Tuning for the 2.4L GM Reflash..... - Tuning Forum

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Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 8:46 AM
What's happenin' my fellow organeers? I have a question that hopefully isn't too hard to answer. I currently bought HPTuners. I have a 99 Z24, but i have the GM S/C, so to make tuning easier i'm wanting to reflash my PCM with the 00+ GM S/C Reflash, how exactly do i go about doing this? Do i have to change my PCM to a 00+ or can i just reflash my 99 PCM for the 00+? Any suggestions or what not will help. Thanks!


NEW SIG COMING SOON FOR 07'!!!

Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 9:06 AM
Just go back and look at your other post... I've said repeatedly "You CAN NOT reflash a '99 or older with the Gm S/C reflash." You'll have to fake a 2bar or swap in a '00. If you swap in the '00 you'll have some dash lights on all the time because the '00 uses a separate BCM.

I'm running one on my '96 BUT I swapped my gauge cluster for digital gauges.





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 9:36 AM
Okay, you did say that....my bad. So, how's you get your digital gauges to work in the car? How did you get past VATS? Details buddy......i need them


NEW SIG COMING SOON FOR 07'!!!
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 9:49 AM
You can read about it HERE. I'm not sure on a '99 if the VAT's works the same as a '96-'98 (I wasn't concerned about it with mine).





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 11:10 AM
Correct me if I'm wrong but you can disable VATS with HPT, so that would be one less thing to worry about. I would just do the 2 bar map fake. That is what it sounds like GM did for the most part. Also has anyone actually tried to load a GM flash tune to a pre 2000 car using HPT?



FU Tuning



Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 11:22 AM
The first thing I checked when I swapped from a '96 to a '97 was to make sure the VAT's was disabled. It might disable it in the PCM but it does not disable it in the dash or the column.

The Operating Software is different between the '99 and older and the '00-'02 (yes I tried).

The only way to get a true MAP load system is with a '00 swap or a complete standalone (Tec3 is sitting on the shelf for when I'm done playing with the HPT).





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 11:30 AM
Quote:

The only way to get a true MAP load system is with a '00 swap or a complete standalone (Tec3 is sitting on the shelf for when I'm done playing with the HPT)


I realize you might not know this answer, but I still wonder if anyone has actually tried saving with HPT a GM flash tune file and then loading it to the pre 00 car.



FU Tuning



Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 11:34 AM
Quote:

The Operating Software is different between the '99 and older and the '00-'02 (yes I tried).


One of my experiments... Tried to flash a '97-'98 and/also a '99 PCM with a '00 S/C reflash. It won't recognize the O/S...





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 11:56 AM
BTW... You can flash a '97-'98 PCM to a '99 program BUT you also have to redo your knock sensor to a 2 wire (I got on the lathe and made a threaded aluminum bushing to fit in the larger one wire hole in the block)...





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 12:05 PM
john317(AKA Gary the Old guy) wrote:
Quote:

The Operating Software is different between the '99 and older and the '00-'02 (yes I tried).


One of my experiments... Tried to flash a '97-'98 and/also a '99 PCM with a '00 S/C reflash. It won't recognize the O/S...


sorry when I first read that I did not take it about the SC reflash part, but just something else.

You know I wish someone could get ahold of the Z24 Techinc ECU and read it with HPt to see what it shows. That was a 97 or 98 and had the GM charger. GM had a program for 97-99 cars for the charger. They had the charger on Matt teske car for a while for testing for auto's. I know they had some problems with it, but still. If we could just our hands on it.



FU Tuning



Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 12:09 PM
Who knows with GM. They could have used a PCM from a S/C GTP or OBD1 Turbo Sunbird.





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"

Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 12:13 PM
john317(AKA Gary the Old guy) wrote:Who knows with GM. They could have used a PCM from a S/C GTP or OBD1 Turbo Sunbird.


True maybe in the Z24 Techinc, but doubtful in Teske car because his was a test car for the auto cars.



FU Tuning



Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 12:36 PM
Ya, they probably just ran some kind of a fake 2bar and then re engineered their software for the newer years ECU.





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 12:55 PM
john317(AKA Gary the Old guy) wrote:Ya, they probably just ran some kind of a fake 2bar and then re engineered their software for the newer years ECU.


I do know on the z24 technic they did not have a IAT sensor, or a MAF either. I thought that was interesting.



FU Tuning



Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 2:37 PM
I know i'll prolly get flamed, but it seems like a good question to me....what is so fifferent about the wiring of an 00-02 cavalier than a 99 besides the BCM, why cant you just put a 00+ pcm on a 99 ? Some say because the wiring is different and so on, but so are the 99's without the high impedence injectors and the smaller starter, is there any chance that if you have those two that you may also have the same wiring other than the BCM?


NEW SIG COMING SOON FOR 07'!!!
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 2:58 PM
When I go home tonight I'll pull my wiring diagrams. You'll have to change 4-6 wires in the plugs at the PCM but it's not that hard.

The '99's are kind of a bastard year but not near as bad as the '96. Most all of the '99's have high impedence injectors. Not sure on the starter but I think it's the smaller case on all of them.





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 4:01 PM
...K

Open 2 windows at one time.

one with your tune, the other with the GM 2k up charger tune.

copy and past the fuel and timing maps.

PRESTO a 99 gm SC map....

thats REFLASHED ON TO YOUR PCM....

thats what i said ohhh soo many times to you.

Chris


'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08

Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 4:22 PM
It's not quite that simple but yes that is a good start on a fake 2bar file...






"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 4:29 PM
Doing it that way makes it a real 2 bar set up. So he would have to get a different MAP and injectors to keep it working correctly.

Chris



'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08

Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 4:34 PM
Brian Mooney wrote:I know i'll prolly get flamed, but it seems like a good question to me....what is so fifferent about the wiring of an 00-02 cavalier than a 99 besides the BCM, why cant you just put a 00+ pcm on a 99 ? Some say because the wiring is different and so on, but so are the 99's without the high impedence injectors and the smaller starter, is there any chance that if you have those two that you may also have the same wiring other than the BCM?


If I recall correct the reason why is because before 2000 the PCM controlled everything, but in 2000 the PCM share control with the BCM. That making the wiring difference be the wiring going to the BCM. Someone correct me if I'm wrong.



FU Tuning



Re: Tuning for the 2.4L GM Reflash.....
Tuesday, December 19, 2006 4:40 PM
YOU are CORRECT Sir!


Chris


'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08


Re: Tuning for the 2.4L GM Reflash.....
Wednesday, December 20, 2006 4:27 AM
Using the most common terms used on this forum;

GM S/C Reflash =
Speed-density is based on engine RPM (speed) and manifold pressure and temperature (air density).

Faking a 2bar =
Alpha-N calculates airflow based on throttle angle (alpha) and engine RPM (N) and some correction based on air temperature.

They are not the same thing. It's like saying Hot Dogs and Bratwurst are the same thing. While they maybe similar in many ways they are not the same.






"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Wednesday, December 20, 2006 12:44 PM
Okay, So I like what Taesch Z24 said about opening 2 windows at the same time and Copy, would this work? That can be my base tune right there , no? Then i wouldn't have to change my PCM or change any wiring, so would this work?


NEW SIG COMING SOON FOR 07'!!!
Re: Tuning for the 2.4L GM Reflash.....
Wednesday, December 20, 2006 1:26 PM
Yes... You'll still need a 2bar map and at least 310cc injectors (the ones that come with the S/C or equivalent). You won't be able to change the IPW vs.VAC to IPW vs. MAP and a few other little things but it's pretty easy to figure out.

The only reason I jumped up to the '00 from the '99 is the fact that the tuning is based on load vs.rpm instead of throttle position vs. rpm. It seems to make more since to me because the load in first gear is not the same in fourth gear. I haven't been back on the dyno since I changed to the '00 but just from driving around and playing with the tune the transitions are much smoother compared to the "Fake 2bar". But the tune for the "Fake 2bar" was far better then the SAFC and FMU. On the one pull that I got on the dyno (they were having problems) I picked up almost 12hp from the HPT and '99 PCM swap.





"The FACTS are always subject to CHANGE once the TRUTH is applied"
"In the entire history of man the only stupid questions are the ones that don't get asked"
Re: Tuning for the 2.4L GM Reflash.....
Wednesday, December 20, 2006 1:43 PM
Well, thats cool to know. So, even if i stay with the 99 pcm i could still just take the S/C reflash file and copy and paste it? Also, the torque management is for auto's right?


NEW SIG COMING SOON FOR 07'!!!
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