6 replies to this topic

[CompCobra]

I know this may have been discussed before, so I apologize, but I have never really seen this exact setup discussed, so here it goes.  I am thinking about making the first power train modification to our stock 2008 Shelby GT500 (no engine mods).  I would like to change rear end gears and install Shelby Alcoas this spring.  We will be running 285/35/20 Michelins in back, so they are just a hair under 28" tall.  Going to a 1" larger tire numerically lowers the rear axle ratio, so would a 4:10 ratio be better than the more common 3.73 ratio?  Our Shelby is really just used for cruising locally and not too much highway, so fuel mileage is not a concern.  I really just want to make our Shelby more clutch friendly (eliminate shuddering) and improve acceleration performance.  My wife wants to start driving our Shelby and is concerned about either stalling out or feathering too much with the stock setup.  If anyone runs this gear ratio/tire size setup and would like to comment, it would be greatly appreciated.  Thanks!

[msb64]

I am still running the stock 3:31 gears, and occasionally switch to 28" tall drag radials for the drag strip (and street).
I don't find very much difference in daily driveablity with the taller tires, other than being a whole lot stickier and noisier when you put your foot in it.
If I were to go for more gear for a good street/strip balance, I would go directly to the 4:10s myself.
For a primarily street driven car, 3.73 is a pretty good choice for that.
The thing that worries me is the number of complaints of noisy gear installs reported, that would be a real pain for a street car.
Not sure if it was just bad installs, bad components or the wrong components, but there are quite a few unhappy people out there.
I also do not do a lot of highway driving, other than maybe the odd 100km run to the track or car show.

I can tell you from experience that the most bang for the buck mod you can make now is to contact VMP for their small pulley, CAI and SCT tuner package, it will really wake your car up and be just as driveable as it currently is.
Watch out for the upgrade slippery slope though

[CompCobra]

Just a bump for this topic....I can't believe that I would be the only one out there thinking about 28" tall tires and 4.10 gears??!!  Thanks for the feedback guys!!

[Snoopy49]

Maybe this will help you decide.

Attached Files

•  2008 Speed Chart 4.10.jpg   222.62K   64 downloads

Edited by Snoopy49, 11 December 2012 - 11:25 AM.

[csx2396]

wE ran a 373 for a long time and liked it better than a 410.

[VNMOUS1]

4.10s
28" slicks
750 rwhp
6500-6600 rpm at the stripe.
low 10s at 138

Do 4.10s if you race it.

[Snoopy49]

New Charts.