Hey Rob- I can speak from experience on gears. I have a 5 speed manual 06 GT with a 2.6L KB blower. IMO, the 4.10s were great before the SC install. After the SC install, the 4.10s spun my heavy chrome 18" wheels/street tires in 1st, 2nd, and 3rd gear. I decided to change to 3.73 gears, and I couldn't be happier.

I have a set of 17" factory bullitt wheels with MT ET Street drag radials that I am going to try out at the track this spring.

Whichever way you decide to go, it will be a blast! I just think you will need to baby the throttle a LOT more with the 4.10s. On the 1/4 mile strip, I am pretty sure you will have to shift into 4th gear before you cross the line with 4.10s, too.

 

The 3.73s because the 4.10s are gonna have to shift into 5th gear...

 

I guess I should have mentioned, I have an auto...

 

I didn't even know they made Shelby GT autos. Is it rare?

 

Depending how you drive but I was referring to the transmission, not that its even a big deal..

 

I had the great opportunity to drive a Novi 2200 S/C Auto w/3.73 rear gears, and then the opportunity to drive the same car with 3.55 gears. The car ran KDWII 285s. The car was "a handful" with the 3.73, but fun as hell. The car with the 3.55 is a straight out, nail it and watch everyone dissappear. The car is basically on auto pilot once you hit it. So, which is faster?

I believe the more predictable traction is, the more consistently fast the car. I wouldn't go Whipple H/O and 4.10s if you want predictable. If this is a car you take to dinner and have "two drinks" and then drive home, I would bet the 4.10s will sober you up in no time! Buzz Kill.

 

I like this guy^^^logical!

 

I'm all for more gear. I had 4.10's in my '93 TBird LX 5.0L, 3.73's in my '89 Mustang LX 5.0L, 4.30's in my '03 Mach 1, 3.90's in my '68 GTO, and now have 4.10's in my supercharged '07 Mustang GT automatic.

However, the instant torque of the twin screw blower coupled with the 4.10's is gonna make for tough traction issues on the street, whereas the 3.31's or 3.55's would hook up a bit better.

At our local 1/4 miles dragstrip on 275/40/17 drag radials, I'm in 5th gear about 200 feet before the finish line (shifting out of 4th gear at 6,400 rpm's). So, if you're going to the track often and don't want to ever get into 5th, don't get 4.10's (unless you plan on running very tall tires to compensate).

Back to the question about lining up three identical twin screw blown GT's with different gear ratios, I believe you'll find a much smaller improvement in ET's from highway gears to 4.10's than you would doing the same matchup in a centrifugal blown GT or naturally aspirated GT. Drag racing is all about torque, and the twin screw makes gobs of torque thus doesn't need extra gearing like a car that's down on torque.

 

yes... not to many were made.

 

Sweet. Rarest of the rare.

 

Yes.... But it's SO much fun.

When I race.... It's over even before it starts...lol I have had cars going 90+ miles an hr coming from behind me and I maybe doing like 60 or so and when I hit it, they never get a chance to pass me.... I want all my power up front and right away....

Guess it depends on when and how you want your hp delivered to you.

 

Rob,

You know my vote... neither. Save that cash for a bottom end buildup.

Your car is hella fast as is.

After you do a bottom end you can just swap a pully.

Gears would be nice but hell you have enough torque to make up for it against almost any car you run into aside from a Veryon (sp?).

If you want to spend some cash.. help me buy my S/C that you linked me to yesterday. :P

 

Well,

I'll help you with the Vortec install and you help me with the motor build! Bring the stogies!

 

I, too, love it when a car is trying to do a fly-by at warp speed on the highway. I nail it right when they're about on my rear bumper and don't let them pass.

A cool thing about my GT's automatic is that I have a 4,800 rpm stall converter. So, even though I'm running a centrifugal blower, any throttle tip in and I'm instantly at 4,800 rpm's and building boost right now - no lag, no waiting. And, on upshifts, rpm's never fall below 4,800 rpm's (unlike lifting for a shift with a manual trans or a steep drop in rpm's with a stock torque converter).

So, anyone with an automatic who installs a centrifugal or turbo should seriously consider a big stall converter to keep your rpm's right where your blower/turbo is most capable when your at wide open throttle.