Understanding big non OE brakes

[Sheefa]

Oh Baz what planet did you actually come from?

 

I have owned 3 Supras over the last years and have been in multiple others on the road and participated in some heavy track days.

 

UK specs are far better than Jspecs in pretty much every driving circumstance, even minor fast road use. There is no point arguing between the two, it's been tried and tested over many years.

 

I was also extremely impressed by the K-Sports that Littlenum had on his track car, they stopped on the button and launched me into the seat harness. I would say they were better than my Uk spec brakes for sure.

Edited December 30, 2016 by Sheefa (see edit history)

[rider]

I think its called Planet baffled. Baffled that you appear unable to either accept or counter actual data with any words of wisdom beyond better. I guess that's why many people writing about brakes mention the words myth and myths often.

 

The data available in this thread shows, as a snapshot admittedly, that off the shelf solutions in alternative brakes can and under comparative testing actually do have very marginal impact on stopping distance. That's an undeniable fact, the data is there in printed text so for normal road use you would have to assume Toyota have the braking bases covered. If you have any other data fantastic, the more the better but please drop simply applying the word better. The real data which hasn't been easy to track down allows people to make their own assessment if with a brake upgrade the cost to benefit is a worthwhile investment for their individual style of driving as not everyone is going to take their car to the limit. That's an entirely good thing. You often see across all marques of car ownership people apply new brakes to their car and their main concern is will my existing wheels fit these big callipers. When, they should have quite a few other questions at the front of their mind when changing their braking setup.

 

Its a complex area but wait till you look into wheel size and tyre width and offset impact on forces, scrub radius and suspension geometry. That is looking complex compared to brake choice. It all points to ordinary people doing things at a DIY level need to know what their expectations are and have realistic expectations around what specific changes will achieve. Background reading never hurt anyone as a means to reduce the opportunity to make poor choices, though unless you can understand the physics you may never become an expert. A little bit of knowledge is good and that undoubtedly does include practical experience, but data is far better as that categorically proves or disproves the theories.

[Chris Wilson]

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.

[Mike2JZ]

Just to throw more fuel on the fire

 

[Annabella]

So really its just decent pads and fluid that give best value for upgrading for people that arent tracking it. Of course tyres come before that, but we should know that already! If you're tracking then bb kit is the way to go to prevent fade and slightly better stopping, which all count if your trying to knock tenths off your time. Unless you've got money you wish to dress your car with and do it anyway

Edited December 31, 2016 by Annabella (see edit history)

[rider]

Just to throw more fuel on the fire

 

 

I think CW has poured some water on the subject as I doubt any of those unable to accept the word of journal and magazine experts and data from testers over their own multi-car experience will be able to bring themselves to call Chris a c*** or suggest he may well have just arrived today from planet Zorg. The inability of some to receive information and knowledge is worrying when they are handling powerful bits of kit on the road. Thank god most employ the services and advice of specialist tuners who take the guesswork out.

 

This thread was never for those who know what they were doing wrt brakes. It was for people like me who know nothing maybe finding out somethings they didn't know. If that saves people money, stops them making bad front only choices its been worthwhile. I'll do a wheel and tyre size choice thread if I can get my head around all the variables there as it appears to be a much more complex area. That aspect is like a chain reaction of change this and that changes a whole shit load of other things. I'm sure there will be some that rather just not know.

[rider]

..

[tintinmt]

I sense that this might be concluding so I am going to share my very limited experience. I have a 1993 NA Supra and a 2003 Lexus GS430. For the Supra, I recently had all four calipers refurbished and replaced all four discs and flexible hoses plus a change of fluid.

I was horrified by the condition of the calipers before refurb but I hadn't noticed any lack of braking in normal driving. As far as I know, the Lexus shares a very similar brake set up to the Supra. This is despite the Lexus surely being much heavier and considerably more powerful. You would expect that Lexus had fitted at least adequate brakes as standard. My current car and one that I drove new years ago, both give the distinct impression that you could arrive at a corner travelling too fast for the brakes to save you from the hedge or worse. This is probably a perception as opposed to reality, but I certainly felt it. My solution for the Lexus has been to fit lowering springs and Supra Turbo front brakes. This solved my issues with the car without a dramatic difference in any aspect of performance. My feeling is that the springs reduced the diving under braking and wallowing into corners. In normal road driving the assumed greater braking performance is probably more in the mind than anything, but it's still nice to have. I should say that the front discs and lower ball joints needed replacing so it seemed to make sense to do the additional work at the same time. Of course I'm now slightly worried that I should be upgrading the rear brakes. I'm going to be leaving the Supra brakes alone now but do plan to take it on a track day soon.

[bignum]

I`m ..........edited lol.

Edited December 31, 2016 by bignum (see edit history)

[Sheefa]

I think its called Planet baffled. Baffled that you appear unable to either accept or counter actual data with any words of wisdom beyond better. I guess that's why many people writing about brakes mention the words myth and myths often.

 

No, quite the contrary myself and others have genuine experience of different braking setups in contrast to your sorry self sat with your Jspecs speculating about differences and criticising as you do.

 

Are you actually a troll in real life? Oh hold on, yes you are.

 

 

 

[Sheefa]

And Chris knows what he is talking about, reliably and thoroughly, you do not. Your threads are pointless.

 

 

 

[rider]

Its clear you knew precious little about better brakes before this thread but your arrogance is such you still cannot accept you probably now know a little bit more. Pleased to be of service.

 

Happy New Year.

[Sheefa]

Its clear you knew precious little about better brakes before this thread but your arrogance is such you still cannot accept you probably now know a little bit more. Pleased to be of service.

 

Happy New Year.

Hence why I had Jspecs on my old one, upgraded to UK's, bought my current car with UK's on and when I weighed up the pros and cons of the AP Racing kit I bought decided it wasn't worth it for the occassional track use and running of spacers etc. Clear arrogance right there or perhaps just a well informed decision without your useless chatter. Point made.

 

 

[Chris Wilson]

Happy and healthy new year everyone, good stopping to all

 

Communal hugs!

[Annabella]

:d

[rider]

Point made.

 

My head is a little sore this morning so my patience is not at its best. You have stomped all over this thread like a toddler in full on tantrum mode. Its a technical post, with technical information and even some data thrown in too. Your input across a good number of post has absolutely no technical merit, none. If you have chosen to ignore the facts or cannot comprehend them that is no justification to be both rude and very immature.

 

There will for certain be owners running on Toyota brakes who will find the technical aspects covered within this thread very informative. There will likely be for owners running Toyota brakes an element of reassurance. There is even some useful information and caveats for those undertaking a larger (better) brake upgrade. What's not to like? You really need to look to and calmly reassess your own involvement in this thread, none of the technical input has been provided or enhanced upon by you in any way.

 

If any moderators happen by on this exciting first day of the New Year I think we can conclude this thread has all the technical content it needs and is likely to receive so it could well be time to close it down. The only braking going on appears to be a members apparent impending breakdown.

 

[Sheefa]

My head is a little sore this morning so my patience is not at its best. You have stomped all over this thread like a toddler in full on tantrum mode. Its a technical post, with technical information and even some data thrown in too. Your input across a good number of post has absolutely no technical merit, none. If you have chosen to ignore the facts or cannot comprehend them that is no justification to be both rude and very immature.

 

There will for certain be owners running on Toyota brakes who will find the technical aspects covered within this thread very informative. There will likely be for owners running Toyota brakes an element of reassurance. There is even some useful information and caveats for those undertaking a larger (better) brake upgrade. What's not to like? You really need to look to and calmly reassess your own involvement in this thread, none of the technical input has been provided or enhanced upon by you in any way.

 

If any moderators happen by on this exciting first day of the New Year I think we can conclude this thread has all the technical content it needs and is likely to receive so it could well be time to close it down. The only braking going on appears to be a members apparent impending breakdown.

 

Good idea to close it before you continue making a fool of yourself. I've read it back and genuinely cannot see what valuable input or relevant questions you have asked that hasn't been covered already.

 

I've been on the forum for over 10 years and I can honestly say you are one of the only idiots I have come across during my tenure here and we are all so thankful that you have graced this place with your presence. Other members have clearly made their views on you now too (Ric, NP89, j_jza80 to name just a few).

 

Note I posted the link on different setups and brake bias, which believe it or not is technical. Perhaps you should apply that diluted brain of yours and use the search function from time to time.

 

Look forward to your next pointless post.

 

 

Edited January 1, 2017 by Sheefa (see edit history)

[bignum]

Greg, i wouldn`t bother reacting to him, i posted a statement a few posts back which i thought was pretty cool but really couldn`t be arsed getting into an argument so i deleted it because it looks to me like rider started the thread just to cause arguments like most of his other posts on here, i reckon he gets a kick out or rubbing people up the wrong way, i can`t understand why as we`re all following the same marque here.

[Sheefa]

Greg, i wouldn`t bother reacting to him, i posted a statement a few posts back which i thought was pretty cool but really couldn`t be arsed getting into an argument so i deleted it because it looks to me like rider started the thread just to cause arguments like most of his other posts on here, i reckon he gets a kick out or rubbing people up the wrong way, i can`t understand why as we`re all following the same marque here.

Fair point mate and I saw you edited your post. As probably one of the most experienced track day users running Brembos and having had multiple setups over the years your input is more valid than ever! Hope all is well bud.

 

 

[Havard]

Someone lock this FFS...!!

 

I reckon my Flintstone brakes are better than any setup on here. Does knacker my new Adidas through but cheaper than replacement pads and fluid.

 

H.