Two weeks ago I got a cusomt tune from RWTD on my GTO (mods in sig). I watched the LTFT's at Part Throttle at 55mph in 4th gear average 5.17 highest being 9.38 and lowest being 1.56. The only time it was at 0.00 or a negative number was cruising for a short time at about 35-40 mph.

Knock Retard at WOT averaged 2.36 highest being 2.99 and lowest being 1.64. At Part Throttle it averaged 0.72. Highest being 1.23 and lowest being
0.09, I also noticed while in 4th gear cruise at 50mph from 1500 - 2000 rpm there is very slight pinging. which concerns me because the temp outside was 56 degrees. What is my can trying to tell? Is it running to lean? I hope no engine damage can occur.

 

You are not going to hurt anything where your trims are now but your trims should be a little negative. The KR is more of a concern. Your timing could be set to high. I have always had a problem with KR and usually the timing was set to high but you have to get your part throttle tuning set first.

I would take your logs and show your tuner.

Bill

 

Yeah I think the timing is set too high also. I posted my results on their forum but he hasnt gotten back to me yet.

 

SO what does a positive percentage mean? The PCM is adding fuel therefore its running lean?

 

That is correct.

Bill

 

Thanks for the info! I scanned my dads car we have the same mods but he has the tune that comes with the predator and his LTFT's are alot close than mine. Hes at 0-5%.

 

It upsets me when I hear of posts like this. Im just a hobby tuner but when ppl. pay mega-bucks for a supposed tune only to get ping and variable closed loop fuelling problems it makes me angry. Any tuner who doesnt take into account ALL the driving paramters of your car and creates ping is nothing more than a hack.

If a tuner doesnt drive on the road with you, log and retune the closed loop airflow they are just doing a WOT tune. Your trims should be negative, something like -3 to -6 to be safe. There should be NO ping whatsoever. Likely they have just flashed a one-size-fits-all spark map and tried to make it work.

Take it back and either ask him/her to refund your money and flash back in the tune you started with or get them to fix it. If they dont think it matters then ask them why does my car now ping where before it didnt?

Rant over.