3.90 Final Drive Ratio - Gauging level of interest


Lorenzo

GT Owner
Mark II Lifetime
Dec 28, 2008
626
U.S.A.
The two mods I chose that were Things Ford should have done, Traction control and 3:90 gears. Best money I ever spent on the car.
 

Brombear

GT Owner
Mark II Lifetime
May 16, 2013
1,406
Frankfurt Area, Germany
Short Shifter first :)
 

SMOKDU

GT Owner
Dec 17, 2011
412
With my 4.0 whipple the car has plenty of fun and a light feel. I think the mod would be great on the track for tip in for the higher gears. I wonder if you wanted just to see straight line performance what would be faster. I think with the extra shifting and wheel spin on an already modded GT you would go slower in the 1/8 or 1/4 mile times and it might effect the mile as well. I can hit 100 in second now at 7000 rpm. I'm kinda the wrong guy because I have a drag race background and never raced on a road course . If the cars was a paddle shift auto I would say do it just my opinion .
 
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rf18412

GT Owner
Feb 28, 2011
72
Omaha, Nebraska
If the option was available I would change to the 3.9
 

Sinovac

GT Owner
Mark II Lifetime
Jul 18, 2006
5,862
Largo, Florida
First gear in the GT500s is very tall as well. A 3.73 gear swap is very popular and makes the car much more enjoyable for all the reasons stated above. It transformed my '08 GT500. I have no doubt the same is true for the GT. I would be interested in the parts only, depending on the vendor.
 
I'd be interested in a total package, but at $10K+ I don't find it necessary or cost effective. At a significantly lower cost, that would be different.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,291
Again, if we can improve the price point - which is primarily in the small run of the gear sets, we will.
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
For $10,000, I can buy a hell of a lot of Michelin Pilot Sport Cup tires (345/30ZR19), which drop my ratio from 3.36 to about 3.7 - and when traveling with my buddy Jeff, we then can stop together for gas. I find it a hell of a good compromise, as I get a reduced ratio and a great track tire at the same time. And, the #2 car loves them. I'm not going to get into the middle of this, just suffice it to say that if you have more interest, PM me. The extra width of the tire is FANTASTIC!

:thumbsup
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,291
Ralphie, I hear you on the price of the gears. The price I estimated was nearly the identical price as it was when the original 3.90 set was offered - despite that was several years ago.

As for running a 345/30 tire on the GT, I could never do this. Seeing an ungodly looking fender well gap from running a tire that is more than 1.75" undersized for the design of the car would just kill me.
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Ralphie, I hear you on the price of the gears. The price I estimated was nearly the identical price as it was when the original 3.90 set was offered - despite that was several years ago.

As for running a 345/30 tire on the GT, I could never do this. Seeing an ungodly looking fender well gap from running a tire that is more than 1.75" undersized for the design of the car would just kill me.

:agree: with Kendell, too big gaps in the wheel wells. The lower ratio is one of the best mods if cost isn't a consideration, but I understand why many would hesitate. I just cost big bucks for small runs of custom parts. If 100 owners came forward I'm sure the price would be significantly less.
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
...Seeing an ungodly looking fender well gap from running a tire that is more than 1.75" undersized for the design of the car would just kill me.

...:agree: with Kendell, too big gaps in the wheel wells....

Ungodly? Check it out...

View attachment 34097
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,483
Kalama, Free part of WA State
Again, if we can improve the price point - which is primarily in the small run of the gear sets, we will.
To add to my earlier response, for $10K I'd rather put a Whipple on it.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,291
Ungodly? Check it out...

OK, so we agree? Chip's car with about zero wheel well gap looks just right? :cheers
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
OK, so we agree? Chip's car with about zero wheel well gap looks just right? :cheers

Fine - sell your gears...
 

sandman

GT Owner
Mark IV Lifetime
Jul 10, 2006
465
Gardnerville, Nv.
We have the 3.90 gears in one car and the stock 3.3 in the other, both cars are otherwise identical, Whipples, exhaust, brakes, short shifter…
The stock geared car is as most everyone knows is long legged; getting 0-60 without a shift will do that. The torque the GT has masks this as to not be a real issue and as we know most people are very happy with the car as is. The 3.90’s surely aren’t for everyone but once you drive one it’s obvious why they have their place. On the road it seems to always be in the heart of the torque curve, a very responsive car in any gear at any speed. Sure my fuel economy took a small hit but my right foot does more damage! How many drive a GT like a prius? On the track it is fantastic, everything it does for the streetcar is exponentially better there, I really can’t overstate how much I enjoy it. Running the mile does require a shift into 6th 400’ from the finish, so not so good but that’s a rare occurrence and it did get me over 210. The stock geared car is still pulling 5th and is the winner there.
As for the cost Kendell is in the same ballpark as the originals. This isn’t ordering a ring and pinion off the shelf, per unit cost, as before, is going to be up there, frankly building only 20 sets I would think most vendors would consider a waste of time so its going to cost you.
The gear change is one of, if not the best mods made to the car, it isn’t seen or heard but it’s felt and it makes me smile.
 

Vince H

GT Owner
Mark II Lifetime
Jul 23, 2012
2,423
Southern California
Fine - sell your gears...

HA! Got a good chuckle from this banter.

Vince H
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Not that I do that very often, but it sure makes driving in bumper to bumper traffic a lot easier.
 

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Shelby#18

GTX1 Owner/Moderator
Mark IV Lifetime
Le Mans 2010 Supporter
Dec 15, 2006
1,623
Nev./So. Cal./Minn.
I also have the 3.90 gears on both my cars. One is a Whipple the other TT. As stated from others it won't help you at the mile. But on the track it sure is nice!
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,291
Ralphie, I still love you! re "the gears", if enough people want to do them, great. If not, that's OK too.
 

B.M.F.

GT Owner
Mark II Lifetime
Jan 29, 2009
1,814
Minnesota
I have a company doing 4.11's and 3.90s. I dont know how far you have gotten with this Kendall but you may want to wait till i see what pricing is going to be on them. The 4.11s are being done first and supposed to be done soon.