Decel tuning????

[mustbbrent]

I think I know what is happening now with the part throttle stuff. I am getting my positive LTFTs and my knock retard when I let off the gas.

Even though it is going into cells 2 & 3, watching the historgraph on the scanner, it only happens when I let off the gas... the same points on the tables when on the gas, have no retard in them.

Any ideas on how to fix this? Or is it a problem? Help. The turbo goes on tomorrow and I will have to fix a ton of other things, I just want as few timing retard issues as possible going into tomorrow's install.

I have used Tiggerfan's table which seems to say, I am fine... it agrees that my LTrims are just slightly positive only in cells 2 and 3... I am more concerned with the retard on decel. Will this hurt my engine with the Turbo on it?

[ZUKI]

you say when you let off the gas. Does that mean just a bit, or you completely let off? There are 2 tables for timing. one is your main, the other base. base is used usually for less that 2% TPS. Not sure what car you have, list what u have a may be able to give a a little advice. I'm still learning too.

[EC_Tune]

Are these forged pistons with a little "extra" piston to wall clearance? Could just be a tad bit of piston slap when you let off.

I may be wrong...

EC

[mustbbrent]

I have a 2003 5350lb Chevrolet Extended cab Silverado SS with a 6.0l motor and an STS Turbo kit utilizing a GT40 turbo pushing almost 9psi. No dyno yet as the truck is AWD and very BIG, but It definitely gets it down the road. ;D Anyway, when I let off the gas all the way, I get pretty major positive readings, but anytime I am on the gas, no positives at all. No forged pistons. No slap.

Thanks in advance for the help.

[mustbbrent]

Oh yeah, and I talked to a few other guys with the Silverado SS... it seems this may be and I stress MAY BE false knock as I can't hear any tapping, but with the turbo on it now... WHO CAN HEAR ANYTHING? Hun???

[EC_Tune]

Yeah, could be false knock.

The 6.0's did have a bad rep the first year or so but I thought everything was cleared up by now.

EC