Thread: 2 different performance tunes

hello all. i am still new to this L67 style engine. i am a lsx guy usually. now, on my ws6 i can have 2 tunes in my pcm(by turning off the engine and flipping a switch) can the same be done with these pcms? I know my 99 has a perf shift button, and if i get a mail order tune the perf tune will only work with the button active. but what about the other "stock tune" can those parameters be changed? i am looking to run a daily tune, and a nitrous tune (same as my ws6) i tried the search function and only came up with 4 results none of which seemed to cover this, so I apologize if this has been covered multiple times.

thanks in advance,
Bruce

No, you cannot run two tunes and switch between them with a toggle switch.

And technically you can't do that with your trans am computer either. You can only have one program ran on the computer at one time, without writing a tune to the vehicle, flipping a switch does nothing.

I've seen people flip a switch to skew the IAT sensor to pull timing and prevent it from blowing up but that's a bad way to do things.

Any of the tuners on the market be it HP Tuners or EFI live that can actually change every parameter inside the PCM has to do a either a full write or a calibration (partial) write to the computer to make any changes.

There is no need to run two tunes either on a supercharged grand prix with no additional things like methanol or NOS. Just keep the performance shift button in all the time, it makes no difference on the engine side of things. It only changes the shift speed and shift pressure by a small amount. I maybe .100 or so of a second but I'd have to check again and it adds a few psi of line pressure.

Hmm, looks like it's for only select vehicles with the correct gen 3 computer in it already (512k - 1M). So a stock computer couldn't use a switch but one with a dual memory chip can, one can assume he bought that then.

You couldn't do that with a 3800 PCM, totally different controller and is 5 times dumber computer than a LS based computer.

Yes that is the pcm i have, didn't get it from them, but same idea. The reason for the separate nitrous tune is to pull timing... this was i can have the hottest tune possible around town, and when I flip that switch i have the best tune possible for the sizebshot of nitrous i am using. (150 shot currently in the t/a, but soon going up )

-Bruce