[ Home ] [ Up ]

Brake Information

If you want to upgrade your brakes you've come to the right place. You'll find very detailed information below on how to perfect the RX-7's brake system.

• How to Install a Big Brake Kit (and/or replace the rotors)

• How to Replace the Brake Lines

• How to Install a Mazda 929 Brake Master Clyinder

• How to Install a Brake Proportioning Valve or Brake Line Lock or Brake Pressure Gauge

• How to Flare a Brake Line

• How to Bleed and Flush the Brakes (and bleed the clutch)

• Cross Drilled and Slotted Brake Rotors

• Brake Pads

• Brake Fluids

• Painting Your Calipers

• Mail List Discussion

The Mandeville Autotech Big Brake kit with 18 inch Mito Modular wheels

Brake Fluids

Wet boiling point is the major specification to consider for brake fluid for street use. Wet boiling point is the temperature where moisture that has been absorbed into the fluid will boil. When this moisture boils it fills your calipers and brake lines with bubbles. These bubbles are easily compressed so your brake pedal gets spongy and you can't apply the same force to the brake caliper pistons--your brakes fade.

The dry boiling point is the temperature where the fluid will boil without any contamination present. The cleaner and fresher your brake fluid is the closer your brake fluid will stay to the dry boiling point. This is why racers always do a complete brake fluid flush before a race.

This info supplied by the ever knowledgeable Trey Jones:

Fluid                                         DRY      WET  Minimum Boiling Points °F
Castrol SRF                               590         518
Motul Racing 600                        585         421
ATE Super Blue Racing               536         392
ATE TYP 200                             536         392
Valvoline Synthetic Dot 3, 4         514          333

Castrol GT LMA DOT 3, 4          446          311
Ford Heavy Duty DOT 3              550         290
Performance Friction HP              550         284

Castrol SRF is a hyper-exotic and hyper-expensive brake fluid that is generally used by wealthy Porsche owners at track events. I've seen prices of $78 per liter for this stuff. It is not suitable for the street because it absorbs moisture quickly. Sold in metal cans. I can't afford this stuff!

Motul Racing 600 is a very exotic and relatively expensive synthetic fluid with high wet and dry boiling points. I use this exclusively in my race cars. Too expensive for the street and requires frequent changing due to its hydroscopic nature. [Rob Robinette adds: Many people do use this stuff in their street car and it's compatible with ABS. The bottle says it will last between 12 and 24 months depending upon the application. That's long enough for me. Sold in plastic bottles at most motorcycle shops for $12 per liter.]

ATE Super Blue Racing and ATE TYP 200 are the same brake fluid in two different colors (blue and amber, respectively). BMW recommends this brake fluid for their street cars because it, like Castrol LMA, absorbs moisture very slowly. The advantage over LMA is that ATE has a much better wet boiling point. You can put this stuff in your car and forget about it for a long time. An excellent choice for a weekend track car which also sees regular street duty. Comes in metal cans. This is what I use in all my street cars.

Castrol GT LMA is very good at rejecting moisture and may be kept in your brake system for a couple years. The LMA stands for "Low Moisture Absorption". This is the minimum quality stuff that I would use in my Impala. It comes in plastic containers which do not have a long shelf life. Don't buy lots of this stuff at a time because moisture can make its way through the plastic containers.

Ford Heavy Duty DOT 3 is VERY inexpensive and is popular among racers because of its excellent dry boiling point. It absorbs moisture quickly, but the racers don't care since they change their fluid frequently. Comes in metal cans so it may be stored. I would not use this in my Impala for the street.

Performance Friction High Performance DOT 3 has a good dry boiling point but a crummy wet boiling point. It comes in metal cans which is good for shelf life and sells for $7.87 per 16 ounce container. If you are even considering this fluid, I would go with the cheaper Ford Heavy Duty DOT 3. In either case, change this fluid frequently due to the poor wet boiling point.

Thanks Trey!

Jon

Cross Drilled and Slotted Brakes

Roger Mandeville of Mandeville Autotech has race prepped a lot of cars. He does not recommend cross drilled rotors because cracks form at the holes. He said some racers run them in short sprint races but then throw away the rotors after the race. For endurance races his cars use standard non-drilled, non-slotted rotors. Even rotors that have their holes formed into the rotors when they are cast will crack. He doesn't recommend slotted brakes either.

Brake Warning Light

Also, my brake light will come on when I drive hard......... Anyone know why?

This could be your brake fluid close to the low mark. When you jostle the car around, it could be tripping the fluid sensor. Also, your parking brake sensor may be loose.

There is a very cheesy switch located to the rear and below the parking brake lever. Your parking brake warning lamp is illuminating, most likely, due to one of the following reasons:

Your emergency brake handle is not fully in the down position. There might also be a foreign object preventing it from going all the way down. Even one "click" up from the down position can make the light go on and off.

Your emergency brake handle is loose, allowing it to slide slightly sideways in the down position. This will cause the parking brake switch to not engage fully.

Your parking brake switch is loose, bad or failing. The console panel pops off pretty easy, allowing access to this switch. The switch is located just below the back of the parking brake lever boot. Good luck, hopefully it will be an easy fix!

Dave

Painting Your Calipers

I painted my calipers using Folia Tec brake caliper lacquer (from Ultra Performance (800) 43ULTRA $49.95). Use a fresh, soft, camel hair 1/4 inch wide paint brush and heed the temperature range for applying the paint. Summit racing also sells high temperature caliper paint for a few dollars a can.

Brake Pads

HP Plus pads in the front and HPS pads on the rear is a good street/track compromise. Hawk Blues will eat your rotors very quickly when used on the street (low temperatures). The more aggressive you brake on the track (a function of your driving ability) the higher the temperature range of your brake pads should be. An average novice at a track school event would be fine with HP Plus and HPS pads. An advanced driver in an actual race could use the Blue MT-4 because he would use his brakes hard enough to keep them their prime operating range.

Mail List Discussion

Last December I participated in my 3rd track event. I went through the same problems you have encountered in your first experience. To give you my perspective on your questions:

1) Forget about using street pads for the track and vice versa. It only takes about 10 minutes to change out both front brake pads and the benefits are enormous. I switched to Hawk Blues my second track event and was blown away by the increased stopping power. In addition, the harder I drive, the better they get. The problem is this ... on the street the Hawk Blue's run cold and will destroy your rotors. On the track when they get hot they are great. If you use a street pad on the track, they will fade when hot because they are designed to run cool and NOT destroy rotors. I personally don't think there is a compromise. I simply switch pads out and I have the best of both worlds. Also, you only really need to switch out your front pads. There is little work done by the rear brakes on a track. The other issue is brake dust. For the track, dust is inevitable, but for street use, dust can be annoying and damaging to your wheels. I use MetalMasters for the street and like them. I hear Bonez pads are good for the street. Both produce relatively small amounts of dusting on the street, however both will fade in track application. Your best bet, do what I did ... purchase a used set of wheels for the track and keep your good wheels for street use. Track wheels can look bad, accumulate dust and be just fine. Save your good wheels for looking good on the street. Hope this helps.

Jon A. Drake

I have run my TII and 3rd gen. at track events for a few years and here is what I have found. There is no good tire for street and track use. For track only I like the BFG R1's and now G force tires. I have tried Hawk Blue, Black, HP+, and HPS, Bendix and Repco. For the track I like Hawk Blue MT-4 pads. Be careful because there are two types of blues and the Hawk Blue 9012s still fade a good bit. The other Hawks I found to fade WAY too much for serious braking. (and they suck on the street). I burned through a new set of Blacks in one weekend. For the street I like the stock organic pads because they are soft and conform to track grooved rotors well. Don't run Blues on the street.

If you are unwilling to change brakes and tires for events then a mediocre compromise would be the Porterfield RE4 pads and pick a tire based on the miles you drive. If you drive less than 5k a year you could probably get away with a true track tire. If you drive more, the A032 might be a good choice. My rational is to buy long wearing street tires to save money, and use the funds to run track tires. Lots of people are selling used stock wheels. Long wearing street tires also allows you to run more negative camber without eating up the insides of your street tires. Alignment has a HUGE effect on handling. The new BFGs are also more negative camber hungry than the old R1's.

Trey Jones

1. Use stock rotors from Mazda Comp or Porterfield ($80/each)

2. Do not allow shops to use air gun to put on wheel lugs and have them properly hand torqued (over torque warps them 2)

3. Do NOT do a high speed fast stop and immediately come to a complete stop and sit. It does make a dam bit of difference what kind of rotor you have if part of it is sitting under the caliper, red hot and cannot cool down at the same rate as the rest of the rotor because you are sitting still. If nothing else, let the car slowly roll for several seconds before coming to a complete stop.

4. Try the Hawk HPS (Street) pad. It is more than adequate for street driving and gives minimum dust. It’ll stop you from 150 to 0, no problem. If you are looking for track level performance (back to back stops as above) then go with the Hawk HP Plus or Blacks. Anything more aggressive (like the Blue) are for the track only, your rotors would likely be worn through before they got a chance to warp.

5. Slotting and drilling are to vent gas and dust and have no significant effect on cooling. Drilled rotors do weaken the rotor and make it more likely to crack. Both mod cost extra and can be done to any stock solid rotor.

6. Use a quality DOT4 brake fluid such as Motul 600 or AP600 and bleed your brakes at least once a year (full flush of system)

John can comment, but in 13 drivers schools (about 40 hours of track time) with stock rotors I have yet to have a problem with fade or dust and have used Mazda stock rotors (HPS pads for the street, Blues for the track).

Hawk HPS - (High Performance Street) pads are good street strip compromise

 Gordon Monsen wrote:
 
  Brad,
 
  i use peter farrell's vented/drilled 12.75" rotors with willwood 4 piston
  calipers. do you think the porsche brembo offers any notable improvement?
  thanks, -Gordon

 Yes. To some racers, Wilwood calipers are cost-effective and replaceable. Unlike
 AP and Brembo units, the Wilwoods I have seen have no dust seals around the
 pistons. While not a big problem, they are not as maintenance-free as the OEM
 quality calipers. No big deal if you tear down and go over your braking system
 after every race. Wilwoods are also popular due to their availability, price, and
 model selection.

 Unfortunately, Wilwoods are structurally far less stiff than the AP/Brembo units.
 If you have someone pump the brakes while you carefully look at the Wilwood
 caliper, you will probably see it flex. You would see no such flex with AP or
 Brembo components. There is a cost differntial, of course. A Wilwood 4 pot
 caliper costs $65-85 from Jegs. A comparible Porsche/Brembo calipers costs
 significantly more (around $300, IIRC) from a Porsche dealer. They are even more
 expensive directly from Brembo, from what I've heard.

 Caliper stiffness is very critical in performance. A stiffer calipers maximizes
 pad life and improves brake feel/modulation. Whether it is worth the extra $$ is
 up to the buyer.

 FYI, the stock aluminum, lightweight, 4 piston front calipers on the 3rd gen are
 very, very nice. You'd be surprised how many "high performance cars" use heavy
 iron calipers with floating pistons. The stock caliper's limitation is that they
 can only accept stock-size rotors (11.5"x.8"). [this is why the Mandeville Autotech big brake kit widens the stock calipers to work with 13"x1.1" rotors] The smallish stock-sized rotors
 can only store so much heat before fade becomes a problem.

 The stock pad size is also relatively small compared to aftermarket alternatives.
 The larger the pad, the longer its life. No big deal on the street, but in an
 endurance race, pad life can be critical. This is why 6 piston calipers are
 popular in certain types of racing. They don't brake any better, but the pads can
 last 50% longer. Downsides: More fluid needs to be displaced. Inital "bite" is
 also reduced. It's a common misconception than a 6 piston caliper will
 "outperform" a comparable 4 piston calipers.

 Only when we get into 8 piston calipers, does actual braking performance improve.
 This is because 8 piston calipers use 2 pads. Approx. 15% of all braking friction
 comes from the leading edge of the pad. Two leading edges-- more friction. Lots
 of pad area as well--- longer pad life. Cost a lot though...

 As for rotors, Brembo units are very nice. Holes are cast in, not drilled in.
 This greatly reduces the chance of stress cracks. They also use very high-quality
 iron and are very thick (typically 1.1-1.25"). All things equal, a thicker rotor
 is stronger and more fade resistant. They are also expensive, no doubt partly
 because of their overseas origins. They are one of the best, nonetheless.

 -Shiv

[ Home ] [ Up ] [ Engine Related Notes ] [ Vendors ] [ Tires ] [ Brakes ] [ Antiroll Bars ] [ Emission Testing ] [ Wheel Offset ] [ 1/4 Mile ET ] [ Top Speed ] [ Tire Diameter ] [ Winter Storage of an RX ] [ Cockpit Instrumentation ] [ 99 RX-7 Updates ] [ Nitrous Primer ] [ War Stories ] [ RX-7 E-Mail List ] [ Time Hack ]