Am I better off getting gears installed at a Ford dealership then taking my car to the tuner shop for SCT and CAI install? I am getting the Auto trans that comes with the 3:15 then going to 3:73..How much time off the clock in 1/4 do u think? and how much of a change in mpg city/hwy?

 

I ran 12.82 @ 106 w/ 3.15's, CAI, and tune. I ran 12.21 @ 116 w/ 3.73's, CAI, and tune on 19" Pirelli PZero Nero all-seasons. I did not get my gears installed at the Ford dealership. They said since the 6R80 transmission didn't come with 3.73's they couldn't adjust the computer to compensate for it, so I went with an SCT tuner and tunes from Brenspeed.

 

I thought the auto ran a 12.8 in stock form? you dropped .6 just from gears? i figure .1 to .3 the most

 

Of course there's always more to the story, but I was sharing my numbers. The 12.82 was on a 95 degree day, 95% humidity, poor track prep, and 2.2 60' times. The 12.21 was a 65 degree day, decent track prep, and 1.9 60' times. It wasn't all gears, but that MPH sure was.

 

a couple of guys have taken their cars to the dealer to have different ratio gears installed and the dealers warned them that it would void the rear end's warranty.

some dealers I would imagine wouldn't have a problem with it but it's something you should be aware of that they may throw out at you.

Also, I'm a big advocate of upgrading the differential during the gear install process. The stock diff isn't doing you many favors under high speed turning and a good limited slip diff can really improve cornering traction.

I don't know if ford uses 28 or 31 spline axles in the GT's (I'm guessing 28) but I put an Auburn pro 28 spline differential into my 97 GT back in the day when I had the 4.10's installed and it made a MASSIVE difference at the track events. I took the car up to deal's gap the weekend after getting them installed and noticed a lot better traction and power to the wheels in all those tight hair pin turns.

The auburn pro I think was around $500 so for me, it was worth it. On the other hand, you could always order some forged 31 spline moser axles and get the Torsen diff that the laguna seca boss uses (but that **** thing is over a grand)....

Either way, having a better differential installed at this time would be a good idea because there would be no increase in cost of labor since the stock diff has to come out anyways to install the gears.

 

The current GT's come standard with 31-spline. I agree with your comment on the differential. I originally just had gears put in, but after several autocross events and a track day I realized that I needed more coming off the corners. I ended up putting an Eaton Posi in the car and couldn't be happier. Now I've had to get better tires to be able to put the power down. I've got new 285 Hankook R-S3's waiting to go on the car.

 

I just changed my gears in my 08 vert auto. Went to 373. I had a very good local tuner do the work and got two tunes, 91 and 93 octane. The car is supercharges also, whipple not inter cooled, I run 7 lbs boost.

On the dyno it came out 380 hp at the wheels. So far i LOVE the gears and so far my mileage has not suffered. But I just had it done. I think a good tuner is the route to go but talk with your service dealership and find out what they think. Mine is cool with anything I do, but I have had zero problems so I have not tested them. If you go with a tuner other changes will be easier (like X pipe) to do.

 

whats a fair price for gears and with the installation?

 

In my opinion, I'd personally buy the gears and the install kit and what not then take everything to your tuner and have them do the install. In the end, you'll save money because the tuner won't be buying the parts and marking them up, only charging for labor. Good luck with whatever you decide on.

 

My guy here locally does the install for $200, gears can be had for $150 or so and you are looking at $60-$70 in small parts and gear lube.

 

A local drive-train shop in the Detroit metro area is quoting $300 bucks for the labor + the cost of the gears. Out the door is $500 or a little less... this will give you a good yardstick to go by. Many dealers quote outrageous prices like a grand or so.

 

Agreed about the dealer statement. They enjoy taking advantage.