This should be read after the original thread 'Tarox 6 pot upgrade' (or something like that).


TAROX BRAKE UPGRADE
====================

MY93 WRX.

I Can't remember a standard performance car ever having such awful brakes. This was highlighted by a joint spirited drive with(against?) a Honda Integra Type R. two big stops only on a straight piece of deserted ring road saw my brakes fade to approximately 20% effectiveness and no pedal.


After dispelling rumours about how badly or unnecessarily designed grooved brakes were (you know who you are), I upgraded to grooved, vented (billet cut) 319mm rotors at the front, clamped by very attractive 6 pot callipers which were actually lighter in comparison than the originals (didn't weigh everything I'm afraid) and steel braided hoses front and rear. The grooves of the disc under heavy pedal pressures will I suspect actually do what they were designed for and cut the face of the pads.


After looking very carefully at brake fluids I opted for Castrol Response Super Dot 4, this has a higher boiling point and other factors than Dot 5.1 fluid so in it went.

The pads in the front apparently use the customised back plate from a Mercedes Truck they are that big and I can believe it.

The rears would have looked odd without the grooved discs so they were upgraded as well, with an intermediate grade pad fitted as I thought that the extra work under load would be too much for the standard pads. The hardest thing about fitting the whole kit from start to finish were the mounting points on the car for the steel braided hoses, they were slightly too small so had to be laboriously filed out by hand.

RESULTS
=======

Pedal feel is vastly improved but not as tactile as I would have expected (bulkhead flex?), stopping power is devastating in anger, the pads take a little bit of warming up from cold and if used just to dawdle about town with (often), feel little different from the original chocolate ones.


On the pace driving will require a couple of hard stops to warm the pads up and I suppose to shake off the glazing caused by posing speeds through town, (you know you have to) ;-)


A deliberate big stop on a constant pedal pressure (Max without lock-up, No ABS) can give what I originally thought to be uneven braking at the limit, almost as if each corner is pulling a varying amount of pressure but in a fluid way. I now suspect it is being caused by differences in the actual road surface at full braking power. (If one corner was braking harder than the others it would do it continuously at that corner).


Front discs look as though the pads are not contacting the whole of the disc surface evenly. this is what I suspect DTV looks like, the areas that do not look like they are connecting properly are blue and mainly on the centre of the swept area of the disc.


After some serious abuse, as you progress back to a more sedate pace I can almost on demand cause by applying a light/medium pressure to the pedal, a heavy shaking/vibration from the front left disc. In the same way that I can cause it, I can avoid it also by not doing what I just described.

From new the discs feel as though they are going to take a very long time to bed in, the manufacturers state 100 miles, I say you need to be looking closer to 500 miles steady and then start gradually upping the pressure, it is how I imagine breaking in a rebellious horse to be.


Worth it? "Oh yes". Better than AP or Brembos? Only a back to back test would determine that, They are certainly in the same league and were about £300 cheaper. A track day is on the cards where they will be pushed to their (my?) limits.

Mike.

[This message has been edited by Mike Tuckwood (edited 09-08-1999).]

Mike,

Instead of wasting your hard earned cash on expensive Italian cosmetic brakes !!!!

You could have got a couple of pizza's,and four bit's of ravioli !!!!

A nice Chianti would do for the dot 4 !!!.


Speak to you soon (maybe !!!)

Mark.

When I've gone old and grey, he finally speaks.

It took you so long to follow up on this Mike that Tarox came out with 8 pot caliper brakes......

Mike

The fact that only the center of the disk is going blue is not a good sign as this means the center of the disk is getting hotter than the edges so you are not getting a very even pressure across the whole disk surface.

With my setup all four disks go completely blue when you have had a hard day at the track!

The reason that the disks are vibrating when you get them hot is that they are warping. This is the reason that more expensive setups have fully floating disks so that this problem is reduced and the feeling isnt fed back through the steering. If you are getting this to happen when you havent got the whole disks to go blue then I would be concerned.

Darren

Malique.
Now...... It's funny you should mention that!

No, maybe I'll save it for later.....possibly next week. http://bbs.scoobynet.co.uk/wink.gif

Darren.
Just re-discovered this thread again.

After the last posting I spoke to the suppliers/importers and they think that the pad may be dragging lightly on the disk in a manner similar to running your finger around the top of a wine glass?

The uneven brake feel I described in my original post I have strong suspicions that it was caused by air in the brake lines, I have re-bled them and they are a lot better.

Disk wear/DTV, the vibration I described does not feel like a warped disc, I have sent a photo of the discs to the manufacturers who will look into it.

Mike.

Aren't TAROX dics notorious for warping?

Regards

Disc warping is....... well exactly that.

After speaking with Pete C at the last PE Dyno day, his view was that grooved discs, because of the grooves are a collection of seperate successive braking surfaces <I>(my interpretation not his exact words)</I> and if they heat up (or cool down) at differing rates, then vibrations can occurr.

This could be seen as a characteristic of the disc(?) but my experience so far is that this is not what appears to be happening.

Perhaps it's just me describing the symptom badly.

After some heavy abuse during which the braking efficiency is phenomenal, without any sign of fade or vibration (other than what could be expected with grooved brakes which are inherantly nosier than plain discs).

During the cooling down period I was able to induce a vibration from the front left disc only, by applying a very light pressure to the pedal. during heavy use it wouldn't do it, during normal use it doesn't do it.

I have not experienced it since bleeding the front brakes recently so wonder if the air in the system was allowing the pad to bounce off of the disc at high frequency due to its hot and sticky condition with a lot of heat in it?

Mike.