3.90 ring and pinion (available again)


PeteK

GT Owner
Apr 18, 2014
1,813
Kalama, Free part of WA State
PeteK - which motor home is yours down by the river? I miss seeing the log home building.
Hah, heh. It’s the one with the broken lawn chairs and empty propane tanks strewn about...

Actually, I’m up on Green Mountain above Kalama. Looking down on the Columbia River and Portland (at a safe distance—30 miles).
 

Brombear

GT Owner
Mark II Lifetime
May 16, 2013
1,375
Frankfurt Area, Germany
.
 

Brombear

GT Owner
Mark II Lifetime
May 16, 2013
1,375
Frankfurt Area, Germany
That would be great.
 

B.M.F.

GT Owner
Mark II Lifetime
Jan 29, 2009
1,668
Minnesota
.
 
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dbk

The Favor Factory™
Staff member
Le Mans 2010 Supporter
Jul 30, 2005
15,063
Metro Detroit
I can't remember when it was but we had a TT 3.90 car at a mile event and it would not go 200. It was 19X.
 

B.M.F.

GT Owner
Mark II Lifetime
Jan 29, 2009
1,668
Minnesota
.
 
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ultrasportracing

GT Owner
Aug 31, 2011
473
Perth Western Australia
Pity I cant drive a car with the lower gears to see if it warrants the $12,000 .
 

JWZ

GT Owner
Mark IV Lifetime
Nov 17, 2013
713
West Texas
Watched a lightly modded GT run 205 at Beeville Texas Mile a few years ago. Stock gears. Stayed in 5th gear (.77). 6th (.63) is useless @ Mile. Am guessing 3.90 gear with similar setup might run 180 ish? We ran 2.70 gear in Mustang to keep RPMs around 7k with tranny in 5th (.8). Best run was 230, Same rear Hoosiers as GTs.
 
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sandman

GT Owner
Mark IV Lifetime
Jul 10, 2006
465
Gardnerville, Nv.
3.90’s aren’t ideal for the mile. I shift into sixth at 185 approximately 3 seconds or around 800 feet from the one mile line, at one mile I’m usually 195mph. It takes a mile and a quarter to get over 200 usually depending on weather. I have done a 218 mph run with the 3.90 whipple gen two car pushed bye a 30mph tail wind In the mile and a half.
The 3.90’s are great fun on a road course or on the street, that’s where they shine. I do like driving the 3.90 car versus the stock geared car in both those instance but in the mile the stock geared car works better.
 
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centerpunch

ex-GT owner x2
Mark II Lifetime
Sep 16, 2005
922
OH/NC
There are several old threads from when the 3.90 gears were first made by Stillen, LOTS of positive feedback from folks who experienced the mod.

FYI for some reason, the forum doesn't always sort posts in the correct order within old threads, but the content is still all there.




 
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B.M.F.

GT Owner
Mark II Lifetime
Jan 29, 2009
1,668
Minnesota
.
 
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MarkH

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
May 19, 2007
510
Katy, Texas
8000rpms? That's it.... We have hung a GT out way further than that.. LOL
 
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B.M.F.

GT Owner
Mark II Lifetime
Jan 29, 2009
1,668
Minnesota
.
 
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B.M.F.

GT Owner
Mark II Lifetime
Jan 29, 2009
1,668
Minnesota
.
 
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HOOKED ON GT

GT Owner
Oct 26, 2006
357
Orlando & Australia
Any new 3:90 gear info out there.... Seems like wez back with nothing on the market again?
BMF has done some post deleting.:confused::unsure:

#hope the dream lives on.

Stu
 

B.M.F.

GT Owner
Mark II Lifetime
Jan 29, 2009
1,668
Minnesota
Any new 3:90 gear info out there.... Seems like wez back with nothing on the market again?
BMF has done some post deleting.:confused::unsure:

#hope the dream lives on.

Stu

They are available from John who had them made. I am just stepping aside and letting him handle sales. HCF is the company out of austin Tx.
 

HOOKED ON GT

GT Owner
Oct 26, 2006
357
Orlando & Australia
Thanks BMF for point of contact.
Thanks for input earlier.

SA
 

HOOKED ON GT

GT Owner
Oct 26, 2006
357
Orlando & Australia
Currently trading emails with John at https://hcfautoparts.com about the GT 3:90 set up.

He sent me some graphs and will post them if ok soon.

Was the top speed on the GT about 205mph ...if so that would be about 6,000rpm in 5th?

A 3:90 would get to 7,000rpm in 5th at abut 200mph... so pretty close (but past peak power), so how would a change into 6th act on climbing past the OE factory top speed?

6th at peak power 6,400rpm = about 225mph. (too much resistance to get there id bet)
A change from 5th to 6th has a 1,200rpm rev drop (assume changing at 6,500rpm)

You have stop watch numbers like many mention like 1/4 mile out to 1 + mile and top speed.
They all get placed on a 1 dimensional piece of paper.
Feel is personal and only the neurones firing in your brain during a peak experience hold tremendous value to you (time slips are for everyone else)

So what if a stock GT gets to 150mph in x time and a 3:90 does in 2 seconds slower (just my story) but your getting more "shit yeah" out of the 3:90 as the effort or "hustle" feels dialled up v's stock.

Your friends say "Dude it's 2 seconds slower" and your face says "like I give a shit"

Imagine if Ford did offer a 3:90 from their performance division, id bet the "reviews" would have picked that as the "choice Ford performance option" v's OE daddy long legs.

It would've taken forever to sell the GT if it came with a 3:90 as the 0=60 would be closing in on 4 secs and get not near the front page attention, but really 5+ to now 15 years later it might have been even more ledgendary?

FYI .... A 3:90 is as short as the trans will go.
 

extrap

GT Owner
Mark II Lifetime
Jul 16, 2020
1,263
Gainesville FL
205 mph is the top speed I've always read; can't remember sources, but possibly actually from Ford. But I seem to remember reading that the test GT taken to a Europe track went around at more than that (212?) for hours. I need to go re-read that part of Joey's book so I can spew out facts instead o_O
 

HOOKED ON GT

GT Owner
Oct 26, 2006
357
Orlando & Australia
I think that run was at Nardo and was about your number (either side of 210) and ripped of tanks of gas at max speed. imagine the concertration.

Actually looking at my 150mph story the 3:90 GT could easily be quicker as its doing 6,500rpm at 150 (approx.) v's stock doing 5,500rpm (approx.)
might be slower to 60, but thats it.
I think the range from 2,500 to 4,000 would be just brilliant (street rpm zone)