Quick Question about how throttle cracker effects AutoVE

[Kevin Doe]

Ok, I am nearly done with my auto VE process. I am at about .98 on all my BENs, and have about 200 data points in each cell (driving for about 2 hours of varying loads making sure I get all the cells). The car still doesn't want to idle taht well, and when comming to a stop it always wants to die. So I did some research and that lead me to the throttle cracker.

It looks like the throttle cracket is active above a given speed, then deactivates at a speed slightly lower than the activate speed. For my stock settings on the throttle cracker, they are set at 3 kmh and 2 kmh.

The table is a stock table, so values at up in the 11 grams/sec range in some of the high rpm areas. It appears as if while I've been driving doing the auto VE process that the throttle cracker would have been active, skewing my autoVE BENs by effecting the AFR feedback from my wideband.

If I change the throttle cracker table, with this bacially mess up the autoVE that I've just done, and have to do it over again?

[Kevin Doe]

Addition:

Here is my latest log. Its got a little over an hour worth of data, sweeping the VE map mostly the entire time.

The second attachment is the new tune I've created from that data, then smoothed over. Take a look if you would like to.

Edit, well I treid to attach, but the forum is having issues, I'll try again later.

[TAQuickness]

I don't think you'll have too much issue from changing the TC table. If you alter TC to allow more air, it should also alter the MAP signal respective to the change made in the TC table. Not much different than if you increased TPS by .5%

As far as getting a smooth idle transistion, it really depends on your mods. When I built my 383 I used a lot of lighter weight components in the rotating assemly, so it took a lot of trial and error with the TC, TF, spark, fuel, etc... in the idle area to find the sweet spot. I would suggest reading thru the idle sticky in the tutorials section. SSpeedDmn has a lot of great idle info in that thread.

[Kevin Doe]

My mods are this:

04 GTO engine/trans (M6), so LS6 manifold.
1 7/8" long tubes to a 3" xpipe, 3" duals all the way out.
Dual 3.5" intake tubes, MAF-less
MS4 cam
Aluminum flywheel

Those are the basic mods.

[TAQuickness]

It's possible that by the time you get your idle tweaked to your liking that the VE table will need a touch up. Nothing major though.

If you want, PM your email address and I can send you a copy of my tune. Not that it will work for you, but it will give you an idea of all the little changes in the idle area I had to make.

[Kevin Doe]

Here is the tune I was trying to attach. Since I crated this thread I asjusted my set screw a touch, and made a few changes to the idle overspeed/underspeed timing corrections, but havn't driven the car yet.

Here is the tune.