PE Mode...

[vipz28]

So uh... While logging I noticed that when I go in to PE mode my commanded AFR is a whopping 11.75:1 above 5200 RPM. Is that bad? :barf:

Seriously... 11.75:1?!?! It sits in the 12-12.3 range for the rest of the RPM range too, holy crap. I need to get my wide bands in to see what it's actually running at, but that is friggen rediculous:bm:

[cobrakid]

...that's not too crazy rich, but in the low 12s would definately be better. Won't hurt anything.

[vipz28]

...that's not too crazy rich, but in the low 12s would definately be better. Won't hurt anything.

Actually it kind of IS crazy rich... 11.75 is close to ring wash rich in n/a applications.

Once the widebands get here I'll be tuning for ~13.2:1 at wot.

[vipz28]

Can someone please view my Dyno run...is it me...or am I running super rich?? on WOT I think the far right graph shows Af....and it dives under 10 pretty fast..my tuner who is well know in the area ..and had hundreds of tunes...took a break from his hetic shop schedule..I NEED some advice.and place in northern cali to tune!!
http://www.youtube.com/watch?v=5SN47KyMXUg
It was only a get together...dyno night...he was scheduling tunes later in the month...I didnt have time..to ask the right questions..he did say .I DEF needed a tune..can anyone tell me what they see and why?? I have only added the Rotofab intake..and flowmasters super 40s out in back ...looks Like i Run really lean..than super rich??
Wow dude way to hijack :nud:

[-Ray-]

He did post another thread, but I got caught up in this one. Sorry 'bout that.
EDIT: posts moved.

[g8_795]

11.75 is not crazy. GM does this by default to over protect the engine. You will not be in PE mode for to long so running a bit rich will not hurt a thing. Now running lean will and that is why the stock tune does this.

[vipz28]

He did post another thread, but I got caught up in this one. Sorry 'bout that.
EDIT: posts moved.LOL I Was kidding but cool

[vipz28]

11.75 is not crazy. GM does this by default to over protect the engine. You will not be in PE mode for to long so running a bit rich will not hurt a thing. Now running lean will and that is why the stock tune does this.
I realize its for such a small time that it's not actually going to cause ring wash, I was being over dramatic, that's just ridiculously rich, and so it's easy to see why there's so much power to be had from tunes.

[sstruck383]

I always tune my engines to 12.5-12.7:1 because #1...its safer to be richer than leaner and #2....most places are going to E10 fuel and thus E10 fuel has a stoith. of 14.1:1 compared to 14.7:1 of gasoline thus needs to be a little bit richer anyways....again...to be safe.

I set PE to be 13:1 at lower rpms for more torque (lean equals torque) and richen it up to 12.5-12.7 in the upper rpms starting the transition about 2750-3000 rpms.

[Kaltech Tuning]

11.75 Won't hurt anything, it simply leaves a few hp on the table. Remember these cars are made to run on 87 octane, last xxx,xxx miles, adapt to different climates, and be able to handle different qualities of fuel. Considering all of that and the fact that you're talking about the rpm range where it'll see highest cylinder pressures what would you expect? Don't sweat it though, like I said it won't hurt anything and once you're tuned that'll be adjusted.

[vipz28]

11.75 Won't hurt anything, it simply leaves a few hp on the table. Remember these cars are made to run on 87 octane, last xxx,xxx miles, adapt to different climates, and be able to handle different qualities of fuel. Considering all of that and the fact that you're talking about the rpm range where it'll see highest cylinder pressures what would you expect? Don't sweat it though, like I said it won't hurt anything and once you're tuned that'll be adjusted.Oh I know, it's more annoyance they are leaving that much on the table. Wideband goes in on monday, so It will be fixed then.