area difference between NA6 and NA8 brake pads

[plohl]

I believe the rear calipers are more or less the same between NA6-8 but the caliper bracket, disc and pads are different.

I went NA8 brakes all around with my car but the biggest increase in wheel stopping power came from fitting Hawk HPS+ pads. I've never had fade from the NA8 brakes and didn't have the NA6 brakes long enough to find out.

NA6 brakes with standard pads fail... hard. Had a few close encounters of the rail kind.

You can just put more appropriate pads and fluid in them though, would be okay for mountain sprints.

Also,
This thread was really about the pad size. I like to think i am capable of making an educated decision about the upgrade. If a set of na8 brakes came up for cheap, i would probably get them. I know mania had a few sets recently, but pm's never got replied too, and I was too busy to chase them up so I never got them. I can get a cheap set of fronts, so now do i try and get a set of rears, or just replace the disc and bracket.

[NitroDann]

Hahaha.

That was really good, and I totally agree, this is more fun.


You assume going to na8 rear disks will increase the torque moment but it wont as the calipers will still be mounted the same axial distance from the hub centre, resulting in the same performance.

Youd have to swap the disks and then mount the calipers further out using na8 caliper brackets.

Now, onto thermal capacity...
the reason that its the most important part here is that on anything less than rs3's or 275 hoosiers, stock 1.6 brakes have enough friction to overcome tyre to road friction, this is assuming they are not overheated. Therefore, unless your overheating them, upgrades are not going to help braking performance. It will only help to improve how little pedal pressure is used, while retaining the same pedal stroke to achieve it. (I say this as opposed to just putting on a long pedal, or using a smaller master cylinder piston t change leverage)


Anyways... unless you can overheat them with current use, be that on the backroads or at the track, upgrades wont help, and if your worried about the new effective brake bias with a rear brake upgrade, get a bias adjuster from FM for 80 bucks.

Dann

[plohl]

Sorry Dann, I don't think I made this clear. I am looking at using the NA8 Bracket, to space out the NA6 Caliper (much cheaper than getting bracket and caliper). This allows you to run the bigger disc at the rear.

I am honestly not too worried about the bias at the moment. I am still getting used to how the car brakes (having previously come from a front wheel drive). I just wanted to see some numbers on the brake upgrade itself. I am very much still in early days setting up the car so bias adjustment would come later. The biggest change I can do to the brakes is to change the pads, but I don't want to spend money on NA6 pads, have to get new discs a few months down the track... and than get a brake upgrade. I'm being stingy and trying to think of the cheapest long term solution haha.

I do understand what you are trying to say, but this wasn't a 'should I upgrade my brakes thread'. I was always going to change them (they feel crap and unsteady - this could be all pads though), but I wanted to see if upgrading the rear would really be worth it.

[NitroDann]

The comment regarding how your new and brake bias wont affect you i disagree with. When you enter turn 2 at your first wakefield day for the first time youll see why too much rear bias is unacceptable. when going fast, we are at the very limit of grip. If your rears over brake by 10% youll HAVE to brake 10% less overall to stop the rears locking and causing you to spin. Remember when braking into a corner we are breaking so hard, 1% more will break the adhesion limit and lock the tyres. This will limit braking by ten whole percent. where as the stock setup can run to 99% of the limit of the tyres friction.

In short, get a bias adjuster to stop the car from spinning or understeering every time you use the middle pedal or it will be worse than stock, brakes arent something you can do in halves, just like upgrading only the front tyres to slicks cos you could only afford 2 wont help.

Dann

[sailaholic]

This is true about not want too much rear bias. But that is unlikely to happen with his proposed upgrade. Too keep the system factory ballanced would be to put na 8 front and rear rotors and calipers on. If he only does the front rotors, calipers and rear rotors then his rears, going by the previous numbers will be UNDER braking , creating more front bias then a stock setup.

[Charlie Brown]

plohl,

Great thread discussion but if you’re looking at doing this on the cheap ‘cause money’s tight then don’t think about going onto the track.

The two main things you go through on the track are pads and tyres in that order, so it’s not a sport you go into if you start off looking at cheap brake upgrade options. I only get around 8,000 kilometres out of a front set of front pads in a combination of a daily drive and track days. So every 5 months it’s a change of pads.

If your main intent is just to improve your current braking on the road and have the odd dabble in a track day or hill climb, then first up buy a set of matching front and rear pads.

Have a look here: http://www.mx5parts.co.uk/index.php/cPa ... /2a/page/1 Go through the three pages to see what’s available. Pick a pad to suit your needs. You will find it’s cheaper to by overseas than local, Ebay included.

Next (and most important) is to change to a DOT 4 brake fluid when the pads are fitted and then change it every year. The fluid will set you back around $40 for a 1 litre bottle.

Last but not least, Mazda engineers with more brains than us, spent considerable time designing the brakes on the MX-5, so they actually work without amateur input. The size of the brake package only went up as the power and weight of the car increased with the model changes, not because the NA6A was “under braked”.

I’m sure that if you get the NA’s brakes performing as they were designed to then all your problems will disappear.

[plohl]

I came to the conclusion that the rear will be under braked by using the NA6 caliper, NA8 bracket and NA8 disc. This can be seen in the maths, where there is a 10% difference between the NA6/NA8 combination rear brake set up and the complete NA8 brake set up. Note, this does not take into account the Difference in the caliper between the front NA6 and front NA8. I am very curious to see how changing only the front brakes will effect the way I brake.

Charlie, I am prepared to spend money on the car in pads, fluid and discs, however, I do not want to spend money on multiple brake systems. For example, I priced out (a while ago) how much it would cost to convert to NA8 brakes all round.

(prices from GSL Rallysport)
RDA Slotted Rotors, F $185, R $159
QFM A1RM $120 per end = $240
NA8 Brakes (MX5Plus) = $340

Total: $924

In order to get my current NA6 brakes up to a decent standard, it would cost me new rotors and pads (~$584). Now i would hate to spend the money on the NA6 Brakes, and realise a few months down the track that I want the larger NA8 brake kit. Which means I could be up for ~$1000 to upgrade. Now I have spent ~$1500. Now, looking at the option of using NA6 rear calipers, with NA8 brackets and discs means it could cost me substantially less (as i am getting a NA8/NB Front brake kit for a good price in a few days.

[tbro]

I might be talking outa me arse but I don't have any problems with the brakes on Scooter and and as far as I know nor did Slammer.

NA8 slotted rotors, QFM specials on the front, NA6 std rotors and QFM specs on the rear. The big difference is I have set up the car with an adjustable bias valve and set it up originally using hydraulic pressure gauges and adjust depending on track conditions.I also have slightly modified suspension and done a couple of track cars before .

Now I know Scooter is maybe a tad bit quicker than some NA6's but there is no way he is under braked regardless of the track. Do you need bigger brakes on a stock or even worked normally aspirated NA6, NO. What you do need is quality pads, clean rotors not units that have had 3 different types of pads run on them, quality brake fluid and good tyres, and bedded in PROPERLY. Sure you can run upgrades but you DON"T need them, you may want them and that is different.

Ok, your running out of brakes during mountain runs. I would be looking at many different thing before I upgraded brakes. DRIVER for a start, routine maintenance, suspension condition and the list goes on. As some may remember I had problems stopping my Clubman at Lakeside on one trackday, had good pads ,fluids etc the problem was the idiot behind the wheel. I wasn't hitting the brakes until I was 50 metres off Hungry flat stick in 4th, certainly wouldn't try that now!!!!!

Your saying your brakes feel crappy, I'll guarantee that your sliders are sticky, very common problem. Flush and bleed brakes, strip and relube sliders and I think you will find a difference. Come and talk to me ( I promise I won't bite straight away)

Terry

[plohl]

So I installed a set on NB (same as NA8) front calipers and rotors on my car the other day.

Firstly, thanks to Tim (saboteur) for selling me these at a great price! and the extra set of brake lines (off the SP kit)

The install was easy - but a pain in the ass for 2 reasons; I had a cold and I was following the instructions from miata garage!

In the guides, they say that to keep the pivot bolt at the top, use the caliper on the wrong side (so right on left and left on right). At first I thought there must be a good reason for doing this, but upon further inspection I noticed that the doing this would mean the bleed nipple was at the bottom! not ideal for bleeding air from a fluid system! So, I ignored this instruction and put them on the right... correct side. I looked at the brake lines, NA, NB and SP lines - with the SP likes being the longest. I tried to use these, though had to file of the corner of the hex at the top of the line to fit into the mount. I tested the steering to make sure the line didnt hit anything and it was all clear.

So, replaced the brake fluid, bleed the system and too it for a test drive.

It took a few runs to bed the pads back in (as I used the second hand ones) and came to the conclusion that me brakes now felt worse... but worked better. I can quickly pull up, however the brakes feel well spongy! I'll probably re-bleed the system tonight to make sure there is no air trapped, but other then it possibly being pads. I am a bit stumped.

So I am away for the next 2 weeks, so when I get back I'll get new pads at least; maybe new discs. I should also have a bias adjuster on the way also (props to badbong).

[NitroDann]

Bigger slave piston area, no master area change would be it.

Dann

[plohl]

A lot of people upgrade from NA6 to NA8 brakes, so I would have thought if the above was the case, more people would have complained about it?

[timk]

Thanks for clearing some space in my shed!

If you are using the pads I gave you with the discs they are just whatever came on my car from Japan, so they could be nasty/economy ones? The spare lines I threw in are SE lines just to clarify. I'd only done carpark speed driving with them installed so can't really comment.

Cheers