Different pads front/rear????

[Spranga]

I fitted some slotted rotors and new pads today.

I managed to pick up some Hawk Blue (rears) and Race Brakes RB74s (fronts) very cheap, but I am a little worried about having different pads front to rear. The hawks are basically a track pad and the RBs more a road/track pad. I know the rear end on mx's don't work very hard so I thought maybe a more bitey pad on the rear would balance things out (I know I should just get a proportioning valve ). ALternatively I am worried the rears won't get hot enough to get to working temperatures in most conditions and will therefore make the RBs work harder; further when the hawks do get to working temps (at the track for instance) the car might get taily because the Hawks are coping with race temps better and are in their working range

I guess I will just have to see how it goes but does anyone have an opinon on how the car is likely to behave?

[NMX516]

I'd suggest that the braking will be inconsistent, especially on the track. Pads are designed to operate at their best within a certain temp range. If the optimum range is different for the front and rear pads, well, it could get interesting. On the road, probably not too noticeable unless either of those pads don't work well from cold. You'd also want to make sure that if running two different types, that the better performing pads were on the front - better a front lock up under emergency braking or on the track, than a rear.... I'd always use same pads front and rear.

[16bit]

its common practive to put different pads front and rear in the spec miata series in the us. however the other way around. don't do it. from what I hear (don't actually know for fact) the na is probably the worst model to put more rear bias on - i think. also don't run blues on the street they are a track only pad.

[Spranga]

Thanks for the info guys! Looks like I need a set of rear RB74's!

[Fatty]

from what I hear (don't actually know for fact) the na is probably the worst model to put more rear bias on - i think.

no, the na6 is very heavilly biased to the front to start with, so adding a bit more to the back is not a bad thing. i fitted a prop valve from an nb8b to my car to add more rear bias. basically i just copied what matty did and it seems to have worked well so far..

[16bit]

i knew it was one way. either way I would not run a stronger compound on the rear. especially when mixing street and track pads.

[Fatty]

i agree

[Spranga]

The rear does not work very hard from what I have read. I always go through the front pads first. I will still change them for the track. Should be OK for some mountain driving as it will be hard to stretch the hawks in the street environment.

[feel_ixx]

Heres a thought though, if you just happend to buy a set of front and rear pads, and at the moment you only change the front. When the rears have finally worn and you put your new never used pads on the rear, will there be unbalancedness?

[Hellmun]

Having the same compound but different wear levels wont' affect breaking much on the street. First time you apply the brakes the fluid will take up the slack in the brake system and they'll break equally again. On the track you may find the thinner pads will overtemp quicker due to less heat dissipation area.

Hawk Blues are very aggressive on rotors when cold. Get a set of blues for the track but I wouldn't use them on the street. I find my rears reach about 180C and fronts can reach in excess of 550C on the track if I don't use the cooldown lap. That's in an NB8B and the hawk blues start working at 100Cish IIRC. I think you'll also find the coefficient of friction on the hawks is higher than the RB74's so without the proportioning valve you'll lock up the rear much earlier. So you'll actually lose braking performance and when you push the limit I hope your prepared to catch the car.

[Damo]

I currently have blues on the front and standard pads on the rear - that will soon change - and this has certainly moved the bias forward so that the car can't be trail-braked any more and so I'd expect that using the blues on the rear would be a risk.

[Spranga]

I did a hardish run up the Putty rd this morning and towards the end of a long twisty section I had to steer against the rear a little while braking for the corners... it was only subtle but in a track environment it would be more pronouced.

[feel_ixx]

Anyone know much about Trust Grex sport brakes? I just bought some from a fellow forumer, but couldnt find much information on them except that they are a race pad suitable for street. Anyone know care to write a review if theyve tried it?

[GS]

Sorry i dont have anything to add to the brake pads conversation. Just thought id post a reply so we get three white NA sigs in a row

[Spranga]

Sorry i dont have anything to add to the brake pads conversation. Just thought id post a reply so we get three white NA sigs in a row

Anyone want to make it 4?