Rally 12 Track Day Tip #1


Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,526
Greenwood, IN
So as R12 excitement builds we are but a short three months away from another fabulous FGT rally during which we will see a number of owners with their new GT’s. It will be a very unique rally. And for roughly 50% of the attendees who did not attend Rally 6 in Utah previously, you are in for a special treat at Utah Motorsports Campus (UMC). Simply a beautiful track with 23 turns and long straights where the driver can exercise the FGT’s incredible speed. This post is targeted at the 05-06 owners wanting to go out on the track and experience the driving potential Ford gave us in the GT. The new GT owners may find this topic interesting but it does not pertain to them…yet.

As speeds can be high on the track at UMC so then must the braking ability be up to the task of pulling them down for the turns. It has been 11 years since our last 2006 GT rolled out of the production facility and hopefully most owners have flushed and changed their brake fluid. The Motorcraft DOT3 (part number PM-1-C) brake fluid originally installed in our cars is a perfectly fine and inexpensive brake fluid, if it is fresh. And by fresh I mean flushing out the whole brake fluid system and replacing it with new fluid. The whole FGT development program was completed using the Motorcraft fluid. The 05-06 FGT passed the demanding certification AMS 10 cycle DSTOP test without any special fluids, pads or tires. Parenthetically, the last three stops of this grueling 10 stop test resulted in the shortest braking distances. Ford gave us good brakes on our FGT. If you have not changed your brake fluid in the last 12 months, you really should give STRONG consideration to doing so.

Changing the fluid is a relatively easy process but if you do not feel comfortable performing this task take your GT to your local mechanic or dealer and have them do it for you. Brake fluid is “hygroscopic” meaning over time the fluid absorbs moisture from the atmosphere. It does this through the caliper piston seals (4 in each caliper) and the master cylinder cap which is vented. As moisture is absorbed into the brake fluid its resistance to boiling is lowered. When enough heat is put into the fluid (by hard braking) to cause it to boil you lose braking ability of the car. From my personal experience, this happened when I needed my brakes the most at the end of a long straight and a sharp upcoming turn. It will get your attention!

All North America brake fluids are controlled by the Federal Motor Carrier Safety Administration (FMCSA) Standard 116. All fluids are required (S5.2.2) to list the brake fluid’s “wet” Boiling Point (BP) (humidified fluid sample per S6.2). Most also list their “dry” (no moisture in the fluid) BP as a means of comparison with other fluids. When you frequently flush your brake system the hope is to have the fluid boiling properties more toward the dry side BP than the wet side. You do not have to select any special high performance brake fluid for your car (although you can easily move into a higher capability and more costly DOT4 fluid). What is most important is freshness. The OE DOT3 Motorcraft fluid has a dry BP of 500F at about $4 per 12oz container. The VERY best brake fluid is Castrol SRF which has a dry BP of 590F at about $62 for 34 oz. Everyone seems to have a favorite so just pick a fluid and have it changed.

A word about packaging. When flushing your brake fluid I suggest purchasing just enough new fluid to make the flush just prior to actually performing the transfer. Do not (ever) use a previously opened brake fluid bottle or one which may have been in your garage you bought years ago for another job. Buy specifically what you need at the time you intend to do the change. Unfortunately the plastic bottling most (but not all) brands use to package their fluid does have a Water Vapor Transmission (WTV) associated with the plastic. Over time sitting on the shelf, the fluid can absorb water vapor compromising the dry BP before you ever add the fluid to your brake system. This WVT can be made very low by selecting more costly plastic compounds but the permeability rate will never be zero as it is with metal packaging. ATE Type 200 is a good reasonably priced fluid (about $17 for 34 oz.) which is packaged in a metal container. There may be other metal container brake fluids as well. The key is again freshness. Whichever fluid you choose, purchase from a store which has a high product turnover. Although FMCSA Std 116 paragraph S5.2.2.1a mandates the fluid packager label each bottle with a manufacture date code I have never found these to be decipherable to any purchasing value. My advice, just buy fresh from a high volume stocking store.

Also while you have the rear wheels off the car for bleeding (inner bleed port first on our dual port Brembo’s) check the axle nut paint line with the mark on the axle shaft threads. When all our cars came off the assembly line this nut was marked to align with a line (also marked) on the axle threads. Make sure the two marks are aligned. If they are not then tighten the axle nut to again realign the match marks. The marks do tend to diverge with drive time so make sure they are aligned. If you have no alignment marks, my build book says the axle nut (35 mm socket) torque was to have been torqued to 400.0 Nm ± 30.0 Nm. And it was identified by Ford as a “critical” torque.

We will have a great time at UMC this year and performing some prior-event maintenance on your car will allow your total concentration to driving the track and enjoying your experience. One other important pre-rally topic is tires and that will be covered in an upcoming thread.
 

Vince H

GT Owner
Mark II Lifetime
Jul 23, 2012
2,417
Southern California
Love the detailed explanation and then the layman's instructions to buy from a high volume store and do it or else. Perfect advise for someone like me and will do just that!

Vince H
 

soroush

Ford Gt Owner
Mark II Lifetime
Aug 8, 2007
5,256
thank you great info
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
Indy is quite right. Last time there several people boiled their brakes. ALSO, change your clutch fluid at the same time. It uses the same stuff. This was probably the BIGGEST problem we had overall (other than overheating and going into limp mode due to the very hot ambient temps). Take into account we'll be doing mountain driving and you can avoid all these problems.
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,526
Greenwood, IN
Good catch Frank!:thumbsup

The clutch master cylinder uses the same brake fluid and should be changed as well. I typically do not change this fluid as frequently as IMO the brake system fluid is more important. But good to do both.
 
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Beez

GT Owner
Mark II Lifetime
Oct 28, 2016
195
South Denver
I am definitely your target audience - thank you so much!

Receipts indicate my car's brake fluid was changed just 400 miles ago, but that was about 2.5 years ago. I had been thinking that was fresh enough, until this very informative post. Indy I eagerly await any future chapters!
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
You had to say that! Now we'll have long chapters.
 

68Rcodeman

GT Owner
Mark II Lifetime
Apr 5, 2008
800
Spring Hill, FL.
Great info! Thanks for this post. Looking forward to the additional chapters.:thumbsup
 

maxemus

GT Owner
Mark IV Lifetime
Apr 25, 2007
886
Miami, Florida
Oooops. I haven't changed mine since rally X
 

Ed Sims

GT Owner
Mark IV Lifetime
Apr 7, 2006
7,850
NorCal
Indy GT is back!

Ed
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,526
Greenwood, IN
Indy GT is back!

Ed

More to come my friend!:thumbsup

And for Frank's sake I will try to be succinct.:biggrin
 

Specracer

GT Owner
Mark IV Lifetime
Nov 28, 2005
7,081
MA
Also with regard to braking, if you have changed your pads from OEM for dust reasons, be sure the replacement pads are track worthy. There was a brief trend where people were using a duralast or something like that. There were 2 members that had these at NOLA, and COOKED them. They did NOT work for the track. Padgid Yellows for me.
 

GTMD

GT Owner
Mark II Lifetime
Jan 4, 2011
957
NorCal
Great post! Keep it coming!! Prepping already for R12.
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
Check you A/C. Anyplace can do it. Standard everything. Takes 16 oz if I remember . A lot of us with unmodded cars run the A/C on the track cause the fans come on earlier.
 

roketman

GT Owner
Mark IV Lifetime
Oct 24, 2005
7,994
ma.
Couldn’t agree more
 

Ed Sims

GT Owner
Mark IV Lifetime
Apr 7, 2006
7,850
NorCal
...And for Frank's sake I will try to be succinct.:biggrin

Ouch!

Ed
 

NorthwoodGT

GT Owner
Jun 12, 2009
1,215
Michigan
Indy is quite right. Last time there several people boiled their brakes. ALSO, change your clutch fluid at the same time. It uses the same stuff. This was probably the BIGGEST problem we had overall (other than overheating and going into limp mode due to the very hot ambient temps). Take into account we'll be doing mountain driving and you can avoid all these problems.

you run the car that hard that you boil the brake fluid? geez
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
Scott, the track temps last time we were there were well over 100 degrees.
 

NorthwoodGT

GT Owner
Jun 12, 2009
1,215
Michigan
I've run tracks all over the south and east in many different cars and never boiled the brake fluid regardless of the ambient or track temp. I guess I'm just a little surprised. I never thought that would be an issue in a GT. jmo
 

KennethClay

GT Owner
Mark IV Lifetime
Oct 15, 2012
860
New York
It mostly has to do with how hard you're braking, not the track temperature.

There's no feeling quite like coming up to a hard left-hander and threshold braking, only to find that the pedal goes to the floor! I made the turn (with my heart in my throat), but decided to put racing fluid in after that and didn't have any more problems.