New clutch


kmillen

Well-known member
Jan 29, 2007
504
First off, sorry it took so long to get this one ready. We've been working hard with AP but there have been some hurdles.

The initial review/description of the clutch came from the AP engineers. To be honest, it was on such a technical level that it was like a different language. We've gone through their description and made it a bit easier to read/understand. If you would like to see the engineers description of the improvements that were made feel free to PM me with your email address and I will forward it to you.

Most of you haven't had the stock clutch out of your car so you don't know exactly what it looks like. Once we get the new clutch from AP I will be taking some comparison pictures to better illustrate these improvements.

There were four primary improvements made to the clutch that result in one major improvement.

1. The two AP friction discs have a reduced wave spring in the middle of the discs. This improves the clutch in a couple of ways:

A) There is a more positive feel to the pedal during engagement
B) The travel is reduced to 65mm (2.55 inches) from 90mm (3.54 inches) from engaged to disengaged. Basically, you won't have to push so far to the floor to get the clutch to disengage.

2. Clutch cover diaphragm springs are tested and selected to have the highest possible rating that is still within Ford's range of allowable tolerances. This is important as an excessively high spring pressure clutch could cause premature engine thrust bearing and/or clutch release failure. This also results in a clutch that is virtually identical to stock in pedal effort.

3. The friction material used is a proprietary AP facing develop for use in their street clutches. This material has much better heat dissipation and fade resistance than the factory Ford F510 material used in the stock clutch. The combination of optimized diaphragm pressures and improved clutch friction material results in a clutch that can transmit 616 ft. lbs. of torque yet still be completely streetable.

4. The friction discs are upgraded to a 6 spring design rather than the 4 spring design of the original. This allows for more torque capacity and increased longevity during heavy use.

This clutch is a direct result of extensive testing done by Stillen on the New Zealand Targa Rally.
 

kmillen

Well-known member
Jan 29, 2007
504
We wanted to keep the cost reasonable so we stayed as close to stock replacement as possible. An O.E.M replacement clutch is $1,829.00. This new and improved clutch will be $1,878.00

We will have the first five clutches arriving within the next few days.
 

Kingman

GT Owner
Mark II Lifetime
Aug 11, 2006
4,072
Surf City, USA
...WOW!! Price gouging! :biggrin

I must say that Stillen is becoming more and more the 'go to' guys!
 

Hammer

GT Owner
Mark II Lifetime
Sep 10, 2006
222
San Diego, CA
Sounds great, Kyle!
 

dbk

Admin
Staff member
Le Mans 2010 Supporter
Jul 30, 2005
15,247
Metro Detroit
I'm gonna copy this to the tech section. :cheers
 

dbk

Admin
Staff member
Le Mans 2010 Supporter
Jul 30, 2005
15,247
Metro Detroit
Sounds like a great deal!

Not that many people drag race their GT's, but would you recommend this clutch at all for that application? Or is it mainly a piece destined for road racing?
 

STORMCAT

GT
Mark IV Lifetime
Le Mans 2010 Supporter
May 25, 2006
7,580
Ft. Lauderdale
Kyle,
Thanks for sharing the details .. Do you have any idea what the stock clutch torque load rating is?
 

kmillen

Well-known member
Jan 29, 2007
504
Sounds like a great deal!

Not that many people drag race their GT's, but would you recommend this clutch at all for that application? Or is it mainly a piece destined for road racing?

Actually this clutch is good for daily drivers as well. After everyone stopped by our shop we all got together and had a mini meeting about how it went and what was the most common thing we had heard. Everyone of us agreed that people were asking for a better clutch.

This clutch has a shorter travel, which allows for easier engagement. The only thing that I don't like about the GT is the long clutch travel. This new clutch cuts that down by a full inch.

After the LA cruise at the Rally a lot of people were telling me that they had a lot of slipping and could even smell their clutches. This clutch will not allow as much slip and will be much easier to operate due to the shorter pedal travel.

Even though this clutch will work well for street driven cars it will also work extremely well for track cars or pretty much anyone that enjoys getting out and driving their car. We are also working on a clutch that will be better suited for track cars. It will be a pretty much all out race clutch. It will be quite a bit lighter, it will be a lot stronger and it will basically be in or out operation.
 

kmillen

Well-known member
Jan 29, 2007
504
Kyle,
Thanks for sharing the details .. Do you have any idea what the stock clutch torque load rating is?

According to AP Racing the stock clutch was built to the declared Ford engine torque of
712Nm or 525 ftlbs.

The upgraded clutch torque load rating will be built to handle 830Nm or 612.17 FTLBS.
 
Last edited:

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
I have RW torque of 676 on the dyno. This clutch is better rated than the stock one, but is there a better one for my application?
 

kmillen

Well-known member
Jan 29, 2007
504
This clutch will work fine for you. By the time we send our car back to New Zealand for the Targa Rally we will be putting down around 800FTLBS at the wheels. This is the clutch that we plan on using in our car. We might put in the race clutch that we're developing right now, but we haven't decided yet. Since the rally mandates that we drive the car from stage to stage through city street we're not sure if we want an all out race clutch all week long.
 

tpraceman

THEE GT OWNER
Mark II Lifetime
Le Mans 2010 Supporter
Feb 20, 2006
2,835
Washington Michigan
When will you be ready for delivery?

Are you thinking after the rally and everyone has a warm fuzzy feeling to start taking orders or??????

My clutch is fine but i would buy one to put on the shelf for the future.
 

kmillen

Well-known member
Jan 29, 2007
504
As soon as we get the first 5 clutches we will be putting one right into our car. Since the NZ rally isn't until next year 11 months away haha, we will be shipping prior to then. We will do some testing and driving around here and if we are confident that we have a nice setup then we'll start shipping. Look for this to be ready for shipping around the end of this month to early December.
 

kmillen

Well-known member
Jan 29, 2007
504
We have just received the clutches from AP Racing. Two of them are spoken for already. We just took some pictures and we will be releasing a complete new product flyer with detailed images in the next few days.
 

tpraceman

THEE GT OWNER
Mark II Lifetime
Le Mans 2010 Supporter
Feb 20, 2006
2,835
Washington Michigan
Any chance Stillen will be at PRI this year?
 

kmillen

Well-known member
Jan 29, 2007
504
Unfortunately we will not be at PRI. PRI is kind of outside our niche. We really make parts for enthusiasts while PRI is dedicate to companies that make parts for racers. Our parts are designed for use by enthusiasts and can be used on race cars, but that's not our focus.
 

kmillen

Well-known member
Jan 29, 2007
504
For those of you interested in AP's history and their experience with racing clutches feel free to check out the AP website...

http://www.apracing.com/car/carbon/index.htm
 

Blue GT

GT Owner
Mar 20, 2007
48
Washington State
What is included in the Clutch assembly?

What is included in the Clutch assembly? Thanks, Dan Vargus
 

dbtgt

One lucky SOB to own a GT
Mark IV Lifetime
Jan 4, 2006
1,106
Tulsa, Oklahoma
kmillen,
I am interested in a clutch but want to know if all the R&D is done? Have you installed one and driven it yet? Can you compare your product to the one that Spec has developed for Joe's TT application?
Thanks!
 

HeritageBruce

GT Owner
Mark II Lifetime
Mar 13, 2006
748
Southern CA
I am definitely in for one when the stock unit goes and it will probably go fairly quick now after the Whipple install.
Question for Kyle,
I don't like the engagement point of the stock clutch which is very high in its travel, will the AP clutch engage lower in the arc?