Millen 3.9 and new clutch feedback


Gimbal

Gimbal

GT Owner
Mark IV Lifetime
Jan 11, 2007
204
Queenstown, New Zealand
I have 500 miles on my new Millen 3.9 differential and their new clutch. Both act and feel fantastic! The 3.9 seems to put each gear in the right power band. Much nicer 1st gear starting too.
The clutch disengages very nice and is allowing me to put into 1st gear much easier and helps minimize the 2nd gear crunch issue. Kyle mentioned the stock clutch disks are "spongier" and require further pedal travel. I'm thinking the stock clutch could still be rubbing even at full clutch travel allowing the 1st and 2nd syncros to have difficulty. I'm no expert but it's starting to make some sense to me.
 
Great feedback.

1) How much rwhp are you running?
2) What tires are you using?
3) How is 1st gear traction?
4) What rpm do you turn at 80 mph?
 
oooh this is the first ive heard of the 3.9 gears installed on a customer's car. anyone know what the top speeds are in each gear now?
 
Are you happy with the clutch for stop and go driving compared to the stock clutch?

I may need a new clutch soon but I don't need the gears.

Thanks
 
I'm running basically stock engine and tires. It's easier to break 1st gear traction but certainly controllable. The change is not super dramatic, but definately makes the whole driving experience more correct and has better pick-up in each gear.
At 80mph my tack was reading 1850rpm and now 2150rpm.
 
Stop and go traffic, which I had two hours of with the old clutch and 2 hours of with the new clutch. New clutch wins by far!
 
:eek
Gimbal said:
Stop and go traffic, which I had two hours of with the old clutch and 2 hours of with the new clutch. New clutch wins by far!
Click to expand...
 
kumar said:
oooh this is the first ive heard of the 3.9 gears installed on a customer's car. anyone know what the top speeds are in each gear now?
Click to expand...

Kumar,

Here is the breakdown for top speed in each gear.

STILLEN 3.9 Ratio Redline Speeds
1st: 53mph
2nd: 81mph
3rd: 112mph
4th: 146mph
5th: 180mph
6th: 220mph

Here is a link to one of the original threads regarding the 3.9.

http://www.fordgtforum.com/forums/showthread.php?t=6774

If anyone has any questions please feel free to either call me or send me an email at [email protected]
 
I am very glad that you are happy with the new gears and clutch and I'm glad to see you made it home safely. On the news last night I thought I saw something about snow in your area and started worrying.

Gimbal said:
Kyle mentioned the stock clutch disks are "spongier" and require further pedal travel.
Click to expand...

Please let me explain this in a bit more detail. Clutches use a two-sided friction plate. In the middle of the friction surfaces there is a wave spring that is designed to flex and condense the friction plate. This accounts for much of your pedal travel. When we developed our clutch with AP Racing we used a better material on the friction plates as well as used a wavespring with less deflection. The end result was a decrease of 1 inch in pedal travel.
 
This is good news Gimbal. Do you think you will ever get a chance to make any kind of timed acceleration runs with the new gears in? :cheers
 
I have an appointment with my GT Shrink today before lunch... the good Dr. Whipple,
perhaps he will recommend a consult with Dr. Stillen?? :)
 
Y'all might be well advised to get an appointment to see Dr. Trac Shuntyre while you're at it. I've heard Dr.s Whipple & Stillen's work is far more sucessful after they've consult him.
 
DBK said:
This is good news Gimbal. Do you think you will ever get a chance to make any kind of timed acceleration runs with the new gears in? :cheers
Click to expand...

I have no experience in that type of running, if I tried I'm sure my results would be too inconsistant to be useful. I do plan on taking it to a track, Sears or Thunderhill but not until late Jan or so.
Perhaps others getting the 3.9 could do some runs soon.
 
B O N Y said:
I have an appointment with my GT Shrink today before lunch... the good Dr. Whipple,
perhaps he will recommend a consult with Dr. Stillen?? :)
Click to expand...

I know it's a bit of a trip for you but if you're ever in the neighborhood feel free to stop by. We will have Steve give you a ride and maybe we can even get you behind the wheel for a first hand feel. :thumbsup
 
I have a one day visa that allows me to go into OC... :)
Stay tuned and Merry Christms
 
I'll tell, it won't be much use in 1st gear, but a Whipple car with the 3.90s would be an absolute freight train between 80-200. :willy
 
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