Ed Blown Vert

iTrader: (2)

After installing my headers, and lowering my IFR to get my LTFT's negative. I am pretty sure I am running rich on PE. So I take it too the track and watch my KR.

I lowered my PE vs RPM 2% at a time to around 14 % and still no KR. My PE table is .87xx is that too low??

Bink

It's hard to say without a wideband. But, you shouldn't have needed to pull the IFR down too much- due to headers only. Strictly from the PE table that's a 16.9 AFR. Of course it would actually be lower due to the IFR adjustment.
Seems kind of dangerous to me to lean it out based on recorded knock.....but I'm No Guru. FWIW.
joel

Ed Blown Vert

iTrader: (2)

You were right, I put the PE back where it was and on the dyno. My A/F was 14.1

Bink

Thanks for the update. At what RPMs was it 14.1???
joel

Ed Blown Vert

iTrader: (2)

The whole run. 4000-6500

Any idea how much to scale down the PE Table for 1 point?

Bink

14.1/13.1 = 1.076. So, multiply your current PE values by 108%. Should put you around 13.1 AFR.
joel

Ed Blown Vert

iTrader: (2)

Well I tried 109% and it only dropped to 13.8

Does it take a while for it to learn?

Bink

PE is WOT, Open Loop. No learning .

Did you rescale your IFR? Did you multiply by 108 % the PE values that resulted in the 14.1 AFR??

.08 is a reasonable value for dropping the AFR, by about one point, in the 15:1 to 12:1 range. It will raise or drop it by .9 - 1.2 points.

-> 0.08 = 8 %.

If you want to lower the AFR multiply the denominator by 108%. For example -> 14.7/1.2050 <-PE RPM value = 12.20 too low so we want to increase. Remember PE value is the Denominator.

1.00-.08= .92 -> *100=92%

1.2050 * .92 = 1.109 <- new PE value

14.7/1.109 = 13.26,.... not perfect- but gets us in the ballpark.


Does this help????

Ed Blown Vert

iTrader: (2)

Ok, no learning needed.

Yes, I did scale down my IFR and multiplied the PE table by 108% to get to 13.8

But doesn't changing the IFR screw up the calculations?

Did turning off COT or installing the headers cause the leaness?

Thanks.