Let's talk rear ends
6/2/10, 08:43 PM
#1
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Let's talk rear ends
ALright I'm talking about the rear end in our cars!! 
Has anybody here went from a 3:55 gear to a 3:73? If so what do you think?
Thanks
Has anybody here went from a 3:55 gear to a 3:73? If so what do you think?Thanks
6/3/10, 10:45 AM
#3
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Its only about a 5% change. If you dialing in some specific performance goal it would be worth it. If my GT came with the 3.55s, I would not have changed to the 3.73s. Having done so, I am happy with them.
6/3/10, 11:32 AM
#4
Cobra Member
4.10's FTW! It does humm a bit at highway speeds though.
I have a cool gearing spreadsheet where you can play with tire size, rear end ratio, trans ratios to see speed in gear, at redline, etc. Someone else created it, I just added peak hp & tq lines to the graph. If you'd like it, send me your email via pm. (It's an excel file that does not work in my website host)
I have a cool gearing spreadsheet where you can play with tire size, rear end ratio, trans ratios to see speed in gear, at redline, etc. Someone else created it, I just added peak hp & tq lines to the graph. If you'd like it, send me your email via pm. (It's an excel file that does not work in my website host)
Last edited by Shotokan1509; 6/3/10 at 12:36 PM.
6/3/10, 12:44 PM
#5
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Thanks for the info, I jumped over to the GT Mods forum as advised and read alot about it. Looks as if most everybody goes with the 4.10. I've had my car for just alittle over two years and had it on the freeway maybe 3 times. Just a play toy, it has 2100 miles on it so that tells ya something. I just dont want it to wear you can't drive it normal, like I said I just play from time to time. From 3.55 to 3.73 I'm sure I would see a slight differance but I know I would see a big differance to a 4.10????? What to do???
6/3/10, 01:43 PM
#6
Mach 1 Member
I'd hesitate to say "most everybody" goes with 4.10s. Pretty clear that those who go with 4.10s are likely to say so. Cognitive dissonance? Look at the terminal RPMs in a quarter-mile race; which gear will you be in at that point? If you plot it for peak HP in fourth or fifth gear, you can go to some pretty extreme ratios, but the car will no longer be a useful street car.
I went from 3.31 to 3.73, and for daily plus a kick-in-the-pants it works well. If I'd started with 3.55, I's still be there. With 3.73s first gear is very short in street driving; second-gear starts from a standstill aren't that bad.
I can't imagine using first gear with 4.10s. Maybe when I look at Shotokan's chart I'll see the difference between 4.10's second gear and "normal" first is pretty small. Wouldn't that mean the whole higher-numerical exercise has just moved everything down the scale and eliminated the advantage of top gear for cruising? At a certain point you'll wish you had 10,000 RPM to work with. Then you start to hear rice-a-poppin'.
In the end it all comes down to what you want do do with your car. I have owned race cars that were useless on the street, and I eventually sold them on because they were only in use one or two or (seldom) three weekends a month. Big investment sitting in the garage just made me feel like I was wasting it. These days I like the idea that the cars I have now are ready for a quick cruise or a long trip: just turn the key and go. With 4.10s I believe I'd have to think a bit before the second choice.
I went from 3.31 to 3.73, and for daily plus a kick-in-the-pants it works well. If I'd started with 3.55, I's still be there. With 3.73s first gear is very short in street driving; second-gear starts from a standstill aren't that bad.
I can't imagine using first gear with 4.10s. Maybe when I look at Shotokan's chart I'll see the difference between 4.10's second gear and "normal" first is pretty small. Wouldn't that mean the whole higher-numerical exercise has just moved everything down the scale and eliminated the advantage of top gear for cruising? At a certain point you'll wish you had 10,000 RPM to work with. Then you start to hear rice-a-poppin'.
In the end it all comes down to what you want do do with your car. I have owned race cars that were useless on the street, and I eventually sold them on because they were only in use one or two or (seldom) three weekends a month. Big investment sitting in the garage just made me feel like I was wasting it. These days I like the idea that the cars I have now are ready for a quick cruise or a long trip: just turn the key and go. With 4.10s I believe I'd have to think a bit before the second choice.
6/3/10, 03:05 PM
#7
Cobra Member
I'd hesitate to say "most everybody" goes with 4.10s. Pretty clear that those who go with 4.10s are likely to say so. Cognitive dissonance? Look at the terminal RPMs in a quarter-mile race; which gear will you be in at that point? If you plot it for peak HP in fourth or fifth gear, you can go to some pretty extreme ratios, but the car will no longer be a useful street car.
I went from 3.31 to 3.73, and for daily plus a kick-in-the-pants it works well. If I'd started with 3.55, I's still be there. With 3.73s first gear is very short in street driving; second-gear starts from a standstill aren't that bad.
I can't imagine using first gear with 4.10s. Maybe when I look at Shotokan's chart I'll see the difference between 4.10's second gear and "normal" first is pretty small. Wouldn't that mean the whole higher-numerical exercise has just moved everything down the scale and eliminated the advantage of top gear for cruising? At a certain point you'll wish you had 10,000 RPM to work with. Then you start to hear rice-a-poppin'.
In the end it all comes down to what you want do do with your car. I have owned race cars that were useless on the street, and I eventually sold them on because they were only in use one or two or (seldom) three weekends a month. Big investment sitting in the garage just made me feel like I was wasting it. These days I like the idea that the cars I have now are ready for a quick cruise or a long trip: just turn the key and go. With 4.10s I believe I'd have to think a bit before the second choice.
I went from 3.31 to 3.73, and for daily plus a kick-in-the-pants it works well. If I'd started with 3.55, I's still be there. With 3.73s first gear is very short in street driving; second-gear starts from a standstill aren't that bad.
I can't imagine using first gear with 4.10s. Maybe when I look at Shotokan's chart I'll see the difference between 4.10's second gear and "normal" first is pretty small. Wouldn't that mean the whole higher-numerical exercise has just moved everything down the scale and eliminated the advantage of top gear for cruising? At a certain point you'll wish you had 10,000 RPM to work with. Then you start to hear rice-a-poppin'.
In the end it all comes down to what you want do do with your car. I have owned race cars that were useless on the street, and I eventually sold them on because they were only in use one or two or (seldom) three weekends a month. Big investment sitting in the garage just made me feel like I was wasting it. These days I like the idea that the cars I have now are ready for a quick cruise or a long trip: just turn the key and go. With 4.10s I believe I'd have to think a bit before the second choice.
6/4/10, 08:37 AM
#8
Bullitt Member
My car came with 3.55's and I'm happy with them. If you ever plan on driving on a freeway you might regret the 4.10 gears. But, since you obviously don't drive it much and if you plan on taking it to the strip then 4.10's should be OK.
6/13/10, 12:45 PM
#10
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I think the 3.73's in the 5 spd are perfect. Both for pullin' 1/4 mile stuff (don't have to shift into 4th), nails 100+ in 3rd; and especially for two lane twisties.
Most 2 lanes I play on I'm in 2nd with revs from 5-6k into and thru the curve and I can hit 65mph without shifting. With 4.10's I'd be forced to shift or hold speed. If its tight switchbacks I'm decelling in 2nd prepping for the next curve. For wide curves I can use 3rd and stay there and play from about 4k and pull up in the straights.
For freeway driving I'm throttled down nice and quiet.
I would not start out in 2nd, but with 4.10's I might.
No 4.10's for my variety of driving. IMO
Most 2 lanes I play on I'm in 2nd with revs from 5-6k into and thru the curve and I can hit 65mph without shifting. With 4.10's I'd be forced to shift or hold speed. If its tight switchbacks I'm decelling in 2nd prepping for the next curve. For wide curves I can use 3rd and stay there and play from about 4k and pull up in the straights.
For freeway driving I'm throttled down nice and quiet.
I would not start out in 2nd, but with 4.10's I might.
No 4.10's for my variety of driving. IMO
Last edited by cdynaco; 6/13/10 at 12:46 PM.
6/15/10, 05:03 PM
#11
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I wouldn't go with 4.10's. As much as I use my car both on the highway and in the city, the gas consumption would kill me. 3.90's are as far as i'm willing to push it.
6/15/10, 09:21 PM
#12
Team Mustang Source
Went from 3:55 to 3:73 and didn't notice any difference. Went from the 3:55 to the 4:10 and found exactly what I was looking for. My gas mileage only suffers because I like stomping on the gas pedal now!
6/17/10, 08:36 AM
#13
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Thats what I'm thinking too, from 3:55 to 3:73 I prolly wouldnt notice.. thanks for the input.
6/19/10, 09:13 PM
#14
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Went from 3.31's to 4.10's. These cars should have left the factory with this gearing. Around town, the ability to cruise around in 5th is very nice. On the highway cruising at 80mph gives an rpm of right about about 2700 rpm. On slower freeways the lower gears also push the cruising rpm above the 1500rpm drone point these cars are prone to with aftermarket exhaust.
The best part? With the 4.10's and addition of the charge motion delete plates, the car cut about 5 tenths off the quarter mile time. 5th is also incredibly useable on the freeway. No downshifting to 4th to try and get around a big rig.
The best part? With the 4.10's and addition of the charge motion delete plates, the car cut about 5 tenths off the quarter mile time. 5th is also incredibly useable on the freeway. No downshifting to 4th to try and get around a big rig.
6/21/10, 09:26 PM
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6/22/10, 12:48 PM
#18
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Besides you wouldn't be racing in 5th anyhow. With the stock size tires and reving the engine just past 6000 rpm still gives you a maximum attainable speed in 4th gear of right at 120mph. Do you really need to be going any faster than this on the street? Not to mention, if you haven't already beaten said "punk kid" by this speed, you need more mods, or simply to stop racing.
6/25/10, 11:46 PM
#20
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I went from 3:55 to 3:73's driven through a TruTrac diff. I noticed more torque in 4th gear. I still retain a good top end and it seems slightly better power band overall. 3:55 to 3:73 is not earth shattering vs the difference you feel from 3:55 to 4:10's. But I like my current drive-ability, rpm range and fuel economy. 