Red Cell

I may be examining a pre-owned Z06 tomorrow and was wondering how could I tell if it's been tuned? The reason I'm asking is that I do not want there to be any warranty issues if I make the purchase..

Thanks.

Red Cell.

thesubfloor

The only way that I could think of would be to find someone with a copy of EFILive or HP Tuners (which I have), pull the current tune and then compare it to a stock one.

Having a tune isn't necessarily a warranty-killer though as it all depends in the individual dealership.

chucky7

Put it through the gears up to 6500 RPM. If it hits the rev limiter, not tuned. If it doesn't start stuttering, it is probably tuned (tuning out the rev limiter).

Charlie

Red Cell

Thanks for the responses-appreciated.

Red Cell.

SL33PER

You could always take it to the dealer for a pre buyer inspection. That way if they find anything wrong they can fix it under warrenty.

haljensen

If it has headers and an intake it most likely was tuned also.

Stock with no bolt ons , most likely no tune.

Still have the 1st to 4th skip shift? If no it's either a tune or a plug in on the rear end.

Wayne88

Not always. My tuner kept the rev limiter the way it was from the factory, 6500 RPM's.

lemans 07

mine did too. Not sure why you would want to remove it.

walterm32

If you are allowed to take a REAL test drive do some WOT redline shifts and see if you feel a pause for a split second at each shift. If you feel a pause the car still has TM in it and probably hasn't been tuned. If you have a somewhat sloppy shift TM will activate and you'll feel that pause but it might never happen so thats a shot in the dark. Other than that only other way to tell that I can think of is to let the car warm up when you first start it and monitor on the DIC to see what temp the radiator fan kicks on. I'm not sure what the stock temp. setting is but if it comes on at a lesser temp than that stock setting than it has been tuned. If you have had plenty of seat time in a stock tuned z you would be able to tell a difference between a tuned and nontuned z when your tearing it up.

BTW a z06 redlines at 7k rpm's

Red Cell

Thanks gang!

All of this information is very useful. I'll go the pre-inspection route via dealer and make mention of it. I'll look for intake/headers and will shy away as it likely would have had a tune.

Given I have limited seat time in a Z, I'm not the best person to ask/determine if it has a tune or not. I just want to make certain there'll never be warranty issues (as last resort, I do have a great relationship with my delaer).

Thanks everyone.

Red Cell.

tjwong

You can verify it easily by taking the car to a Chevy dealership. Have the Tech use his tech2 scan tool to verify the PCM engine calibration verification numbers. If they match the CVNs as published by GM you are good to go, if not then the PCM calibration is NOT STOCK.

Red Cell

Bingo!

Thanks a million!

Red Cell.

mlongo99

If there's a plug, the skip shift light will still come on during the conditions it is supposed to activate. If it was tuned out, the light will never come on.

AORoads

hmm, so that's true of the C6, too? It was true for the C4 and I had 2 skip shift eliminators. Don't feel the need for it in my C6; seems to be much less obtrusive in this model for some reason.

btw, also good info from tjwong re the CVN.