I have an option of buying Autotap/MAFT or getting a custom tune on site with a dyno and LS1 Edit. Which would be better? They would be about the same price. I am leaning toward the custom tune since I could lose TM, change shift points, have gears changed at the same time, change fan temps, etc. I could save up enough and have a gear/cam/tune all at once at one of our sponsors..... <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> Sound like a good plan. But, I'd like to hear everyone's opiniong first.

 

Go for the custom tune! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

i'd buy ls1edit myself and get it close with autotap and then finish the tune at the dyno

 

FWIW, a MAFT is only a bandaid-like device to fool the PCM into pulling fuel for you. The PCM will relearn the parameters in it's program soon after you've tuned with the MAFT and you'll be back where you started.

A custom tune changes, not only, fuel tables but adds timing. LS1's can run a lot more timing than they have from the factory too! A good custom tuner could make you a deal to work with you and your future mods as well.

Buying LS1 edit could work for you as well, but that depends on how comfortable you are with the knowledge of your car. Engines get expensive if blown apart. There's a lot of info on these message boards to learn from. The learning curve could take a while too.

Good Luck! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

BV the pcm does not "learn around" maft settings.
Get a car up to full operating temp...set the maft and it wont revert back to prior settings. A maft modifies the output signal of the MAF to the pcm. Think of it like an OLD bathroom scale <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> When you arent on the scale, a lot of them wont return to zero lbs. They would show like 5lbs with nothing on the scale. You always had that little dial on the scale to skew the reading back to show zero lbs. Now the scale LOOKS right to you but we all know that the calibration is a little off. The scale=maf....dial=maft .... the maft skews the maf signal so it looks "right" to the pcm. Its that simple.

 

I'd go for the custom tune.

MAF T can only really be used to adjust your A/F ratio and even then in a very rudimentary fashion.

I had one and just ditched it since it was a temporary solution.

 

That is oversimplified however. With base changes in particular it takes quite a bit of driving in between for the readings to stabilize. If you can get the cruise LTrims in the -2,-3 range and then dial in your WOT to whatever O2 level you wish you will be more consistent. With positive Ltrims enrichment occurs at WOT.
thanks,
Chris