i finally got HPT, but my wideband wont be hear until christmas eve. I was doing some reading on cobaltss.net and found this method. Since my PE delay is set to 6200 rpm from the factory, the fuel trims are adjusting for stoich almost the entire RPM range. What if I clear the fuel trims, set up a histo to log fuel trims against TPS and RPM. I can use this data to adjust VE tables by percentage (based on what the fuel trims are doing). Lather rinse and repeat. Once the fuel trims are near zero %, the VE tables are set accurately for stoich. That means if the injector constant is correct, and I lower the PE delay, the commanded AFR should equal the actual AFR in power enrichment.
Note this is for a mild N/A build application - nothing extreme. I/H/E/TB/LE5 mani/ 30lb injectors
Feel free to punch all kinds of holes in my logic
Quote:
PE Delay is disabled in all car calibrations.
Changing these numbers doesn't affect anything.
Taken from many threads on HPTuners forums. PE Delay RPM only affects trucks.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Quote:
It wouldn't matter of you enter 0 or 6000 or any number in the Mode Delay RPM field. The OS used on the cars do not use that parameter for entering PE mode. Only the % TPS vs RPM tables. ...only applies to the trucks.
More testimony from HPTuners forums.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Wow, that's all news to me. People have blamed that PE Delay for commanding stoich at high RPM for a long time...
Regardless, my question still applies
The fuel trims bounce up and down at any given RPM in such a way that you'd be getting basically near 0% in the cell you log in the histogram.. I don't think it would work.
Just wait the couple days before you get your wideband.. lol
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
I missed a part of the process - the LTFT's must be reset in between each tuning iteration - the STFT's are logged and plotted in the histogram to determine what the closed loop operation is adding in any given cell to reach stoich. Once the VE tables are tuned for stoich, the commanded AFR should almost equal the actual AFR in PE, because it's going to add a percentage of extra fuel based on the injector constant, the value in the VE cell, and the difference in the commanded AFR cell and stoich. THIS is basically what I'm trying to verify.
[ion wrote: C2]Quote:
PE Delay is disabled in all car calibrations.
Changing these numbers doesn't affect anything.
Taken from many threads on HPTuners forums. PE Delay RPM only affects trucks.
I don't believe that. I've seen evidence of otherwise on more than one occasion. Wideband and dyno readings I have seen first hand (my car and a friends car) point to the exact opposite of that statement.
Are these testimonies by people who have tuned the
J-body ecu?
The J's I've seen that have the delay in place will ramp in PE instead of going directly to the PE AFR.
As far as the described tuning method goes.....it will get you in the ballpark. You'll have to do repeated full load runs in closed loop to get a good average though.....possibly/probably sending your combustion chamber temps through the roof. Is it really worth risking some engine damage for the sake of getting at your car 2 days earlier? Wait for the wideband......if you just got HPTuners, there are plenty of other things to tinker with while waiting for the wideband to come.
Innovative Tuning
HPTuner Custom Tuning
Superchips Dealer
innovativetuning@rogers.com
Shane @ Innovative Tuning wrote:The J's I've seen that have the delay in place will ramp in PE instead of going directly to the PE AFR.
As far as the described tuning method goes.....it will get you in the ballpark. You'll have to do repeated full load runs in closed loop to get a good average though.....possibly/probably sending your combustion chamber temps through the roof. Is it really worth risking some engine damage for the sake of getting at your car 2 days earlier? Wait for the wideband......if you just got HPTuners, there are plenty of other things to tinker with while waiting for the wideband to come.
I understand your concern, but how if I'm tuning via STFT's, i'm in closed loop on the stock tune, 6200rpm delay and all. How is that different than just running down the 1/4 mile a couple times?
Good news though, the wideband showed up today, so the fun begins tomorrow. I'm going to install it and get it working first and take some logs. I'll post up if i observe stoich upto 6200 rpm. I'm also going to check the injector duty cycle before making changes to the calibration. If the other's experiences posted here are an indication they will be through the roof at WOT, probably from 5000rpm and up with the mods I have. Following that the 30lb/hr injectors will go in and I'll get her dialed in to 7k rpm. Dyno numbers and 1/4 mile times will follow in the spring.
don't forget to do an offset voltage calibration if the HPT readout doesn't match your WB gauge.
[ion wrote: C2]Quote:
It wouldn't matter of you enter 0 or 6000 or any number in the Mode Delay RPM field. The OS used on the cars do not use that parameter for entering PE mode. Only the % TPS vs RPM tables. ...only applies to the trucks.
More testimony from HPTuners forums.
please refer to this post:
ecu investigation: PE Delay
Its kind of a moot point now that you have your wideband, but my concern with the described method is that during normal operation you're only wide open at stoich for maybe a few seconds. To tune the entire VE map with fuel trims would require running the car at WOT in closed loop for considerably longer periods of time to get good averages.
Innovative Tuning
HPTuner Custom Tuning
Superchips Dealer
innovativetuning@rogers.com
DaFlyinSkwir(LS61) /PJ/ OEM+ wrote:
please refer to this post:
ecu investigation: PE Delay
Hm. I can't see your scans here at work, but I have my laptop here and looking over my scans and tune, I see:
My PE enable Delay RPM is set to
3400. My car entered PE at 33% throttle with an RPM of
2550. If you look at the PE
Enable TPS vs. RPM table, under the 2400 RPM column, a 32% enable TPS is the data in the cell. (At least on my MP45 tune)
The AFR does ramp down to the target 11.8 in a smooth curve and then remains static at 11.8 once it reaches it, throughout PE. It does this also when I entered PE at 35% throttle at 3478 RPM, started at 14.68 in closed loop then ramped down to 11.8ish.
Apparently our cars are slightly different? Or yours is a truck?
No idea, but changing it doesn't affect anything on my car.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Shane @ Innovative Tuning wrote:Its kind of a moot point now that you have your wideband, but my concern with the described method is that during normal operation you're only wide open at stoich for maybe a few seconds. To tune the entire VE map with fuel trims would require running the car at WOT in closed loop for considerably longer periods of time to get good averages.
You're right - I'd have to go out and "abuse" her for some time to fill up the histo hitting all the TPS vs RPM cells, but that issue aside, it should be a reasonably accurate way to dial in the table. Thanks for your insights.
I would never trust the tuning by STFT. As we have found soo many things are not what they seem.
FU Tuning
[ion wrote: C2]Straight from Chris@HPTuners, by the way:
Quote:
PE Delay is disabled in all car calibrations.
Changing these numbers doesn't affect anything.
Quote:
it is only very rarely used on some trucks
He is "gameover" on LS1Tech:
http://ls1tech.com/forums/pcm-diagnostics-tuning/322088-pe-enable-mode-delay-rpm-insight.html
This thread (the one in the link) is from 2005. Many things in both the editier and the scanner have been improved upon. Also keep in mind they are talking about mostly LSX PCMs, not ours...
P&P Tuning
420.5whp / 359.8wtq
ImPhat0260/Cavattack2000 wrote:keep in mind they are talking about mostly LSX PCMs, not ours...
Chris@HPTuners wrote:PE Delay is disabled in all car calibrations
Usually "all cars" means
all cars, not just LSX computers... but we'll see. This has been posted on HPTuners. Also in the other dedicated thread on the topic that PJ made in this very Tuning forum.
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
[ion wrote: C2]ImPhat0260/Cavattack2000 wrote:keep in mind they are talking about mostly LSX PCMs, not ours...
Chris@HPTuners wrote:PE Delay is disabled in all car calibrations
Usually "all cars" means all cars, not just LSX computers... but we'll see. This has been posted on HPTuners. Also in the other dedicated thread on the topic that PJ made in this very Tuning forum.
Please take into consideration that you are getting this info off an LSx platform website originally posted in 2005 when HPT was just starting to support our PCM. Nobody on an LSx website gives 2 sh!ts about what our PCMs do as they have little support compared to
all other cars that are supported by HPT. Anybody that has tuned enough of these (Jbody) PCMs knows that this parameter does in fact work. PJ just simply put it on the table for all to see. I applaud you PJ, I thought about doing the same but to be honest I just don't have the time to reply to every thread (here or HPT) about these things.
BTW, Chris(HPT) has posted on HPT forums about this situation.
Chris@HPTuners;154098 wrote:be careful of the context of my quote as it was probably in relation to the LS1 V8.
Chris...
P&P Tuning
420.5whp / 359.8wtq
ImPhat0260/Cavattack2000 wrote:[ion wrote: C2]Straight from Chris@HPTuners, by the way:
Quote:
PE Delay is disabled in all car calibrations.
Changing these numbers doesn't affect anything.
Quote:
it is only very rarely used on some trucks
He is "gameover" on LS1Tech:
http://ls1tech.com/forums/pcm-diagnostics-tuning/322088-pe-enable-mode-delay-rpm-insight.html
This thread (the one in the link) is from 2005. Many things in both the editier and the scanner have been improved upon. Also keep in mind they are talking about mostly LSX PCMs, not ours...
Exactly, when it first came out not all the tables worked in all calibrations. From what I have seen HPT has ironed out most those issues.
___________________________________________________________________
Mitsu TD06-20g |3" Turbo-back Exhaust | 61mm Bored TB |
HP Tuners | Innovate WB02 | Spec Stage 3 | Team Green LSD | TurboTech Upper | Full Addco Sways | Sportlines & Yellows |
Tuning with STFT will work...of course using a wideband is better....BUT make sure you have it set up right (the gauge calibrated the same as what's in HPT)...otherwise this seemingly small difference can throw the percentages off by enough that you'll never get it right because you'll just keep going back and forth, overcorrecting/undercorrecting etc.
