A very basic question with an (expectedly broad) answer... I dyno tuned the car today and need help with air fuel ratio. The car was rock steady on the AFR, usually 11.2 - 11.5 each run through the entire RPM band. I was happy to see it safe and have a decent baseline but now I'm wanting to dive into my tune a little deeper. I'm a semi-noob to LT1_Edit and have played with a few things (injector size, converter lock-up, etc) but the performance tuning was done by a friend. He knew his way around the car and the program much better than I but I moved (he hopefully still in Fl and I in Mo) and was looking to become a little smarter. Is there a simple answer on how to lean the AFR from 11.5s to 12.5s? If so or even if not, feel free to teach me about LT1_Edit and fuel tuning. Thanks!!!

 

PE vs RPM table

 

If you're a/f ratio is fairly linear like you say it is, leaning the car out should be fairly straightforward.
PE vs RPM table is what you want. A good rule of thumb is that for every 10 points of PE vs RPM you add or subtract, you're changing your a/f ratio approximately 1 point. So by subtracting 10 points out you should effectively lean your car to to 12.2-12.5 to 1.
Make sense?

 

Dan & TriPinTaz,
Thanks for your reply. PE versus RPM makes sense (I did some searching/reading as well). And the info regarding the number of approx points is just what I was looking for. I appreciate your response and hope to report back with gains.

 

Just to be sure (I know dumb question) but by lowering my PE vs. RPM approximately 10 POINTS, is this 1%? For example the block would have 2.0 @ whatever RPM and I should lower it to 1.0? Not -8.0 right? Or 6.6 and I should lower it to 5.6? Meaning .1 equals 1 POINT . Sorry for the Noob type question but just wanting to be sure.

 

subscribing

 

Thanks for the update, LOL.

 

Agreed... Um thanks RPM. So is a point 1 whole percent or .1 of a percent? I think 10% change makes more sense for the change but just want to be sure.

 

Example:
If you have 10 in your entire rpm range and with a wideband O2 sensor you're seeing 12:1 a/f ratio...
If you knock the pe vs rpm down to 0 for the entire range you should see approximately 13:1 a/f ratio.