Brakes Dilemma

OK heres the deal my supra needs new brake pads all round and judging by the discs although in good overall condition (no rust) they are very worn and i expect will require replacing very soon.

So the question is do i -:

1. Buy a full UK brake set (rotors, calipers, pads and fitting kit)

or

2. Buy all four J-Spec discs, new pads and fit aftermarket brake lines.

Anyone know the approxiamate costs difference for the just the parts and the difference in fitting cost between option 1. and 2. assuming im not doing the job myself.

I know UK brakes are the nuts and i know i wouldnt regret it but im just trying to way up the costs difference to see if i can find the extra cash.

Cheers

Chris

do you get any sort of fading etc issues?

I been able to drive both a stock pad uk set up and a Chris Wilson Race spec pad J-spec setup back to back, and the J-specs have far more initial bite. I'd say they would out do the stock uk's on the road or track etc, but they are definitely not expensive aftermarket alloy friendly with the amount of dust produced.

What i'm saying is same pads and uk's are better than J-spec, but performance can be increased so J's are better, but squealing and alloy eating dust is the trade off.....

.....stock uk's let me brake well with none of the negatives.

are your wheels valuable!

I've got UK front brakes and I really can't hardly tell the difference. I know folks say the UKs don't fade as much as the JSpecs but I've never had a problem with that so far. (Never done a track day or owt like that)

TBH, If it wasn't for the improved look of the UKs I'd have been quite disappointed with them, I was expecting a HUUUGE difference in braking power, going by the comments of folks on here.

I can think of better ways of spending £1500 (or whatever a full set of UKs are.)

Originally posted by Scooter

do you get any sort of fading etc issues?

 

I been able to drive both a stock pad uk set up and a Chris Wilson Race spec pad J-spec setup back to back, and the J-specs have far more initial bite. I'd say they would out do the stock uk's on the road or track etc, but they are definitely not expensive aftermarket alloy friendly with the amount of dust produced.

 

What i'm saying is same pads and uk's are better than J-spec, but performance can be increased so J's are better, but squealing and alloy eating dust is the trade off.....

 

.....stock uk's let me brake well with none of the negatives.

 

are your wheels valuable!

Scooter,

No brake fade as i currently use Chris Wilsons Race Pads however as you say the brake dust and squeal is the sacrifice and as im getting new wheels very soon i dont want to go for them again. Its got to be standard pads whatever i choose. That said the pads are awsome, the intial bite especially.

Originally posted by Jake

I've got UK front brakes and I really can't hardly tell the difference. I know folks say the UKs don't fade as much as the JSpecs but I've never had a problem with that so far. (Never done a track day or owt like that)

TBH, If it wasn't for the improved look of the UKs I'd have been quite disappointed with them, I was expecting a HUUUGE difference in braking power, going by the comments of folks on here.

I can think of better ways of spending £1500 (or whatever a full set of UKs are.)

Jake, your right about the cost. For the cash involved i may be better going with new J-Spec rotors and aftermarket brake lines. I dont do track days and im not heavy on the brakes anyway. The CW race pads have eaten my discs and the pads worn in no time.

Thanks Scooter and Jake

Before I got my UK brakes, I was going along the M27 on the way home from work when an old shape 325 beemer in front of me had to do an emergency stop because there had just been an accident in the fast lane right in front of him.

I was too close to him (yeah yeah I know) so I had to brake VERY hard as well. The thing was, when I'd come to a complete stop the Beemer was still screetching it's tyres. From 80mph I could stop at least 50 feet before the BMW.

Those 'crap' JSpec brakes are good enough for me.

Originally posted by Jake

Those 'crap' JSpec brakes are good enough for me.

This is true, i have never found them to be dangerous. They do a good job.

I nearly died today with 3 in the car in a straight line. Obviously I was going quick but put it down to the brakes, they were terrible.

If/when I have the money I'll get a full set of Brembo monster disks and mucho pot calipers. The car's too heavy and fast for J-Spec setup I reckon and that's just BPU.

The better the brakes the faster you can go.

If the brakes are capable of locking the wheels (which Jspec and UK are) then both are going to stop you in the same distance (provided you press hard enough of course). The bigger brakes will just allow you to do this more times before overheating and fading. I've never had brake fade with UK brakes, and I know other people have with Jspec ones. The other factor is pedal feel, I've never driven a Supra with small brakes so I don't know how they compare that way.

I never had any problems with my J-spec brakes but then again i had a 112 limiter so I probably wouldn't have had. But before I went for more power and removed the limiter I changed to UK fronts. I would say more for the confidence factor than anything else. Also its nice to have shiny new brakes on a 10 year old car.

Apparently it's when you brake from 120+ to zero the j-specs really begin to fall apart just before you stop.

I think I faded my UK ones with CW pads the other day while racing my housemate in his VX220 turbo While braking hard a Lexus decides it can pull out into the right hand lane, instantly halving my slowing-down distance, whee. Leant on the pedal some more and it squished down a bit more and there was a strong smell of burning friction lining. Actually I reckon it was just cleaning corrosion off the pads or something, heh, honest guv. I must try murdering them one late night with northing around, see if I can replicate it and also see if I can still lock the wheels up...

SimonB is spot on, it infuriates me when people think "bigger brakes = stops faster". Simon - to the FAQ thread in technical with you!

-Ian

its the tyres at the end of the day, if they aint gripping then u can have best brakes in world but ull just lock up and slide off instead of slowing slowly with brakes that have faded and still be in control.

I have had fade on my J-spec but mine are warped so that is not gonna help at all

I've driven both, and if you get a decent set of pads on the JDM brakes, they can be good. However, I've never back-to-back compared them to a set of UK's with uprated pads...

IMO the JDM brakes with stock pads are terrible at speeds above 80mph. If you get far enough into 3 figures and have the need to stop suddenly, well, it won't happen.

I used to get brake fade on a stock JDM set up, just because I was late home for dinner, let along track days!

I have had fade on the UK set-up, but it takes far more braking for it to happen, and they can stop you from over 100.

Personally I'd get, at least, the front UK set-up.

I've got a complete set of front and rear J-Spec brakes with almost new pads and braided lines if you're interested.

I've had the front and rear Brembo kit for a few months now and they're seriously good The J-Specs were as much use as tits on fish, initial bite was good but the brake fade was terrible.

Time to repost my little brake article "wot i wrote"

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.

Chris,

You know i nearly put a link in to a previous thread where this was posted before.

I had remembered your thoughts on just upgrading the fronts, regarding imbalance etc.... Allot of owners seem to do this and dont seem to report ill effects.

I need to decide then whether to upgrade the whole lot to UK or stick with J-Spec and upgrade brake lines to improve pedal feel. I would just have accept brake fade will still occur if hammering the brakes on a high speed drive.

I wish i could live with the brake dust generated by your race pads as they are a good combination with J-Spec Brakes however as im getting some new wheels i want to go back to stock pads.

Cheers for everyones input so far.

I know this has been covered many times before however for me i know i want UK Brakes, its the cost V's benefits thats the main issue.

Thanks

Chris

I've been using the j-spec brakes with CW fast road pads and found them very good - i'm quite heavy on the brakes as well, living in a twisty rural area. My pedal was very mushy when I bought the car, but some stainless steel brakelines firmed it up a lot. Braided lines and the pads have tranformed the brakes, the dust is insignificant compared to the improvements gained.

Saying that, i've got a full set of UK brakes going on this week. My front discs are shot and I found the UK's for £500, a no brainer really. I'll let you know what I think of them in a couple of days

I ordered a set of new jap front discs from Toyota before I bought the new brakes and they won't take them back (special order or something ) so if you want brand new, unopened j-spec front discs PM me.

I've also got some fast road pads on my outgoing jap brakes, not sure how much is left of them though...

I had no confidence at all in the Jspecs I could fade them quite easily, only really discovered what the supe could do when I ran uk's - they are much better IMHO.

They give you equivalent performance to the likes of Brembo/AP for half the price.

I got UK Callipers, Discs etc from Mr T, Porterfield Fast Road pads, stainless hoses all round, Motul Fluid, Porterfields to replace the rear pads (leaving the discs and callipers jspec) and that lot cost about 900. Fooking bargain IMHO for the change in the brake's abilities.

If anyone has a big brake budget sufficient to cover the monster brembo front and rear set up I fitted to Nicks car, then that was an awesome kit, well engineered and sufficient for even serious track day usage.

Oh:( I have fitted UK brakes to the front only on my N/A. Without the aid of ABS have I unwittingly made my car dangerous in the wet???

Originally posted by Ian C

SimonB is spot on, it infuriates me when people think "bigger brakes = stops faster". Simon - to the FAQ thread in technical with you!

-Ian

I'm on form at the moment I tell you, with this thread and the suspension one as well