Found this on another site, but it explained it better than I could.

Another Factory control that holds back the cars performance is the use of Power Enrichment Delay. This literally delays the cars fuel response to being full throttle. Since this does not delay the throttle position, it results in an initially lean acceleration. By eliminating the delay, you can expect to have not only a safer acceleration, but a more powerful one as a result of the additional fuel now being added during the first few moments of heavy acceleration. Power enrichment can also be richened up to add more fuel to the higher RPM ranges to accommodate more timing, but without larger fuel injectors, it is not possible to add much fuel without going beyond the stock injectors safe capabilities. To take advantage of the additional timing, a higher RPM limiter is used, which will allow you to drive the engine harder than previously capable if desired. The raise in RPM capabilities is minor in the Level 1 tuning, due to the capabilities of the cars stock fuel injectors. The stock injectors are really pushing the limits as they are, and without significantly larger injectors, you can only expect to see a couple hundred more rpms.

 

so explain, what do we do to eliminate this? tune and bigger injectors?

 

haha, no when ya tune you remove the delay and tune accordingly. :-P

 

Yep, I have no PE delay in my car right now. It does take out a lot of that bog feeling you get with a stock SS/SC (or GM Stage 2) right when you hit the gas.

 

interesting. good explination.

 

damn need to find someone to tune me so that i can get some better mileage and performance. and get rid of this.

 

is the pe delay there to make better milage or whats the reasoning for it from factory.

 

well the intent i believe is for better gas mileage, it runs the car lean in my car for about 5 seconds. i believe they probably did this because they figure your accelerating to pass under normal circumstances and are just easing passed.

whereas a motor head wants access to as much power as they can get when they want to get it. :-)

 

thanks for the info, good find.

 

how much would tuning affect the PE timing in a five speed though, i mean you're still down-shifting to accelerate while passing?

 

it still runs lean for 5 seconds, from the time u begin your rev match to the point in which the 5 seconds is up. at least in ls'

 

Nope to all who dont understand tuning power enrichment. U can tune for when p.e comes in as like. you dont want power enrichemtn to come in till 3600rpm, but you want it to come in at 50 kps. And you want it to come in at a 1.235 ratio. What people are not understanding is you have to set the settings for all the requiremtns for the same point or close to it to have p.e come in. Tuning it is the fun part trust me i have my p.e set to 10.5-11.3. I am way rich, but i tuned my car for 115-12.5 but my car runs cooler, loves it better, anddrives smoother. And even sounds ay better when running 10.5 wot. My car does not bog, jsut spins tiers 1-2-3- and chirps 4 gear with my seetings for traction off, when it is on, i tune it for 50% traction basically and i still spin, because i am running rich. So what people need to undersatnd is The p.e table is something you tune with wot for. Not daily drivin. It does not take 5 seconds for it to kickin, if it does you have somthing called a freaking mototr gonna blow if you are boostin more then stock. LEANN. Number 4 piston comin out.

Keep her rich.

 

when i hit around 3k rpm feels like VTAK kicked in....lol

you can do a test...put it in L or 1 and find the spot by going WOT at different RPMs and you can feel it

 

perhaps you should talk to Vince w/ Trifecta. while some of what you say makes sense, i think your missing the point of why people have been tuning to lower the PE delay.

If you need an example of what I'm talking about, look at my dyno sheet. Imagine on the interstate, you down shift one gear(not high rev) on a stock tune and gun it. your actually leaning out your engine up until the point PE kicks in.

So with that said, if you look at the tuned afr, you'll see exactly what I'm talking about even if you don't agree with the 5 seconds that has been mentioned. The point was, there is a few seconds of delay before PE kicks in and the engine gets the fuel it really needs to make more power.

 

i tuned my car several ways with my logs, and every thing so i know how my afr are. I have a tune for racing, street/ strip which my P.E TABLE COMES IN AT 1500, 9LBS OF BOOST,. i ALSO HAVE A TUNE FOR REGUALR DRIVING, WHICH I SET MY P.E TABLE TO COME IN AT 3600 THE ONE I WAS TALKING ABOUT BEFORE. So when say you are in cruise, and you are driving up a hill, or at a decel, and then you go to a higher rpm, more then likley you will hit the pe table if your p.e tables are set low, for better power down low. So i know what you mean about the tuning the p.e table, but waht i was tring to say is the best bet for people is to tune a P.E TABLE to 3600 rpm, so you are not alsway hitting it.

thanks

james