On 2001-07-05 19:35, KellyZ06 spewed forth this drivel:
I have a white Z06 and have a brand new Gertag 3.73 rear end still in the box(for 3 months) plus the GM fluids plus the powerloader to tell the PCM about it, just in case I need it. (I know that most people who have done this mod say it isn't necessary). With all the posts about warranties and how common leaks are from the diff (had one myself with a 99 vert) I really don't know what to do. Any imput, advice, flames would be GREATLY appreciated. I really want to do this mod but.....
Many thanks /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_confused.gif
I'll give some balance for you to chew on before deciding.
1. Consider that due to the rear drivetrain design and the heat issues within the trannie and rear end and then consider increasing RPMs due to a lower gear ratio ?
2. If you drag race, consider where with the stock gear you could cross the line in third gear but with a 3.73 you now are forced into using 4th gear and the cost to the E.T because of it and having to use 4th gear outside of the power band.
3. On start starting line, 3.73s make it even worse in getting off the dang line.
4. Into topend speeds, 3.73s reduces what the stock gear topend was.
5. If your into Open Road Racing like I am, 3.73s cause lots more 5th/6th shifting unbalancing the car into corners at high speed, and clearly overheats rearend drivetrain due to higher RPMs.
6. A don't care but does reduce the MPG....
7. Not a simple swap like in a C4, whole rear end has to come out to ake the swap. Better have a real good wrencher doing the work and then getting rear end aligned again.
8. Consider G.M has adjustable values in the PCM not only for rear end gear but also wheel/tire size.
Now consider PCM products like Superchips, Hypertech, etc allow you to change those values.
Now consider all those saying a gear change needs no re-cal of speedo.
Not always true.. as example if you also then change the tire sidewall size with a 3.73 gear and speedo, elapsed distance, are no longer correct. My '99 is 2 MPH off from the real speed.
7. a 3.73 might voild your G.M warranty depending on if your dealer is a A-hole or not.
I know for I have 3.73s, drag race, ORR, and street drive and all the above is seen with my '99.