which sensor do you feel can respond faster for the A/F effect of AE? i say TPS. what you say?

 

I would think TPS just because it would be more of a "direct" measured change (if that makes sense). Also, the Pumpshot due to TPS can be put in on a delta TPS% of only 3.1 which is a very small change. Whereas, with the MAP the first stage of differential MAP is 20KPA. So I think the TPS would react quicker.

But they also both have "0" differentials. Anyone know how pumpshot is added with a change in MAP or TPS of 0%/0KPa that doesn't seem to make sense, or am I missing something?

 

yea that puzzled me too. i just made the 0 tps same as 3%. i can log the % as a function of voltage in LM1. i wonder what a 3% change of throttle means in volts? .52 to 4.00v i believe the tps volts show in log. in that case i will load up the AE/TPS and remove some AE MAP. stumble. see my other AE Q. no response on it?

 

Well if the TPS volts range from 0.52 - 4.00V then a 3% change would be about .1044 V. I didn't see your other AE question?

 

TPS because it is directly linked to your foot via the linkage and throttle blades/shaft.

The MAP takes a fraction of a second longer due to the fact it takes a slightly longer amount of time for the incoming rush of air to drop the vacuum in the intake and the MAP.

 

The AE functions of the 8746 and the 7747 are a bit different. The 8746 has teh slow filtered MAP AE, but has the tps based on change in throttle over 12.5 ms. Ive gotten to around 3% change in tps over that time period, but I had to wind up and slam my foot down to do it.

In the 7747, both the TPS and MAP will have slow filtered terms that can be used to generate the deltas used in the lookups.

To properly tune the AE, you need to datalog near real time. Lockers is what Id recommend. You need to construct the delta MAP and TPS terms used for the lookups from the slow filtered MAP/TPS and regular MAP/tps terms. That way you can correlate the ammount of AE to the O2 readings and adjust as necessary. Theres no other way to really properly do it. You have those slow filtered terms in real time to really get a feel for how much AE you have. The idea of the slow filtered terms is to generate AE that slowly decays down and the whole table needs to be close for the AE to work right. GM already does half the work for you. The term used in the MAP AE lookup is stored each time around. They may even store the TPS term used for the lookup as well in the 7747.

Its also possible to patch the portion of the code on the prom and store the actual async AE PW's, but the bottom line is you need to datalog real time to sort this out.

 

I didn't realize it was over 12.5 ms. If that is the case wouldn't that mean that basically the entire AE vs. delta TPS table is pointless? I mean you could never make a significant change in TPS in 0.0125 seconds. So does the motor ever even experience the higher delta TPS AE values?

 

Exactly. Most of the time only the first two, maybe three cells can be used under normal conditions.

Edit: in my reply that was previous to this one, I meant to say that ive gotten to around 12% delta tps, which is nearly the full table, but < 3% delta tps is all youd expect to see while driving.

 

Quote:t it has the tps based on change in throttle over 12.5 ms

Bron: .012 seconds?

i am seeing in logs the onset of AE. i will have to look at log over a longer time interval? hard to explain. i saw a double spike(enrich) a few tunes back that were actually .25 to .50 sec behind the TPS movement. i improved that to .25 or less. i am assuming the first is the TPS and the second map? thereforet i assume the tps is quicker to show in log. they were equal last i looked at about 12.5/1/13.0/1 on a moderate TP movement(reg driving). heavy throttle 11.0/1. a bit rich. there appears this time delay that causes the bog. seems the velocity in intake/TB is inadequate at low rpms AE invoke. as in engaging clutch. the unatomized air gets to combustion chamber before the AE enriched air. does this make sense? see my Q DIY Prom. next experiment is too add more in all TPSAE and remove equal in MAP AE.

 

When I moved more fuel to the TPS AE, I had some issues with off idle drivability, it basicly just flooded the engine, and it wanted to stall. I had to move it into the MAP AE, and leave any real TPS added, in only the high percentage areas.

FWIW, I still cannot get the AE where I want it, with the wet flow AE is REALLY picky.

 

Dewey: thank you. i may have misinterpreted my WB logs. i may be experiencing a rich spike causing bog. after the delay(bog) it may be clearing of the AE richness that allows me to accell. as i stated i see the onset of TPS increase then the AE event in log. again only dead stop to clutching to accell to about 5 miles/hour. back to drawing board and will clear out additions to the AE TPS(back to stock GM) i had done. i think the prominator will be helpful loading in six bins with variations in my AE tables. right now is is maybe 2 chips a week i am burning. ordering Prom next week.

 

Mine only had issues at low RPM, part throttle AE. Basilcy, when leaving from a stop light, with light throttle, it bogged. from a roll, with some RPM's up, it ran fine, or if I floored it off the line.

If you are interested, when I get home from work, I can post my AE tables for you.

--John

 

Ronny, keep in mind that the delta used for the AE lookup slides down the tables as teh AE decays out. If the MAP/TPS values are too high at very low/0 values on the TPS/MAP AE table, itll cause a rich spike some time after you hit the gas. I had to zero the lowermost entry as it would cause the motor to want to quit after I entered AE. The computer would slide across that entry and gag the motor with fuel.

I too am still messing with AE, havnt settled on my final setup yet so things keep on changing.

 

Thats where I am at also, timing and VE tables are well sorted out, WOT was nailed with WB and DYno'ing. AE is still giving me headaches.

 

i misinterpreted the WB log. too fat on AE. will go lean and sneak up.

QUOTE: I had to zero the lowermost entry as it would cause the motor

both the TPS and MAP ??

 

Yes.

To some extent it also depends on the lag filtering. If the slow filtered terms catch up too quickly, then the AE can terminate while the engine still needs it, which can cause you to need AE in the lower cells.

Just a WAG, but I would think youd want to have the slow filtered terms finally catch up jsut as the engine no longer needs AE so the AE doesnt suddenly fall off and leave the motor hanging.

Even more things to think about...

I wouldnt mess with these, though untill you can see there is a clear need to stretch out the AE.

Did I mention you need lockers? AE is already a pain in the butt, having to tune it by guesswork will make it nearly impossible.

 

Come On SpeedReader!!!!

(still quitely waiting for this)

 

You're not kiddin Dewey! When they first made it the ETA was end of last summer! I want that bad boy.