raise teh primary above 7 ) once I installed 2 HD valves it all worked fine apparently teh previous owner only raised teh secondary boost as he had only one valve and no pills.

so tomorrow a friend and I will be out with the camera trying this tuning with the WB

while crusing on the freeway with the cruise set I have it leaned out a bit about 15.5-16 AFR. seems pretty happy and I think the mileage has improved a bit.

 

Don't you think 16:1 is a bit lean, even for cruise?? I figured nothing more than 14:1 AFR at cruise let alone hitting the 16's..So, whatch getting now, 35mpg, hehe??

 

No not 35 MPG not even close. 16:1 is a bit lean but I remember from tuning other cars that the engine will surge very lightly in this condition when it get's too lean.
I haven't felt the surging yet... also I figure when I put the stock sensor on and turn the o2 sensor control on it'll be pretty happy here.
the fact that we can turn that O2 controll off it GREAT for tuning while driving.

 

General guidelines:

All in FOURTH GEAR, you can use 3rd to get it close (AFR is usually slightly leaner in 3rd than 4th gear) and then do 4th just once to verify it's where you want it.

If you have an airpump you need to disable it and closed loop if you want to tune low load and RPM. If you have a cat you need the sensor to be before the catalyst.

WOT:
11.5 at moderate boost (10+) and richer as boost goes up. Some run leaner with race gas, some run richer for more safety.

0psi-10psi:
about 12.5 to 12.0 or high 11's

Vacuum:
about 13.5

Cruise:
should be closed loop, you really can't tune this unless you disable closed loop first...


Stock maps are basically the same as above except full boost maxes out most widebands at 10:1 or richer. This is why you can do about all the mods you can dream with a stock ECU and if you keep boost at or below 10psi, you still won't run lean. Also, the stock ECU gets progressively richer as RPMs go up even if load is light.

The Power FC maps are reasonably close to the stock ECU fuel wise. Most likely you won't have to make any changes at all, or very slight changes. My car ran slightly lean for my taste at WOT at 12-13psi with a PFC, but I have about all the standard bolt on mods.

Wade

 

Thanks Wade. this is teh information I was looking for with my first post.
I noticed I didn't need to change much with the stock fuel maps either. lean it out a bit and richen in a few areas but not by much