Big Brakes!!!

[colinrx7surrey]

hello all,,im looking for some advice really--i need to change my brake pads,but at the same time im going to also change the discs,,,,really and trully wat i want to do is,get upgrade the pads and discs!! i quite fancy grooved discs,,wat size can i go up to??
has any one got any fitted on there 2nd gen rex?
wat sorta price im i lookin at?
where from??
fitting techniques?

cheers guys

[Grizzly]

I am not to clued up on Disks but i\'ve tried most fast road/Track pads and can recomend Hawks. Not stupid price ither.

[jetpilot]

Hi Mate
i am in the process of trying to get some fd discs and cailpers on at the moment. The fd calipers fit straight on but the fd discs are bigger and have slightly different bores than fc. I have had to get the hubs machined a fraction to accept the discs, the car goes in next week to have the brakes fitted but i am forseeing that i will have to get a small bracket fabricated to mount the calipers cuase of the increase in diameter on the discs. I will let you know.

[TRex]

Cross-drilling rotors is not a good idea due to the fact that you are removing metal.  By removing metal, you decrease heat retention by the rotors.  If the rotors become saturated by the extreme heat, the heat looks for other avenues to escape - typically into the brake pads and eventually to the brake fluid.  In extreme cases, the rotor will crack due to too much heat!  Drilled holes tend to crack radially.   Cross-drilled rotors ultimately end up being a purely cosmetic mod.

Rotors were first drilled because early brake pad materials gave off gasses when heated to racing temperatures, a process known as "gassing out."  These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction.  
 
 The holes were implemented to give the gasses somewhere to go.  It was an effective solution, but today\'s friction materials do not exhibit the same gassing out phenomenon as the early pads.  For this reason, the holes have carried over more as a design feature than a performance feature.
 Contrary to popular belief, they don\'t lower temperatures.  (In fact, by removing weight from the rotor, they can actually cause temperatures to increase a little.)  These holes create stress risers that allow the rotor to crack sooner, and make a mess of brake pads - sort of like a cheesegrater rubbing against them at every stop.

[g11ary]

Ah good thread starting,
So my non expert opinion.
Lots of guys on here run pads that are not really up to track days but they still use them, I thought that when a cold pad gets over heated it tends to have a glaze which goes hard, then a drilled or grooved rotor would yes wear it quicker but take that hard surface off and give better braking because its on a freash surface?
Interesting  that Endless race rotors are only grooved but confusing there endurance rotors are grooved & drilled, although I guess fro racing you would simply replace as money would be no object?

Chris Wilson used to be a resident guru, does he still frequent these pages?

[jetpilot]

A good write up Trex, as your electric radiator thread. Thanks. It would seem strange though as Gary mentions and from my viewings, that just about any track/fast/performance car and bike for that matter has drilled and grooved. I suppose maybe they can replace at will, but it surely must help to some degree or what would be the point in wasting money and labour process of drilling.

[TRex]

Yes, Grooved or Cutting thin slots across the face of the rotor can actually help to clean the face of the brake pads over time, helping to reduce the glazing often found during high-speed use which can lower the coefficient of friction.  
 While there may still be a small concern over creating stress risers in the face of the rotor, if the slots are shallow and cut properly, the trade-off appears to be worth the risk.  
If you need to worry about brake pad degassing, then go with slotted rotors.  Grooved type disc is a better way of preventing decreased brake performace due to brake pad degassing.

 Brake pad degassing is the condition when inferior quality brake pad compounds vaporize due to extreme heat. This gas that is emitted by the brake pad tends to float the brake pad over the rotor face, causing reduced brake friction!

 With regard to drilling / slotting again, most racing applications use massive brakes(disc) to improve braking area efficency. But then the rotating mass and overall weight is increased, so drilling holes are the main reason for mass reduction!

[Brett]

With drilled discs you increase the possibility of the disc cracking.  I\'m running slotted discs at the moment (brembos) on the EGi with greestuff pads.  This all seems very good for road use and the braking performance is improved, but by how much I cant really say.
 Grooved/slotted discs keep the pad surface smooth and remove glazing as it happens.  Pad wear is increased but bedding in times of pads is reduced.

 I\'d reccommed checking that your standard brake system is upto scratch first, ie all the calipers are working correctly and are not seized, the master cylinder and booster are in good condition etc.  If your intending to give the brakes a hammering then braided lines from the arches to the calipers would be a good idea too.

[FD3SNuttah]

im no expert on bracking systems but i can change brakes easily and know what good brakes are!!! here is my experience with cross drilled and grooved disks,

when i had my first car (a pug) i used to get brake fade all the time with standard disks! It seemed to take forever to stop sometimes, then after nearly being in ana accident, i decided to get some black diamond combis on there, i read various reviews and all of that jazz, and they had a nice finish on them too (which got rusty in the end)

black diamond combi\'s are grooved and drilled. The performance from these brakes was phenomenal! I could lock the wheels at 70 mph if i wanted to very easily. i had to adopt a new driving style i.e I had to learn to feather the brakes, and could brake really late but i knew if there was any trouble i would be able to stop!

the disks are still on the car (my mate bought it off me) and they have worn very well, they never cracked and it isnt from not trying either! (he more of a nuttah than me!) these disks are about four years old.

THerefore i would recommend drilled and groved,  it makes a huge difference as you will see! and as far as cracking goes, i think thats a little rare factor, cos race cars have drilled disks! some mercs and big german motors come with them standard too, so if cracking was common place you know you wouldnt see it as standard would you?

- Nas

[TRex]

Nas

 Don\'t go there dude.............. :bandit

 What I have posted there is not about putting \'BiG Brakes\' on a pug/nova whatever.
 It\'s scientific facts................. Facts that I can post pages and pages about, not from my experiences but from R&D (Research and Development) from Big manufactures and Professionals.

  I guess when you changed the Disc you also put new pads and fluid or even bled the fluid etc etc among other things!

[Brett]

As above,

   Bear in mind also that a racing car has specially treated discs, road discs have to operate under an entirely different set of conditions. This often results in hardend patches appearing on the discs which, if the area is weakend (ie holes in it) can lead to fatigue if you have to stop quickly from 60mph...

[antnicuk]

I have just fitted some direct replacement black diamond combi discs and pads to my TII,  i havent had them long but over stock ones they are much better,   and good price to,  less than 200 quid for the lot from Shy Autos and took 3 days to get.    They also do rears.

I dont how good they will be on a track day but i wont be using them on a track!

If you want good track day stuff then you tend to lose nice feel when on the road.  Its a compramise,  like wanting a big turbo that has no lag,  very hard to find!!

As for fitting FD discs,   in my opinion its not worth it for the 6mm each side that you get,  and trying to space a caliper out by such a small amount is difficult because where you want the new bolts to be will be overlapping the bolts holding the bracket on, unless you move the caliper round a bit.

Its a lot of work for 6mm!  i dont think anyone would notice the difference in breaking compared to good stock ones.

I have just fitted a set of 360mm monsters to an FD which is not much more work, at a cost of 360 quid (thanks re worx), took the stock discs,  machined the meat off it leaving a bell,  drill holes in it and mount the new disc onto your home made bell, and using stock calipers which are easier to space out because you have 30 - 40 mm to play with, (no overlap with existing holes).

[TRex]

Originally posted by antnicuk
 AsI have just fitted a set of 360mm monsters to an FD which is not much more work, at a cost of 360 quid (thanks re worx), took the stock discs,  machined the meat off it leaving a bell,  drill holes in it and mount the new disc onto your home made bell, and using stock calipers which are easier to space out because you have 30 - 40 mm to play with, (no overlap with existing holes).

  I have seen these myself....

 Thats an amazing project Tony, the whole car . :god

 Agreed about fitting FD disc, it\'s not worth the hassel. Mainly because as I understand it, you need to machine(grind) down a bit either on the Hub or the Disc itself for them to fit the FC Hubs.
(correct me if this is wrong)....
 There is no way I will Grind anything on the brakes(remove material) for no gain in anything really... if there will be a gain, it will be hughly offset by what it took to do.

 On the other hand I know the FD Calipers will fit bang on an FC as I have done this myself.
Not as a performance mod, but the FC calipers have a tendency to leak, corrode etc.  2 things, these bloody things are almost 18-20 odd years old now and the materials and design used on the FD ones are improved....
 I even have a fully rebuilt pair of FD calipers standby if needed.

 There are 2 things you should never feck about or take any chances with on your car!
 1. Brakes
 2. Steering............
 
 \'Power is nothing without control\'  :burnout

[Brett]

dont take the chance on letting your g/f drive it either!

 So are the FD calipers a direct fit on the FC then?  What amount of hassel are they to change? (Considering mine hasnt turned a wheel in 4 years the calipers will be knackeered anyway...)

[FD3SNuttah]

hi guys..

yeh i drove a pug as my first car so what? i loved it it handled really good, fair play in its later years it started rattling all the time and falling to bits! the aftermarket disks i changed wasnt bigger than the stock items they were a direct replacement! i failed to mention that (granted).

brakes are brakes, even if they are on a pug or a nova! so dont go there yourself!

Like i said i dont know that much in the context of materials and methods used to produce brakes.

I was letting you know the HUGE difference i experienced over using the stock rubbish when i upgraded.

I didnt change the fluid, obviously i changed the pads when i did the disks!

as far as cracking and doom and gloom goes, i havent had any experience of that or know of anyone who has. maybe you lot just bought disks that were not made properly!!!

if you dont want to talk about race applications then fair enough, but on street setups i think they work better than normal solid disks (of the same size)