Ford's official answer to what gears you should put in your car

[HighMileage]

I would bet all SOHC and DOHC do better with 4.10, but nothing less. Their torque is all way up.

 

[Hissing Cobra]

What you guys fail to mention is torque vs. high rpm horsepower. This is a major difference in gear choices. The reason I run 4.30's is because I only make 279 ft. lbs. of torque on the dyno. I NEED the 4.30's to get it out of the hole and run my 12.70-12.80 timeslips.

I have seen other H/C/I cars make 320 ft.lbs. of torque at the wheels and they don't need the gears that I do. Why? Because they have the engine's torque to get it out of the hole. Many of these cars run 12.80's as well. Who's to say who'd get to 110 first?

I can rev mine to 6,800 rpms to make up the difference at the other end of the track while the other cars are usually shifting at 5,800. Many times, I'll get beat coming out of the hole but I'll catch 'em at the top end of the track.

If I put 3.73's or 4.10's in mine, I'd go through the traps at a much lower RPM. This would sacrifice power on the top end thus slowing me down.

Ideally, you want to select a gear ratio that would put you at the rpm where you make peak power while you're going through the traps.

 

[5spd GT]

Hissing Cobra - That is talking "track talk" by picking a gear to put you at an optimum rpm at a marked off distance. I choose not to pick a gear by that. I choose to pick a overall gear. Not a gear I deal with everyday in 99% non-trapping scenarios.

Is your car 100% daily driver? Do you have another option? Just curious...

Just remember the "out of the hole" time is literally less than a second in most cases. The next 11-14 seconds of the race are spent in the higher rpm band. The out of the hole deal does help me select an optimum gear. I pick more overall.

 

[Hissing Cobra]

Right. Most of the people on this board want to go fast. They also want to do it in a quarter of a mile, not a 10 mile race. Who really cares who's faster on the highway from 80-100? Not me, not when the tickets around here cost $400.00 for one at 100 miles per hour, plus the possible losing of your license for 90 days.

My car is not a daily driver, but you know what? I drive it everyday that it's nice out. Usually I'll drive it 20 minutes to work 2-3 days per week, 2 to 3 cruise nights during the week, and a Sunday show that's 45 minutes away. I also drive it to Connecticut (2 hour ride-one way) 2 to 3 times each summer for car shows. I also drive it 2.5 hours (one way) to Epping, New Hampshire and beat it going down the track. Then I'll drive it home (3 times last summer.) Though I don't "rely" on it daily, it gets more mileage than my daily driver (except in the winter.)

 

[Grn92LX]

Hissing, what transmission do you have? How high do you rev on the highway at like 70mph with 4.30's? I wanna do my rear up down the road. I know my car would love a 4.30, I feel a 4.10 is the better choice. I have 3.73's now that aren't enough for my new combo i'm building + they hum so they gotta go anyway.

How much rpm would going from a 25.5" tire to a 26" drop the rpm on the highway? Just curious.

 

[Hissing Cobra]

I've got a Tremec 3550. I'm not too sure what it's revving at during 70 mph driving. I'd guess that it would be at 2,400-2,600? I know that it's 3,000 at 80 mph. I don't really notice it too much. I usually stay in the left lane and cruise with everyone else. I do notice that it's between 2k-3k during regular highway cruising. My speedometer is off about 10 mph because of the gears (Ford doesn't make a tranny gear for the 4.30's. So, I've got the one for the 4.10's as that was the closest.) We did the math and that's how we calculated 3k @ 80.

As for the tire sizes, I can't help you there. I would guess that it would be close to 200 rpm?

 

[willys1]

That is a possibility but it isn't set in stone because it depends on mods...because one gear may not allow a shift and another gear will shift (which equals more time taken up) instead of power put to the ground.

Just to many variables to say 373's are faster from 80-100mph no matter what.

I got a trans-go shift kit Im not losing any time,not like you 5-6 spd guys

 

[5spd GT]

I got a trans-go shift kit Im not losing any time,not like you 5-6 spd guys

Well your losing somesort of time with the shift...but hey we have less drivetrain loss

 

[88 Fox GT]

How hard is it to drive a 5-speed with 3.55 gears in the snow? Also, how much of a fuel mileage decrease have you guys noticed when swapping out gears? I'm suffering with 2.73s right now.

 

[stang22]

How hard is it to drive a 5-speed with 3.55 gears in the snow? (

Mustang were not made to drive in the snow. I am not saying you can't, but that would really suck. Do you start off in 2nd or 3rd?

Tim

 

[willys1]

Well your losing somesort of time with the shift...but hey we have less drivetrain loss

Yeah,but theres nothing like a high speed stall

 

[willys1]

How hard is it to drive a 5-speed with 3.55 gears in the snow? Also, how much of a fuel mileage decrease have you guys noticed when swapping out gears? I'm suffering with 2.73s right now.

Like stang22 said there not made for the snow,not even an inch Going from 273's to 355's? "Maybe" 1 or 2 mpg,if that!!! I got caught in our first snow fall last year on my way home from somewhere,I still had my Nitto DR's on,it was quite interesting

 

[89MustangGX]

How hard is it to drive a 5-speed with 3.55 gears in the snow? Also, how much of a fuel mileage decrease have you guys noticed when swapping out gears? I'm suffering with 2.73s right now.

I drove my first Mustang w/ 3.73's all year round (in snowy Connecticut) for years. It's all a matter of patience and experience.

As for fuel mileage -- I have actually seen an increase before, depends on how you drive.

 

[5spd GT]

Yeah some increases have been shown from 273's to a gear like 3:55's. On the highway for example you do not need as much foot on the gas because of the cruising rpms. Your car will have better "sustaining" power at a higher rpm that the 3:55's give you rather than the 273's at 60mph for example. More effiecient.

As for the snow...I drove my car for a couple days when the roads were quite literally 95% ice. It did fine. One time I decided to have a little fun (back in January) during that icestorm and well I ended up in the ditch Needless to say I was a bit late for work. It actually isn't to bad IMO. If you live in the "winter zones" you need to be prepared for that with different tires/spikes/chains/etc.

 

[Stang89LXCPE]

my old 86 GT went through about 4 winters. I usually had about 3 sand tubes in the back. Surprising it wasn't that bad, and actually drove better in the snow when it was still an auto. With the stick it didn't matter what gear I started in, with 300+ ft lbs, it will spin regardless!.

In that car, I had 3.27's and had an increase in fuel milage! I didn't drive it easy either!

 

[88 Fox GT]

Oh, I wouldn't drive it in the snow without some weight in the hatch! Thanks for the info on the fuel mileage and snow though. I really need gears for this car, even if it is the daily driver!