3.91 rear end question

[Twoblindsheep]

hmmm my dealer installed my 3.91 for free since i use the voucher i got from camarofest. i still dont have a tune because they were told the tune wont be out till the end of this year.. but there is still no update on it..

[Sandor]

Originally Posted by Twoblindsheep

hmmm my dealer installed my 3.91 for free since i use the voucher i got from camarofest. i still dont have a tune because they were told the tune wont be out till the end of this year.. but there is still no update on it..

California is issuing an E.O. and that is now in the final stages. We expect the cal to be in dealer hands within the next few weeks, stay tuned.

[OHIOSS]

I had my 2010 SS/M6 gears changed to 3.91 a few weeks ago. One dealer told me that GM didn't support this gear set so they couldn't do anything. I called another dealer last week because they told me they could do it....well after leaving my car there all day they called and said they can't do it now! My car is well out of warranty so I'm not worried about any warranty issues, I just want to get the speedo right.

How did the other's that posted they got their speedo's reprogrammed, how did they do it??

Russ

[MiSTER]

Originally Posted by Sandor

California is issuing an E.O. and that is now in the final stages. We expect the cal to be in dealer hands within the next few weeks, stay tuned.

That is awesome! Definitely Keep us up to date.

[Scott@Bjorn3D]

Originally Posted by Sandor

Camguynj,

I am with Chevrolet Performance. California is issuing an E.O. and that is now in the final stages. We expect the cal to be in dealer hands within the next few weeks, stay tuned.

Hope so since that is what I was told in April after dealer put rearend in my car. Told no latter that June. Guess how many freaking miles have been falsely put on my DD now. And my 36K 3 year warranty is being shot to hell. I used to be calm about this but now I am f#@!$g mad as hell. Hoping to get a mileage ryder at least added to my warranty since I was promised only a couple of months by many at GM.

[SSDan]

Originally Posted by OHIOSS

I had my 2010 SS/M6 gears changed to 3.91 a few weeks ago. One dealer told me that GM didn't support this gear set so they couldn't do anything. I called another dealer last week because they told me they could do it....well after leaving my car there all day they called and said they can't do it now! My car is well out of warranty so I'm not worried about any warranty issues, I just want to get the speedo right.

How did the other's that posted they got their speedo's reprogrammed, how did they do it??

Russ

If you are willing to get past the whole "voided warranty" stuff then you will need to get someone to plug in an aftermarket tuning device/ software and its an easy table update from there. Programs like HP Tuners, EFI Live, SCT, can easily take care of this for you. It might be time to throw some headers on that LS3 and get a dyno tune at a performance shop. They can wake that beast up, reset your gear ratio and get rid of shift skip. Lots of upside for you if you go that way.

[OHIOSS]

Originally Posted by SSDan

If you are willing to get past the whole "voided warranty" stuff then you will need to get someone to plug in an aftermarket tuning device/ software and its an easy table update from there. Programs like HP Tuners, EFI Live, SCT, can easily take care of this for you. It might be time to throw some headers on that LS3 and get a dyno tune at a performance shop. They can wake that beast up, reset your gear ratio and get rid of shift skip. Lots of upside for you if you go that way.

I've already had all of that stuff done, headers, cutouts, professional tune, and 3.91 gear set. If I buy one of these after market tuners will it screw up the professional tune that I have already had done?? Or is there some kind of an app in the software that I can JUST change the speedo?

I never thought about the extra miles showing on the car until Scott just posted that. I would be even more pissed off if I had to wait that long and the odometer showing more miles than you actually drove.

I told both dealers that the 3.91 IS SUPPORTED BY GM in the 1LE Camaro so I am at a total loss why they keep telling me it's a gear set ratio that GM has never supported. Hell they are genuine GM gears that I purchased!

[SSDan]

Originally Posted by OHIOSS

I've already had all of that stuff done, headers, cutouts, professional tune, and 3.91 gear set. If I buy one of these after market tuners will it screw up the professional tune that I have already had done?? Or is there some kind of an app in the software that I can JUST change the speedo?

I never thought about the extra miles showing on the car until Scott just posted that. I would be even more pissed off if I had to wait that long and the odometer showing more miles than you actually drove.

I told both dealers that the 3.91 IS SUPPORTED BY GM in the 1LE Camaro so I am at a total loss why they keep telling me it's a gear set ratio that GM has never supported. Hell they are genuine GM gears that I purchased!

Your shop's tuner should be able to do this for you using the same aftermarket tuning software (HP Tuners, EFI Live, SCT, etc) he used to tune your car the first time. For me it was as simple as my guy going to the table in the software that had the input field for final gear ratio and over typing 3.45 with 3.91 and then uploading the change to the car's ECM via the port under the dash. It took 5 minutes.

GM will not let dealers use aftermarket tuning software so it's become a big,slow deal for GM to create the needed re-calibration to flash into the ECU.

[SSMickey]

Originally Posted by OHIOSS

I told both dealers that the 3.91 IS SUPPORTED BY GM in the 1LE Camaro so I am at a total loss why they keep telling me it's a gear set ratio that GM has never supported. Hell they are genuine GM gears that I purchased!

3.91 is supported in the 1LE, but not in the SS because there transmission ratios are different. That's why GM is having to jump through hoops with CARB and other agency's to get it approved. However unpleasant, you were told the truth.

Originally Posted by SSDan

GM will not let dealers use aftermarket tuning software so it's become a big,slow deal for GM to create the needed re-calibration to flash into the ECU.

And when GM does issue the update and the dealers flash it to your ECU, it will be an entire overwrite. If you have a custom tune, it will be gone. Only the aftermarket tuning solutions have the ability to update a current tune without wiping out your current tune. This fact is probably going to catch a few people off guard that have custom tunes and want the dealer to update their gear ratio.

[OHIOSS]

Originally Posted by SSDan

Your shop's tuner should be able to do this for you using the same aftermarket tuning software (HP Tuners, EFI Live, SCT, etc) he used to tune your car the first time. For me it was as simple as my guy going to the table in the software that had the input field for final gear ratio and over typing 3.45 with 3.91 and then uploading the change to the car's ECM via the port under the dash. It took 5 minutes.

GM will not let dealers use aftermarket tuning software so it's become a big,slow deal for GM to create the needed re-calibration to flash into the ECU.

Thanks for the info everyone. The company that did my tune is a couple of hour drive away. I was planning on putting the car away for the season this Saturday so I guess I will just wait until next year and hopefully the dealer's will have the software update by next spring.

[joeybsyc]

So you can simply plug in your SCT handheld and reprogram for 3.91 gears? I am seriously considering these myself... Where's the cheapest place to buy them and the installation kit?

[camguynj]

Originally Posted by Sandor

Camguynj,

I am with Chevrolet Performance. California is issuing an E.O. and that is now in the final stages. We expect the cal to be in dealer hands within the next few weeks, stay tuned.

Hey, Check this out, a guy in Alabama said his Chevy dealer did the recalibration! Can you followup and confirm the 3.91 CARB EO has been approved for GM dealers ? Thanks!

http://www.camaro5.com/forums/showth...54#post7323954

[Snidely Whiplash]

Originally Posted by OHIOSS

I've already had all of that stuff done, headers, cutouts, professional tune, and 3.91 gear set. If I buy one of these after market tuners will it screw up the professional tune that I have already had done?? Or is there some kind of an app in the software that I can JUST change the speedo?

I never thought about the extra miles showing on the car until Scott just posted that. I would be even more pissed off if I had to wait that long and the odometer showing more miles than you actually drove.

I told both dealers that the 3.91 IS SUPPORTED BY GM in the 1LE Camaro so I am at a total loss why they keep telling me it's a gear set ratio that GM has never supported. Hell they are genuine GM gears that I purchased!

The SS manual tranny has a VERY low first gear compared to the 1LE. It's easy to break drivetrain parts with an SS 3.01 first gear and 3.91 rears.

[camguynj]

Originally Posted by Snidely Whiplash

The SS manual tranny has a VERY low first gear compared to the 1LE. It's easy to break drivetrain parts with an SS 3.01 first gear and 3.91 rears.

See in this link from Chevy perfomance Parts where it says installing 3.91s " Will Not Void Your Warranty"
http://www.chevrolet.com/performance...3/issue07.html

Why do you think GM offer the 3.91 upgrade with a warranty if as you say "it's easy to break drivetrain parts with an SS 3.01 first gear and 3.91 rears"