yes, i know. i gave the definition. thats why i was saying i think the site was misleading.
i guess its normal, it just struck me as strange that the front would be fixed and the rear would be sliding. that may be normal, i'm not sure.
i checked mazdamark.com and couldnt find info on the rear, but one listing showed the front brake of an 89 GTU to be a single piston. i guess thats that.

 

well i understood most of the first 2 pages but these last few post have me searching www.google.com "brakes for noobs"

i was wrong about the SS.

great info guys keep talking.

 

wow, i didn't know brakes was such a hot topic.

first off, maybe i can clear somethings up on this whole brake caliper issue (or not). it's not really strange that Mazda decided to have the option of a fixed 4 piston caliper in front and a single piston in the back. the fact is, a 4 piston caliper will produce more friction. this is due to the fact that the caliper would not be able to flex as much, and the pads were able to maintain better contact than in a single piston caliper. the traditional problem with this design is reliability. after all, instead of having one durable piston to break, you have 4 smaller ones. the most common source of failure was leaking due to corrosion. however, at the time of the RX-7, they had developed the 4 piston caliper to be much less prone to this type of failure. besides, in true sports car fashion, they would rather have more stopping power than reliability. anyways, the maintained the single piston in the rear because not as much friction is required back there. today single pistons are the norm, but multi-piston designs still provide more friction. so yes, today single pistons are the standard, but more so for reliability than pure performance. of course, it should be noted that Porsche widely uses 4 and 6 piston calipers...

 

far be it from me to argue with you. i am no technician. that shall be my disclaimer: i am no technician. but i still would like to quote this:
"If you have sliding calipers, they push on the brake pads with both the piston and the back wall of the cylinder, so your calculation has to account for twice the actual piston area. A single-piston sliding caliper will clamp as hard as a two-piston fixed caliper with the same piston sizes."
"Sliding calipers act like they have twice their actual piston area."

 

That's true about needing double the piston area in a fixed caliper to match the clamping force of a sliding caliper. In reality, it is slighty less that double the area that is required, since the sliding mechanism reduces the force on the sliding caliper a little bit. Fortunately, getting enough piston area is not a big problem, and sliding calipers are limited to having pistons on only one side, so that sort of negates the clamping force advantage they might otherwise seem to have. A fixed caliper with one 1.5" piston on each side actually has a little more clamping force than a sliding caliper with a single 1.5" piston, since none of the force is wasted on the sliding mechanism.

In general, fixed calipers are better for performance than sliding calipers. They are stiffer for their weight, less prone to sticking, offer better pedal feel, don't waste energy on a sliding mechanism, etc. Purpose-built race cars use fixed calipers almost exclusively, and fixed calipers are present on many high performance road cars as well. Almost all low performance road cars have sliding calipers. Sliders are cheaper to make, and may have some reliability benefits, however, I've had much less trouble with fixed calipers on my cars. Iron sliders tend to rust and go to **** after a while.

-Max

 

did they make any 2nd gens with sliding. i dont want my post to become a big deal and people fight over it. if yes then please list the years and moddles that had sliding.

 

i believe the only two calipers you will see (stock) are 4 piston fixed and 1-piston sliding. i want to say they all had the one-sliding in the rear, and some had the 4-piston in the front.
i can't quote the models. i dont have that memorized yet.

 

thanks for all that. yea, i'm not experienced nor have i read specifics, so thanks for that info. i guess all the math can show you whatever numbers, but trial and error is where it counts. good to know, though.

 

gee this certainly is a hot topic!!!! great reading!

 

So I guess the answer Pitch, no, no one has done it

Either we stick to stock, or spend the money for a big brake kit..

PaulC

 

strange. i would have thought something like this would be quite popular as a cheap alternative to a full on big brake kit - esp if you dont want to have 17" wheels or bigger

 

what big brake kit is the most common? i want to upgrade all four corners to upgraded 4 pot calipers and 13" slotted disc's. i was lookin at Endless big brake kit and it looks good but does it come as a complete set or just a pair?

 

It depends on what you mean by "cheap".
K2RD used to sell a Stage I brake kit based on the Wilwood Dynalite calipers for just the front for about $1,000.  It's not the best caliper out there, but brake pads are CHEAP and easily available for this particular caliper model.  I run this kit on my FC right now.

"Shimming" the stock caliper will compromise the stock caliper strength.  It wasn't designed for that width, and I would not feel safe with such a set-up.  At the very least, it hasn't been tested.

Using an adapter to run larger diameter rotors is almost in the same ballpark.

Brakes is something that you do not fool around with.  It is something I wouldn't want to get cheap on either.  Either they work or they don't.  If they don't, you can get seriously hurt or killed.

Most of these aftermarket brake kits have been thoroughly tested for safety.  This is part of the price that you don't have to deal with - R&D.



-Ted

 

Wow, you got several thousand dollars burning a hole in your pocket?  I envy you...


-Ted

 

i wouldn't be too worried about not upgrading the whole system. the front brakes are the ones that cause brake fade since they see most of the applied friction (due to weight transfer). here is what you can do: get a big brake kit for the fronts, and make sure you have the stock vented in the rear. then all you have to do is change the brake bias to account for the increased stopping power up front. don't know if you can do this with the stock system, but a proportioning valve doesn't cost too much...

 

all this brake talk has got me thinking...

optimizing cooling is one way to increase brake performance, right? well what about a brake fluid cooler? i'm sure it wouldn't be that hard to incorporate into the system. i was thinking maybe a cooler like one of these:
http://www.flex-a-lite.com/auto/html/remote-mount.html

the only think would be to circulate the fluid properly, since the fluid can't "flow" as in your engine or transmission oil, in that it has to be stationary between the master cylinder and caliper...anyone have ideas on this? or how about placing electric fans in the brake ducts? this would definetly be useful at the autocross track while you are waiting between runs...maybe i should start a new thread...

oh, and i found another rotor that looks pretty good, made by Brembo:
http://www.gothamracing.com/catalog/...roducts_id=556

 

Just get some good pads and provide some ducting for them and take the money you saved to put into something else like the engine to get some power to justify a big brake kit.

If you want the bling-bling, order some powerslot etc cross-drilled/slotted hoopla with some better pads.

btw, when anyone has proof that cross-drilling or slotting improves braking performance, let the brake manufacturers know because they don't think so either. Yeah they sell them, but that's because people buy them....

 

he already stated that he runs long road course sessions. dont insult too quickly with the 'bling bling' factor.
if anyone has proof against the cross drilled and/or slotted rotors, that would be nice to see as well.
and which brake manufacturer to you speak to or hear say that they didn't think slotted or drilled helped braking performance?

 

Just my thoughts.

I don’t think you need to cool the brake fluid. One because even racecars don’t have coolers for there brake fluid as fare as I know. I could very well be wrong.

Although we still don’t know all the facts on all the different models of fc's we do know that the front brakes are better in most cases. COLDFIRE said "change the brake bias to account for the increased stopping power up front" this brings me to say... don’t we already have increased stopping power up front? Do we need to account for this even greater stopping power up front now? (I’m learning)

Another thing to talk about.....

1. We know the brakes are better in the front
2 the size of the breaks in the front are the same as in the back.
3 the hookup for both calipers are the same as the front and back
With this can't I go to the junk yard take some t2 or 88 GTU front brakes and calipers and put them on the back for a very cheep upgrade for rear breaks and then if I wanted to just upgrade the front breaks with one of the many things listed.

One more thing. Are the breaks of the rear of a T2 better then of an na. What I want to know is how are the breaks different from an na to a T2. I think I could search for this, if I find a thread on this I will post it.

Wow that’s long

 

"racecars" is an open term. formula mazdas use solid disk single (or dual) piston calipers on all 4 corners. why? they weigh low 1100 pounds dry (13xx regulation race wegh). they almost NEVER replace their rotors, either. they run Motul brake fluid.

coldfire said to upgrade the fronts, which would (possibly) give them too much more advantage over not-upgraded rears. thus adjusting brake bias more to the rear.

the size is actually different front to rear when it comes down to your spec. i dont know the factory mm diameter/width, but i know the width minimum spec is wider for the fronts.

i mentioned once about having front calipers in the rear. for some reason i thought i did, but i was wrong. if you do this, you may have too much power in the rear. you don't want to upgrade brakes to be unequal without being able to adjust the bias.

as for any difference between T2 and n/a, not that i know of, but i dont know. i believe the rotor sizes varied some. check the sheets on www.mazdamark.com. i remember them having inch diameter.

 

I think you're overthinking everything.
You need to go drive your car more than think less.
Get some real-world experience under your belt before suggesting things that are downright DANGEROUS as the above.

The links you provided are for MOTOR OIL COOLING.
Brake systems can run pressure into the THOUSANDS of PSI.
Those "coolers" are not made for pressures that high.

The stock brakes are fantastic with upgrade brake pads and decent brake fluid.  This is enough for 99% of the people in here require.

Leave the racing stuff to the professionals.


-Ted

 

You're missing the integrated proportioning valve that's built into the system.


-Ted

 

This is what I have learned from this thread.

All you have to do is get good pads unless you are racing. If you are racing then you shouldn’t need to read this as you should already have good brakes because you are racing.

 

its fine to correct people, but must you purposely sound like an *** when doing it?

 

RETed - i wouldnt recomment wilwood for road use - none of them have dust covers (or whatever they are called) right???

rx-heven - big brakes are definately no bling bling for me...afterall i will be getting plain discs

also RETed, Mandeville has quite a good reputation in america for rotories right? surely they wouldnt offer to widen the stock caliper if it was dangerous???

on a side note - have anyone dealt with mandeville auto tech? do they have a website/email addy?