Hondata

chris2000 · Joined: 05 Oct 2006 Posts: 31 Location: Asia

This is on a race dc2 with b18cr 11.5:1 with toda cams.

The car was tuned on dynojet to 13-12.8:1 A/F on dyno with water temp above 81'c.

1st test on track showed that water temp was hovering just below 81'c. about 79-80'c. And A/F was like 11.8-12.2:1. Then noted water compensation shows add over 20% fuel at 75'c.

So when back to dyno to touch up a/f further and try using 0% compensation at 75'c. On dyno it shows that it work and a/f consistent.

back to track for testing, water temp throughout datalogs shows water temp was 79.7'c consistent. And a/f once again drop to 12-12.2:1 instead of 13-12.8:1 that we set on dyno.

Could this be low water temp problem??? But even i set 0 compensation at 75'c and 81'c will the ECU some how still override and add fuel to a cool engine?

I'm now thinking of changing to a higher temp themostat but wanted to get some idea/suggestion from here before burning more money on parts, dyno time and track fee testing...

:cry:

Hondata · Posted: Sat May 29, 2010 8:47 am Post subject:

Always use a stock thermostat. Post your calibration. It could be that the temp compensations are not correct.

chris2000 · Joined: 05 Oct 2006 Posts: 31 Location: Asia

but i have already set the water compensation at 75'c and 81'c to 0% compensation.

Anyway, i have change the thermostat now and will try to get the calibration up tomorrow.

thanks.

newsoltsc · Joined: 09 Oct 2009 Posts: 88 Location: Bay Area, CA

The conditions at the dyno are different then at the track.

Your afs will never be the same once you are off the dyno.

blackek4 · Joined: 17 Jan 2010 Posts: 17

take a look at your IAT compensation table. that might be your problem, the intake temperatures are very diferent in the dyno and on the track/road.