1995 lt1 M6 tuning

[Trevor]

As has been the case through out this you have saved the day Steveo. I’m glad you have a donation button on your page as you certainly deserve it. I dislike the norton antivirus and I’m sure there is nothing bad in any of your files, but it was late at night and I didn’t have time to try much. I’m not new to the idea of tuning, just new to efi tuning. I could mail order but I wouldn’t be satisfied and I’m addicted to learning new skills. It’s not awfully different then jetting and distributor timing and setting advance. Eehack is very user friendly, and I doubt I will have any issues. But I have a spare impala ss Ecm and z28 if things do go bad. I’m also willing to try the maf but I may need a little guidance when it comes that time.

[steveo]

It’s not awfully different then jetting and distributor timing and setting advance.

it's easier

you have more adjustment and you don't have to take a carb or distributor apart to make actual changes.

you can use eehack to tune idle by feel just like clocking a distributor and tweaking a pilot jet

I’m also willing to try the maf but I may need a little guidance when it comes that time.

i doubt it'll need much actual tuning on the maf end of things. typically a cam swapped LT1 just needs some low airflow adjustment since the pulsation from the cam at low rpm throws off calibration.

don't be afraid to let closed loop take care of some portion of the fuel adjustments needed, a few percent of fuel variance isn't noticeable at all.

just so you know what a typical lt1 tune looks like with that size of cam and a maf,

you will probably end up adding some o2 delay time just because it seems like it makes sense,

subtracting 'bout ~10% of fuel below ~4khz, bout ~5% to 8khz,

drop anywhere from 5-10% of power enrichment fuel,

jack up idle timing advance upwards of 35 degrees, increase idle speed speed slightly, maybe reduce the idle speed timing corrections to get less flutter,

add a bit of wide open throttle timing but push the curve back a bit so it comes in slightly later,

maybe a bit more timing advance in cruise range, or maybe a bit less depending on whether it wants to surge or not,

might run into some false knock and have to kill knock detection in a region or two...

something along those lines.

then it'll run just great, and you can O.C.D the hell out of timing and fuel trying to get maximum smoothness, fuel economy, performance, etc.

[johnny_b]

One thing I would look at changing that doesnt get mentioned much is the BLM MAP & RPM boundaries. From the factory they are set kind of weird. It really seems to help with part -throttle drive-ability as well as BLM numbers.

Also since you have a m6 look at desensitizing or deactivating all together the "stall saver". steveo has covered this subject in-depth on his fbodytech website.

I made these two small changes on an otherwise stock Z28 LT1 M6 and I could definitely tell a difference