I am planning on changing the rear end rears on my GSLSE for improved 60 foot times and just overall acceleration off the line. I have stock gearing and stock tire height right now. I am leaning toward the racingbeat 4.875 set. I do intend on doing a S4 transmission swap to gain a taller 5th gear to compensate for the gearing on the highway.

Looking for feedback from those running various gear set please.

 

good for track but you will hate it at highway. about 6K at freeway speed and a 1986 hyundai excel, rodney king edition, will beat ya

 

yeah I'll have to hit up the rpm calculators to see

 

Using the following calculator,I should be running 3041 rpm at 65 mph, seems right. Keeping the same transmission, a 4.875 gear set would put me at 3625 rpm, not too bad. If I do the s4 tranny swap, I would be down to 3131 rpm. Pretty suitable noting the gains i would see through 1st, 2nd and 3rd. The 4.875 with my trans would plant me at 5600 rpm at 100 mph (end of the 1/4 mile).

 

Are you running the 1/8 or the 1/4 with the RX-7? This can also help you determine a good gear ratio too.

 

1/4

 

I have looked at doing the exact same gear and transmission swap. I did the calculations and came out with the same numbers. I think its a great idea to help in the 1/4. Even if you have additional power mods you should be good to about 120mph before running out of gear. That would take lots of power to get to in the 1/4. If you do it, let me know how it works out and any problems you run into.

 

I went from stock SE gearing and tire size to a 4.44 My gas milage has suffered some, but overall it feels peppier off the line and still has a REAL good topend. No 86 rodney king hyuandi is putting a wooping on me and crusing the highway still feels good.

 

Notable better off the line? I have a camden on mine and drive the car for pleasure just a couple or 3 times a week. Since i can't seem to keep my foot out of it as it is gas mileage isn't a factor. My trusty saturn takes me to work every day.

 

I thought gas milage wasn't a factor either but my milage kind stunk before the gear swap, going even lower really stunks... ha.

I'm still n/a with a 13B, YAW carb, headers, 12A tranny... peppy little sucker. The gear swap was the last thing I did upgrade wise, and yea the change was somewhat noticable.

 

Well after scoring a spare pumpkin I have ordered the 4.875 gears. Has anyone sourced out alternate speedometer gears for the transmission to make the correction??

 

man the speed o gears would be sweet for sure.
BTW a friend has a 488 rear gear and is able to hit 120+ on the back straight so you should be good with everything you have figured out.

 

http://solomiata.com/Drivetrain.html

 

With my stock gearing in my Se of 3.90 as it is a 85 model and the 2nd Gen transmission model year 88 I am around 3100 RPM at 90 MPH.