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SE-R Brake Performance Tips

Written by Mike Kojima

Last updated: 12/22/98


Jump to: Some additional information that people might be interested in:

If you want to go, First you must stop. One of my favorite sayings is "Speed doesn’t kill, rapid deceleration does"!

As braking is critical to your safety and modifying your brakes can affect your own and others safety, please read the disclaimer below before continuing.

Warning! Modifying your car is hazardous. Any kind of high performance driving can be hazardous. Before doing anything to your car, realize that you and you alone are responsible for anything that could happen to yourself and others that you come into contact with. Please work on your car and test in a safe, legal manner. The editors of se-r.net are not responsible for yours or others well being. If you cannot accept responsibility and are the type that will sue, you are scum, please disregard everything below and never come back to se-r.net again!

The Classic SE-R and the 200SX are both blessed with pretty good brakes right off of the showroom floor. Power assisted 4 wheel disc brakes with vented front rotors come as standard equipment. With proper preparation I have raced totally stock brakes right down to stock pads with pretty good results. I guess I should start off this section with an explanation of some common brake problems encountered in fast driving and how to counter them.

 

Brake Fade

Brake fade is the number one high performance driving braking problem that is encountered. Brake fade is a dangerous situation when after braking hard several times in a row such as when you are racing, you lose brake effectiveness. This usually occurs gradually so you can compensate in your brake point by braking sooner, but sometimes happens so suddenly you can end up going on a wild off-road excursion with sometimes fatal results.

There are three kinds of fade commonly encountered in fast driving; pad fade, green fade and fluid fade. Below are listed an explanation of each.


Pad Fade
Pad fade occurs for several reasons. All friction material (brake pad stuff) has a coefficient of friction curve over temperature. Friction materials have an optimal working temperature where the coefficient of friction is the highest. Sometimes you can use the brakes so hard that you get the temperature over the point of maximum friction to where the coefficient of friction curve starts to decline.

The mechanics of this decline in the coefficient of friction are varied. At a certain temperature, certain elements of the pad can melt or smear causing a lubrication effect, this is the classic glazed pad. Usually the organic binder resin starts to go first, then even the metallic elements of the friction material can start to melt. At really high temperatures the friction material starts to vaporize and the pad can sort of hydroplane on a boundary layer of vaporized metal and friction material which acts like a lubricant. Pad fade is felt as a car that still has a decent, non mushy feeling brake pedal that won’t stop even if you are pushing as hard as you can. Usually it builds somewhat slowly giving you time to compensate for it ,but some friction materials have a sudden drop off of friction when the heat is put on them resulting in sudden dangerous fade.


Green Fade
This is perhaps the most dangerous type of fade that has injured more race car drivers than any other type of brake incident.

Green fade is a type of fade that manifests itself on brand new brake pads. Brake pads are usually made of different types of heat resistant materials bound together with a phenolic resin binder. These are thermosetting plastic resins with a high heat resistance. On a new brake pad, these resins will out-gas or cure when used hard on their first few heat cycles. The new pad can hydroplane on this layer of excreted gas. Green fade is dangerous because many people assume that new brakes are perfect and can be used hard right off the bat. Green fade typically will occur much earlier than normal fade so it can catch a driver that is used to a certain car’s characteristics unaware. Typically the onset of green fade is rather sudden, further increasing the danger factor. I was a victim of green fade once. The crew forgot to tell me that new brake pads were installed on the car and when I went out on the track, I was flying down the escape road at about the third corner! Some teams have a new pads warning sign that they place on the steering wheel to inform the drive to be careful on his first few laps.

Green fade can occur if you change the pads and drive on the street for a few hundred or even thousand miles, never braking hard, then suddenly start using the brakes hard. I think that this is the fade that many list member complain about on their own cars.

Green fade can be prevented by bedding the pads. This is a simple procedure to boil off the resins and break in the pads under controlled conditions which I will explain later.


Fluid fade
Fluid fade is caused by the boiling of the brake fluid in the calipers. This produces bubbles in the brake system. Since bubbles are compressible, this makes for a soft spongy pedal. In worse cases, the pedal can plunge to the floor with very little slowing! Fluid fade can be avoided by running a high grade racing type brake fluid and/or frequent changes of brake fluid. Also if you change the pads before they get super thin, the remaining friction material will help insulate the calipers from the heat. Some people have had some success with having swaintech spray thermal barrier coating on the backing plate of the pads to help isolate the heat but I have never tried this.

Fluid fade usually has a gradual onset.


If you are having an exceptionally bad day your brakes can fade from all three of the above reasons at the same time! The reason why I am explaining them to you is so that you can identify what kind of fade that you are suffering from and do the proper thing to fix the type of fade that you have with the correct countermeasure. If you are experiencing pad fade, switching brands of brake fluid won’t help. If you are getting fluid fade, the trickiest carbon pads won’t stop you a bit sooner. If you have the finest brake parts available, you could still fall prey to green fade.

 

How to Fix Brake Fade

Reducing Pad Fade

Pad fade is fixed by getting pads with a higher coefficient of friction at higher temperatures. On our cars the stock pads, Genuine Nissan only, are remarkably good. At the 12 hours of Sebring we miscalculated the wear rate of our trick Performance Friction carbon pads. During practice, we ran out of replacement pads for our two car team. We did a mad dash to a local Nissan dealer and put bone stock pads in one of the cars, the one that had no chance of winning, the one I was driving!

I bedded the pads and went out, braking carefully. As it ended up, the pads worked pretty well, fading slightly then stabilizing. We ended up running the race on those pads for one car.

Granted, Sebring is not a super heavy braking track, but it still means that the stock pads, if bedded properly are not half bad. So don’t pitch them in the trash unless you feel that you really need them.

Brake pads can be roughly broken down into about 4 types:

  1. Organic - Made of stuff like cellulose, which is like ground up cardboard! The cellulose is held together with a phenolic resin binder which is a heat resistant thermosetting resin. Pot handles and stuff like that is made of phenolics. Organic pads used to have asbestos to give better high temp properties but since asbestos is now a carcinogenic a no-no, kevlar, fiberglass and mineral fillers are now also used. Organic pads have a good coefficient of friction for a light pedal effort, work well at low temperatures and are very quite. They do not work so good for high performance use as they quickly wear, fade, oxidize and crumble. Organic pads are kind of old school and are common on cheap aftermarket replacement pads for older and sometimes new cars. These pads do not wear the rotors very much. Some cars have these as stock pads. Beware of these as they are worse than the stock pads. Suspect any cheap aftermarket pad. Organic pads are usually a light brown or tan in color.
  2. Semi-Metallic - These have some powdered metal added to the mix to help stabilize the coefficient of friction at higher temperatures. Typically powdered Brass, iron or Bronze is added. Chopped brass or bronze wire is sometimes added to help give the pad more mechanical strength. Most stock pads on newer car are semi-metallic. Usually these pads are excellent for all-around use. They can run the gamut from very little metal to almost all metal. The more metal usually means better high temp properties, more noise, more rotor wear and less effective cold braking. Semi-Metallics run the gamut from light tan with metal flecks in them to a dark gray in color. The darker pads usually indicate a higher metal content.
  3. Full metallic - These pads are made of sintered metal with very little binder. Sintered metal is powdered metal that is pressed into a mold at high temperatures until it becomes a more or less homogeneous piece. Pads of this type are pretty aggressive with ones made of brass, bronze or copper or a mix of metals being more streetable and ones using iron being more high temperature oriented. For very high temperature use, ceramic powder is added to the pad material. Axxiss Metal Matrix pads are streetable nearly full metallic pads that are made of brass and bronze powder with a resin binder. They are very streetable but I would not consider the other pads in this category as usable or even safe for street driving. Full metal pads are noisy, don’t grip when cold or wet and chew up rotors with annoying regularity. These pads make killer corrosive black brake dust so clean your rims frequently! I don’t think anyone on this list, even racers should consider anything more aggressive than the Metal Matrix or the new carbon pads. These pads are usually a dark gray to black and sometimes even copper-looking with a lustrous sheen.
  4. Carbon - Carbon pads available to us mere mortals are not the amorphous carbon-carbon exotica that F-1 cars, the space shuttle and high performance jets use. They are not "carbon-fiber" either. Carbon pads that are available to us normal people are semi-metallic pads that have powdered carbon added to them to improve their high temperature properties. Personally I like most of these pads. For the most part, they have the cold friction of a good mild semi-metallic with the high temp properties of medium aggressive full metallic. Even the full race, high metal/carbon pads seem to have a fairly wide effective heat range. They for the most part are fairly good on the rotors also. Since they work so well over a broad range, carbon pads seem to have taken over the high-performance street pad market. The only drawback that these pads have is cost. They are pretty pricey. In my experience, they seem to wear a little faster than one might expect also. They also leave lots of black, corrosive, yucky, sticky, brake dust which is the main reason I will not use them on my street car. The full race carbon pads seem to eat rotors pretty well to. Carbon pads are a flat dark gray to black with a flinty look.

Pad recommendations
In my opinion, most casual high performance drivers can get along fine on a set of properly bedded stock genuine Nissan pads. Even autocrossers and racers can get away with stock pads under certain conditions.

If you are overdriving your pads you will notice a gradual onset of lack of braking. If this happens you will have to back off and maybe the pads will recover. If you continue to beat on them, the pads will be ruined by becoming permanently glazed. If you keep going, the pads will chunk and start to physically break up. If you still insist on going, the pistons will wear through the backing plates causing a major loss of hydraulic pressure in the brake system and you will die. Don’t laugh. On an Escort endurance race that I was working, one of our drivers did just that at Mid Ohio. Ever see a 3600 lb. turbo Supra fly 60 ft in the air? After clearing a couple of motorhomes the Supra landed right in the middle of a BBQ flattening it. Fortunately no one was seriously hurt but the Supra was very totaled and the BBQ was around inch tall.

As a warning for you weekend warriors that commute in your race car, or for street bombers that drive hard on the street, usually in the case of brake pads, friction materials that work well for higher temperatures work worse at colder temperatures. This can make the first few morning stops kinda hairy. In the rain or cold days can be sketchy as well. Some extreme pad materials never get up to operating temperature on the street. Brake pads that work well at high temp’s usually have a higher metallic content which makes for more squeals and squeaks also.

For the money, I think it’s pretty hard to beat Axxiss Metal Matrix pads, if you are a Solo competitor, or just drive hard. These pads last a long time, don’t kill rotors, and are reasonable in the cold (be careful at the first couple of morning stops!). These pads are about the price of carbon pads. They are even good for light use race pads. Best off (for me!) they make very little dust, minimizing cleaning chores.

If money and cleaning are not an issue, you can go for the techy carbon pads. Carbon pads have the widest operating heat range making them the best multipurpose pad. Hawk HPS compound pads are good for street and even some pretty good race action. If racing on a heavy braking course, the Hawk Blue pads will not even fade at all! Do not even think of using these on the street. I put them in my twin turbo Z and in about 1000 miles they totally ate my rotors! A few people have told me (Steve at SMC, Terry at KVR) that if they are operating at normal (hot) temperatures the rotor wear is better. It was a sad sight to pull my rotors that were ground off about close to 1/8 inch on either side to find that the brake pads were like brand new! Porterfield’s R4-S and Performance Friction’s Z compound are good carbon pads for mild racing or hard core street also. Porterfield and Performance Friction have more aggressive, higher temperature compounds available also but I have never had to use them, even when racing. Just stick with the more mild entries unless you have a specific need to go to an aggressive pad. Be sure and remove the black dust from your wheels frequently or it will become permanent. The black menace can even eat up the paint on the sides of your car if you leave it there too long.

In short, to avoid pad fade, select a pad whose operating temperature matches the type of driving you do. If you drive mostly on the street, be realistic and select a pad whose operating temperature matches street conditions, as a pad with poor cold characteristics can actually be dangerous. You can change to a more aggressive pad for weekend action in less than an hour so don’t give yourself pads with poor cold stopping for everyday use!

Reducing Green Fade
The way to eliminate green fade is to properly bed or break in your pads before you have to use them hard. The trick is to get rid of the volatile elements of the binder resin without overheating or glazing the pad. If you have ever seen your brakes smoke? That smelly stuff is the volatile resins being cooked out of your pads. Bedded pads will not smoke very easily.

It is better to bed new pads on older rotors. Older rotors are seasoned and more dimensionally stable making them less likely to warp or crack while bedding. Older rotors for some reason are less likely to glaze new pads. I am not sure why on this but Carrol Smith, the renowned race car engineer once told me this as a tip. You should always run a new rotor in with bedded pads also for the same reasons. I have gotten away with violating this rule many times but Carrol is super smart so I at least try to follow his sage advice.

When replacing your pads, sand your rotors with an electric drill with a 220 grit sanding disc, putting a light cross hatch pattern on them. This helps break the glaze on the rotor and aides in bedding the new pads quickly. Install your new pads and go for your bedding run. Before making the first stop after changing pads pump the brake pedal before you really need to stop. The pistons are fully retracted into the caliper when you change the pads and the pedal will be real long at the first brake application. I witnessed a serious racing accident caused by this where the driver was nearly killed. It was the 12 hours of Sebring and we drove under a yellow for almost one hour while they cut the poor guy out of his Prelude. The car had just pitted, the crew had changed pads and a new driver was put in the car. In a red mist the driver tore out of the pits and jammed down the pit road and front strait. He did not touch the brake pedal until turn one when he discovered that the pedal went to the floor. The Prelude hit the tire wall head on at well over 100 mph. The car was very totaled and the driver suffered serious leg, arm, head and internal injuries.

When bedding the pads, be very careful as the brakes will not work to well until you are done. The way that I bed brakes is as follows:

I do my bedding on the open road when there is little traffic. Drive at about 50-60 mph and apply the brakes, dragging them while giving the car gas to maintain the speed. Drag brakes for about 10 seconds and release. Drive for about 1 minute to allow the brakes to cool, then drag the brakes again for about 20 seconds. The brakes may begin to smoke, stink and you might feel a bit of green fade at this point but that is normal. Drive for another minute to cool things off again and drag the brakes for 30 seconds. You should defiantly be smelling the brakes now and feeling some green fade. Be careful at this point as now you will not be able to stop too well if you had to. Drive about two minutes and repeat the process. You might have to repeat this up to three times. You can tell when the pads are bedded when you don’t feel the onset of green fade any more. Be careful not to overdo the bedding process or you could glaze your brand new pads or even warp or crack your rotors.

Note that these are general bedding instructions. Some pad manufactures have very specific bedding instructions that you should follow. Call the maker of your pads to find out what is the best for them.

When returning to the pits or home, be sure not to apply the parking brake until the brake are completely cool as this might warp the rear rotors. In fact it is a good idea to take a cool down lap if you are at the track to allow your brakes to cool off before coming into the pits. Heat soak after hard running can damage the caliper seals and warp the rotors.

To bed the brakes on the track, simply drive carefully at about 80%, anticipating the green fade and maybe dragging the brakes lightly on the straits. When you feel green fade coming, back off and drive without braking for about lap to let the brakes cool. Repeat until you don’t get any green fade. Never start a race on new unbedded pads. All of your spare pads should be bedded beforehand. Even if you have bedded pads, if they are freshly bedded I would still be cautious about green fade for a few laps especially until you get a good feel for the bedding procedure with your favorite brand of pads. If you are new to bedding, you may not bed your pads completely and still get some green fade, a nasty surprise if you are not anticipating it.

Many of the new generation Carbon pads do not need to be bedded much. When running those I simply bring them up to operating temp while allowing myself some extra run out just in case, before I go all out. On the street, I would run them through one bedding cycle to burnish them in. Consult with the maker of your Carbon pads though, as some of them may have some different bedding procedure than what I am describing.

Harder, high temperature pads usually have an overall lower coefficient of friction even when they are in their ideal operating temperature. Because of this you can expect having to push on the brake pedal much harder with them installed unless you go to a bigger brake system with more pad area. Softer, lower temperature pads generally have more initial bite and require less pedal effort but they will fade much quicker.

Through proper selection of brake pad material and careful bedding you should be able to reduce pad fade to a manageable level except in the most extreme racing conditions.

Reducing fluid fade
Fluid fade is caused by boiling of the hydraulic fluid in the brake system usually in the calipers and even sometimes the lines under hard use. This localized boiling allows bubbles to form in the brake’s hydraulic system. Since air bubbles are compressible, the end result is a long and mushy brake pedal. In extreme conditions the pedal will go all the way to the floor without much retardation in your speed!

Brake fluid is hydroscopic which means it has an affinity to water and absorbs water from the air. When brake fluid absorbs water it’s boiling point drops rapidly. That why it is important to use only very fresh brake fluid, preferably from a recently opened bottle where the factory seal has just been broken. When bleeding brakes, keep the bottle capped except when you are poring the fluid out. It is also a good practice to keep the cap of the master cylinder reservoir on, but only loosely screwed about turn while you are bleeding, as the brake fluid pulls in the humidity from the air thus you want to minimize its exposure to the air.

You should also bleed your system and change your fluid at least once a year to get the moisture laden old fluid out. Your brake system will last much longer this way as the moisture in old fluid causes corrosion of the brake systems internal parts. If you are racing the fluid changes should be much more frequent than that.

If faced with fluid fade you can sometimes save your ass by rapidly pumping the brake pedal. This sometimes builds up enough pressure for you to stop or slow enough to avoid disaster. A better way to deal with this is to properly prepare and maintain your vehicle to avoid fluid fade.

My own personal close call with fluid fade goes back to my wayward youth. Being young and dumb (after reading Bob Bonderant’s book on high performance driving) I decided to go out and practice. I bombed around for quite a bit and noted that my brake pedal was getting kinda low. I was hauling around a long radius turn when I noticed , much to my dismay that a whole family was about to cross the street in front of my speeding car. They underestimated my approach speed and proceeded to cross the street. It was Dad, Mom, a Toddler and a stroller. I slammed on the brakes and much to my horror, the poor, abused 10 year old brake fluid gave up the ghost and the pedal went to the floor! I frantically pumped the pedal in a near panic and with the grace of God managed to slow enough to swerve around the family. I can remember with crystal clear clarity the fear in the adults faces as I almost creamed them. I was real fortunate to have missed those people for if I hit them I would have ruined a lot of lives including my own. So folks never drive fast on the street in an uncontrolled situation!

So sparked my interest in brakes!

Fluid fad can be avoided nowadays to a large degree with modern high-performance brake fluid. When I began racing I used Castrol LMA. I chose that because LMA seemed like a cool name! With LMA I’d have to bleed the brakes system several times in a race weekend to keep the pedal firm. Later when I started learning more about things I bought some AP550 brake fluid, which at the time was the best that you could buy. With AP550 the pedal would stay firm for the greater part of a race weekend, but you would still have to do some bleeding. The trouble was that the stuff cost like 15 bucks for a pint tiny little bottle. So I read somewhere that Ford brake fluid worked well. For $6 a quart, it seemed like a good deal. Ford fluid was great! It worked nearly as well as AP550 and cost just a fraction of the price. I still recommend Ford fluid as a great poor mans racing brake fluid.

At one race, the Motul rep gave me a bottle of their DOT 3 brake fluid. At the time Motul was well known in the racing motorcycle world but they had not really gotten into the car market yet. I tried the Motul and was amazed. When I previously had to bleed my brakes at least once on a race weekend, I now did not even have to touch my brakes at all! This was a boon to in-between round pit work as fiddle farting with the brakes was a time consuming chore. Motul would last a half season of sprint races! During a three hour endurance race, we would normally have to do quickly bleed the brakes during one pit stop. With Motul the brakes were nearly as good at the end of a race as they were at the start. Motul was more expensive than Ford, at $12 a per liter but was much cheaper than AP550. With Motul you used about as much fluid so price wise it was a wash.

Motul has since improved their fluid. For racing you can buy Motul 600. This has a boiling point of over 600 degrees F! There is also Motul DOT 5.1 Both of these fluids have superior performance over that of the original Motul that I fell in love with. Motul 5.1 has a slightly thinner viscosity to work better with ABS brakes but I have used racing 600 in ABS equipped cars with no noticeable loss in performance. Note that DOT 5.1 is not the same as DOT 5. DOT 5 is silicon based brake fluid which is a big no-no. Silicon fluid is compressible and you will be plagued with spongy brakes. I have read that DOT 5.0 fluid is thicker and more prone to cavitation produced bubbling also. The major advantage of silicon is that it has a very high boiling point, does not eat paint and does not absorb water from the atmosphere. These properties make it an excellent brake fluid for museum stored cars and such. Some performance gurus plug silicon but my advice is for you to stay away from it.

Some of my fellow list members that I supply with Motul, report that it’s track performance is excellent with some reporting to me that Motul 600’s pedal gets even harder once the brakes get hot. I don’t understand why this happens, but that is a good thing.

I am so enamored with Motul that I do not have any other experiences with any other brake fluids because I have stopped searching. I have never experienced any significant fluid fade with Motul and it’s cheap so I haven’t bothered experimenting with any brands. If other list members have good experiences with other brands of brake fluid let me know for the extension of our database.

Bleeding brakes

The following is based on recommendations made by brake guru Mac Tilton. Mac is best known as the man that brought Carbon pads and rotors to racing. He is also the owner of Tilton Engineering; one of the main suppliers of brakes and clutches to Indy and F-1. I have added some things based on my own experiences also.

When bleeding brakes it is best to manually bleed them as pressure bleeders can cause cavitation and bubbles inside the system. Empty the brake reservoir with a turkey baster then fill the reservoir with a high quality brake fluid. Start bleeding at the furthest wheel away from the M/C and progress to the closest. So that would go RR, LR, RF, LF. Attach a length of clear Tigon tubing (available form any auto parts store) to the bleeder nipple, put the other end of the line into some sort of container so the other end will be submerged in brake fluid and open the nipple. Have someone in the car to pump the brakes. Slowly pump all of the old fluid out of the line until new clear fluid comes out, then have the person in the car hold the pedal down while you close the bleeder. Have the person lift the pedal up slowly and then push down slowly while you open the nipple. You have to communicate with the pumper because the bleeder should only be open on the down stroke of the brake pedal. It is important to pump slowly to avoid bubble-forming cavitation. Continue to pump until you cannot observe any bubbles in the clear Tigon tube.

Get a rubber mallet and tap the caliper to dislodge any bubbles that may be stuck inside the caliper and bleed some more until no more bubbles come out. Do this at all the wheels and you are done. Be careful not to let the reservoir run dry or you will have to start all over. On ABS equipped cars you want to be extra careful about this because it takes forever and a lot of fluid to bleed a completely dry ABS system. Some ABS cars require bleeding from nipples on the ABS modulator so check your manual.

Brake Hop ups

You have now done the basic steps of brake prep and should have some brakes that can handle quite a bit of abuse. To get more performance out of your brakes we will now get into hopping your brakes up.

As you modify you car for more power, you may need some more stopping to make for a better balanced machine. We will talk about some of the common brake mods and what they do for you.

Braided steel lines
Braided lines help pedal feel and brake modulation. Unlike the stock rubber hose, they do not expand with internal pressure. Braided lines help make sure that all the pedal force gets to the caliper. I think that the pedal gets significantly firmer and modulation improves. Some companies claim big decreases in stopping distances with braided lines but I am a bit skeptical of their claims. Not all braided lines are DOT approved. Although much stronger than stock rubber hoses, braided hoses usually fail the DOT whip test. This is when the hoses are attached to a drill motor like fixture and spun at high rpm for x hours. The steel fatigues and the lines fail in this sort of test. Since this has very little bearing on actual stresses while installed in a car, I myself am not to concerned if a braided line does not have DOT approval. DOT hoses have a little plastic sleeve that keeps the hose from bending as much when spun in the whip test. I doubt that this little piece of plastic makes the line any safer in the real world. Braided hoses have much higher burst strength than rubber hoses and I feel that this is a valid concern. Beware of a heavily advertised brand of hoses that has a colorful plastic cover. These hoses are cheaply priced but are junk. Steve at SMC showed be a set that he bought to check out. With a firm tug, the end fittings could be pulled off by hand!

SMC, Stillen and Goodridge all make good hose kits. SMC uses high quality forged end fittings that are reusable so I myself like them, but they are not DOT approved. Like I said, I don’t think a small plastic sleeve alone makes for a safe brake hose.

In short, I feel that braided hoses make a big difference in brake feel and being reasonably priced, I think that they are worth it.

Drilled sport rotors
Rotors are drilled because the drilling lets vaporized pad material escape from under the pads, minimizing the hydroplaning effect under hard braking thus giving the pads better grip under these extreme conditions. Drilling also lets water escape in much the same manor in rainy weather. Test done by KVR show that drilled rotors can cool down up to 20 percent quicker than solid rotors. Drilling also helps deglaze the rotors or keeps them from glazing up due to a cheese grater effect.

I myself think that drilled stock rotors or sport rotors may be somewhat questionable because since small stock brakes are run close to their thermal limit with high performance pads, the drilling can contribute to cracking. If you are buying drilled rotors check to see if the holes have be chamfered. Chamfering helps reduce the likelihood of cracking. Drilled solid rotors like the rear rotors on SE-R’s make a weird whirring noise when the brakes are applied. Some people have said that drilled rotors cause faster pad wear but I myself have not experienced it. Drilled real racing brakes with sufficient thermal capacity are functional and useful. Better than drilling but perhaps lacking some of the racy pizzazz are slotted rotors. Slotting does the same thing as drilling but without the cracking problem. I don’t think slotted rotors cool any faster but they are a lot less likely to crack. If you are running stock sized rotors , I’d go for slotted for this reason.

Overall, I feel that drilled sport rotors are mostly a cosmetic trick and have never tested drilled, slotted and solid back to back. They really look cool though and fall in to the disco/rice boy category as all of my personal cars have them!

Big Brakes
A stock SE-R has pretty good street brakes as is. But to really stop consistently from high speeds like in road racing, you will have to upgrade your brakes. NX2000’s already have a bigger set of brakes stock so this is not as critical. The bigger NX2000 brakes are known as the Nismo or AD22VF upgrade. They are really no more than stock Nissan parts. The rotors of AD22VF brakes are, I believe only slightly larger in diameter but are much thicker being 26mm thick vs. the Standard Sentra brake thickness of 18mm.
B13 Brakes (16558 bytes)

This thickness allows the rotors to dissipate much more heat than the stock Sentra rotors thus enabling a lower operating temperature. The thick rotors also resist warping. About their only disadvantage is their increased weight.

[We have more information on the B13 brake upgrade (AD22VF)]

The part number as carried by Nissan Motorsports is 99996-B13BK. The AD22VF brakes require 14-inch rims and the removal of the front backing plates for fit. They are a direct bolt on. Nissan Motorsports also recommends a different M/C with more front brake bias. I don’t like it too much as I think our cars have a little too much front brake as it is but if you wanted to follow Motorsports recommendations the part numbers are: 46010-69Y20 for non ABS cars and 46010-60Y71 for ABS cars. Other list members have said that the Motorsports recommended m/c makes the pedal more mushy.

As a warning to you NX owners, several NX driving list members had had their brakes fail because the first owner of their car installed regular thin Sentra front rotors. Perhaps they had been told by the parts counter guy that "all of them Nissans take the same rotor" or something. It will work for a little while with new pads right until the piston comes past the seals in the caliper bore and yow no brakes!

I have extensively raced both an NX and a Sentra equipped with the AD22VF brakes and have found that when properly prepared, they can consistently out brake almost any other production based car that is likely to be encountered in Showroom stock sedan type racing. It is hard to imagine needing better brakes than this even for racing, unless of course you have the power to hit higher speeds on the straights.

In this case there is an even bigger option. SMC Products and KVR make what is known jokingly as the Big Ass Brake Kit or BABK for short. The BABK contains a 11.7 inch forged steel Coleman racing rotor mounted to an alloy hat with a Willwood 4 piston caliper. These huge brakes are 1.5 inches bigger than the stock rotors and are 6 lbs. lighter due to mostly the alloy hat and caliper. The bad part is that they only fit in some 15-inch wheels. 16 and 17-inch wheels are no problem. The do not fit in the stock 200SX alloys unfortunately. To run these brakes you should use an Altima master cylinder as that has a bigger piston bore (15/16" vs 7/8"). The bigger bore is needed to give the brakes better feel as the stock M/C’s bore makes the pedal feel long. The brake ports line up with the stock hard lines for a quick bolt in. On our cars the proportioning valve is located in the master cylinder. The proportioning valve cuts the line pressure to the rear brakes at a certain point to prevent the rear brakes from locking up as the car’s weight transfers forward. On my car I run no prop valve as the brake proportioning is 82 percent front as is which is close to ideal for a FWD car. If you run on low traction surface like water, dirt or ice you might want to put the SE-R prop valve out of your stock M/C into the Altima one as the SE-R M/C has more rear brake bias. There is no sano kit to remove the prop valves from the Altima M/C yet either so you will have to machine some plugs with o-rings to replace the plugs that hold in the prop valves and where the brake lines screw in. Mine is rigged with lots of carefully applied Teflon tape, a method so half-assed that I cannot recommend it to the general public. Like I suggested before, just replace the Altima prop valve bits with your stock ones and you will be ok.

On the 200SX you can make a big rear brake upgrade with some brakes off of a 95-present Maxima or I30 Infiniti. The caliper is a direct bolt on with the lines and parking brake hooking right up with no fuss. KVR and SMC sell a modified Maxima rotor with a 4x100 bolt pattern re-drilled into it. The Maxima rotor is nearly 11 inches up from the stock 9.2 inches. The Maxima brake upgrade really helps balance the big front brake set up. This trick will not work on a classic because I have been told that the caliper bolt pattern is slightly different. However a simple adapter bracket could be fabricated to allow the calipers to be used.

Why go to the real big brake setup? First of the bigger brakes operate at a much lower temperature which allows you to use a higher coefficient of friction, less aggressive brake pad. This gives a lower, easier to modulate more consistent brake pedal effort. With the big brakes you get a feeling of immensely powerful stopping ability which bolsters you confidence. Since the brakes operate at a much lower temperature, the seals and other heat sensitive components last much longer. You can also run drilled rotors with little concern with cracking.

On my big brake setup, I can run a nearly organic, pretty soft, semi-metallic pad in the front and stock pads in the rear. Normally I would have to select a much more aggressive pad to avoid fade. These pads are quite forgiving and easy on the rotors. They work very well when cold and do not have much dust, squeak or squeal. So the main advantage is that I have an under stressed brake system that gives stock like performance on the street which gives excellent racing condition performance on the track, in a package that is lighter than stock. If you look at what the Sunny (Japanese Sentra) 2 liter touring car racers are running, which is a 14 inch rotor, twin caliper set up, the big brake kit looks pretty reasonable! The big brakes are totally awesome. I have raced plenty of AD22VF equipped cars and although these brakes work quite well when set up with a good racing pad, the pedal effort is still pretty high once they come up to temperature. The big brakes require only a light touch, which is a lot easier to modulate with precision. Other list members that have driven my car have raved about the brake’s performance. If you want to see what they look like, check out this link to Merlin’s page.

The other Disco aspect of the big brakes is that they look really awesome. If you have 17 or 18 inch wheels, the stock brakes will really be exposed and look pretty wimpy. The rear brakes look especially ridiculous. If you are in to car show’s, the Judges dig stuff like racing brakes because they haven’t caught on with general the performance crowd yet. If you have an open style of wheel, the racing brakes really make your car look special.

Soon I will be working with Brembo to help develop a 12 inch Brembo system that will be the ultimate Street/track setup for our cars.

General SE-R brake tips

Here are some tips that I have found useful specifically for SE-R’s.

Brake pedal Mushy after bleeding

If you brakes feel mushy after a careful bleeding, check your pads. Pads worn thin allow for lots of fluid in the caliper because the pistons are poking out pretty far. You want the least amount of fluid in there to get the best brake feel. Replace your pads and see if the pedal improves. I would suspect anything worn much past the 5/8’s point. Also worn pads can cause early fading even in prepped brakes. This is because the thin worn out pad will allow more heat to be transferred to the caliper as the pad material acts like insulation. Porterfield puts thermal barrier coating on the back of their pads to help prevent this and Swain Tech has a special coating to help reduce this heat transfer.

Master cylinder staging

If your pedal feels mushy even after careful bleeding with new thick pads, you may need to adjust the master cylinder staging. This is basically the free play of the pedal to the rod that operates the master cylinder piston. You can adjust this inside the car up where the pedal linkage goes into the m/c. There is a jamb nut on the rod and an adjusting screw. Adjust the rod longer to reduce the play. Leave some play in there so that when the brake fluid expands with operating heat the brakes won’t drag. If you over do this adjustment the brakes will drag causing massive overheating and you could ruin everything!

Wrong front rotors in a NX2000

This is a repeat of what I mentioned earlier. Some list members have had the wrong rotors installed in there NX2000’s by mechanics that put Sentra or 1600cc NX rotors in by mistake. The NX2000 rotors are 26mm vs. the regular rotors 18mm. The thinner rotors will work for a while but the car will have a terminal mushy pedal. After the pads wear the pistons will lose there seal and catastrophic brake failure will result!

Removing the brakes backing plates

Our car’s brakes are equipped with a dust/water shield backing plate. To cool the brakes better or for on track use these plates can be pried off the hub and cut away with tin snips. The down side of this is that the brakes will not work as well in wet conditions as water can splash on the rotors. It is not super bad but you should still remember to test your brakes after driving through a puddle and tap them periodically to dry them off. If you never race then you might want to leave them on for this reason. The shields must be removed when retrofitting AD22VF brakes or the super big brake upgrade for clearance reasons.

Sticky or Bent Caliper Floater Pins

A common problem with SE-R’s and cars with floating type calipers in general, is that the pins that the calipers slide back and forth on can become corroded or even sometimes bent with use. The pins are protected by a rubber boot that often becomes cracked and oxidized with heat allowing water to enter which corrodes the pins. I am not sure how the pins can become bent but I have seen that happen also.

Corroded or bent pins results in the caliper binding as it tries to slide back and forth as the brakes are applied. It can also prevent the brake from releasing completely. You can tell if the pins are sticking by looking at the pads. If one pad is worn significantly more than the other than you most likely have some binding. If you replace your pads and the brakes drag, or if the car has uneven side to side braking, the first thing to check is the pins also. Another symptom is that your brakes are really hot all the time and your pads wear out unusually fast for no apparent reason.

To inspect your calipers, move the caliper on the pins by hand, it should move freely. Inspect the rubber boots on the pins and replace them if necessary if they are cracked, oxidized or missing. Cars that run track events are prone to this as track driving really gets the brakes cooking. The high heat causes the rubber parts to deteriorate quickly. It is a good idea to grease the pins with high temperature disc brake grease every time you service the brakes. If the pins are bent they should be replaced immediately.


Well, these are all the brake tips that I can think of for now. Apply them with caution as brakes are the number one safety device in your car and happy hunting!

 

Reader's Contributions

red_triangle.gif (202 bytes) Mike Pahls writes:

Someone on the list has been mentioning brake problems lately, so I thought I'd pass along low buck things that have worked for me. I auto-x my car and due to my trail braking, I often lost my brake pedal by the end of a 50 sec run. Sure I probably dragged the brake a little more than some people, but I had to fix this problem to stay safe and comfortable driving the car.

1. The first and most obvious thing to do is change you brake fluid. There are plenty of decent brands of brake fluid out there. Sure you can get really good stuff too, but just changing your fluid with some brand name H-D brake fluid will make a difference. Changing/Flushing the brake system really is not hard at all (especially if a friend helps and you can open the bleeder valves w/o breaking them). I'm not going to outline this procedure so you'll just have to look it up yourself. Changing the fluid will remove the moisture that the system has absorbed over the years and will delay the onset of a type of brake fade.

2. Occasionally (Annually or Semi-annually) I would recommend cleaning and inspection all the calipers. This is a simple procedure that I bet just about anyone on the list can perform. Just go around to each corner of the car and yank the wheel off. I would suggest removing the caliper pins first so you can remove and inspect the caliper. Make sure it doesn't show any signs of leaking and that the dust boots around the piston and caliper pins are in good shape. Also inspect the caliper pins for excessive wear or rust. If needed, clean the pin up with a Scotch-Brite pad. Then remove the caliper mounting bracket that is attached to the spindle. You may need some good rust penetrating oil to remove those bolts. Pull the pads out and inspect the metal clips.  Odds are that you'll have to pop the clips out and clean them up with Scotch-Brite too. While you're at it clean the pads' ends too.

Visually inspect the condition of the rotor and wear surface of the pads. Is there sufficient pad material left? Is the rotor severely grooved? Is it cracked? Then just clean every thing up and slap it back together, and bleed the brakes. Also don't forget to lube the caliper pins and make sure that they can let the caliper 'float'. Also make sure the pads can move on the clips before assembly. Often brakes will wear prematurely or unevenly due to either the caliper not 'floating' freely or from one of the pads 'hanging up', so this little inspection/cleaning may correct these common maladies.

3. Rebuild the front calipers. Nissan sells many of the components for the brakes in kits. For the front calipers there is a rebuild kit that comes with the piston seal, piston dust cover, retaining ring for the cover, caliper pin dust covers, and the misc greases needed for the rebuild. To start first remove the caliper and disconnect the brake line. I would suggest that you remove the brake line from the strut and wire or zip-tie the end of the line as high on the suspension spring as possible. If tied off high enough the line won't drip fluid. The removal and replacement of the caliper pin seals/dust covers is fairly crude and straightforward. The rebuild of the piston components requires patience and a soft hand.

Remove the retaining ring and dust cover from the caliper. If you are going to replace this cover then you can just rip it out and then go fishing for the retaining ring. Although it's a PITA the retaining ring does comes out. Wipe any crud off that is just loose around the piston area. Now wrap or place the caliper in a clean rag and remove the piston by blowing compressed air into the tapped hole that the banjo fitting was connected to. Be careful to handle the piston like an expensive piece of jewelry. If you don't have compressed air then you may have to remove the piston like I did, but be very careful so as not to damage the piston or bore. You can take an extension from your 1/4 drive socket set, and feed it through the tapped hole.  Then carefully and evenly push on the extension until the piston comes out. Finally remove the seal inside the bore. Now just clean and inspect everything very carefully and use plenty of clean rags. I didn't hone out the bore since every thing seemed to be in good shape, so I just re-assembled the caliper using the new rubber pieces and the old piston. During the assembly I noticed that the new piston seals really seemed to fit snugger than the old seals (even thought the old ones never leaked). This little re-build alone seemed to firm up the brakes.

4. Rear calipers: From my experience with our rear calipers, if the parking brake mechanism is hanging up or stuck, it's probably best to just get a new/rebuilt caliper. You may be able to loosen up the frozen mechanism, but in two separate SE-Rs this problem has just returned within a month. The obvious sign that it is reoccurring is when smoke comes billowing out of the rear wheel well or you smell hot brake pad material when stopped at a traffic light. I know this has been a long post, but with all the talk about how to make our car cars fast, we rarely upgrade our brakes. Our cars are blessed with pretty good brakes and if they are working properly they can handle most of the crap we demand of them. So take the time to check them out.


red_triangle.gif (202 bytes) Terry Gosse (owner of KVR) writes:

The AP Racing brake fluid technical information is as follows:

  Boiling Point

Retail Pricing
(per 500ml)

Dry Wet
AP Super 600 600F / 315C 410F / 210C $18.95
AP 550 563F / 295C 293F / 145C $13.95
AP Ultra 5.1 518F / 270C 375F / 191C $9.95

AP Racing is one of the best brake manufacturers in the world. They know what is required for brake fluid.