the higher the duty cycle, the less effect it seems to have.. its just at very low throttle inputs where there is very low injector duty where this makes the most difference.. at least from my experience.. It does have some effect, just not as critical that it will throw off your tune completely if you alter it to get your trims in check, at least for the small adjustments necessary..

 

i just didn't think al's map would throw them of by over 10 being that i'm on stock injectors with minor bolt-ons, i figured they'd be a little closer.

 

Every car is a little different.. And I have yet to see a stock car that was consistently within 10% also...

 

If you want to be really on the safe side when you change any of your fuel settings, then (assuming you have a working wideband gauge and sensor) throw some racegas in it and log the difference in AFR - that's how I'm tuning my AFRs. Once I have them where I think they should be, I switch back to pump gas and make sure that there is no knock.

l8r)

 

If you do this, depending on what race gas you use, the specific gravity of the gas will be different, and thus the AFRs. So, please keep this in mind if you are tuning for a specific AFR for your pump gas tune.


Eric

 

I use 100 Oct unleaded (usually mixed with 1/8 tank of 93) and I only use it for two things as far as fueling goes:
1.) to understand the relationship between the AFR target number and the actual AFR
2.) to get the tune to a safe number (e.g. 10.9 AFR), but have a good safety margin in case of a typo or f'up on my part

l8r)