- My model of MX-5 is:na __
- I’m based near: ulster__
- I’m looking for technical help or recommendations on: front brakes and calipers__
while i was rebuilding my machine during last summer i rebuilt the sliding caliper brakes with kits and they are working quite as they should , however i’m minded to search for either a 2 or 4 pot caliper which would allow a bigger disc and a stronger bite when braking if it will work with the std master cyclinder size and still fit without issue under my new revolution minilight 8 spoke wheels ET 31.
.I have seen 2 piston calipers for sale which seemingly are used in nb 2.5 cars but when linking to see if they will fit my NA answer was no, are they using a different stub axle…W
biggest effect is the pad that you can fit area-wise. So compare the brake pads. the bigger the pad the better your brakes will be. Physically they need to fit inside the wheel. also consideration is the weight, this is part of the unsprung mass. so the lighter the brake calliper the better (more responsive) the wishbone can move. Obviously if you can change the disk as well then, low weight is preferable (reduce unsrpung mass as possible) as well as bigger disk diameter will greatly increase braking force. There are composite material disks that are bigger but almost the same weight as the stock disks. however they are fairly costly.
as for disks, do not go for the drilled ones as they crack/wrap during heavy braking track use (under high thermal loads). instead prefer the grooved or the solid disks
Better for what?
Biggest issue with MX-5 braking is normally what you have is not working as it should. All of the one make Mazda race championships in the UK use standard brakes.
If you are running a gazillion phowa’s then maybe you need bigger brakes, but usually just the right pads is good enough. Limiting factor is the grip of the tyres.
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I don’t like sliding calipers and mine are all working as they should, the brakes are adequate but not inspiring when driving really hard on back roads…and they are the small discs, early 1.6 stuff… my other vehicles albeit heavier are 300mm and 350mm…
Change the caliper carriers and discs to 1.8 spec.
Companies like Flyin’ Miata will sell you various Wilwood kits if that’s your thing, designed for fitment to early cars.
I’ve used lots of slotted discs on track cars. There’s a “new” track car in-build and it has bigger and thicker discs with 4 pot Brembo/Renault callipers to hold bigger pads, and 3" channelled cooling ducts going to custom backing plates. Massive overkill, but I’m hoping for the endurance pads to last a long time, and to reduce my cost per lap, as well as feeling and acting the same for many consecutive laps. Because the brakes are so big, I’ve been advised by the pad manufacturer to go with plain discs, to avoid slotted ones slicing a layer of pad off every time they’re used, and drilled ones doing the same, as well as cracking.
Excellent brakes. No trouble slowing a heavy Renault down, lap after lap. You will however make an already front brake bias car even more so.
True that. NAs and NBs both suffer from this. I may need to go bigger on the rear too.
The rear bias is easily sorted with an adjustable tap in the rear hard line… as long as there is no abs on board, however it takes a few attempts to get it set to suit the car , the driver and the track or event…I’m not a heavy on the brakes driver , carry a lot of corner speed so when I use them they need to work… thanks for the heads up so far…w
I would very much disagree with that. I have a very depressing video somewhere from a wet race at Snetterton, where without ABS and just a brake bias valve, attempting to get the balance right was a nightmare. On top of which they tend to snatch and more to the point, seem to destroy any cadence braking as, certainly for the set up we had, the system seemed to hold on to the pressure momentarily meaning even lifting fully off the pedal did not instantly return rotation to the wheels. We spend not a small amount of effort getting ABS back into the car, and it has worked very well and brought us back into parity with the cars that already had it.
It is a very common thing to see on track driving pages, people have the opinion that to get rid of ABS is a good thing. It is not. The reason it is not used on a number of race case is that is is not allowed in certain regs. The reason for this is to increase the skill level, and to some extent jeopardy involved in wet racing. I have seen, even the best drivers mess up and you only have to look at F1 so see they all make mistakes as the grip levels vary corner to corner and by time as well as a track dries or gets wetter.
You can see just on the second corner, which was damp, of this video, that I have to brake 20 to 30 yards earlier to avoid locking up while the car in front with ABS does not need to. We always had issues under braking trying to get balance, wet of dry and could rarely attack under brakes.
Video
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[quote=“wacee, post:1, topic:128948, full:true”]
- My model of MX-5 is:na __
- I’m based near: ulster__
- I’m looking for technical help or recommendations on: front brakes and calipers__
my take …
I hear what you say, but where i’m coming from is a vast experience of driving all sorts of competition cars on all sorts of surfaces with all sorts of tyres over wet gravelly dry loose before Mercedes et al started to install abs basically for those who couldn’t stop a heavy car without lock up, and now everyone is using abs as the safety tool and also systems that ensure real hard pressure is placed on the brake pedal. so many in the last 20 years aren’t experienced at all in fast heavy braking on wet and damp roads without their abs system thats keeping them out of skidding experience …sorry again but if your system was ‘‘snatching’’ there was something amiss with your calipers not releasing likely seized slide pins or sticky rusty caliper piston as all that valve does is stop the designed pressure going to the rear calipers , did you remove the oem one at the master cyclinder but if your car originally had abs and u removed it there wouldn’t be a reducer in the rear hard line at the master cyc. the problem with those removing abs is that when you do you get way more pressure in the rear lines than a std car sans abs has, and that can be an issue setting up the line pressure…if you’d ever driven quickly a fast 911 back in the 70’s and 80’s without pas or abs you’d have a heart attack, the fronts locked if you got it wrong…w
Just out of interest, surely by upgrading the front brakes and not the rear you will upset the brake balance of the car?
I still stand by ABS being the better option. Yes I have driven 70’s and 80’s Porsche’s, but any vehicle that locks the front wheels has the potential to put you in an emotional position and allowing you to steer is exactly what it was invented for. MX-5’s are generally front bias in the first place and so it is not locking them that is the issue, so it is the fronts you mainly need to limit. I have driven and raced a lot of MK3’s and my experience has been that as standard they are very servo’ed and if you lock up in the wet, you literally need to take your foot right off the pedal to regain rotation. If you leave even the slightest pressure you are heading off the track. The other thing being that if you remove the ABS pump you tend to suffer pad knock off and so need frequent taps with the left foot to have a pedal when you need it. As for the brakes holding pressure with the bias valve, the brakes were very regularly serviced and so I am confident it was not that. It was a Tilton valve, so not an eBay special, but maybe back to the situation above, just the slightest bit of residual pressure may have held the brakes on. And by that I don’t mean it took second to release, just that momentary delay that is enough to put you where you don’t want to be. We tried all sorts of set up but could never get to a point that was good. ABS can have it’s issue though, especially in FWD when trying to brake into a corner. The inside rear wheel can lift, and the zero rotation can cause it have a bit of a fit and the brake pedal goes are hard stops slowing you. You can drive around it once you know about it.
All said and done, going into Shell Oils at 100 plus, I would far rather have ABS than not.
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Any rear wheel drive is always biased towards the front brake, the exception is ABS, and as the MX5 range diluted itself towards comfort and style it was only natural when competitors Toyota etc were showing them heels numbers wise, imo no longer being designed by guys who liked driving rear wheel driven cars on the edge of grip and balance, yet sticking the 2lt Duratec plant in for a lazy165 brakehorse… my idea of a larger front brake is for power, instant retardation like you might do on a blind hilly corner, a confidence prod and lift…perhaps my experience is more loose surface against the clock and ditto with tarmac than in close contact with unskilled unlicensed testosterone filled would be race drivers, I watched the vids of a few ‘‘races’’ and many didn’t carry corner speed that ime could have been driven around even if you had to 4 wheel drift at high speed… ok I know thats my take But my view you cannot be consistently quick in any motorsport except you are getting out every week and thats how experience is gained, at the time I was competing I was living in a car doing maybe 5/800 miles a week in my work…we don’t have as many motorways as you chaps…