DodgeCharger.com Forum

Mopar Garage => Engine, Transmission, Rearend, & Exhaust => Topic started by: Pouria on December 17, 2015, 05:05:41 AM

Title: 8 3/4 lowest gear ratio available
Post by: Pouria on December 17, 2015, 05:05:41 AM
Does anybody know the lowest ratio gear available for 8 3/4? Is it possible to custom order the gear near a specific ratio?
Title: Re: 8 3/4 lowest gear ratio available
Post by: green69rt on December 17, 2015, 08:54:42 AM
Look at reply #15 (about.)

http://www.dodgecharger.com/forum/index.php/topic,112559.0.html
Title: Re: 8 3/4 lowest gear ratio available
Post by: heyoldguy on December 17, 2015, 09:19:42 AM
Seems to me that generally 5.13:1 is the lowest ratio I've seen. A few years back I was running a 4.89:1
Title: Re: 8 3/4 lowest gear ratio available
Post by: Pouria on December 17, 2015, 10:18:52 AM
Quote from: green69rt on December 17, 2015, 08:54:42 AM
Look at reply #15 (about.)

http://www.dodgecharger.com/forum/index.php/topic,112559.0.html
Thanks a lot :2thumbs:

Quote from: heyoldguy on December 17, 2015, 09:19:42 AM
Seems to me that generally 5.13:1 is the lowest ratio I've seen. A few years back I was running a 4.89:1
I think you got me wrong or maybe I asked a wrong question. I need lower ratio (higher with your point of view, for example 2.5:1 or something)!
Title: Re: 8 3/4 lowest gear ratio available
Post by: maxwellwedge on December 17, 2015, 10:34:47 AM
Yes - A question that has always been confusing depending on how you look at it.

I seem to recall a 2.76:1 or something like that.
Title: Re: 8 3/4 lowest gear ratio available
Post by: birdsandbees on December 17, 2015, 10:42:57 AM
I have a 2.76:1 (high gear) pot in my '69 Superbee. Highway cops never liked me I can tell you that..  :icon_smile_big: Think on my refurb, while I have the car torn down, I may return it to it's factory 3.23:1.
Title: Re: 8 3/4 lowest gear ratio available
Post by: Pouria on December 17, 2015, 11:40:36 AM
Quote from: birdsandbees on December 17, 2015, 10:42:57 AM
I have a 2.76:1 (high gear) pot in my '69 Superbee. Highway cops never liked me I can tell you that..  :icon_smile_big: Think on my refurb, while I have the car torn down, I may return it to it's factory 3.23:1.
Thank you.
May I know your full setup? Engine, tranny, HP and torque? Are you ok with the launch at start-up?

Maxwellwedge, thank you too :2thumbs:
Title: Re: 8 3/4 lowest gear ratio available
Post by: John_Kunkel on December 17, 2015, 03:36:17 PM

2.76 is the highest (lowest numeric) ratio ever made for the 8 3/4".
Title: Re: 8 3/4 lowest gear ratio available
Post by: Alaskan_TA on December 17, 2015, 04:27:10 PM
The numbers confuse some folks.

The higher the number, the lower the gear & the lower the number, the higher the gear.

High sets for gas mileage & low sets for drag racing & pulling stumps with your truck.
Title: Re: 8 3/4 lowest gear ratio available
Post by: birdsandbees on December 17, 2015, 05:14:40 PM
Quote from: Pouria on December 17, 2015, 11:40:36 AM
Quote from: birdsandbees on December 17, 2015, 10:42:57 AM
I have a 2.76:1 (high gear) pot in my '69 Superbee. Highway cops never liked me I can tell you that..  :icon_smile_big: Think on my refurb, while I have the car torn down, I may return it to it's factory 3.23:1.
Thank you.
May I know your full setup? Engine, tranny, HP and torque? Are you ok with the launch at start-up?

Maxwellwedge, thank you too :2thumbs:

Basically a factory stock 383 magnum, 4 gear car. Only thing not stock is the Mcleod Street / Strip clutch because I use to burn a factory clutch out in a couple high power drops. It's not a screamer off the line... but I do have a time slip around here somewhere from 1981, pulling off a 101.8 MPH 1/4 mile with it bracket racing. Definitely a highway cruiser... and why I'm probably going to put it back to a 3.23 when I restore this winter.
Title: Re: 8 3/4 lowest gear ratio available
Post by: AKcharger on December 17, 2015, 06:34:33 PM
I've got a 2:76 pull 19 MPH on the highway...really
Title: Re: 8 3/4 lowest gear ratio available
Post by: A383Wing on December 17, 2015, 08:23:29 PM
I got 2.76 and the best mileage I got was 24.5mpg in the Daytona
Title: Re: 8 3/4 lowest gear ratio available
Post by: cdr on December 17, 2015, 08:42:07 PM
I took out the 3.91 & put in a 3.23, so with my overdrive .69 it is 2.23 final drive.
Title: Re: 8 3/4 lowest gear ratio available
Post by: c00nhunterjoe on December 17, 2015, 10:06:32 PM
I have 4.88s and avg 8mpg right now. But i prefer to measure in miles per smile. Its a much better unit of measure in my opinion.
Title: Re: 8 3/4 lowest gear ratio available
Post by: Kern Dog on December 18, 2015, 01:30:02 AM
With the loss of the Auto Shop instruction in schools, it is no wonder the latest generation of gearheads do not know the basics.
Lower gears can be thought of as lower top speed. Higher or taller gears should be thought of as ones that allow a higher top speed.
The reason that Ma Mopar stopped at 2.76 is because as the numbers get lower....From say 3.91 to 3.23, the pinion gear gets bigger. The 2.76 pinion gear is huge and barely fits in the case. To fit any gear taller such as a 2.56, 2.41 or 2.29 like GM used, the 8 3/4 case would have to be either hogged out with a die grinder or recast with more clearance for the pinion gear.
Title: Re: 8 3/4 lowest gear ratio available
Post by: Pouria on December 18, 2015, 09:43:48 AM
Quote from: AKcharger on December 17, 2015, 06:34:33 PM
I've got a 2:76 pull 19 MPH on the highway...really

Thank you for sharing your experience :2thumbs:

Quote from: A383Wing on December 17, 2015, 08:23:29 PM
I got 2.76 and the best mileage I got was 24.5mpg in the Daytona
24.5mpg?!!!! :o It is amazing, at what speed did you achieve it?

Quote from: cdr on December 17, 2015, 08:42:07 PM
I took out the 3.91 & put in a 3.23, so with my overdrive .69 it is 2.23 final drive.
May I know how do you feel it runs?

Quote from: Kern Dog on December 18, 2015, 01:30:02 AM
With the loss of the Auto Shop instruction in schools, it is no wonder the latest generation of gearheads do not know the basics.
Lower gears can be thought of as lower top speed. Higher or taller gears should be thought of as ones that allow a higher top speed.
The reason that Ma Mopar stopped at 2.76 is because as the numbers get lower....From say 3.91 to 3.23, the pinion gear gets bigger. The 2.76 pinion gear is huge and barely fits in the case. To fit any gear taller such as a 2.56, 2.41 or 2.29 like GM used, the 8 3/4 case would have to be either hogged out with a die grinder or recast with more clearance for the pinion gear.
Correct! I have another problem as well and it is my English because I am not American ;) Thank you for the useful info, but just for my information, isn't it possible to make smaller crown wheels instead of bigger pinions? :shruggy:
Title: Re: 8 3/4 lowest gear ratio available
Post by: John_Kunkel on December 18, 2015, 03:34:25 PM
Quote from: Alaskan_TA on December 17, 2015, 04:27:10 PM
The numbers confuse some folks.

The higher the number, the lower the gear & the lower the number, the higher the gear.

High sets for gas mileage & low sets for drag racing & pulling stumps with your truck.

Another analogy is to think of it in transmission terms, low gear and high gear.