4 speed Mods
Aug 14, 2006 | 03:29 AM
Thread Starter
Instructor
Joined: May 2006
Posts: 122
Likes: 0
From: Dana Point Ca
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?
Aug 14, 2006 | 08:36 AM
Le Mans Master
Joined: Mar 2001
Posts: 6,231
Likes: 1,009
From: Watkinsville, GA and Glen Cove, NY
Go to
www.autogear.net . They make an overdrive 4 speed Muncie.
Aug 14, 2006 | 04:36 PM
Thread Starter
Instructor
Joined: May 2006
Posts: 122
Likes: 0
From: Dana Point Ca
Thanks not too much info there.
Looking to get better MPG on highways.
Aug 14, 2006 | 04:51 PM
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
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.
Aug 14, 2006 | 04:57 PM
Pro
Joined: Sep 2004
Posts: 690
Likes: 0
From: Madison WI
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.
Aug 14, 2006 | 05:14 PM
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
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!
Aug 14, 2006 | 05:23 PM
Race Director
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
I have added a Keisler 5 speed OD tranny to mine. Works like a champ.
Aug 14, 2006 | 05:33 PM
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Quote:
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.
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Aug 14, 2006 | 06:08 PM
Burning Brakes
Joined: Oct 2002
Posts: 914
Likes: 14
From: Aberdeen, Scotland
Gear Vendors ... ?
I really like the Gear Vendors idea. Has anyone done it or have pictures?
carbster
Aug 14, 2006 | 07:02 PM
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Quote:
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.
Aug 14, 2006 | 07:16 PM
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
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.