opinions on rear gear ratios

thexrcist68

New Member

Apr 22, 2006

63

0

0

Spotsy County, VA

Sep 29, 2008

#1

• Sep 29, 2008

• #1

im ordering gears for my cougar and i wanted to get some input on what a good ratio would be. its a 8 inch with 2.79s now i wanna go at least 3.8 but was also considering the 4.11s to take advantage of the fact my engine has a lot of top end. its only driven occasionally and around town so mileage isn't an issue, but i'm worried the 4.1 might be too low
so what do yall think

 

blown65

Founding Member

Jul 7, 1999

1,938

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39

Queen Creek Arizona

Sep 29, 2008

#2

• Sep 29, 2008

• #2

If your not driving much highway stuff at all, then 4.11 would be fine, if its some mix then 3.89 is a good choice. I drive my 4.56's all over town and they dont bother me, but it never sees the freeway where I life so I could care less.

 

SadbutTrue

Founding Member

May 1, 2002

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Granada Hills, California

Sep 29, 2008

#3

• Sep 29, 2008

• #3

With a C4 I wouldn't want more than 3.55s. When I had my C4 I put in 3.25s. They worked okay but that was with a mostly stock engine. In an application like yours, I might have been willing to go 3.73s or 3.89s. 4.11s are a lot for a C4...

With my T5, I now kinda wish I had 3.55s or maybe 3.73s. With my heads/cam, it'd be nice for the gears to be a little more 'rev-happy'. However I'd have to get quieter mufflers if I did that, the Flows I have now already are a bit too loud on the freeway even with 3.25s.

However, my mustang has always needed to be at least a semi-DD. It sees freeway use, needs to get decent gas mileage, can't overheat and doesn't have a $1000 radiator setup, etc... so 4000 rpms at 60 mph wasn't acceptable. For your purposes, it might be.

 

blown65

Founding Member

Jul 7, 1999

1,938

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39

Queen Creek Arizona

Sep 29, 2008

#4

• Sep 29, 2008

• #4

Mine had 3.89's since High School with a C4. It worked just fine with no over heating. Its about 3000 rpm at 60mph. Was that way for about 4 yrs as my daily driver.

 

thexrcist68

New Member

Apr 22, 2006

63

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0

Spotsy County, VA

Sep 29, 2008

#5

• Sep 29, 2008

• #5

thanks for the comments, goin with the 3.8s but just out of curiosity is there a noticeable performance difference between the 2 doesnt seem like thered be a whole lot

 

thexrcist68

New Member

Apr 22, 2006

63

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0

Spotsy County, VA

Sep 29, 2008

#6

• Sep 29, 2008

• #6

btw blown 65, your car sounds awesome, im hoping to build an engine like that for my capri one day in the distant future

 

jcode68

Active Member

Jul 15, 2003

892

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29

Massachussetts

Sep 29, 2008

#7

• Sep 29, 2008

• #7

I went from 2.79 to 3.8 with my T5 and the difference is dramatic. I think it's a great ratio for all around driving situations.
Posted via Mobile Device

 

blown65

Founding Member

Jul 7, 1999

1,938

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39

Queen Creek Arizona

Sep 29, 2008

#8

• Sep 29, 2008

• #8

ya, mine was 2.79's way back in the 8" before I blew it up. LOL Going to 3.89's is night and day difference, especially on a mild build. Not sure what your stall of your converter is, but having the gears with it is going to make it even more noticeable IMO.

 

thexrcist68

New Member

Apr 22, 2006

63

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0

Spotsy County, VA

Sep 29, 2008

#9

• Sep 29, 2008

• #9

it stalls around 3k, and i just ordered the gears, cant wait to put em in and go for a test run, hopefully they'le help the trans run cooler too due to the tc slipping less