thewarmachine

Get the 3.73 unless you like pulling stumps.

4.10 = useless 1st gear
4.10 = 2,450rpm in 5th at 70mph

I do like my 4.10 gears, but 3.73 would have been more optimal.

Obviously, some people on here who cry out "Don't fear the gear" are fearing some gear themselves.... Anyone got 4.56? ;-)

baddog671

My father has a 50´s Ford van that was used in excuvating to hual equipment and sometimes stone. 17 blade leafsprings per side, and the rear end is either 4.56 or 5.x6, cant remember. It´s a straight 6, weighs a shtload, and will pull wheelies

pigman 440

I hadn't heard any feedback about 3.90s being noisy. Should be no reason for any ratio to be noisy unless the install clearances weren't right?? Another post mentioned 3.90s were crappy ,did you mean in your personal install or generally. I went with the 3.90s because of the 19" wheels which should end up similar to 3.73s on 18" or fairly close. Will give feedback when they are in and had a chance to test the car. Previous drag cars (stock bodied) I have run gears as low as 5.38 for the 1/8th mile tracks. Basically I want a gear that may result in one less gear change in the quarter and still not be past peak HP RPMs at the end.

jdmcbride

Wheel size has nothing to do with the ratio. The overall diameter of the tire is what you should be concerned with.

For example:
255/45/18 on 18 x 8.5 wheel = 27" diameter with a 4.5" sidewall <--- Same diamater
255/40/19 on 19 x 9.0 wheel = 27" diameter with a 4.0" sidewall <--- Same diameter

Your logic only applies if you keep the same sidewall height of the tire thus increasing the overall diameter:
255/45/19 on 19 x 9.0 wheel = 28.1" diameter with a 4.5" sidewall <--- Larger overall diameter
... but most people go with a lower profile tire when increasing wheel size.

HTH

2011Black5.0

i think it has to do with the quality of the gears and how hard they are to install. This shop around me wont do 3.90s, I took it to another and he f'ed it up and it was whining really bad. Almost howling. It gets really annoying really fast for a DD

cstretten

Not to hijack the thread, but when I read this I checked out the online build & price and I can't select both automatic and 3.73 gears... it seems it's set up (at least online) for manual transmission only. Nor can I select the "performance brake" upgrade unless manual.

By the way, this is for the Canada site (ford.ca)

Can one simply override when ordering their car from the dealer?

Cheers!

jdmcbride

There is no need for 3.73 gears or the "performance brake" package if you are purchasing an automatic IMO (Hell, I think the 3.73 gears makes 1st gear useless with the manual 6-speed - I suggest 3.55s for the 2011 GT manual.).

Gearing for 1st gear in the new 6-speed auto is a lot lower than last year's 1st gear and should be enough with the 3.15s. The Brembo brakes are more for autox IMO where an automatic will usually perform poorly.

Sorry, you can't override this - even at the dealer.

SirKnightTG

You're doing it wrong.

JasperGT

I have 4.10s installed in my car. I am currently in need of new gears, because I busted them at the track. I talked to my installer about getting 4.30s installed, and here's what he told me.

The gears that are labeled as FRPP gears actually come from different vendors. The Motive gears have a softer surface than other gears that are also labeled as FRPP gears. The FRPP gears with the harder surface do not come in the 3.90, 4.30, and 4.56 varieties. He would have no problem installing them and giving me the car back with no initial gear whine, but once I drove off, he would not guarantee that I would continue to have no whine. The other gear ratios (with non-Motive part numbers) on the other hand, he will guarantee since he knows from experience that any gear whine from these gears would be a result of poor installation.

So it looks like it's 4.10s FTW! They are a minimum IMO if you have cams like my stage II comp cams.