I dialed in my cruising FTC to where the LTRIMS are in the -4 to -5 range

My autotap runs show my avg (forward) O2 sensors are 936.95454545455 mv
I want to adjust the values in the PE RPM table to get them in the 890-910 range.

According to LS1Edit doc,
Values can be Greater than 1 (Adding fuel) or less than 1 (Subtracting fuel).

Please confirm that I do indeed want to subtract fuel by scaling the table down (by some value < 100%)
Also, how sensitive are these values to input. I don't want to dramatically adjust them and wind up whit a very lean condition
Thank you,
Scott

 

I tried tuning via PE vs RPM when I first got Edit. I was using the stock o2's. Basically my adjustments ended up going all over the place. I would recommend getting an in-car wideband o2 prior to doing in depth A/F tuning. I know it is costly but in the long run it is well worth it. Just my 2 cents. Good luck.

 

^^ I agree.The only accurate and safe way is with a Wideband O2.
joel(Bink)

 

Thanks guys - I do agree with the wideband suggestion......I was hoping to ballpark my WOT settings then wideband down the line.....


Thanks again!

 

I did some "ball-park" adjustments before ever getting widebanded on a dyno, and my numbers were almost dead on. I think it is definitely worth it. Some common sense goes a long way with tuning this stuff.

For example, lets say you scaled your IFR by 90% to get your LTRMs negative. You computer is going to automatically make you run 10% richer at WOT because it thinks the injectors are smaller. So scaling your PEvsRPM anywhere from 99% to 90% SHOULD be fine. This is how I did it, and my A/F was perfect except for the very upper RPM range were I actually had to make it even leaner.

The 890-910mv rule is not too bad, but use common sense, log for knock, etc, and you should be ok. Definitely get a dyno tune eventually, but no reason to run extra rich in the mean time.

Just my $.02

Tommy

 

You can use a calculator to figure out a ballpark on how much to adjust the table. (for example) While I don't recommend tuning with just your 02's. If you are shooting for say .900 02's at WOT and your currently at .937, then divide .900 (target) by .937 (actual) and you get the multiple for the PE table. In this case it's 96%. I would only modify values from 3200rpm's and up.

 

i agree with tatommy, i havent had any trouble tuning my car with the factory 02 outputs. just go a little at a time.