Tuning 2004 GTP

[zharvek]

New here, but trying to learn everything slowly and take my time. I have been all over the forums, searching and reading up on all of the informative posts, and stickies.

I acquired the update from HPT so I can scan and such now. I found the CPIG Vehicle Tuning Guide on the forums, and was wondering if this is a good guide to follow for my car, or if there is another (better, or different for my case) guide for 3800 owners.

Car: 2004 Grand Prix GTP

I've noticed some of the options that he has, are not available to me, thus why I am asking.

I would like to start on some small stuff and work up, going slowly. Looking at my scans, it seems that I need to work on the LTFTs first, as they seem way off to me. I have attached a scan to help in case you want to see what I mean.

I currently use a DHP PCM, and was wondering if I could just make the slight changes to this, or if anyone has had problems with them? (I do have my original so, If I must go back and do this all myself, it really is no problem, just will take more time).

Here are two scans I have done, I have not gone WOT with any of these two. If you need a WOT run, let me know. Also posting the Original tune from the ECU, and one that I have slightly modified according to the CPIG document with LTFT. I have not flashed anything yet.

Thanks in advance to anyone who can point me in the correct direction, I'm always wanting to learn new things.

[MMGT1]

Russ K's and Tuning write up on the following link...Great info for using HPT with the V6's

http://www.hptuners.com/forum/showthread.php?t=10615

[Eddie-98GTP]

I'll have to wait until I get home to look at the scans, but a lot of people who have a DHP pcm just use the transmission and torque management stuff. As in any canned tune, you will be able to do a better job yourself after learning what does what and why. Is your current PCM a DHP 1.0 or did someone flash a 1.5 for you? The 1.5 was a starter file, nothing more, and the 1.0 was a fully (canned) tuned PCM.

Short answer - I would start with the file currently in the car.

[zharvek]

Thanks for the posts guys. MMGT1, I found that post while doing one of my first searches. Good information, so at the moment I will be using the CPIG document and try to do things slowly.

Eddie, my PCM is currently a 1.0

The DHP is in the car currently. Thanks for taking a look when you get a chance. I will go ahead and make a good backup, try to make some slight changes, and then write it.

[zharvek]

I've gone ahead and started to play slightly with the LTFT since they seem very off. I've disabled PE mode by changing the PE Enable TPS all to 100%.

I am a little confused on which way to tune the LTFT though. I have used the CPIG guide, but after a few hour runs and pasting Special - Add, seems to work, the second run and Add, always messes up. I then searched the forums, and found people telling others to use the Paste Special -- Multiply %, so I tried this a few times, and yet, after the second run and Paste Special -- Multiply % the car runs like crap, the graphs seem smooth and everything.

This morning, browsing the forums, I found the post http://www.hptuners.com/forum/showthread.php?t=14169 that says I should be using the Histogram for LTFT vs. Mass Air Flow Freq. Hz that 5_Liter_Eater posted. (Although for some reason, I cannot Import Histograms, I get an 'Not Available' error. I found a post earlier that possibly 5_liter_Eater walked somebody through to create one).

Is using this new custom histogram the way to do LTFT tuning, I'm just a little confused here. Since I've researched, and have many ways to do this.

I'll attach some screen shots. Currently, I am back to using the standard tune that is attached to the first post. This just shows the histogram with the error message for importing a histogram, also just shows the table I have setup for logging.

Thanks guys.

[Bill@HPTuners]

I'll attach some screen shots. Currently, I am back to using the standard tune that is attached to the first post. This just shows the histogram with the error message for importing a histogram, also just shows the table I have setup for logging.

Thanks guys.

sounds like you're running a beta version, please update to 2.22 located on your customer login page.

-Bill