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The mkiv Supra Owners Club

K Sport or D2 breaks


Supraleeturbo
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Lee, I would save your money mate. I haven't been happy with my brakes for a long time (UK brakes) but I finally cracked it for Dragonball v2! :)

 

I use my brakes hard, high speed stops down to roundabout speeds in concession, and have nearly set on fire two sets of CW fast road pads, and would always get brake fade too quickly.

 

So before Dragonball I gave it one last shot before I ditched the UK's and went for a big brake kit, and had all the old brake fluid flushed out and replaced with Motul RBF600, and the pads changed for Porterfield R4 Race Pads. All I can say is WOW! The do exactly what I want when I want, and didn't once get brake fade on DB, and I was really pushing them hard.

 

Lee just try a setup the same as mine and tell me what you think ;)

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Lee, I would save your money mate. I haven't been happy with my brakes for a long time (UK brakes) but I finally cracked it for Dragonball v2! :)

 

I use my brakes hard, high speed stops down to roundabout speeds in concession, and have nearly set on fire two sets of CW fast road pads, and would always get brake fade too quickly.

 

So before Dragonball I gave it one last shot before I ditched the UK's and went for a big brake kit, and had all the old brake fluid flushed out and replaced with Motul RBF600, and the pads changed for Porterfield R4 Race Pads. All I can say is WOW! The do exactly what I want when I want, and didn't once get brake fade on DB, and I was really pushing them hard.

 

Lee just try a setup the same as mine and tell me what you think ;)

 

Thanks mate I think I'm going for the 8pot ksport With either the porterfields or ebc yellow stuff as they come highly recommend

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Lee, I would save your money mate. I haven't been happy with my brakes for a long time (UK brakes) but I finally cracked it for Dragonball v2! :)

 

I use my brakes hard, high speed stops down to roundabout speeds in concession, and have nearly set on fire two sets of CW fast road pads, and would always get brake fade too quickly.

 

So before Dragonball I gave it one last shot before I ditched the UK's and went for a big brake kit, and had all the old brake fluid flushed out and replaced with Motul RBF600, and the pads changed for Porterfield R4 Race Pads. All I can say is WOW! The do exactly what I want when I want, and didn't once get brake fade on DB, and I was really pushing them hard.

 

Lee just try a setup the same as mine and tell me what you think ;)

 

It helps when your brake fluid isn't full of air and looks like a drunks piss sample, And cheers for leaving that job to me haha

 

Tim

TB Developments

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I've got Alcon brakes on my car. Having run a car with both J-Spec and then UK spec brakes I have to say the Alcon brakes certainly feel more positive and are less prone to fade on spirited driving.

 

The UK brakes were certainly very good. Especially with the CW fast road pads. But I do think the Alcon brakes are a step up from the UK setup.

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It helps when your brake fluid isn't full of air and looks like a drunks piss sample, And cheers for leaving that job to me haha

 

Tim

TB Developments

 

Thanks mate, you love it lol

 

What make are the pads mate ?

 

The make is Performance Friction Lee, Chris Wilson's race pads use to be these, until they stopped producing them in the UK caliper size :( I know of a couple of members who do a lot of track days and The Ring, who have changed their calipers just so they can run Performance Friction pads, they are that good! I would love a set for my UK calipers :(

 

Below is the link for you Lee:

 

http://www.pfcbrakes.com/

Edited by Burna (see edit history)
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But surely if you got more Pistons pushing the pad the better the friction so better stopping ?

 

 

Sorry, this is totally false. Multi piston calipers are designed to reduce taper wear of long pads, just the same friction is achievable with 2 pistons. 8 piston calipers are purely pub talk material. You need to be addressing the areas you find the current brakes deficient. I wrote this years ago, it may have some useful info for you. I don't have time to write a long post on where multi piston calipers are of benefit but google caliper pistons, piston size and pad taper wear.

 

 

 

Brake upgrades can set out to try to achieve several objectives.

The commonest are to increase resistance to fade and or increase

braking effort for a given pedal effort. IE, the pads are

pushed against the discs harder for a given pedal effort than

before the upgrade, or the brakes will stop the car from 100 MPH,

hard, for more times before fade sets in, than previously. The feel

from the pedal, that almost intangible quality, can also be addressed

and sometimes improved upon by brake size, or pad material changes, or

brake flexi hose upgrades to something less squashy than rubber.

It's easy to get carried away by the thought of brake upgrades.

The limitation in most cars as to how short a distance they can

stop in is tyre friction. Leaving aside pedal feedback, and fade,

it is almost certain that a Supra on stock Jap spec brakes will

stop in just as short a distance as one with an AP six pot kit on

it, a Brembo kit, Pauls KAD kit, or whatever. It may not feel to

the driver that it does, but usually such is the case if you just

nail the pedal as hard as you can. The fancy kits may *FEEL* to

stop the car faster, due to less pedal effort, and a better bite,

but in reality, if you hit the pedal as hard as you can with stock

Jap spec brakes, UK spec brakes, AP kit, KAD, whatever, the car

will stop in the same distance. Repeat this test 10 times and stock

Jap brakes may be on fire and long since faded, or the fluid boiled,

UK ones may be very hot and bothered, but the upgraded ones will

probably still be working within pad, disc and brake fluid temp

limits. Add in the intangible "feel" factor, and a desire to brake

as hard as possible, using as little skill as possible, but WITHOUT

relying on the ABS to take over, and for sure a well set up brake

upgrade may well allow more finesse.

 

Herein though lies the rub.

 

Upgrade only the fronts and the brake balance of the stock car may

well be compromised. Let's take stock brakes. You press smoothly on

the brake pedal with (say) 50 pounds force. The car stops fine. 70

pounds, the fronts are just beginning to lock (car makers ALWAYS aim

for the fronts to lock first, as rear wheel lock makes the car very

unstable and liable to swap ends). The rears are doing as much work

as the brake engineers deemed safe to prevent premature rear lock up.

The ABS cuts in, and maximum retardation has been reached. Now, take

a car with big front discs and calipers. Only 40 pounds pressure now

gives a smooth, lock free and powerful retardation. 50 pounds and the

new, more powerful, (for the same pedal pressure), fronts are locking.

The ABS cuts in. BUT, and this is the crux, those original rear

calipers and discs are still well below the caliper pressure where

they are able to achieve maximum retardation without fear of the

rears locking.

 

In other words the FRONT brakes are doing TOO MUCH work, albeit without

breaking into a sweat, and the rears are, to exaggerate a bit,

just along for the ride. The BEST scenario is to upgrade front AND

rear brakes, carefully ensuring the original balance of effort at any

given brake pedal pressure remains as designed, but that the more efficient

front AND rear brakes stay cooler for more hard stops, and that old

intangible "feel" from the brake pedal is improved, at lower rates of

driver effort on the pedal. The latter may or may not be good or

desirable, and can be engineered out by changing BOTH front and rear

caliper piston sizes, or pad areas. In a race car the balance would

be adjustable via 2 brake master cylinders, with a driver selectable

change in mechanical leverage effort between front and rear brake circuits,

one cylinder operating the front brake calipers, the other the rear. This

can also be achieved on road cars, but to do so is usually complex and

expensive, especially if ABS and brake circuit failure safeguards are to be

maintained. It is far easier to calculate the caliper and disc sizes, along with

pad area and compound to achieve this, as near as available off the

shelf equipment will allow.

 

Caveat. I said before makers engineer more effort on the front brakes to

encourage straight line stopping if the tyres are locked up . They err on

the excessive side, as, in the wet, the rear tyres can take a lot more

braking effort than in the dry, due to less weight transfer onto the front

tyres, as they will lock before as much weight is transferred when the grip

of the road surface is reduced. So adding yet more front brake effort worsens

this existing imbalance, especially in the wet. If it were not for the

ABS the front wheels would be locking up very early. On the Supra a

relatively sophisticated ABS allows some effort to be taken off JUST

the fronts, and an artificial and very inefficient balance is returned.

On cars with lesser (1 or 2 channel) ABS, or no ABS at all, a brake

upgrade on just one end of the car can be lethal.

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I have fitted the 6-pot Jeep Bimbo brakes to a Supra, they really need 19" wheels to clear, but with a re profile do just go under 18's".

 

Not a job for the feint hearted.

 

Nice job. I was considering these a couple of months back but never went down that road, not yet anyway.

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Those Brembo SRT conversions did catch my eye, but I wasn't sure how viable an option they'd be compared with the dedicated Supra specific setups (F50 for example) in terms of brake bias etc. Obviously the price is drastically different, but I wouldn't want to feel the need to buy twice if they weren't 'right'? :)

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I have been very pleased with my D2 8 pots with Pagid SR19 pads. I have been considering upgrading my jspec rears to UK rears to try and re-address brake bias as per CW's previous post.

I would steer clear of any EBC pads. Can recommend Pagid and Porterfield pads.

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