Rear End Gearing

[cs69camaro]

What rear end gear ratio are you guys using in your cars? I have a 4L80E in my car with a 3.73 rear end gear now with a 25" tire and it is running to many rpm at highway speed for me. I'm contemplating a 3.23 or 3.08 swap but am looking for some insight.

 

[Mr.Spool]

have a 4L80E in my car with a 3.73 rear end gear now with a 25" tire and it is running to many rpm at highway speed for me.

need a taller tire,28 inch would be very noticeable difference.or you can do the math and target your gear change with rpm and your current tire.

 

[SpeedRacerX]

What is the rpm now and what do you want it to be? I'll do some quick Calcs for you.

Sent from my SAMSUNG-SM-G900A using Tapatalk

 

[cs69camaro]

I am thinking of going with. 3.08 or 3.23. The rpm at 80 with the 3.08 would be 2500 which I believe would be better.

 

[TT/Ameasap]

30" tall DR's will give you excellent traction on the street and track.

 

[cs69camaro]

The biggest I can go with my wheels and still fit the car is 27". It's a turbo 5.3 and I've been reading that a taller gear actually helps it build boost. Here's a pic is the car.

 

[Mr.Spool]

The biggest I can go with my wheels and still fit the car is 27". It's a turbo 5.3 and I've been reading that a taller gear actually helps it build boost. Here's a pic is the car.

don't believe everything you read.the fact is if you want 80 mph on those tires you have you must drop the gearing down,if you are prepared to go up in tire size different ball game.

 

[Chuck Leeper]

Why only 27"??

 

[cs69camaro]

The 18" wheels...I'm not wanting to have any issues with the tires contacting the fender wells. The wheel size limits the tire options for a drag radial.

 

[Chuck Leeper]

The 18" wheels...I'm not wanting to have any issues with the tires contacting the fender wells. The wheel size limits the tire options for a drag radial.

And, limits the sidewall hgt... Something needed to help w/ traction..Short sidewall not always the best for max traction....

 

[cs69camaro]

Yeah I know it wont be the fastest car and will have traction issues due to sidewall but I built it to be a fun car to drive and have plenty of power. That's why I'm looking at the gearing as it will see lots of road trips.

 

[turbo89]

What rear end gear ratio are you guys using in your cars? I have a 4L80E in my car with a 3.73 rear end gear now with a 25" tire and it is running to many rpm at highway speed for me. I'm contemplating a 3.23 or 3.08 swap but am looking for some insight.

If you have a real strong motor .. I wouldn't be afraid of the 3.08 with a 26 /27 inch tire .. the 3.73 is killing you

 

[Ernie GN]

Go to Tremec Transmissions.com there is a link that you could calculate RPM and gear ratios to find out exactly what will work best for you also there are many other online calculators that will help you.

If you have a real strong motor .. I wouldn't be afraid of the 3.08 with a 26 /27 inch tire .. the 3.73 is killing you