Re-Programming after rear end gear change ??

[Corvette-Pilot]

I am looking at changing my 94 auto rear end gears from the stock 2.59 to the 3.07s. On my year car you have to reprogram the computer with the new info but I wanted to find the best method to do this.



I can try and get a used Hypertech off ebay ~ $150-200 range.

I also hear there is some software out there that will do the same thing plus a whole lot more ??
I have a laptop and PDA so I guess I would need the software and connection cable of some sort.
What is it I would need in this case and where to find and how much $$$ Looking for opinions,
Thanks

 

[Skant]

You'd use LT1 Edit.

http://carputing.tripod.com/9495LT1Edit.htm

Keep in mind you need to get a very special cable for it. And the software isn't cheap, either.

LT1 Edit does let you do a lot more stuff with your car. HOWEVER... you'd better know what you're doing. It's meant for people with expertise in tuning cars, and you can turn your computer into an expensive paperweight with it very easily. Their documentation warns about all sorts of easy to make errors you can make which will unrecoverably wreck the computer.


The Hypertech programmer, on the other hand, is idiot-resistant (I never say idiot-proof because there is no such thing). It has very good instructions. And it recovers gracefully from errors and mistakes without endangering your vehicle computer. In my case, after adding all the hidden costs up, I also found that it was a good bit cheaper.


I went for the Hypertech myself... also to change my rear gearing. Once I had it, I also decided to use the fan tempurature reprogramming... and ultimately their power tuning program as well. I was uncertain whether to go for the power tuning or stay with the stock tuning because I've read a lot of comments that it hurts power. However, I was able to measure about a 10hp improvement with the Hypertech on my LT4. Which matches closely with Hypertech's back to back dyno claim of 8hp on this application.


Hypertech's manuals are online and very detailed. So you can read through the procedure ahead of time. The whole operation takes about 30 mins (15 mins of programming time).


Hope that helps.

- Skant

 

[Mr Mojo]

Look around for someone with LT1 edit probably best, butthe Hypertech does the job also.

 

[switch]

Another option is TunerCat, similar to LT1edit with a better GUI. Also a bit cheaper. They all will do the trick. Also, a good monitoring program is Datamaster if you are looking for data logging.
I have used all three on my 95.

Gordon
WitchHunter Performance
www.witchhunter.com

 

[Corvette-Pilot]

I'll have to look into some of these options. But now I think I am scared into sticking with the Hypertech. Sounds like the other options are more useful but also much more dangerous.

 

[garycr14]

I am looking at changing my 94 auto rear end gears from the stock 2.59 to the 3.07s. On my year car you have to reprogram the computer with the new info but I wanted to find the best method to do this.



I can try and get a used Hypertech off ebay ~ $150-200 range.

I would agree with Skant, the hypertech is the way to go if your car is mostly stock, with a few "bolt ons", if you have more agressive mods, heads, cam and such, you'd want a custom program from fastchip.com. I would consider going to the 3.54 gears as long as your in there. I have the stock 3.07's in mine, wouldn't mind having a bot more gear.

Good Luck!

 

[94 Octane]

I am looking at changing my 94 auto rear end gears from the stock 2.59 to the 3.07s. On my year car you have to reprogram the computer with the new info but I wanted to find the best method to do this.



I can try and get a used Hypertech off ebay ~ $150-200 range.

I also hear there is some software out there that will do the same thing plus a whole lot more ??
I have a laptop and PDA so I guess I would need the software and connection cable of some sort.
What is it I would need in this case and where to find and how much $$$ Looking for opinions,
Thanks

I recently went from 2.59 to 3.73 on my 94. My speedo is way off. I ordered the Hypertech III yesterday. Until I read this thread I was not aware of additional options. I will post results of re-programming next week.



BTW. The results of the gear change are dramatic (to say the least). If you drive a lot of miles you may want to go with the 3.45 or 3.09. Gas mileage has gone down, but that's not why I bought the car. If your car is a garage queen or you drive it occasionally, go with the 3.73.



After a break in period of about 200 miles with short slow trips and letting the rear end cool down completely in between trips, the first time I "stuffed" it, all I could say was HOLY Sh!t.

 

[Corvette-Pilot]

I would consider going to the 3.54 gears as long as your in there. I have the stock 3.07's in mine, wouldn't mind having a bot more gear.
Good Luck!

I am debating this issue now as well.
I found someone with the 3.07 rear end for $400 and would think it will make a big difference.
3.54 is as tall as I would go since I do a lot of highway driving so I want a compromise for MPG/RPM/get up and go, ect .....

What kind of RPMs do you get with your 3.54 on the highway ~70MPH - MPGs ??
Ever run 1/4 mile, what sorta times ??

 

[garycr14]

I am debating this issue now as well.
I found someone with the 3.07 rear end for $400 and would think it will make a big difference.
3.54 is as tall as I would go since I do a lot of highway driving so I want a compromise for MPG/RPM/get up and go, ect .....

What kind of RPMs do you get with your 3.54 on the highway ~70MPH - MPGs ??
Ever run 1/4 mile, what sorta times ??

Sorry, I don't have the 3.54, but is what I am thinking about. I want to see how my car runs when I take it to the strip next month. I have the stock 3.07 (G92 RPO), with the mods I've done I am hope to get into the high 12's range, if I don't the taller gears is the next option to try and get there.

 

[Moonunit 451]

I am debating this issue now as well.
I found someone with the 3.07 rear end for $400 and would think it will make a big difference.
3.54 is as tall as I would go since I do a lot of highway driving so I want a compromise for MPG/RPM/get up and go, ect .....

What kind of RPMs do you get with your 3.54 on the highway ~70MPH - MPGs ??
Ever run 1/4 mile, what sorta times ??

Went from a 2.59 to a 3.33 5 MPH on the speedo, and, well low 12's in an easy 11's car with all the mods. I think I'd've been happy with a 3.07, but I'm definately cool with the 3.33, 21+ MPG getting it when I feel like it