HPTuners VE Tuning issues...
Thread Starter
TECH Apprentice
Joined: Jun 2008
Posts: 391
Likes: 0
From: Mesa, AZ
HPTuners VE Tuning issues... I'm very, very new to tuning, so bear with me.
I'm attaching a .cfg (nope, ls1tech won't let me attach it... should be logging just the same as the default imperial, except I changed the minimum cell count for the ltft's to 15) and a log from my last little drive.
I was following the Cpig's HPT Tuning Guide for VE tuning using fuel trims... and it seems that I can't get my LTFT's to go below 10% no matter how many times I iterate.
I'm starting the scanner, connecting, resetting fuel trims. Then I drive for an hour or so, trying to hit all the cells from 0-4000rpm a lot to let it learn the ltft's. Then I stop the car, disconnect the scanner, reconnect, make sure the car is up to temp, then start scanning again... save the data after 20-40 minutes or so. I then add the averaged LTFT's and STFT's from that last 20-40 minute session to the VE Primary table in my tune. Then start the process over again from the beginning of this paragraph... supposedly until the LTFT's are all at 10 or under?
Well, I've gone through the process three times now, and I seem to be chasing the fuel trims, which aren't moving back much as far as I can tell. The current iteration of the tune (after applying the LTFT's from the attached log...it's called 2nd retune because I fugged it up and saved over the 2nd retune instead of saving as the 3rd.) is also attached. I think I'm doing something wrong, as some of my VE values are over 100, and my table looks NOTHING like the tables for similar setups in the repository. I'm somewhat afraid to even flash this to my PCM.
99 Camaro, LS1 with stock internals, lid, LT's ORY and catback... should be a fairly simple tune, right?
Also, any chance someone could let me know if I deleted the rear O2's, EGR, and AIR correctly? That would be very helpful.
I'm attaching a .cfg (nope, ls1tech won't let me attach it... should be logging just the same as the default imperial, except I changed the minimum cell count for the ltft's to 15) and a log from my last little drive.
I was following the Cpig's HPT Tuning Guide for VE tuning using fuel trims... and it seems that I can't get my LTFT's to go below 10% no matter how many times I iterate.
I'm starting the scanner, connecting, resetting fuel trims. Then I drive for an hour or so, trying to hit all the cells from 0-4000rpm a lot to let it learn the ltft's. Then I stop the car, disconnect the scanner, reconnect, make sure the car is up to temp, then start scanning again... save the data after 20-40 minutes or so. I then add the averaged LTFT's and STFT's from that last 20-40 minute session to the VE Primary table in my tune. Then start the process over again from the beginning of this paragraph... supposedly until the LTFT's are all at 10 or under?
Well, I've gone through the process three times now, and I seem to be chasing the fuel trims, which aren't moving back much as far as I can tell. The current iteration of the tune (after applying the LTFT's from the attached log...it's called 2nd retune because I fugged it up and saved over the 2nd retune instead of saving as the 3rd.) is also attached. I think I'm doing something wrong, as some of my VE values are over 100, and my table looks NOTHING like the tables for similar setups in the repository. I'm somewhat afraid to even flash this to my PCM.
99 Camaro, LS1 with stock internals, lid, LT's ORY and catback... should be a fairly simple tune, right?
Also, any chance someone could let me know if I deleted the rear O2's, EGR, and AIR correctly? That would be very helpful.
Stay away from trying to tune LTFTs with the VE table.
Disable LTFTs (set the enable ECT to like 280* or something like that), disable the MAF if you have one (set the low fail to 0 and high fail to 13500) and then go log STFTs in your drive.
Apply the necessary adjustments to the VE table based on your STFT log, then when you're satisfied go back and re-enable the MAF and LTFTs.
Disable LTFTs (set the enable ECT to like 280* or something like that), disable the MAF if you have one (set the low fail to 0 and high fail to 13500) and then go log STFTs in your drive.
Apply the necessary adjustments to the VE table based on your STFT log, then when you're satisfied go back and re-enable the MAF and LTFTs.
Thread Starter
TECH Apprentice
Joined: Jun 2008
Posts: 391
Likes: 0
From: Mesa, AZ
I assume that I would be using the average STFT's?
From what I understand (and I could be absolutely completely wrong here), disabling the LTFT's and using just STFT's should ideally give the same final result as using both ltft's and stft's? But I'm guessing from what you posted here that that IS, indeed, incorrect.
Also, I have a wideband arriving in the mail any minute now, so that might be a moot point, but it's still knowledge I would like to have.
From what I understand (and I could be absolutely completely wrong here), disabling the LTFT's and using just STFT's should ideally give the same final result as using both ltft's and stft's? But I'm guessing from what you posted here that that IS, indeed, incorrect.
Also, I have a wideband arriving in the mail any minute now, so that might be a moot point, but it's still knowledge I would like to have.
