RPM********% Change
0**********3.1
400********3.1
800********3.1
1200*******3.1
1600*******6.3
2000*******-5.5 (negative ?)
2400*******0.0
2800*******0.0
3200*******3.1
3600*******6.3
4000*******7.8
4400*******5.5
4800*******-2.3 (?)
5200*******-2.3 (?)
5600*******-2.3 (?)
6000*******-2.3 (?)
6400*******-2.3 (?)
Can someone please explain to me the purpose of the negative numbers and zeros in PE mode? Also, what is the purpose of the values from 2000 thru 2800 RPM? This is in TC.

 

zero means add nothing
negative means less than zero, a concept sometimes referred to as subtraction.

I'm not sure what your question is.

 

Why would you subtract fuel under power enrichment? I though that is why it is called enrichment, not Power Enleanment?

 

I think its important to realize this is an addition or subtraction to a sort of baseline fuel suppliy already. So it your -3.1 now and you go to -5.1, you effectively eliminated 2% fuel addition.

Don't overthink the tables. If your lean at a particular AFR, increase the %. If your rich reduce the %. That is all there is to it.

 

Another thing to add, remember that the table your looking at is for a more or less stock car where the Torque convertor may lock up around 2000?

The 5000+ valvues where your taking fuel away with -2.3, remember, the stock TPI intake will never make power up that high, if you spin the stock intake up that high it will be drowning in gas.

I'm still realizing that just because the chip has a value of one thing, that doesn't make it correct for your application.

 

A question one might ask themself, 'is this the only table that adds fuel at WOT?'

 

Good Question! Is this the only table that adds fuel (and subtracts) under wide open throttle?

 

Its the only one that I found that I need to adjust, provided that the part throttle blms are on or near 128.

 

Hmmm:

; PWR ENRICH F/A %CHG vs COOLANT

The %CHG is the change in AFR from lambda, which in most cases will be 14.7. And the math is (for lambda = 14.7):

; WOT AFR = 6553.6/((TBL L8608 + TBL L860D + 128) * 445)/256)

Just remember that the TBL L8608 & TBL L860D in the above equation are the raw bin values, not TC's values.

RBob.

 

I try not to complicate things by messing with those tables too much,I made mine all positives slightly ramping from 2.0 - 3.5 and back after torque peak.
I use the upper ve for most WOT a/f changes,being that the higher rpm ranges are nevr used when not in pe,and if they are it wont hurt to be a little rich - its safer.
You may use the f/a adder vs. coolant temp table to make a more global change.

 

You see the f/a adder vs. Coolant temp will add 22.7 % already across the board and since your v/e will only reach to 5600 the negative numbers will decrease fuel from that global adder.

 

When you enable PE you go to your PE AFR.
It's PE AFR vs Coolant temp..

So you might have your PE AFR set at 12.5:1.
That might be a little lean or rich in spots, so the PE% trim by RPM allows you to trim the AFR to exactly what the engine needs.

While the engine might need 12.5:1 at 5,500 RPM, it might be happier with 13:1 at 2,000 RPM.

And we all want happy engines.

 

I think I got it now. So I can add (or subtract) the % change Vs. RPM to the % change VS. coolant temp and see how much fuel it is adding? Thanks