Gears ~ 3.55's or 3.73's? and a mph question...

88SaleenClone · Mar 18, 2007

Right now I'm running 2.73's....1st and 2nd gear are ok since the car is pretty fast with the mods it has. But 3rd gear is just way too long and 4th and 5th are real sluggish. I wouldn't be drag racing the car much if at all, so which is the better gear for everyday street use? I know they aren't much different though. Anyone know the max speeds in each gear (1-5 manual) using both 3.55's and/or 3.73's? How about what rpm is the engine turning at 65 mph with each gear?

myslo50 · Mar 18, 2007

i have 3.73 gears in mine and there a little too much for my combo right now. in usually shifting into 4 th around 85 mph. my motor is stock plus whetever my mods are in my sig. crusing on the highway its like around 2300 rpm.

if your motor maked power till like 6000 rpm, i would go 3.73. i shift at 5k cause thats all my motor has, any more the valves float. but sure is fun slamming gears.

i would run 3.73 and drag radials, that will slingshot out of the hole fast.

theres only like a couple hundred rpm diff between 3.73 @ 3.55 @65 mph

90mustangGT · Mar 18, 2007

There will only be about a 200rpm difference in 5th gear between the two ratios. But in the lower gears, it is a much bigger difference. 3.73 minimal if you ask me.

If I were to do it over again (which I might end up doing this) I would go 4.10+ but put a T-56 trans, it will cruise like a 3.55 gear in a 5 speed but break necks in the lower gears.

86bluecobra · Mar 18, 2007

3.73 all the way. Nicest gear with a t-5 IMO. at 65 mph in 4th your turning about 3100 rpm in fifth it is a little more then 2100rpm. That being if you are running a 26 inch tire in the rear.

jimdrechsler · Mar 18, 2007

I have had both, 3.73 and 3.55's. I have 3.55's in this car and at times I like having these gears so I can actually stay in first and second longer than a second at other times I wish I had 3.73's to have that little extra gain when racing on the street
im not even sure you can notice a huge difference with 1/4 mile times between the two. I know on the highway when I race and downshift, I can hit third and stay there for a while, where as if you have 3.73's, you may be able to hit third for only a quick second, then have to go to fourth.

SO, I don't have an answer for you... I guess I have been happy with both gears!
Good luck!

5spd GT · Mar 18, 2007

90mustangGT said:
There will only be about a 200rpm difference in 5th gear between the two ratios. But in the lower gears, it is a much bigger difference. 3.73 minimal if you ask me.

If I were to do it over again (which I might end up doing this) I would go 4.10+ but put a T-56 trans, it will cruise like a 3.55 gear in a 5 speed but break necks in the lower gears.

I looked at ddperformance.com for the difference in final gear ratios for the t56 and t5, and it was .62 for the t56 and .63 for the t5. Your not going to notice that difference.

90mustangGT · Mar 18, 2007

5spd GT said:
I looked at ddperformance.com for the difference in final gear ratios for the t56 and t5, and it was .62 for the t56 and .63 for the t5. Your not going to notice that difference.

my buddy has a t56 Camaro, with 4.11 gear he turns a little less rpm on the highway than I did with 3.73's.

Foxfan88 · Mar 18, 2007

i have 3.90s and went from a stock 3.35 t5 to a D&D 2.95 t5 that includes a higher OD and i noticed a NICE difference. with my 3.90s it turns right at 2k at 65.

and about the topic

either gear will be a night and day difference. if you like your gears to stretch out a little long get 3.55s, i rode in a nice 5.0 with them and the car had the perfect mix of easy driving with les shifting and still gave you the good sotp gain.

while it wont be much a difference. your car will want to spin the tires a little easier with the 3.73s. and will turn higher rpm on the highway and each gear will be a little shorter.

getting a set of gears will usually make 1st gear useless on the street. if your car is pretty much a pure street car u may want 3.55, if u dont care and go to the track alot get a lower gear.

lots of racers get LOW gears because they have slicks and will still be able to bite even with a lower gear.

blackened88lx · Mar 18, 2007

I would say it really depends on what you're doing. If you're at the track with slicks, I would want 4.10s. On the street, with 3.55s, 1st goes by VERY quick even with my stock motor. With some more power, 1st gear would be useless on the street.

5spd GT · Mar 18, 2007

90mustangGT said:
my buddy has a t56 Camaro, with 4.11 gear he turns a little less rpm on the highway than I did with 3.73's.

The camaro t56 has a .50 6th gear Jason. That might be why

86bluecobra · Mar 18, 2007

I still say get the 3.73's. You won't regret it at all. Even with my 3.35 1st gear i like the 3.73's.

MustangOwner · Mar 18, 2007

My neighbor is running 3:73's. He liked them alot before he put his blower on. Now that he installed his blower, he wishes he had installed 3:55's. Because 1st is useless with 3:73's. I personally am gonna install 3:55. As of right now i don't have a blower, but i will within this summer. And also i had to change the tail shafter gear in my transmission to make my speedo read right if i went with 3:73's. If i install 3:55 i only have to install the speedo gear! So i say 3:55's

88SaleenClone · Mar 19, 2007

Alright, thanks for all the input!

AP1995V6 · Mar 19, 2007

5spd GT said:
The camaro t56 has a .50 6th gear Jason. That might be why

Yep. GM's T-56 actually uses 6th gear as an over drive where as Ford's T-56 just gives your more gears to shift through. I guess it also really depends on your style of driving and set up to figure out which gear set you'd like.

So instead of hijacking the thread, I'll add my .02 about gears. If you end up going high power and sticking to street tires, I'd go 3.55. Otherwise, 3.73. I went 3.55 in my street car just for convenience for stop light to stop light driving. I wish I had actually gone smaller (originally had 2.73s as well) since I'm not 1/8 racing or anything in this car. If I add too much more hp goodies, I may end up wishing I never switched out the 2.73s

88SaleenClone · Mar 19, 2007

Ya, I've also thought about going to 3.08's or 3.27's. Anyone know the top speeds in each gear @ 6000 rpm for 3.08's?

jimdrechsler · Mar 19, 2007

91FoxSaleenGTLX said:
My neighbor is running 3:73's. He liked them alot before he put his blower on. Now that he installed his blower, he wishes he had installed 3:55's. Because 1st is useless with 3:73's. I personally am gonna install 3:55. As of right now i don't have a blower, but i will within this summer. And also i had to change the tail shafter gear in my transmission to make my speedo read right if i went with 3:73's. If i install 3:55 i only have to install the speedo gear! So i say 3:55's

i wonder if that is the same problem my speedo is off with the correct gear in there! it has always been off a few mph AFTER the change in gears!

Gears ~ 3.55's or 3.73's? and a mph question...

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