my little red 90

Gentlemen,
I have several brake questions.

I drive on the street and plan to do more road courses this season.

[ul][*]Is there any real differences in brands od DOT4 fluid? Mine states the boiling point of 311 degrees F.[*]I've been to Buttonwillow 2 times. I have a pretty good setup, but am still learing to drive the car, so probably not going fast enough to really heat things up. I have now experienced any noticable fade, but we only get 15 to 20 minute runs.[*]I have 13" Cobra front rotors with Hawk HP+ pads. The rears are from an '88 MK VII. I can't find anyone that supports better pads. Someday I will be able to go faster and will need more braking. any suggestions?[*]Will running air ducting to the rotors help enough for the money?[/ul]
Thanks

jayel579

I think DOT4 or DOT5 is a silicon base, I am not possitive on which. What you want to be concerned with is your Wet Boiling point, that is what the boiling point is once water or moisture mixes with the actual brake fluid. Obviously the higher your Dry boiling point the better but the wet boiling point is the one to be conerned with. Any high temp brake fluid will work as long as it is clear and not cloudy at all. Motul, ATE or even Ford HD fuild is very good. A 20 minute session is about all you are going to get while you are still learning so I wouldnt worry about that. You can step up to a more aggressive pad, like a HT-10 or I think they are DTC-60 now made by Hawk. If you have a good setup I am going to assume you know how to work on your car. Change you pads at the track, anything more aggressive then a HP+ isnt going to be good on the street. You cant go wrong with air ducting, I dont have it for my car yet but I also plan on adding them on my car. But I think you are loosing out on braking from your fluid, step up to a better fluid instead of an off the shelf fuild from your parts store.

PonyGT2005

1) Yes there are differences btw different brands of Dot4.

The wet boiling point comes into play when water is absorbed into the brake system (which will happen as the flluid brakes down). Products aimed to track/competition use will have a higher operating range.
311 degrees is the minimum temp the wet boiling point for Dot4. Prestone and other base brands meet the minimum.
Not only is the actual minimum temp important but more important is how quickly the fluid will brake down under stress (heat/cool/heat cycles under pressure).

Motul is one of the best products out there that I have used for club racing applications.

FYI - Dot 3, 4 and 5.1 are all glycol ether based - DOT 5 is silicone based and not appropriate for racing applications (well neither is 3 for that matter).

2) In short, if you are comfortable with your setup, just pay appropriate attention to maintenance on fluids, pads, lines etc. and you should be good. I usually bleed my brake fluid every event and sometimes multiple times during a weekend (when we are not too busy). At most of the tracks I am at there is a shop that can measure brake fluid temp and tell if it needs to be replaced. A good habit is to take the time to eyeball your brake components (pad thickness, lines for crimps, splits or drips, etc.) before you hit the track each and every time.

Once you get more experience and start looking for optimum performance, it will be important to pay more attention to your brake system as a *whole sytem* instead of just a bunch of interchangeable parts.
I find most of my time under braking and as you start learning various braking techniques you'll expect and need more out of the system.

Ultimately, its important to mate your fluids, pads, rotors and the calipers as a "system". Rotors and pads have a temperature range in which they provide the best braking performance. Managing the brake components in that *sweet spot* is part art (the driving) and part science (the prep and maintenance). For the science part, heat sensitive paint on your rotors is a good method of finding the temps at which you are running. A pyrometer is a good tool as well. Both pretty much require you to have someone to check the temps for you when you come off track so that you can get accurate readings.

3) For most 2 or 1 (e.g. rear) piston brake systems on Mustangs I am partial to the EBC line of products (I really liked the EBC yellow pads on my stock brake system). Hawke has a good line as well. You did not mention what calipers you have mated to those 13" rotors. I am running Mintex on my AP racing calipers (4 piston) right now and have been pretty happy with them, butI am probably looking to try some other pads through the next season once I get some proper temp data. Performance Friction has a great line of brake products as well and they are quite pricey (but you pay for great performance).

4) In general, yes ducting is worth the money. On the high speed parts of the course, it will help bring the brake components back into the "sweet spot".

my little red 90

thank you both.
the front rotors & calipers are Ford FRPPP pieces. the rear are Linclon MK VII. i have checked both Hawk & EBC, but neither list anything for the rear. Maybe i can find a Hollander # to see what else used these rear calipers. They are single piston, but so far they work OK for me. When i get up to speed, i expect i will need more.

CMC#11

Your rear pads are nowhere near as important as your fronts. I know guys that always race on stock rear pads and never have issue. I personally have EBC yellow stuff on the rear of mine and they last forever. I am not sure of the availablilty for Mark VII pads though.

Brake cooling ducts help out greatly as well, also a proportioning valve.

I would get everything up to snuff with your fronts (pads, fluid, cooling ducts) before you even think about the rear.

PonyGT2005

I totally agree on with CMC#11's comment on the rear pads....EXCEPT that one time ... I was at TWSlast April.
I had checked all my pads Friday night and the fronts were brand new(just changed and bedded that week) and the rears were over 50%. I figured good enough. During Saturday I checked the fronts only thinking, "rears only do about 10% of the braking so they won't have changed much".
Fronts looked great - obvious wear but still plenty. Sunday AM, same thing...fronts only.

Sunday around noon I came off - brakes felt fine but I decided to check anyway...a nagging feeling told me to check the rears....when I did there was ZERO pad left...in fact the shim was pretty much all that was left. There was oviously grooving (a lot less than I thought there would be) in the rotors and the calipers were locked up solid (completely frozen).

So, moral to the story -I check my rear pads when I check my fronts.

my little red 90

Thanks to all!
I have a manual proportioning valve, SS lines and i am investing in some good quality fluid.
Quantum Motorsports has a duct kit that will connect to my spindles, but with the LX facia, it will be more challenging to mount it into the air than it would on a GT. Going to get it and fabricate something that will keep it pointed into the air.

Your advice should increase the fun and decrease the dust.