C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

4 speed Mods

Thread Tools
 
Search this Thread
 
Old Aug 14, 2006 | 03:29 AM
  #1  
CarShowDVD's Avatar
CarShowDVD
Thread Starter
Instructor
 
Joined: May 2006
Posts: 122
Likes: 0
From: Dana Point Ca
Default 4 speed Mods

Any way to change the 1:1 fourth gear from to a 0.71 or 0.57

Like a OD gear?

Lowest usable gear ratio?

Anyone ever try this?

Sound crazy or make any kind of since?
Reply
Old Aug 14, 2006 | 08:36 AM
  #2  
69ttop502's Avatar
69ttop502
Le Mans Master
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2001
Posts: 6,240
Likes: 1,013
From: Watkinsville, GA and Glen Cove, NY
Default

Go to www.autogear.net. They make an overdrive 4 speed Muncie.
Reply
Old Aug 14, 2006 | 04:36 PM
  #3  
CarShowDVD's Avatar
CarShowDVD
Thread Starter
Instructor
 
Joined: May 2006
Posts: 122
Likes: 0
From: Dana Point Ca
Default

Thanks not too much info there.
Looking to get better MPG on highways.
Reply
Old Aug 14, 2006 | 04:51 PM
  #4  
Kalway's Avatar
Kalway
Safety Car
 
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Default

If I were to try and make the 4 speed muncie an OD unit I'd change all 4 gears to a ratio that the 700R4 or 2004R use. That way it doesn't have an ackward shift feel.
Reply
Old Aug 14, 2006 | 04:57 PM
  #5  
72Tornado's Avatar
72Tornado
Pro
 
Joined: Sep 2004
Posts: 690
Likes: 0
From: Madison WI
Default

Couple different ways...completely change all the gear ratios, or (much better idea) install a GearVendors Under/Overdrive unit. They're very trick, and will essentially make your tranny an 8-speed, giving you a "1st-and-a-half," "2nd-and-a-half," and so on. It shifts using a planetary gear set (like an automatic) to go from whatever gear you are in into the overdrive version of the gear - think of it like having two rear ends that you can switch between however you want. The units are pricey but can be picked up on eBay for under $1000.
Reply
Old Aug 14, 2006 | 05:14 PM
  #6  
BerniesVette's Avatar
BerniesVette
Melting Slicks
 
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
Default

I installed a T5 in my '79 for $1,200.00. Best mod I have ever done. Went from turning 3400 rpm at 70 to 2100 rpm!
Reply
Old Aug 14, 2006 | 05:23 PM
  #7  
Eddie 70's Avatar
Eddie 70
Race Director
Supporting Lifetime Gold
St. Jude 10 Year Donor
25 Year Member
Liked
Community Favorite
 
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Default

I have added a Keisler 5 speed OD tranny to mine. Works like a champ.
Reply
Old Aug 14, 2006 | 05:33 PM
  #8  
Gordonm's Avatar
Gordonm
Race Director
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Default

Originally Posted by Eddie 70
I have added a Keisler 5 speed OD tranny to mine. Works like a champ.
Would not go back to a 4 speed.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Aug 14, 2006 | 06:08 PM
  #9  
carbster09's Avatar
carbster09
Burning Brakes
15 Year Member
 
Joined: Oct 2002
Posts: 914
Likes: 14
From: Aberdeen, Scotland
Default Gear Vendors ... ?

I really like the Gear Vendors idea. Has anyone done it or have pictures?

carbster
Reply
Old Aug 14, 2006 | 07:02 PM
  #10  
Kalway's Avatar
Kalway
Safety Car
 
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Default

Originally Posted by carbster09
I really like the Gear Vendors idea. Has anyone done it or have pictures?

carbster
Looks rather heavy and I'm not sure how well it'd fit in our transmission tunnel. I'd rather just go with a transmission designed with an overdrive.

The gearvendors idea has been around since like the 50s/60s. Old Triumphs came with those things.
Reply
Old Aug 14, 2006 | 07:16 PM
  #11  
Gordonm's Avatar
Gordonm
Race Director
25 Year Member
Liked
Loved
Community Favorite
 
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Default

Check out the cost of the Gear Vendors. It is about the same as an OD tranny. I doubt it will fit in the trans tunnel. It is pretty tight back there.
Reply

Get notified of new replies

To 4 speed Mods





All times are GMT -4. The time now is 03:06 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE