3:55 gears

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Gear installs cost way to much money out here. :(

I wouldn't put in 3.55s for the average amount of $700 installed here in the Seattle area. I'm going to have my 4.10s installed soon with 31 spline axles and have to bite the bullet.
 
codyGT said:
Why do all of the 4.10 lovers think that 3.27s suck so bad?

My 1991 GT had 2.73 w/5-speed only option was 3.08. One of my LT1's had 3.23 and another 2.73.

I myself would rather have 3.55 or 3.73 in my GT.

IMO 4.10 suck and make a nice car feel like junk. I have raced a GT w/4.10's and was unimpressed.

That is not really a good comparison. You need to look at the final drive ratio which is a combination of gearing and tire and wheel height. The older stangs used smaller tires and wheels which had the same affect of a different gear. So on a 1991 GT, a 3.08 might have been like a 3.55 on a new stang because of the difference in tire and wheel height.

Also, the motors are totally different. The later Mustangs are a bit weak down low and strong up high. 3.73 and 4.10's get the car into the power band quicker.

a 4.10 might be a good choice on a 2000 GT but a crappy choice on a 1996 Vette.
 
codyGT said:
You sure aren't moving quicker. You are reving out faster, that doesn't mean you are moving quicker.

How does that make any sense? If two cars are equal in everything but gearing, the one with shorter gears will accelerate faster. It's not rocket science.
 
Well that might be true to a point. But just because you are going through gears like a mad man doesn't mean that the car with 4.10 will be faster.

It's the same reason my SS will kill a Mach1, it's even right off the line but I can run my gears out longer and pull hard.

The soulution to everything isn't 4.10's.
 
codyGT said:
Well that might be true to a point. But just because you are going through gears like a mad man doesn't mean that the car with 4.10 will be faster.

It's the same reason my SS will kill a Mach1, it's even right off the line but I can run my gears out longer and pull hard.

The soulution to everything isn't 4.10's.

Those are two completely different cars. And stick 4.10s on the Mach and you wouldn't be killing it. It's a proven fact that our cars, stock, are great with 4.10s.
 
codyGT said:
Well that might be true to a point. But just because you are going through gears like a mad man doesn't mean that the car with 4.10 will be faster.

Yep. The instantaneous acceleration will be faster, sure, but the speed at the shift will be lower. Bottom line is that gears do not produce more wheel HP, the parameter that makes a car fast when legging it out over the long run, like a quarter mile dash. Gears can be used to dig a car out of the hole better, better match to a particular engine or to give a certain "feel" (i.e. more "oomph" across an intersection) but because they're not helping power output at all, they don't end up making a car faster in the long run.

Personally, I think the low-RPM torque challenged 4.6 could use a shorter gear. I plan on 3.73s to help it around town. 3.55 just don't really seem to be worth the considerable cost and effort to put them in. I'd say eBay them and buy some 3.73 or 4.10 cogs.
 
Rear-end gears are the final reduction ratio from the transmission output to the wheel axles. Just like on a bicycle, the final ratio determines how many pedals (RPM) your engine must turn to make one rotation of the tires. This is pure physics - you can do more work (move the car) with less effort (torque) with a higher ratio, and that means better acceleration. A typical final ratio of 3.27:1 means that it takes 3.27 revolutions of the drive-shaft to make one revolution of the wheels. Its easy to see that if we're relying on the engine to make 1 revolution of the tire with 3.27 revolutions of the engine, it should be able to do it faster with say 3.55 revolutions, or 3.73, or even 4.10. Numerically higher gears won't give you more power, but they will improve the way your Mustang uses what it has. The flip-side of the coin is lower top speed, but unless you cruise at 80+ mph a reasonable gear swap won't affect your regular commute.
 
Why do you think the guy had the 3.55's changed? I went to 3.73's since I run allot highway for outside sales work in my car. I like them very much. It runs so much better around town. Your 4 valve needs to be in the higher rpms to run in its sweet spot anyway. You could go 3.90's for a compromise. Motive are said to be good gears with this ratio. FFRP doe not have them.

If you do an o/r x or h midpipe, pulleys, K&N you will get better mpg. This is no bull. I was getting an average of 3mpg better with these mods. I lost 1 mpg after going from the 3.08's to the 3.73's. Now I get an average of 20 mpg. Your 4 valve motor is supposed to do better than my 2v, especially mine having an Automatic.

In Kansas City I had mine installed for 200.00. I think you aught to drive out and have them installed here. Even with the drive you would save 300.00?