Brake pad wear

[markc123]

I'm doing my first track day this weekend, and looking for some advice.

I have a Mk1 MX5, which the previous owner upgraded, with the 1.8 brakes, decent rotors and axxis ultimate pads - stops very well. It's on road tyres for this day, and I have a spare set so all good for this, my only concern (apart from stacking it!) is brake wear - the front axxis have about 4-5mm on them - will this be enough? From what I can tell, they have done 2 track days already so the wear should be OK, but I thought I would check with the almighty PH :-).

I did look for some spares, but struggling to find any online, so could either take a set of road pads (make sure I can get home safely if they do wear excessively) or maybe swap in some Yellowstuff pads?

Any advice welcome.

[HustleRussell]

Have you actually got as little as 4mm on any one of the four pads? That is majorly borderline. Their performance will rapidly deteriorate from that point. I would not be turning up at a trackday with as little as 4mm.

[Toltec]

Given it is your first td you are probably not going to be trying too hard

The pads will need replacing eventually in any case so taking a spare set will give you peace of mind if nothing else.

[upsidedownmark]

It's an mx5, you don't need brakes

More seriously, it's light, not particularly powerful and so doesn't stress the brakes. Ran ordinary road pads on mine (with 1.8 rotors), never had an issue. From my recollection they probably only have 8mm new, I'd not worry at 4-5.

[HustleRussell]

I may be wrong but IIRC new pads have more like 12mm

[C70R]

On something that weighs less than a tonne, you'd be hard-pressed to burn through 5mm of brake material on your first day out. Particularly as you're unlikely to be doing a Stig impression on your first time out!

I'd recommend taking it relatively sensibly in the morning (not going after top speed on the straights or being 'last of the late brakers', and evaluating the state of the pads at lunchtime. This should give you an indication of how much you can get away with in the afternoon.

I'm not the best at taking my own advice, in truth. I cooked my rear tyres on my first day, and had a (largely uneventful) spin around mid-afternoon. My co-owner and I were giving the tyres a cursory glance between stints, but repeated use eventually did for them as we pushed a bit harder.

Good luck. Take care, and enjoy.

[markc123]

Thanks guys, I'll whip the wheels off and double check them as it was hard to see the inside pad last night then monitor wear on track - and take a set of standard road ones as a back up, and I can always back off, call it early as this is about learning about how the days work, what the car does and where I maybe need to continue the mods to make it what I want.

I read through your thread C70R - looks like you are having a lot of fun.

Then I will have to pick out the next set of track pads as I quite fancy Oulton in Dec, and I highly doubt these pads have 2 days in em :-).

[markc123]

Checked them tonight, both pads in the offside had slightly over 5mm, wearing equally and looked to be in good order. I'll measure again post track day and again when I put new pads in. I rather like the remove 1 bolt, and pivot caliper up and off design of these brakes - none of the 7mm allen key pin nonsense of my old pug.

And for bonus points, changed the blown headlight on the polo.

[Oilchange]

Having had brake failure when assuming I had enough material in the pads I'd say be a bit paranoid and check them after each session at least. If not simply change them and have the worn ones as spares.

You can do brake checks before corners if you are feeling under confident with them towards the end too.

[git-r]

HustleRussell said:

Have you actually got as little as 4mm on any one of the four pads? That is majorly borderline. Their performance will rapidly deteriorate from that point. I would not be turning up at a trackday with as little as 4mm.

Why does pad depth make a difference?

[HaylingJag]

depends what track your doing aswell!!

i have tracked standard and turbocharged 5's and neither are partically heavy on brakes. i tend to dab on a bit prior to a gearchange before turn in leaving the engine to slow you down and being in the right gear to floor it on exit

D

[DanGPR]

git-r said:

Why does pad depth make a difference?

Basic logic would assume if you are down to say 2mm of brake pad compared to 12mm, heat transfer is going to be massively increased to the backing plate and thus caliper and fluid.

[checkmate91]

I did this at Snetterton in a 2009 Focus RS, pads were near end-of-life, like 2mm. To be fair we over-drove the car a bit and deposited a fair amount of the remaining pad on the disc. Little did I know until some time later that I also warped the offside front hub that day, probably as a result. That was a VERY expensive main dealer rookie error!