B3any Posted January 25, 2003 Share Posted January 25, 2003 Right then fella's anyone whose toyed with the idea of uprating brakes, but decided that with new pads its good enough you'd be wrong...... My m8, Zac whose on here did have UK rears with uprated pads on the front (j-spec front), and it stops bloody well far better than mine anyway.... However he rings me up today and says hes got a new toy on his Supe, so i go up and have a look and jesus christ theres a set of discs behind the wheels like Dustbin Lids!!! And big ass red 6 pot Calipers the size of my normal Discs!!! Bought them from Paul down at Whifbitz who installed them and set them up as well. They look the dogs Bollocks!!! So he takes me out down the local thrash road, we reach 120 Leptons and then he applies the anchors, I was scraping my face off the window i kid you not, we braked too 30 in the bat of an eye impressive is not the word:thumbs: Im definetly going to invest in a set, Anyone else get these phonemenal stoppers? Quote Link to comment Share on other sites More sharing options...
Bobbeh Posted January 25, 2003 Share Posted January 25, 2003 Are these KAD breaks? Quote Link to comment Share on other sites More sharing options...
B3any Posted January 25, 2003 Author Share Posted January 25, 2003 Yep, look sweet........... Quote Link to comment Share on other sites More sharing options...
roboldham Posted January 25, 2003 Share Posted January 25, 2003 I'm getting new anchors when I get the new wheels (!) - do you have any more specs and/or pics? R Quote Link to comment Share on other sites More sharing options...
Thorin Posted January 25, 2003 Share Posted January 25, 2003 Originally posted by roboldham I'm getting new anchors when I get the new wheels (!) - do you have any more specs and/or pics? R http://www.whifbitz.co.uk/suprabrakes.htm Quote Link to comment Share on other sites More sharing options...
B3any Posted January 25, 2003 Author Share Posted January 25, 2003 http://www.whifbitz.co.uk/images/kadbrakes.jpg Quote Link to comment Share on other sites More sharing options...
B3any Posted January 25, 2003 Author Share Posted January 25, 2003 http://www.whifbitz.co.uk/images/suprakad.jpg Quote Link to comment Share on other sites More sharing options...
B3any Posted January 25, 2003 Author Share Posted January 25, 2003 There the size of my wheels!!! Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted January 25, 2003 Share Posted January 25, 2003 Not for long mate. Quote Link to comment Share on other sites More sharing options...
B3any Posted January 25, 2003 Author Share Posted January 25, 2003 hehe very true They look superb under Zacs wheels though m8. And they just braked like nothing i've been in....... got back in mine and thought i was braking with pushbike brakes Can you get the calipers and the other red thingy in any colour ??? Quote Link to comment Share on other sites More sharing options...
Paul Whiffin Posted January 25, 2003 Share Posted January 25, 2003 Yep, there very good aren't they, looks the biz as well. I should have taken a pic with the wheels on, completely forgot, I'll take a pic tomoz at the pod. There available in more or less any colour you can think of! Pink if you like? Quote Link to comment Share on other sites More sharing options...
Mark D Posted January 25, 2003 Share Posted January 25, 2003 I really don't know enough yet, but why is it ok to upgrade just the front brakes and leave the rear ones relatively underpowered? Surely this will cause an imbalance in braking particularly when not in a straight line which could lead to loss of control. I would be most grateful if somone could explain this to me before I think about any brake upgrade. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 25, 2003 Share Posted January 25, 2003 MarkD: Brake upgrades can set out to try to achieve several objectives. The commonest are to increase resistance to fade and or increase whee braking effort for a given pedal effort. IE, the pads are pushed against the discs harder for a give 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 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, still just along for the ride. The BEST scanario is to upgrade front AND rear brakes, carefully ensuring the original balance of effort at any given brake pedal pressure remains as designed, but the more efficient front AND rear brakes stay cooler for more hard stops, and the 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 cahnge in effort between front and rear brake circuits, one cylinder doing the front brake calipers, the other the rear. This can be achieved on road cars, but is complex and expensive, especially if ABS and brake circuit failure safeguards are to be maintained. Far easier to design the caliper and disc sizes, along with pad area and compound to achieve this, as near as available equipment will allow. Caveat. I said before makers put more effort on the front brakes to allow straight line stopping. 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. Written hurriedly, and briefly, as my typing speed is terrible, but hope it helps explain the gist of the potential problems. 1 Quote Link to comment Share on other sites More sharing options...
B3any Posted January 25, 2003 Author Share Posted January 25, 2003 Jesus Chris if thats briefly i'd hate to see what the full explanation would have been like Helps explain a few things though;) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 25, 2003 Share Posted January 25, 2003 Originally posted by B3any Jesus Chris if thats briefly i'd hate to see what the full explanation would have been like Helps explain a few things though;) Brake technology and brake system design, upgrading and testing can and does fill large books Quote Link to comment Share on other sites More sharing options...
Adam W Posted January 25, 2003 Share Posted January 25, 2003 "I'm not interested in brakes, they only slow you down" - Tazio Nuvolari. Top post Chris, something I'd often wondered about myself. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 25, 2003 Share Posted January 25, 2003 Thanks Adam. True story: Pal and me, shared a race car for a few weeks. He went testing, after having a similar amount of seat time in the car as I had. He furtled all day with gear ratios and the engine. Went a couple of tenths quicker in the end. I spent a day playing with pads and brake balance, and changed master cylinder sizes. Went a second and a half quicker. he jumps in the car, goes 2 seconds quicker... The car probably didn't stop any quicker after I'd finished with it, but the "indefinable feel" gave a load more confidence in the really late braking, and the *DRIVERS* were quicker. Tyres, handling and braking will always find more time that 20% more HP on all but well sorted race cars. Quote Link to comment Share on other sites More sharing options...
springbok Posted January 26, 2003 Share Posted January 26, 2003 Chris, Is the MAN!!! ... well said. I was thinking of pad change to my standard UK spec brakes and braided hoses. If I change the brakes it would be for looks only. But the UK brakes seem to suit the car very well. Quote Link to comment Share on other sites More sharing options...
Mark D Posted January 26, 2003 Share Posted January 26, 2003 Thank you for that explanation written in a way that allows people like me to understand. Obviously in my normal day to day driving I am never really in a situation where I have to worry about repeated hard braking, but this may change if I start to think about doing track days. Then if I am flush with cash all 4 brakes will be upgraded. I read somewhere that the braking system in the Supra had 'lateral G sensors'. You mentioned that the Supra had a slightly sophisticated ABS setup. Does anyone know if this is true and how it works? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 26, 2003 Share Posted January 26, 2003 Mark D: I didn't think that the J-Spec MKIV had lateral G sensing ability, and I am fairly sure the UK / US models don't, either. I know the Skyline GTR's, from R32 to R34 models do have. So do the newr Porsches. The very late ABS systems are excellent, most race drivers opt to use them when fitted, especially in the wet. Bosch have made great strides in ABS development, and they are now better than the best drivers, IYSWIM Quote Link to comment Share on other sites More sharing options...
JamesG Posted January 26, 2003 Share Posted January 26, 2003 Originally posted by Mark D I read somewhere that the braking system in the Supra had 'lateral G sensors'. You mentioned that the Supra had a slightly sophisticated ABS setup. This Supra diagram from Toyota mentions a linear G sensor that improves braking when cornering. Maybe that's what you were thinking of. I don't know what it is though. http://www.mkiv.com/mkiv_gallery/mkiv_gallery/stock/large/cutaway.jpg James. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted January 26, 2003 Share Posted January 26, 2003 For sure the UK / US market cars have a more sophisticated ABS, with different functionality. This seems to suggest it also has lateral G sensing ability, too. Thanks for the post! (Maybe the J-Spec ahs, too, but I don't THINK it has... Quote Link to comment Share on other sites More sharing options...
Sharpie Posted January 26, 2003 Share Posted January 26, 2003 Good Post Chris - Thanks Quote Link to comment Share on other sites More sharing options...
lust2luv Posted January 26, 2003 Share Posted January 26, 2003 Ooo, another thing to add to the "UK better than Jap" list maybe! It's been said a lot already, but top post Chris - especially if your typing is a slow as you say! Even I understood it, so it must have been well written! Quote Link to comment Share on other sites More sharing options...
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