Brake Upgrades?
 

Question time...

Has anyone made/used/worked out a cost effective brake upgrade for the BG/BA platform?

I've managed to establish that MX-5 SP discs do in fact slot straight onto our 4-stud hubs, and offer a larger diameter of 270mm against the stock 257mm

Not much in measure but a significant move in rotational braking terms.

I suspect the stock BA calipers could be used, but regular MX5 ones aren't able to hande the thicker disc, mounts would obviously need to change.

I haven't got a MX5 caliper bracket to look at to see if its different to a stock BA caliper bracket, etc....

But me thinks there's an exercise about to happen.

Thoughts?

A.

i remember someone from MRT rally mentioned that the MX5 SP discs and the 4pot calipers from a Series 4/5/6 RX7 would work (with custom brackets of course). I intend to give that a try one day, but i've never seen it done personally.

mmmm - I've been reading some more. The 2002ish and later MX5s (hence the SPs) had the 270mm discs. The MX5 Calipers changed to suit as well - previously they ran the same caliper from the first models to the 2000 changing only the pads, brackets and rotors.

The key change was the thickness of the discs from 2000ish to 2002ish as well as that 23mm diameter increase. Now work with me here:

From 1989 Mx5 to 2000 MX5 there was a step up in diameter of about 20mm - yet he calipers stayed the same. Width went up a little (2mm) which would be comfrotably in tolerence of the calipers.

For the later (270mm) we see a corresponding increase in diameter, and another 2mm rotor thickness. This would be outside the parameter of the "old" calipers, but suddenly steps into the width used by the BG/BA Astina (and corresponding lasers). It's interesting to note that the calipers of both cars look very similar.

So I guess the question is can the 270mm Mx5 caliper brackets be used to mount the BG/BA calipers and hence when used with 270mm pads (woich would fit in the 270mm caliper brackets) give the resultant 270mm brakes for the price of brackets and rotors/pads?

Hows that for tricky?

A.

My theory on this is...why bother engineering stock calipers (be it MX5 or BG/BA) onto our hubs for a rotor that is ~15mm bigger in diameter.

I for the last year have been procrastinating about a brake upgrade and have already purchased and trial fitted the MX5 rotors...but the problem is, finding a worthwhile caliper that is going to fit.

After dicking around with RX7, VT/Y/X and Volvo calipers, Ive just about come to the line and thinking, it's just not worth it. You'd get just as much braking performance from buying some DBA slotted rotors alround and using ultimate or Greenstuff pads....and it'd be half the cost.

Unfortunately practicality rather than individuality has just about won me over.

i have looked into this idea also, the idea is sound, its not just the 20mm increase in diameter that helps, but the larger pads also give a larger surface against the rotors. me + mx5 mate calculated a 20% more pad to rotor surface area. they'll fit but a bracket or something need to be made.

ryan

The diffrence in braking performance from stock rotors to dba slotted is quite amazing.
And so is the amount of time it takes for your pads to wear out.
my previous car i got 1250 from a set of pads

The Lynx runs DBA Golds and Bendix Ultimates - IMHO possibly the sh!test aftermarket enhanced brakes I've had. They're woefull when cold, barely adequate when warm and good only when stinking hot.

The MX5 stock brakes suck - but the pads and rotors are a few years old and probably shagged by the previous owner...

Hate to say it but the XR6T running stock BA Falcon brakes out does both these cars hands down.

The "trick" I'm looking for is easy(ish) size increase which in turn will give a increase in performance. If it can be done with off-the-shelf parts then it's very easy to do, cost effective and all that jazz...But only if you're planning on binning the stock pads and rotors anyways.

Yes the cost benefit equation could be looked at - but ask yourself - just why did Mazda up the brake size between the 2001 and 2002 models years? The cars were the same weight, same engine output yet the brakes got bigger?

Same with why are the brakes on a low spec 323 smaller than the more powerful 1.8L models?

We're not talking disc vs drum - we're talking bigger disc etc again only 20mm(ish) but still....

There's something in it, it's a matter of whether it can be achieved at the budget an individual wants to spend.

Any list of "not worthwhile" calipers that do fit would be appreciated...

A.

626, mx-6, mx-5 brakes and thats about it. unless you got the V6's brakes and hubs out. maybe series 1/2/3 rx7, rx4 or rx3 rotors if you re-drill them

After talking to Dan last night I think we're onto a few different tracks.

1. The (270mm) MX5 discs will maintain the same centre line as the stock discs. From a distribution of force point of view (engineering certification) this is important. It also means that we have a "easy" point of measure to establish clearances on suspension and wheels.

2. RX7 (s5 4 spot) Calipers are wider (obviously) with a lot more caliper on the outside. This may foul on some wheel combinations. The stock brakes are maybe 25mm higher than the outer surface of the disc.

3. Astinas/Lasers (BG, BA KH,KJ) use leading calipers - that is they mount to the front side. MX5 uses trailing calipers. This is no great drama, but may require the calipers to be swapped L<>R

4. The MX5 uses a different caliper design. They mount the calipers to an assembly that looks like this:

http://www.bigllama.com/miata/brake/xferbits.jpg and http://www.mx5parts.co.uk/images/caliperfront16new.jpg

While the stock brakes are a one piece type caliper that is less efficient. The floating MX5 kind is better.

Interestingly according to most parts resellers all Mk2/2.5 1.8L MX5 calipers are the same. This means that the brackets and pads again are our only variance.

5. We cannot replicate the Caliper brackets from the MX, but what's the chance that Mazda kept the caliper mounting setup the same across the range (within reason)? This is the next point of measure. To measure the mounting bolt spacing on the Hub carriers and knuckles of a few different Mazdas. Their relationship to the disc centre line and radial positioning

6. From looking at pics of the Genuine Mazda pads between the two different sized MX5 setups the pads have a fair bit more surface area.


In short I think the swap is valid, is most likely going to deliver better stopping - especially when you consider the range of MX5 pads and rotors out there. A conversion to a larger MX5 configuration my be possible for more $$$

The 4 spot calipers are definately an option but now it all comes down to measuring. However what we're looking for now is a Mazda/ish caliper that clamps a 22mm thick disc of about 270mm that is either floating or one-piece. mmmm Bravo? E series? 929? Cosmo?

A.

what about 3 and 6 brakes and rotors, i know they arent 4 stud but they are 300mm rotors std

Yeah the calipers are possibly an option - although the disc thickness comes into play then. What most are looking for is a swap that is essentially bolt-on using off the shelf parts. That way you're not at the mercy of mega $$ bills for new rotors or pads.

For V6 owners it gets real easy as it appears the Mazda3 SP23 front end stuff just bolts on.

A.

really?? im also lookin at brkes atm cos now with the coilovers the brakes dont last long. by bolt on do you mean i have to get a custom bracket for the caliper and a custom hat for the rotor?

The Stock v6 Rotors interchange with the stock Mazda6 rotors, (exact same basically) and the Familia GTR...Oh and the BJ SP20 as well... all the same discs...

The SP23 rotors are larger Diameter and I believe swap (but haven't checked the published measures).

I do know a 2.0L Mazda3 can be switched to the bigger brakes of the SP23 with just caliper prackets and the rotors/pads - it's in a ProtegeFAQ somewhere.

If I was smart I'd be saying you need special bits, then selling kits to upgrade Mazda3's

A.

Mazda3 2.0L to SP23 Upgrade
 

Cut from the ProtegeFAQ

OK That's WRONG. The Mazda6 abnd Mazda3 rotors don't interchange. Their hat heights are different.

The Mazda3 rotors Won't place themselves correctly. The Maxda6 rotors are slightly different but probably within caliper tolerences. BUT they're not bigger. Only the SP23 has bigger discs. You'd probably be wanting to use SP23 calipers, caliper mounts and discs to make it all work - assumign it bolts up and maintains relative locations.

There is another option for discs that are 302.4mm or 320mm and have correct placement BUT then caliper mounting becomes your issue.

A.

have done a brake upgrade

what is 270mm seriously it's nothing

you want to spend money on a upgrade get serious

300mm min use a PBR twinspot adaptor keep your 4 stud pattern etc.

might have to change master might not. I didn't need too.

I went from about 260mm to 300+ mm disc pulls up like hell.
it's got abs still working
I admit I finished my stocka's even with minor upgrade but the pwoer and weight needed more.

It took an accident for a mate to do his upgrade.

don't worry too much with S4/5 calipers biggest disc you can really fit is 280-290mm and you need offset wheels to clear them hard on FWD - I tried but too hard now use bigger disc and caliper only twin spot but works great.

the v6 rotors std are 274mm front rotors to start with, i wanna keep a standered looking caliper, im tryin to keep my car lookin as stock as possible but be modifyed, of that makes sense.

the dba cataloge says this for rotor sizes

mazda3 2.0L - 278mm
mazda sp32 - 295mm(but on the specs on the mazda site it says 300)
mazda6 all - 274mm

so the mazda6 been the biggest and heavyest car gets the smallest brakes??

Yeah Cra23, it's odd isn't it. In your position I'd be wondering if the SP23 caliper mounts and calipers from any Mazda3 would bolt up to the stock knuckles and clamp an RX8 disc.

RodHog, You really need to post some pics and/or more info because there's basically no _real_ evidence of anyone doing that sort of swap themselves.

In fact the only big brakes on any of these cars are all very much based on takign $$$ to RaceBrakes etc and picking up the car a week or two later.

Runnign a one piece rotor? Or a two piece with custom hats?

Using the VT calipers or the proper PBR vette calipers?

Are they twin piston as in one per side, or twin piston on same side?

M/C change isn't necessary, but obviously is a great way to get more fundamental pressure to the calipers.

The concept of going to say 270mm MX5 sourced bits is the increase in pad area, better (marginally) caliper design, for no real effort. If you're already wanting to buy DBA etc then the cost difference is so all to do it to the 270mm. I may get a chance to test swap some MX5 parts next week.

The RX7 calipers are still an intersting option as there's so many schools of thought about whether they fit or not. That's in both the MX5 and the GTX/Familia/Astina camps...

Given the similarities in key dimensions on all those cars it's strange to think they'd work for one model well, and be completely worng for the next.

A.

brakes are so important to a car, it's why I did give it to someone else.
I tried with workshop to get the S4/5 calipers I had to work and it was just too hard. Plus not worth it.

Brakes are things you don't really want to mess with. Get it all wrong and it can kill you.

here is thread with pics
http://www.ozmazdaclub.com/forums/sh...ht=race+brakes

my custom brakes on my Mx-6.


if you want the standard look the smart option is
do a full hub and brake conversion from a V6 - best place to get all is buy a whole smashed BA v6, take it from me you buy the car $500(say cheaper or more so ) you take waht you need sell off what you don't and you can actually make money covers your tow costs etc. Not only that you know it will bolt straight onto the car.

I've done it for Vt -to clubsport upgrades, my own MTX conversion, a Supra upgrade and still plans for some type honda - friends got a motor need a donar car to do.

Hey Aaron,
Where you finding the mazda brake pictures from ??
The upgrade I have been looking at is using 330mm Mustang Cobra 069 rotors which
have an overall height of 45mm against 45.5mm original. Calipers will then be either
PBR or PBR sport twinspot. This does involve changing to 5 stud and machining the
inside hub hole 1mm larger but will open up mag selection quite a bit. I bought 2
Astina front V6 hubs for $100, the pbr slotted rotors are roughly $135 each, VT PBR
calipers off ebay $75 and then hopefully when I am ready have brackets made up
for around $300-400 which makes for a fairly cheap upgrade but none of this has
been tested yet.
When I do if you need either Astina calipers or hubs (unlikely as FWD) let me know.

Mal
p.s would love some pics of the rear still wouldn't mind upgrading to MX5 SP rears at
276mm