REAR AXLE RATIO TO 3:73 OR 4:10

[Bigtime53]

I need some info. The tracks around our area are all eighth mile and I been thinkin if I changed the ratio to 3:73 or 4:10 my car would turn a better time. Now it is a auto trans so I wondered if it would screw up the computer on the shift points or what would happen? Has anyone else done this or tryed it?

[360ss]

The tire diameter plays a significant role in that sequence . I believe there was a thread on the forum somewhere . Wallah... Here you go bro
http://www.camaro5.com/forums/showth...ight=101+gears

[cam99]

There are no gear ratio's available for the rear in these cars other than factory as far as I know

[Bigtime53]

Well I read the whole thread and like some of the guys I am dizzy now! Would someone weigh in on this and give me the skinny about lower gears and if I have to have a tune to do it. Ted maybe you could jump in here and let me and others know if it is worth doing this or not for eighth mile tracks. Thanks

[SamHouseIII]

Originally Posted by Bigtime53

I need some info. The tracks around our area are all eighth mile and I been thinkin if I changed the ratio to 3:73 or 4:10 my car would turn a better time. Now it is a auto trans so I wondered if it would screw up the computer on the shift points or what would happen? Has anyone else done this or tryed it?

Have you been to Thunder Valley 1/4 mile track south of OKC.

[Stephen12ZL1]

if your car is an auto, leave it stock 3.23. Nothing to gain with the 3.73 gears from a 6 speed car. Get some hp mods and leave the gearing alone.

[tpower]

Originally Posted by Stephen12ZL1

if your car is an auto, leave it stock 3.23. Nothing to gain with the 3.73 gears from a 6 speed car. Get some hp mods and leave the gearing alone.

There would be no gain in 60' with a 3.73 for the auto ?

[cam99]

Originally Posted by Bigtime53

Well I read the whole thread and like some of the guys I am dizzy now! Would someone weigh in on this and give me the skinny about lower gears and if I have to have a tune to do it. Ted maybe you could jump in here and let me and others know if it is worth doing this or not for eighth mile tracks. Thanks

I run 26" tall drag radials which effectively raises your final drive gearing numerically and it doesn't affect the shifting of the transmission. You do have to disable the traction control or it sends it into a panic because the rear wheels are going a different rpm than the front, but if you're racing on drs or slicks you want that turned off anyway.

[Stephen12ZL1]

Originally Posted by tpower

There would be no gain in 60' with a 3.73 for the auto ?

Maybe a little in the 60' but consider the tuning issues that would accompany such a swap. Also, I doubt it would be cost effective for the minimal gain. 1st gear in the auto is very steep so 3.23 is a great complement. Many here (including myself) get 1.5x 60' times with the 3.23 gear and stock torque converter. The biggest issue the ZL1 has is weight. In other words, spend your money wisely and leave the stock gears alone...work on hp mods to get this car down the track faster.

[Stephen12ZL1]

my best 1/8 mile et is 6.89@102.46 1.60'...stock 3.23 gears. Mostly traction dependent...super sticky tires are your friend. With perfect traction 1.57-1.58 are my best 60'.

[jessrayo]

Once again, Stephen12ZL1 comes in with very good advice. If you for some reason want to leave the rest of the engine stock, it would give you faster 1/4 mile times. It would require a complete reprogram of the computer with the tune at least for the speedometer. This was fairly easy for the manual when I switched my ratios's to the auto rear gears. ADM is not far from you and could do it right if that is what you want.

If you only run eighth mile it is more practical than 1/4 mile. If you swap to the 3.73 rear with an auto and add just a little power to the engine the car will try to shift to 5th before the end of the 1/4. This may make you a little slower in the quarter.

It can be done but I agree with Stephen, your dollars are better spent in pulley upgrades, intake, headers, cam, and if you don't have drag radials it won't do anything but make it harder to control wheel spin.

[Bigtime53]

Originally Posted by SamHouseIII

Have you been to Thunder Valley 1/4 mile track south of OKC.

Yes sir I have but we have two tracks close to me that are eighth mile. I will listen to what all of you have said and just mod the motor. Seems like some are really doing good with some mods so I guess I will have to break down one of these days and bite the bullit! Thanks for all of the input guys.