k04/rs6north

I think this one is worth looking at, it was for me, and I hope this will help those out there trying to dial in their fueling curves, or stimulate discussion / arguement as to what is the best fueling curve.

Below is a great dyno chart where Tony at EPL did 2 back to back (think heat soak) pulls on my car with 93 octane. The darker lines were with the leaner fueling done first and the lighter lines were with the richer fueling done second and right after the first pull. Some poeple say that leaner is faster, and it would appear that they "may" be correct at least in part of the rpm curve or for "maybe" one fats run / half a drag race. What I see in this graph is that the second run, done just after the first run and with a richer fueling curve, eventually as rpms rise have minisculely higher hp and tq - BUT actually was able to replicate almost exactly the first run with likely hotter intercoolers. I will leave you to draw your own conclusions, but Tony has gone with the richer a/f curve on my car.

<img src="http://pictureposter.audiworld.com/47960/pump_gas_airfuel.jpg">

The actual timing dyno logs of these two runs were also captured. The first run &lt;pink&gt; on the dyno was leaner - the second run &lt;blue&gt; on the dyno was right after and richer - note the better timing

<img src="http://pictureposter.audiworld.com/47960/timing_compare.jpg">

Next, is various logs from my 100 octane file that I will use for 25 minute track road course track sessions. The lemmi channels have been left open so it is easy to detune the car via timing reduction or turbo cel scaling to dial back the car to lower boost / lower timing curves if desired.

These logs were taken today, somtime this morning by a dood named Tony who is joy riding my car all over CT becoming a FATS / race gas junky. I told him if he would toss some of the crap out of the car and go on a diet the car could have done a 2.9x FATs

<img src="http://pictureposter.audiworld.com/47960/race_gas_fats.jpg">
<img src="http://pictureposter.audiworld.com/47960/race_gas_fatsplus.jpg">
<img src="http://pictureposter.audiworld.com/47960/race_gas_o2s.jpg">
<img src="http://pictureposter.audiworld.com/47960/race_gas_timing.jpg">
<img src="http://pictureposter.audiworld.com/47960/race_gas_iats.jpg">
<img src="http://pictureposter.audiworld.com/47960/race_gas_egs.jpg">
<img src="http://pictureposter.audiworld.com/47960/race_gas_fid.jpg">
<img src="http://pictureposter.audiworld.com/47960/race_gas_n75.jpg">

B5QShip

zOMGHI2TIMINGAND&amp;0.89O2s

BLK01S4

wow how come on race gas you don't have a leaner AFR?

PSmalls::AnalRetentiveNumbNut

time between the 2 sets of runs so conditions were similar between the 2 AFRs. From that graph there, not sure we can make anything of it. It'd be nice to see the car with an AFR between the 2 as well, ~11.5 or so.

What's the boost curve on your road course program? Data looks good, but damn your 02s show rich.

I guess my totally uneducated opinion is you're probably running richer than you have to. It'd be *very* cool to see more conclusive testing on this although I understand time is money and neither grow on trees.

BLK01S4

your car got more timing but leaning out a tad?

Mike2kS4

~11.3 seems to be my magic number too.

EdyJun

<center><img src="http://pictureposter.audiworld.com/47960/race_gas_o2s.jpg"></center><p>of AFR of 11.3?

And that on race gas you car runs better @ that O2 signal. (AFR 11.3)?

Edy

B5QShip

er, but the curve didn't change slope, and if anything (especially blue trace) starting sloping down

BLK01S4

I think thats to rich for race gas IMHO.

BLK01S4

lower is the 100 octane file .. Look at the MarkP graph.