Gear ratios

Chris951 · #1 (**permalink**) 12-18-2008, 02:49 AM

For drag racing auto is where it's at. Manual is fun but sometimes I wish I had an auto for daily driving. A fox body 5 speed mustang with 4.10 gears is rediculous. I hate my gears. I should have got 3.73s. My 1st gear lasts me like 10 feet then I shift to 2nd. It's rediculous for real

apolloGT · #2 (**permalink**) 12-18-2008, 07:32 PM

Quote:

Originally Posted by Chris951

For drag racing auto is where it's at. Manual is fun but sometimes I wish I had an auto for daily driving. A fox body 5 speed mustang with 4.10 gears is rediculous. I hate my gears. I should have got 3.73s. My 1st gear lasts me like 10 feet then I shift to 2nd. It's rediculous for real

haha, yeah I'm going with 3.73s because I'm planning on a kb blower. 4.10s probably work better on modular 4.6 engines, because ours weigh more.

Chris951 · #3 (**permalink**) 12-18-2008, 09:07 PM

Quote:

Originally Posted by apolloGT

haha, yeah I'm going with 3.73s because I'm planning on a kb blower. 4.10s probably work better on modular 4.6 engines, because ours weigh more.

4.10's are better for mod motors because they like the revs and the 4.10's keep the engine in the powerband.

apolloGT · #4 (**permalink**) 12-18-2008, 10:42 PM

Quote:

Originally Posted by Chris951

4.10's are better for mod motors because they like the revs and the 4.10's keep the engine in the powerband.

I'd heard it both ways, but they say with forced induction you'll get way too much spin with 4.10s. Ford Racing recommends 3.73s, as well as many gets with a 4.6 supercharged setup.

I'd definitely go with 4.10s if I was gonna get cams, injectors, etc.. you know.. stay n/a

kendallcschm · #5 (**permalink**) 12-19-2008, 06:51 AM

why are 4.10's better for a mod engine? more torque?

apolloGT · #6 (**permalink**) 12-19-2008, 11:00 AM

Quote:

Originally Posted by kendallcschm

why are 4.10's better for a mod engine? more torque?

They're better IMO if you're not getting a turbo or supercharger. The higher you're rear end gear ratio, the better your jump off the line. That's why guys with 4.10s and good launch capabilities can sometimes jump vettes off the line (here's a tip: unless you have a cobra, GT500, or ridiculous GT, I don't recommend roll racing a new Corvette).

3.73s are better for forced induction because you won't get as much wheel spin, but you still get that nice bite on the line (which, with a s/c you'll be gaining speed like a freight train.. with a turbo you'd have a nice balance)

kendallcschm · #7 (**permalink**) 12-19-2008, 12:41 PM

i see... so as a temp thing before a supercharger i could do 4.10's and when i got foce induction i would change to 3.73's because they give you the same off line jump but with less wheel spin? so am i right on this?

apolloGT · #8 (**permalink**) 12-19-2008, 01:02 PM

Quote:

Originally Posted by kendallcschm

i see... so as a temp thing before a supercharger i could do 4.10's and when i got foce induction i would change to 3.73's because they give you the same off line jump but with less wheel spin? so am i right on this?

yes.. I thought of that too.. but rear gear installation is extremely complicated, and you essentially have to disassemble the whole rear of the car. If I could do it, I probably would, given that gears are about $170... but with installation costs it goes up to about $600. I'm just gonna get 3.73s soon anyways, because you can still tell the difference from stock.

Chris951 · #9 (**permalink**) 12-19-2008, 01:32 PM

did you not read my post?

kendallcschm · #10 (**permalink**) 12-19-2008, 09:25 PM

yes i did read your post.... and wow... thats alot of work

ShelbyCobra2007 · #11 (**permalink**) 12-19-2008, 09:58 PM

My Mach 1 has a 3:55 gear, its pretty bad ass, it luanches so well, and accelerates 0-70 faster than the 530 rwhp Shelby with a 3:31, or at least it seems it does. I know a lot of people who went with the 3.73, i would reconmend it, though its not popular and a little lower, the 3:55 also seems great

MY69GOAT · #12 (**permalink**) 12-19-2008, 10:58 PM

With all this talk of swapping ring and pinion setups I thought it best to note that if you have not done this before, please seek the help of an experienced professional. The proper shimming needs to be done as well as dealing with the compression bushing. Skimping on any of this will cause the rear to be miss adjusted and problems will ensue. Don't let anyone fool you either. That meshing sound is not due to close tolerances. It's the sound made when your rear end is eating itself.

apolloGT · #13 (**permalink**) 12-19-2008, 11:40 PM

Quote:

Originally Posted by MY69GOAT

With all this talk of swapping ring and pinion setups I thought it best to note that if you have not done this before, please seek the help of an experienced professional. The proper shimming needs to be done as well as dealing with the compression bushing. Skimping on any of this will cause the rear to be miss adjusted and problems will ensue. Don't let anyone fool you either. That meshing sound is not due to close tolerances. It's the sound made when your rear end is eating itself.

Yeah I'm having mine done by P and J Speed Shop. They're local, but nationally known. They've been in a number of magazines.

P and J Speed Shop

apolloGT · #14 (**permalink**) 12-19-2008, 11:43 PM

Quote:

Originally Posted by ShelbyCobra2007

My Mach 1 has a 3:55 gear, its pretty bad ass, it luanches so well, and accelerates 0-70 faster than the 530 rwhp Shelby with a 3:31, or at least it seems it does. I know a lot of people who went with the 3.73, i would reconmend it, though its not popular and a little lower, the 3:55 also seems great

Yeah I've heard a few people rave about 3.90s as well. The Mach 1 is also a 4V and more powerful.. hence the goodies inside can handle more hp as well. I really wanna squeak every last hp out of my 2V... and I think the 3.73s would compliment that with a nice bite off the line.

Also, a good set of wide rear tires is a must for a good launch in a powerful car. I really wanna slap some 285s on the back.

Chris951 · #15 (**permalink**) 12-20-2008, 12:21 AM

315's or go home son. I'm puttin some 275s on my 10 holes haha. I'm trying to look for some welds or some widened pony rims so I can go with some meatier tires