Learning to tune with Directscan

[rb68rr]

Right now I have a TT 93 octane chip which Eric reccomends running 16 lbs of boost. I put some 100 octane fuel in and raised the boost to 20 psi. The only other chip I have is a TT race chip which he reccomends 24 lbs of boost. Not enough octane for that chip. Anyways, I noticed on DS that the commanded a/f was 10.0 at the top of 1st gear at 5300 rpm and the 02's were 824. At the top of 2nd gear the commanded a/f was 10.1 at 5275 rpm and the 02's were 773. In 3rd gear the commanded a/f went from 11.3 down to 10.4 by the end of the quarter. In the same period the 02's went from 773 down to 740. Does this seem about right? The commanded a/f ratio looks rich towards the end but the 02's look lean. It looks like the only way to correct the low 02's at the finish would be to raise the fuel pressure a little but wouldn't that make it really rich at the beginning? Is this about as good as I can tune it running too much boost on a street chip? Thanks, R.B.

 

[rb68rr]

ttt

 

[Googs]

You can change the WOT fueling, +/- 10%, on his chips with Directscan.

 

[turbocody]

rob, do not pay attention to the a/f ratio on the directscan...it's not accurate. use the o2 voltage only and shoot for 760's-790's in all gears, it's ok if it's in the low 800's, just make sure you stay above the 740 range and you will be fine.

 

[Lee Thompson]

Ds

A lot of the stuff on DS is useless
Torque
Horsepower
Boost
A/F ratio

 

[turbopaul]

To add to the useless count, the ignition timing indicated does not take into account any knock retard.

Paul