The Much Awaited #230 (L99) Update.

[Scott@Bjorn3D]

Originally Posted by faninc

I realize different engines but do all ECM's learn based on octane used and could they perform better and relearn under higher octane? That was the question...

I can ask that when we have our conference call next week.

[Slvr1SSA6]

Originally Posted by irpq11

I'm gonna wait to see what they tell my dealer to do with mine. Scott wants me to wait till it gets cooler in 3 or 4 months. Right now I'm still over a half second slower than the car they brought with them (after the .2 adjustment for the wheels) so I'm hoping it wont take too long for the dealer to get to it.

I am going to be heading to Detroit in early November. If the cooler temps dont do what I think they should (I dont think they will) I will be going to see Livernois Motorsports.

[PQ]

Originally Posted by Scott@Bjorn3D

I can ask that when we have our conference call next week.

Wanna race.

[69Bird]

Could it be the re-learn from 87 back to 93 octane is much slower to make sure detonation does not occur and blow a hole in a piston? These motors have a pretty high compression ratio's and just a couple of twists with heavy detonation will destroy a motor. Keep in mind these cars have a long warranty and over time any amount of detonation takes miles off a motor. Just my .02 cents.

[RipGear]

Scott -

So how does anyone else get thier slow L99 fixed?

What happens if you are unable to find 93 octane? Will the computer let your motor knock like crazy?

Did you press the brake pedal with the battery disconnected? I've read and been told to do this when trying to reset an ECU, but it may just be a myth.

This sounds like putting a band-aid on a gunshot wound. I hope the GM engineers will figure out why the computer is not "learning" the octane being used and issue an actual fix. I'm still trying to hold out on making the purchase until this issue is properly addressed, but it is very hard.

[HOME-BY9]

Scott:

First off; Best wishes to Stephanie.

Question: Was 5.7 the best pass your car made after they reset the program, and did these guys actually get to see your car run a poor o-60?

[Ltdodge]

Originally Posted by 1320junkie

you know there is a difference in the L99 and the LS3 right?

yes I do....my only question is if you shouldn't turn it off in the L99 because of oil and stuff and possible losing control when launching...then would it be the same in the LS3 or any car?

[PQ]

Originally Posted by Slvr1SSA6

I am going to be heading to Detroit in early November. If the cooler temps dont do what I think they should (I dont think they will) I will be going to see Livernois Motorsports.

Unless I can get mine adjusted the same as Scotts.

Originally Posted by HOME-BY9

Scott:

First off; Best wishes to Stephanie.

Question: Was 5.7 the best pass your car made after they reset the program, and did these guys actually get to see your car run a poor o-60?

Well he said the car they had ran 5.4 and 5.5 and his ran .2 to .3 faster than thiers. So that should put his runing in the 5.2 to 5.3 range. about a half second or so loss from the elements.

[UCF w00t]

I'm a bit confused... what was the fix? Just resetting the ECM? Or did they actually change the code on the ECM?

Originally Posted by Ltdodge

yes I do....my only question is if you shouldn't turn it off in the L99 because of oil and stuff and possible losing control when launching...then would it be the same in the LS3 or any car?

They're saying not to hold the button for 7secs and turn everything off. You still want to have the safety there that exists in competitive mode.

[GMRULZ]

I beleive their explanation to be true. If the computer senses knock it will change to the low octane tables in the ECM. These run much less timing and hurt performance. To be on the safe side I`m sure GM makes the computer take a long learning curve to get back to the higher octane tables once good high octane gas has been restored, just to be sure.

To give you an example, I just dynoed my car, put down 319rwhp, run 2
319rwhp, pulled the ecm fuse to clear the memory waited about 5 minutes put it back in run 3 327rwhp....Gained 8rwhp by reseting the Long Term Fuel Trims and possibly moving back to the high octane table from a lower one, I`ve only had 2 tanks of gas in it. So this computer is very, very conservative, if it senses anything it doesn`t like it will take drastic steps to fix minor issues.

If a tuner can turn this learning curve off or at least desensitize it it will help greatly.

Irpq11,

I think your huge dip in air fuel was cat over temp protection, it sensed an overheat of the catalytic converter and dumped a bunch of fuel in to save the cat. Other than that I can`t explain your a/f dip.

[camarossrs2150]

so how do you reset your ecm . i put low octane in by mistake also when i first got my car and it felt a little sluggish .been puting 93 after that but still feels sluggish

[PQ]

Originally Posted by UCF w00t

I'm a bit confused... what was the fix? Just resetting the ECM? Or did they actually change the code on the ECM?


They're saying not to hold the button for 7secs and turn everything off. You still want to have the safety there that exists in competitive mode.

Originally Posted by camarossrs2150

so how do you reset your ecm . i put low octane in by mistake also when i first got my car and it felt a little sluggish .been puting 93 after that but still feels sluggish

Sounds like they adjusted only the part that was the problem. Resetting the whole commputer didn't do my car any favors. On my Dyno, they unplugged the battery for anout 5-10 minutes and it didn't really change anything. The next pull was 2 extra HP. Whatever they did, it gained Scott about half a second or more.

[pharmd]

Did anyone ever think that maybe GM is just BS'ing Scott (to save face) and they up loaded a correct tune or installed a new ECM? I understand the concepts being discussed in here and how the "adaptive" ECM's function....but generally adapatation occurs quicker than this...I mean come on he's got 4000 miles on it, this was his first tank of gas ever that was 87 octane. I find it VERY hard to believe it took 3700 miles for the ECM to adapt...I'm sure alot of other folks have been running better gas in theirs since they first got it, and theirs is not pepping up...I understand the concept, but it just seems like a stretch to me.

[camaro1]

i agree, someting is not right here,, with the miles he has on the car it sould have reset,, and i think he did a battery disconnect for 20 min,, that is plenty of time for the fuel trims to reset

how does the car launch now, any car with a 400hp engine should be able to roast the tires easy from a stop

i think there is some smoke and mirrors going on here,, all of a sudden the car is running 2 sec faster 0-60 than before, and it is running faster than there test car?? and all they did was reset the ecm, i dont think so!, as i have said before if gm isnt going to admit any problems.