Mustang Gears
12-26-2007, 06:14 AM
#5
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
RE: Mustang Gears
I'm guessing that he got a couple of the numbers switched around here and there and wants to know about the FRPP 3.73's vs the base OE 3.31's.
Arendii - there is no such thing as 'better' as far as gears are concerneduntil you say something about what you want them to do.
3.73's can be expected to give you better acceleration than 3.31's as long as everything else about the car stays the same.
3.31's will give lower rpm at any given road speed and will give at least better highway fuel economy than 3.73's, again assuming that nothing else about the car is changed.
Better top speed could go either way.
I don't know for sure whether the 3.73's are physically stronger than the 3.31's, but I wouldn't be surprised if they were (something about pinion tooth count).
Norm
Arendii - there is no such thing as 'better' as far as gears are concerneduntil you say something about what you want them to do.
3.73's can be expected to give you better acceleration than 3.31's as long as everything else about the car stays the same.
3.31's will give lower rpm at any given road speed and will give at least better highway fuel economy than 3.73's, again assuming that nothing else about the car is changed.
Better top speed could go either way.
I don't know for sure whether the 3.73's are physically stronger than the 3.31's, but I wouldn't be surprised if they were (something about pinion tooth count).
Norm
12-26-2007, 08:39 AM
#7
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
RE: Mustang Gears
You cannot assume that you'll pull the same revs in 5th with those two different gears. You won't pull redline in 5th with either.
But you will pull higher revs in 5th gear with the 4.10's (guessing maybe 5500-ish) than you can with the 3.55's (4700-ish?). Whether you'll pull enough more revs with the 4.10's to end up with a higher road speed than you'd get with 3.55's cannot be determined without an engine torque curve or horsepower plot, but it's at least possible.
Actually, it's also possible that with something like 2.93's or 3.00's that you could have a higher top speed than with either 3.55's or 4.10's. But you'd have to be in 4th gear (5th gear would quit on you at a lower speed).
BTW, feel free to use the default font size. Even these old eyes cope with it just fine.
Norm
But you will pull higher revs in 5th gear with the 4.10's (guessing maybe 5500-ish) than you can with the 3.55's (4700-ish?). Whether you'll pull enough more revs with the 4.10's to end up with a higher road speed than you'd get with 3.55's cannot be determined without an engine torque curve or horsepower plot, but it's at least possible.
Actually, it's also possible that with something like 2.93's or 3.00's that you could have a higher top speed than with either 3.55's or 4.10's. But you'd have to be in 4th gear (5th gear would quit on you at a lower speed).
BTW, feel free to use the default font size. Even these old eyes cope with it just fine.
Norm
12-26-2007, 08:41 AM
#8
RE: Mustang Gears
Can you please make your font size small, it's kinda annoying.
Thank you.
Shortgears such as 3.73, 3.90, 4.10, 4.30; will make your gears shorter. Your engine will be in its powerband more of the time, and you will accelerate harder, you will also be shifting alot more, and at highway speeds your engine will be revving more so you will lose a little bit of fuel economy.
Tall gears such as 3.55, 3.31; will make your gears longer. You won't have to shift as often and you will have better highway fuel economy.
Here's an example, with 4.10 or 4.30 in a quarter mile race you'll need to shift all the way to 4th or even 5th gear. With 3.31 (maybe 3.55 too, not sure) you can do a 1/4 mile pass without shifting into 4th gear.
Thank you.
Shortgears such as 3.73, 3.90, 4.10, 4.30; will make your gears shorter. Your engine will be in its powerband more of the time, and you will accelerate harder, you will also be shifting alot more, and at highway speeds your engine will be revving more so you will lose a little bit of fuel economy.
Tall gears such as 3.55, 3.31; will make your gears longer. You won't have to shift as often and you will have better highway fuel economy.
Here's an example, with 4.10 or 4.30 in a quarter mile race you'll need to shift all the way to 4th or even 5th gear. With 3.31 (maybe 3.55 too, not sure) you can do a 1/4 mile pass without shifting into 4th gear.
