eci

I just made this. You'll see the major advantage 4.10's will provide down low versus 3.73 when upgrading from 3.55. 4.10's are the way to go on the manual. In the low RPM's, where the engine lacks torque, is where you NEED the torque multiplication of the 4.10's. 3.73 isn't enough. You'll also notice cruising RPM in 5th gear isn't as bad as people make it out to be. Attached.

sound wave

cool. if it isnt too much trouble, could you also make one for the auto? thanks in advance.

metroplex

Here you go. The 5R55S worksheet is for the auto, Tr-6060 is for the GT500 (Although I didn't input the correct tire rev/mil for the GT500; 775 vs 766 isn't a big diff), and the TR-3650 is for the S197 GT.

I noticed using 3.55s on the 5R55S is the equivalent to having 3.73s on the TR-3650 based on the spreadsheet. I plan to stick with 3.55s with the TR-3650 for better fuel economy and a higher driveline critical vehicle speed.

sound wave

perfect. that really helps out a lot. thanks.

hiznherponies

is there any way to view that without using microsoft word?

ScottM

Wow, thanks a lot! I'm one of them that "was" scared of 4.10's, as a matter of fact, I have a set of 3.73's in the garage waiting to go in, only because I got them so cheap. I think I'm going to get rid of them and go ahead and go with the 4.10's. The difference in RPM's isn't near as dramatic as I thought.

Again, I appreciate it!

By the way, it's not Word, it's Excel. If you don't have Microsoft Excel, click on the following link for Microsoft's Excel viewer.

http://www.microsoft.com/downloads/d...displaylang=EN

YaoNYC

hi metroplex,
did you ever do the 3.55 rear upgrade?

thanks!

metroplex

Hi Yao,

My GT came from the factory with 3.55s, so I'm going to stick with them for now. I get 20-21 mpg in combined driving, and 24-25 mpg with a bias towards highway driving. I figure there may be a 1-2 mpg hit with 3.73s and 2-3 mpg hit with 4.10s. In retrospect I should have stuck with the 3.31s for even better gas mileage.