its been so fast on track with a standard engine, I have not even thought of that route....

the tyres make a HUGE difference, I will be going for RSRs again soon as I'm down to 2 mill now...

my insurance company says FARB is no cost, so thats going on soon! but its 3rd...

1st) front tyres (before my sept ring trip! will finish the current ones off at castle coomb summer action day!)

2nd) better brake pads.... I may have to bite the bullet and get some that are £135 :( tarox corsa....... in theory I will be ALOT faster with brakes that dont overheat... brakes are still the weak point at the moment....

3rd) H&R FARB.... over the winter hopefully , for next years track days

Dave,

We both have EBC yellow stuff pads (mines are 312mm Brakes) but maybe u should consider replacing your brake fluid with the one that has higher boiling temp...? That might help you on the track and the one I'm currently running costs only £10 for 1 ltr.

You could try that before Castle Comber and before you spend over £100 on the new pads...

Matty

good point Matty...... yours are 312's though and i'm still 288mm.... BUT you didn't fade with the same pads... so maybe a fluid upgrade would work....

I've got some 312s if your interested Dave?

Gulf RF1000 is rather nice.

What about changing rotors as well? Same size, just premium brand

Just a few thoughts.

 

Compared to Matty Dave your car is putting out circa 60bhp more and you have track tyres on so you are putting far more pressure on your brakes when you are using them.  So you just might be putting the extra hurt on the Yellowstuff to see them fade.

 

I have had a 312mm disc and a 288mm disc side by side, to my eyes I cannot for the life in me see why everyone is convinced that they are so superior to the 288's either in stopping power or heat dissipation.  Perhaps the 312mm pad is larger I don't know.  But I know Matty swears his were a big upgrade and that's good enough for me as he clearly isn't shy on pushing his car.

 

I think the ATE Super Blue is a must considering it is so darn cheap, you will only need a 1 litre can to do the car, I went off Sy's recommendation to use 1.3/1.5 litres and still have a spare full can even after bleeding the brakes a couple of times.  But it sounds like you have pad fade rather than spongy pedal.  Has everything returned to normal since Bedford brakes wise?

Well said Mark and Dave, as per my PM yesterday I'm using the ATE Super Blue and I think being that cheap it well worth it... 

 

Try the fluid before you upgrade your pads as I have the Yellow Pads and really happy with them so far...

 

 

I have had a 312mm disc and a 288mm disc side by side, to my eyes I cannot for the life in me see why everyone is convinced that they are so superior to the 288's either in stopping power or heat dissipation.  Perhaps the 312mm pad is larger I don't know.  

 

It is interesting what you said. I assume you had both on your vRS when you had it. Did you notice the difference then? 

It is interesting what you said. I assume you had both on your vRS when you had it. Did you notice the difference then?

No sorry Jabo, I went straight from 288 to 323mm with the Leon Brembo's.

The previous owner of the Brembo's ran them with 312mm discs, which I didn't use I bought new correct size larger discs.

So I was able to put a set of 288 and 312 discs side by side, I haven't seen the 312 caliper though and compared.

Oh, all right then, now I understand, thanks

 

Assuming everything equal bigger discs will have pads sitting further away from the rotation centre therefore exerting more breaking force on the wheel by the virtue of the length of the force arm being larger. 

Theoretically have it big enough and you can stop your car with your fingertips  :p

Just a few thoughts.

 

Compared to Matty Dave your car is putting out circa 60bhp more and you have track tyres on so you are putting far more pressure on your brakes when you are using them.  So you just might be putting the extra hurt on the Yellowstuff to see them fade.

 

I have had a 312mm disc and a 288mm disc side by side, to my eyes I cannot for the life in me see why everyone is convinced that they are so superior to the 288's either in stopping power or heat dissipation.  Perhaps the 312mm pad is larger I don't know.  But I know Matty swears his were a big upgrade and that's good enough for me as he clearly isn't shy on pushing his car.

 

I think the ATE Super Blue is a must considering it is so darn cheap, you will only need a 1 litre can to do the car, I went off Sy's recommendation to use 1.3/1.5 litres and still have a spare full can even after bleeding the brakes a couple of times.  But it sounds like you have pad fade rather than spongy pedal.  Has everything returned to normal since Bedford brakes wise?

thats how haydn does it on the brisk rover, cheap standard discs... the is NO problem with stoppping "power" , just need to keep the heat down...

 

I may try the fluid, as its cheap... but here is thething... the brakes would still work at blyton, but the pedal would start to go further down.... so It could have been jusyt the fluid... the yellowstuff is supposed to handle 900c, so for the cheapness, fluid change is next I think

Oh, all right then, now I understand, thanks

 

Assuming everything equal bigger discs will have pads sitting further away from the rotation centre therefore exerting more breaking force on the wheel by the virtue of the length of the force arm being larger. 

Theoretically have it big enough and you can stop your car with your fingertips  :p

 

true but when that distance is (28.8cm to 31.2cm divide by 2) then in theory the centre of the pad moves no more than 12mm.  I just can't see it having much impact, in spite of all the hype.

 

It has been said many times, most people refresh their pads, discs and fluids at the same time of an upgrade which will contribute far more to the feel of improvement.

 

Anyway, these were just some thoughts.

thats how haydn does it on the brisk rover, cheap standard discs... the is NO problem with stoppping "power" , just need to keep the heat down...

 

I may try the fluid, as its cheap... but here is thething... the brakes would still work at blyton, but the pedal would start to go further down.... so It could have been jusyt the fluid... the yellowstuff is supposed to handle 900c, so for the cheapness, fluid change is next I think

Good Man...

true but when that distance is (28.8cm to 31.2cm divide by 2) then in theory the centre of the pad moves no more than 12mm.  I just can't see it having much impact, in spite of all the hype.

 

It has been said many times, most people refresh their pads, discs and fluids at the same time of an upgrade which will contribute far more to the feel of improvement.

 

Anyway, these were just some thoughts.

 

7.7% more braking force to be precise as the effective radius is directly proportional to braking torque applied. 

G'day guys

 

Hopefully I can help put the question of standard size rotors and yellow stuff pads to bed soon. I have just picked up a set of brand new Yellow stuff pads today and plan to ran them at the SMP Brabham circuit (4.5km) next month which has a much higher top speed (between 180-200km) then the two circuits I have been running on previously. For the last 10 months I have done 7 track days using Remsa pads and after market slotted DBA Rotors. On the SMP South circuit (1.8km) I am hitting a top speed of 140km twice a lap (both with 90 degree braking zones) with some brake fade only if I am pushing hard lap after lap. However when I am running at Wakefield Park (2.2km) where I hit a top speed of 165km on the main straight and 140km on the back straight (both with 135 degree roughly braking zones) where I am suffering from brake fade so bad that after one hard lap I am starting to lock up my rear brakes. Given that the first braking zone with an entry speed of 200km at the SMP Brabham circuit has a 180 degree turn before the two 140km braking zones from the South circuit plus another 160km braking zone before the main straight, I am just a little bit worried about how well the brakes will last???? I am just hoping that the extra length of the track will give the brakes some extra time to cool down a little.

 

After a lot of research I have settled on a BBK that should improve braking without a weight handicap while still keeping the costs down a bit. But that will not happen till next year.

 

BTW... The bilstien shocks do improve the handling feel greatly but the lap times not so much. The difference at Wakefield Park on my first flying lap was about half a second (but this is a track where my brakes perform badly).

 

Of course all of this means nothing to 99% of you.

Edited 22 August, 201411 yr by mmmRacer

7.7% more braking force to be precise as the effective radius is directly proportional to braking torque applied.

Change in moment of inertia, surface area of larger pads and dynamic friction taken into account - far too many variables to give a . answer.

The end result of actual stopping is All down to the grip of your tyres - larger brakes just let you get to that point with less force from the brake peddle. It doesn't matter what the mechanical lever is the wheels will still lock once you have overcome the dynamic friction of your tyres which doesn't change by adding bigger brakes.

If you ran slicks with oem brakes you will be able to apply more brakes before the wheels lock than with upgraded brakes and normal road tyres.

Think of a torque wrench. If you set it to 30nm, it doesnt matter how long the torque wrench is it will still click at 30nm. A longer wrench will just mean you need to put less force in to reach 30nm.

Well the last few posts may aswell be in dutch to me.... im fitting yellowstuff pads with oem discs and new race fluid tomorrow. I'll let you know if it solves my braking issue. True test is at combe though..

we'll have to have a chat at coomb If I suffer, and you don't then its directly the fault of my fluid! I may change it before coomb though

 

 

thanks for the input mmmracer, let me know how your next track day goes have you upgraded the fluid?

Change in moment of inertia, surface area of larger pads and dynamic friction taken into account - far too many variables to give a . answer.

The end result of actual stopping is All down to the grip of your tyres - larger brakes just let you get to that point with less force from the brake peddle. It doesn't matter what the mechanical lever is the wheels will still lock once you have overcome the dynamic friction of your tyres which doesn't change by adding bigger brakes.

If you ran slicks with oem brakes you will be able to apply more brakes before the wheels lock than with upgraded brakes and normal road tyres.

Think of a torque wrench. If you set it to 30nm, it doesnt matter how long the torque wrench is it will still click at 30nm. A longer wrench will just mean you need to put less force in to reach 30nm.

 

True, with one proviso, you can actually lock your fronts time and time again meaning that indeed your braking system provides torque enough to overcome the grip tyres can provide. Not he case sadly with vRS even on factory tyres, not to mention RS-R's!!! Tyres have WAAAY more grip for the braking systems.

Ask Sharkrider how much my back was dancing under heavy braking and fronts ware still turning at Blyton/Bedford- that is with emergency braking assist in full swing as well...

 

However, not to be picky but I did clearly say all else being equal so the same pads etc just rotors bigger.

BTW, what is "dynamic friction"?

 

I like the torque wrench analogy. Good illustration of staying within or going beyond tyres abilities to grip under dynamic load shifting during track work

we'll have to have a chat at coomb If I suffer, and you don't then its directly the fault of my fluid! I may change it before coomb though

 

 

thanks for the input mmmracer, let me know how your next track day goes have you upgraded the fluid?

 

Friday lunch time pub visit Dave?

 

I suppose it is possible to drop in for a casual session of Coombe from Sydney? unless it was not mmmRacer you wanted to have a chat with lol

I ment the grinch :P

ordered some fluid an a bleed kit... gonna try and do it before coomb

Worth checking Dave, but you might need someone with VCDS to assist helping you bleed the brakes fully, unless you have the cable yourself?

The VCDS option is much quicker and takes circa 10-15 mins to do all 4 sides...And we didn't have the kit with us when we did it

 

I also had this done without the VCDS which this means you need to have the car on the ramp with someone under the car and in the car pressing the pedal until person under the car sees the fluid coming out...This one took us over an hour and one brake bulb had to be replaced after I pressed the pedal over 100 times 

 

Matty

I bleed all four corners myself without any kits whatsoever (just a bottle with 8mm fuel type hose attached to avoid spillage) in 45 mins 

VCDS is for bleeding the servo, if you keep fluid in the reservoir at all times (just frequent topping up while you bleed) no need for VCDS procedure, no?