PE enable rpm?
Thread Starter
10 Second Club
iTrader: (8)
Joined: Apr 2004
Posts: 2,247
Likes: 0
From: Portsmouth, VA
PE enable rpm? in short, Ive got a cam and 4000 stall. is there a particular area where I should command PE to be enabled? I was thinking that: while at the track, I'd want to brake stall the car 2500-3000rpms so I'd want PE to kick in after I've launched. My converter flashes something like 4200rpms. should i be setting PE enable even lower (currently set at something like 3500rpms) or to my converter flash stall? thanks
Sure, that would work. I would set it just above your launch rpm (+100). But if you plan on adjusting the rpm, for better launches then this may not work so well. If it is for bracket racing reason, and you will launch consistently all the time, then yes it will work very good. 
Hey George; why is this?
Since the throttle applied to stall up the converter isn't enough to push the PCM into PE until after the throttle is floored (and car is launched), why move the PE enable around? What is the benefit?
Since the throttle applied to stall up the converter isn't enough to push the PCM into PE until after the throttle is floored (and car is launched), why move the PE enable around? What is the benefit?
Last edited by Frost; Feb 21, 2007 at 02:20 PM.
You want to be very sure that the PE enable RPM is high
enough that you won't fall out of it on the upshift, that's a
lean spike you won't enjoy.
I'd think about using the MAP threshold more than RPM,
foot-braking you ought to be at a non-WOT position and
a less-than-full MAP value.
I don't really know why you'd want to cut PE below some
RPM, this seems like a recipe for ping when lugging (if you
are set up with the trans, such that you can see high MAP
at low RPM). Figuring that at (say) 1/4 throttle you might
well get full MAP, full cylinder air, at RPM below 2000 or so.
The throttle doesn't throttle so much as RPM falls.
To me enrichment ought to follow MAP primarily, more than
RPM for sure. Oddly we have a PE vs RPM table but the
open loop EQ vs MAP is something we don't use until PE
mode is satisfied. Seems backwards to me, if GM had a
good reason I don't know it (CAFE not being good, only
necessary).
enough that you won't fall out of it on the upshift, that's a
lean spike you won't enjoy.
I'd think about using the MAP threshold more than RPM,
foot-braking you ought to be at a non-WOT position and
a less-than-full MAP value.
I don't really know why you'd want to cut PE below some
RPM, this seems like a recipe for ping when lugging (if you
are set up with the trans, such that you can see high MAP
at low RPM). Figuring that at (say) 1/4 throttle you might
well get full MAP, full cylinder air, at RPM below 2000 or so.
The throttle doesn't throttle so much as RPM falls.
To me enrichment ought to follow MAP primarily, more than
RPM for sure. Oddly we have a PE vs RPM table but the
open loop EQ vs MAP is something we don't use until PE
mode is satisfied. Seems backwards to me, if GM had a
good reason I don't know it (CAFE not being good, only
necessary).
Sometimes the TPS% threshold is at say 30% depending on the PE Enable vs TPS%. Let's use a example setup: A4, 3000 stall. And the PE Enable settings as follows: MAP = 30, RPM = 2000, TQ = 0%, TPS% = 30% ... it may throw the car in to PE Mode while sitting there waiting for the other guy to stage, dumping extra fuel which is not really needed. If you set your PE Enable settings just above the example vehicle, you can prevent unwanted PE Mode. This is the thinking behind all of these PE enablers, to prevent unwanted PE when it is "not" required. It is most notable in towing applications, but as you can see it could be of good or bad on your set up. If you are not exceeding the TPS% threshold, then their is no point, it is only valid if it is triggering PE Mode unwanted. For your example, chances are you will never be under your flash stall and require PE Mode. Looser converters may require more throttle to stall up, which could enable PE based on TPS% alone.
I set my 2001 SS to enable PE above my brake stall which is about 2400 (IIRC), so I set the RPM at 2500. You do not need to use these settings, but can adjust them to suite your needs, should you not want to enter PE when not needed.
I set my 2001 SS to enable PE above my brake stall which is about 2400 (IIRC), so I set the RPM at 2500. You do not need to use these settings, but can adjust them to suite your needs, should you not want to enter PE when not needed.
I understand the desire to not want to sit in PE while stalled at the line, and the MAP and TPS settings take care of this... it's generally been my preference to use those to enable PE and set the RPM enable to 0.
Thanks guys.
Thanks guys.
