Gears? 3.73 v. 3.55
#1
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Gears? 3.73 v. 3.55
Specing out a 8.8 and I either want 3.73 or 3.55 gear set. I daily drive my car and it would be nice to have the RPM alittle bit lower in 6th at 75mph. Been in a Cobra w/ 3.55 but much different power levels haha.
Will the change to 3.55 gears be noticeable considering i just have boltons? Always thought the rule of thumbs was that the more power you have, the taller the gearing you can get away with.
Anyone running anything different then 3.73?
Will the change to 3.55 gears be noticeable considering i just have boltons? Always thought the rule of thumbs was that the more power you have, the taller the gearing you can get away with.
Anyone running anything different then 3.73?
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If you plan on sticking with just bolt ons, I would say 3.73s are the best. If you want to go F/I, 3.55s is what I would do.
The only real difference you will notice is the better MPGs on the highway and a slightly more usable 1st and 2nd gear.
The only real difference you will notice is the better MPGs on the highway and a slightly more usable 1st and 2nd gear.
Last edited by ColeGraham; 05-08-2012 at 01:10 PM.
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Honestly... I wish at times my buddy would have stuck with 3.73's since its a daily but with that big 6th gear... It didnt make it much worse. I'm not interested in going with a 3.55. To each their own but I'd either stay 3.73 or go 4.10. I like having the torque happy gear to get the car moving quick down low.
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Those ratios are really close anyways. Not like you are going from a 3.73 to a 3.23 or 2.73. You can keep the 3.73 and go to a slightly taller tire next time to gain some driveability or go 3.55 with a shorter tire to keep performance.
I have always felt that 3.73s are a great gear for best of both
I have always felt that 3.73s are a great gear for best of both
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Specing out a 8.8 and I either want 3.73 or 3.55 gear set. I daily drive my car and it would be nice to have the RPM alittle bit lower in 6th at 75mph. Been in a Cobra w/ 3.55 but much different power levels haha.
Will the change to 3.55 gears be noticeable considering i just have boltons? Always thought the rule of thumbs was that the more power you have, the taller the gearing you can get away with.
Anyone running anything different then 3.73?
Will the change to 3.55 gears be noticeable considering i just have boltons? Always thought the rule of thumbs was that the more power you have, the taller the gearing you can get away with.
Anyone running anything different then 3.73?
=RPM/(Diff Ratio * Trans Gear Ratio) * Tire Diameter in inches *0.002975
Tire size on standard 18s on stock tire is 26.7, rear is 3.73, and trans ratio for 6th is 0.57
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My car cam'd with 4.10's still gets an average of 22mpg on the highway at 70-75. Old car got 24mpg at the speed so not a huge loss considering the big performance difference.
#11
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This is correct, but sixth gear is not the only one used. The 2.97 first gear ratio will feel a LOT different with 3.55's than with the stock 3.73's. I believe that 3.73 is the overall optimal diff ratio, just not with our trans.
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These guys hit the nail on the head...if you are going FI use the higher (lower numerically) gears such as 3.55 or 3.42. Boost needs a load to work against and the really short gear ratio's in our trans doesn't help any. Take a stroll through the FI section here and you will see quite a few people running 9's and 10's with 2.73 and 3.08 ratio's on boost.
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These guys hit the nail on the head...if you are going FI use the higher (lower numerically) gears such as 3.55 or 3.42. Boost needs a load to work against and the really short gear ratio's in our trans doesn't help any. Take a stroll through the FI section here and you will see quite a few people running 9's and 10's with 2.73 and 3.08 ratio's on boost.
This is correct, but sixth gear is not the only one used. The 2.97 first gear ratio will feel a LOT different with 3.55's than with the stock 3.73's. I believe that 3.73 is the overall optimal diff ratio, just not with our trans.
This is correct, but sixth gear is not the only one used. The 2.97 first gear ratio will feel a LOT different with 3.55's than with the stock 3.73's. I believe that 3.73 is the overall optimal diff ratio, just not with our trans.
#14
OP- 3.73 would be my choice out of the two options.
4.10 would be my ideal choice when using a T56 or T6060. - And yes, thats with power adders.
I dont agree. You cant categorize all types of FI into a group 'boost'. As mentioned, Centrifugal type. This would apply to Turbos more than other types of FI.
4.10 would be my ideal choice when using a T56 or T6060. - And yes, thats with power adders.
I dont agree. You cant categorize all types of FI into a group 'boost'. As mentioned, Centrifugal type. This would apply to Turbos more than other types of FI.
#16
I went with 3.89's combined with the Maggie... it's a rolling second gear burnoutfest. More tire is definitely required... but I must say... walking on new stock v's, blown Challengers, and holding up to elder 600cc motorcycles is really a LOOOOOT of fun.
#19