Gears & Axles - 04 c5z T56 what gears 3.73s or 3.90s ?

car - 04 C5 Z
cam - comp XE R 236 238 .601 .605 112+4 LSA

this will be a street car only will never see the track...

going to have T56 and REAR END rebuilt by RPM or TICK to a level 5...

questions...

1) 27 spline or should i go with a 30 spline output shaft ?

2) what gears 3.73s or 3.90s ?


thanks fellas,

Jay

390 man, that thing is gonna want to sing

For starters there is no good reason to fuck with this shit and never go to the track. It's just dumb not to want to measure your performance in the real world.

If you have full bolt-ons and a that cam your probably gonna need 3.73's. With everything right you could trapp 130+. I have 3.90's with a bolt-on ls6. I've trapped as high as 130 and I don't think it could go much faster. I really don't think 3.73's would hurt me any. I run a faceplated t-56 with stock inputs + outputs and everything else inside.

What kind of mid-range power do you have? What rpm do you turn it? How tall is your tire?

For starters there is no good reason to fuck with this shit and never go to the track. It's just dumb not to want to measure your performance in the real world.

If you have full bolt-ons and a that cam your probably gonna need 3.73's. I have 3.90's with a bolt-on ls6. I've trapped as high as 130 and I don't think it could go much faster. I really don't think 3.73's would hurt me any. I run a faceplated t-56 with stock inputs + outputs and everything else inside.

What kind of mid-range power do you have? What rpm do you turn it?

as soon as i can get a chance i can try to post my dyno graph , car made 433 RWHP 400 RWTQ

its got LG longtubes catless pipes and a vararam thats it,

i spin to 6500 even though the rev limiter is set higher, and i was just thinking of doing gears since i am having the trans done at the same time, i asked about the output shaft because a friend recommended to go with a 30 spline,

so should i go 3.73s or 3.90s,

like i said no track just a street car, will only be a cam/head/intake, car maybe a little(150 shot) nitrous later ,,

If your gonna hit it with nitrous then definetly 3.73. You would be out of gear or throwing 5th before ya know it. If you ever were to take it to the track you would not make it to the trapps spraying it before you maxed rpm.

If your gonna hit it with nitrous then definetly 3.73. You would be out of gear or throwing 5th before ya know it. If you ever were to take it to the track you would not make it to the trapps spraying it before you maxed rpm.

now that you have me thinking i will take it to the track just to see what it does but that will be after i have the rear end and trans finished,

like i said H/C/I/E and nitrous 150 shot at the most, but i will rarely use the nitrous,

so what gears so i dont max out before the traps, what would be the difference between my stock 3.42s to the 3.73s, is it a big difference

Goin from 3.42 to a 3.73 is a pretty good change. Here is a good gear calculator
http://www.f-body.org/gears/. 4th gear is the same on the z06 and the fbody. Maybe someone else has a better calculator for the z06 trans. If not you can input your numbers for everything.

If you are never going to go to the track I say don't waste the money at all. You'll just loose MPG and street ability goes down a little as well. Don't get me wrong, I went to 3.90s but I go to the track often.

If you are never going to go to the track I say don't waste the money at all. You'll just loose MPG and street ability goes down a little as well. Don't get me wrong, I went to 3.90s but I go to the track often.

thanks bro,

but i will keep thinking about it so far im still thinking 3.42s since i will never race the car at the track, just want a street car with some power, and dependable drivetrain,

If you are never going to go to the track I say don't waste the money at all. You'll just loose MPG and street ability goes down a little as well. Don't get me wrong, I went to 3.90s but I go to the track often.

No you won't. Hell I have got my best mpg with 4.10's on the highway. Town driving there is no difference in mpg or driveability.......where do you come up with this stuff?

No you won't. Hell I have got my best mpg with 4.10's on the highway. Town driving there is no difference in mpg or driveability.......where do you come up with this stuff?

now im confused who do i listen too,

It's pretty simple. If your gonna spray you need 3.73......that's assuming you have a 26" tall tire. You should trapp well over 130 on the spray.

i say 3.90 and you will pick up mpgs with any of them 3.73,3.90 or 4.10. the car lugs to move itself less. less work= better mpg. i saw 3.90 because it will make it a funner street car, your not gunna be useing the spray often so pick a gear that is more n/a friendly.

i say 3.90 and you will pick up mpgs with any of them 3.73,3.90 or 4.10. the car lugs to move itself less. less work= better mpg. i saw 3.90 because it will make it a funner street car, your not gunna be useing the spray often so pick a gear that is more n/a friendly.

thanks,
and yea thats what i would look for something fun to drive in the street with or with out traffic, i will rarely use the nitrous i am more into N/A,

Then get the 3.90. I have 3.90 but I don't think 3.73 would hurt my car at all. Do you do any roll racing?

Then get the 3.90. I have 3.90 but I don't think 3.73 would hurt my car at all. Do you do any roll racing?

"roll racing" of course , will it benefit from the 3.90s, also take off hard from the hole,

will it kill my gas mileage not that it matters but just to take into consideration?

roll racing would be better with 3.73.....well it would depend on the speed your running to. Neither will affect your mileage at all. You never have said what your tire height is. That makes a big difference. I'm assuming it's 26" but I don't know what's on a vette.

roll racing would be better with 3.73.....well it would depend on the speed your running to. Neither will affect your mileage at all. You never have said what your tire height is. That makes a big difference. I'm assuming it's 26" but I don't know what's on a vette.

factory wheels 18 x 10.5 with stock tire sizes BFGs KDWs 295/35/18

,

i notice 1st to 2nd shifts at around 45MPH, 2nd to 3rd shifts at around 70MPH more less and
3rd to 4th shifts at 100MPH, 4th to 5th at 140MPH more less,

would i shift sooner or later with a 3.73, how much of a diff in MPH would my shifts be off by ???

thanks