Mark D Posted January 20, 2003 Share Posted January 20, 2003 I was thinking of attending a meeting at Elvington where there is an opportunity to try out the top speed. I was wondering what the stopping distance would be from about 180mph (I presume this is the probably the fastest most would go)? I also wonder what the difference in stopping distances would be between stock J-Spec brakes and UK Brakes and perhaps Paul Whiffin's larger KAD Brakes? Apparently the runway is 2 miles long. (i.e. 1/4 mile for acceleration and 1 and 3/4 miles for me to stop with my J-Spec brakes.) Quote Link to comment Share on other sites More sharing options...
Doughie Posted January 20, 2003 Share Posted January 20, 2003 180mph - zero. err, longer than you think is about as helpful as i can be i'm afraid. you cover ground at over 100mph very very quickly. If someone can give me the average deceleration of a Supra braking at the max. (in negative g) then i can give you an exact figure mate. anyone want to have a stab ? Negative 0.5g from 180mph ?? Quote Link to comment Share on other sites More sharing options...
Bobbeh Posted January 20, 2003 Share Posted January 20, 2003 According to a magazine article it was 110 ft from 60mph to 0.. so I'd imagine somewhere between 400-600 ft? I'd imagine the wind resistance alone would knock lots of speed off at 180. Quote Link to comment Share on other sites More sharing options...
Doughie Posted January 21, 2003 Share Posted January 21, 2003 Originally posted by Bobbeh According to a magazine article it was 110 ft from 60mph to 0.. so I'd imagine somewhere between 400-600 ft? I'd imagine the wind resistance alone would knock lots of speed off at 180. OK I worked it out on that basis and 60mph to 0mph in 110ft = 1.1g average negative g braking, which is really quite impressive. (assuming it was actually only 110ft). Assuming the same rate of deceleration from 180mph gives distance to stop from 180mph to 0mph of 301metres. It will probavbly be a bit shorter than this as, (as Bobbeh mentioned) the air drag at 180mph will be very large and will contribute greatly to braking. effectively the whole bodyshell of the car acts as an air-brake at this speed. But this is assuming that you REALLY nail the brakes all the way down to 0mph, i.e. ABS cutting in, or just abut to cut in the whole way down. Remember to have your seat-belt on ......... Quote Link to comment Share on other sites More sharing options...
lust2luv Posted January 21, 2003 Share Posted January 21, 2003 I imagine the timing gear will be around the 1.5 mile mark, giving you 800m to brake - should be ample, but don't go hanging around, since at 180mph you'll be 10 seconds away from flying spectacularly off the end of the runway. Bear in mind too that you'll probably be turning off onto a taxiway at the end, so you only have to break down to 50mph or so. My advice would be certainly don't be tempted to hold the throttle open a second after the speed trap/timing gear thinking you can... just... make... 180... Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted January 21, 2003 Share Posted January 21, 2003 stock J-Spec brakes From 180mph! and only 800m! Quote Link to comment Share on other sites More sharing options...
Syed Shah Posted January 21, 2003 Share Posted January 21, 2003 Those figures are for the export-spec brakes. I would think it would be nearer the 500m mark for a j-spec. So as soon as you hit (literally for some ) the timing trap, hit the brakes. Quote Link to comment Share on other sites More sharing options...
chrispazzi Posted January 21, 2003 Share Posted January 21, 2003 At 180mph you're going to travel a further 85 metres (roughly) for every second you delay your braking! I wonder if it's better to go for it with your brakes stone cold or warmed up a bit? I would worry about putting a 180mph emergency stop through cold discs, from a cracking/warping point of view as well as performance. Quote Link to comment Share on other sites More sharing options...
Ian C Posted January 21, 2003 Share Posted January 21, 2003 Originally posted by Syed Shah So as soon as you hit (literally for some ) the timing trap, hit the brakes. Oi! I hear J-spec brakes can experience fade during braking from around 130mph to zero, can't remember who said it, but worth a thought? Obviously, your braking distance is a factor of tyre grip and suspension setup, if your brakes can stop you once without fading. It's repeated stops that bigger brakes are good for... -Ian Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted January 21, 2003 Share Posted January 21, 2003 I hear J-spec brakes can experience fade during braking from around 130mph to zero The word "can" is misleading, and the "zero" unlikely! Or was it just my J-spec brakes - 135 to 80 was a problem. Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted January 21, 2003 Share Posted January 21, 2003 I stopped hard from 160 to zero once... I got brake fade within seconds, (Can't tell you what speed), by the time I was below 50 the brakes were next to usless and most importantly, I ruined all four disks in one go. I've got a UK set up now. Only experienced brake fade twice. I used to get it frequently with the J-spec brakes. (They were stock pads). Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted January 21, 2003 Share Posted January 21, 2003 Silverstone GP circuit track day, J-spec brakes faded to useless in the first run into Stowe! Goodwood track day, UK spec & R4 pads - no sign of fade, just a bit of disc vibration. Cooling ducts are on their way. Quote Link to comment Share on other sites More sharing options...
Ian C Posted January 21, 2003 Share Posted January 21, 2003 Nasty. I braked from 150 to zero and experienced head fade! Those UK specs with Porterfield pads are the best damn brakes I've ever experienced -Ian Quote Link to comment Share on other sites More sharing options...
Doughie Posted January 21, 2003 Share Posted January 21, 2003 150 ot 0 in a 1.6tonne car is a pretty extreme test of he brakes, but having said that, since Toyota *built* a 1.6 tonne 150+mph car then it damn well ought to be able to brake v hard to 0mph without fade. German Autobahn, quiet morning, serious 150mph speed, and see an accident a few hundred metres ahead ......... you're going to do the 150-0 thing. Surprised Toyota didn't put better higher friction / higher temp. tolerant pads in as stock. There's plenty of Porterfield and other pads available that Toyota could have sub-licensed or something. adds to the cost, yes, but if it stops the car in time without fade then they should be on there. Bound to be pad fade due to exccessive temperature reducing coefficient of friction of pads to low levels. Fluid wouldn't boil in such a short space of time. (and if it did boil that really *IS* disastrous. Happened to me at RAF Elvington) Quote Link to comment Share on other sites More sharing options...
Terminator Posted January 21, 2003 Share Posted January 21, 2003 Originally posted by Doughie Fluid wouldn't boil in such a short space of time. (and if it did boil that really *IS* disastrous. Happened to me at RAF Elvington) I take it that was using stock fluid???? Quote Link to comment Share on other sites More sharing options...
lust2luv Posted January 22, 2003 Share Posted January 22, 2003 Even at 180mph I don't think you'd need to (or of course want to) slam on the brakes, rather it'd be a lengthy fairly hard braking manoeuvre, and once you're down to around 70mph you're fairly okay, needing only to knock off a little more speed to exit the runway. It's not like you'll be locking up all 4 wheels from 180-0, certainly wouldn't fancy that, with or without Jap brakes. Was probably a bit of a different story for Ronnie braking from 209mph in an even heavier car! Quote Link to comment Share on other sites More sharing options...
Gaz Walker Posted January 22, 2003 Share Posted January 22, 2003 Any recommendations for sorting my brakes out. I need new discs & pads, plus I'm going to put some braided hoses and 5.1 Fluid in there. Whats the best disc & pad combo for the UK spec? Gaz. Quote Link to comment Share on other sites More sharing options...
Ian C Posted January 22, 2003 Share Posted January 22, 2003 OEM Toyota discs and CW or Porterfield pads. -Ian Quote Link to comment Share on other sites More sharing options...
Gaz Walker Posted January 22, 2003 Share Posted January 22, 2003 Originally posted by Ian C OEM Toyota discs and CW or Porterfield pads. -Ian Righty-Oh, cheers Ian... Gaz. Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted January 22, 2003 Share Posted January 22, 2003 Originally posted by Ian C Nasty. I braked from 150 to zero and experienced head fade! Those UK specs with Porterfield pads are the best damn brakes I've ever experienced -Ian LOL, I can relate to that, and I'm still using oem pads I can get a similar reaction out of people with braking as I can accelerating Doughie, I assume Toyota didn't feel it necessary to put anything better than the J-spec brakes for their JDM, as they're limited to 112 anyway. Has anyone ever gone from standard UK disks to something like Black Diamond Combi's or similar? Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted January 22, 2003 Share Posted January 22, 2003 UK discs are as good as any. I managed to crack both a front & rear set, but also managed that with RMM slotted's. CW sells the BEST pads for the MKIV. Quote Link to comment Share on other sites More sharing options...
Sharpie Posted January 23, 2003 Share Posted January 23, 2003 Originally posted by Terry S UK discs are as good as any. I managed to crack both a front & rear set, but also managed that with RMM slotted's. CW sells the BEST pads for the MKIV. I had CW fast road pads fitted in November and then braided S/S hoses fitted and DOT5.1 in December and the difference from stock is very noticeable - good pedal feel and much better stopping. Well-pleased - Thanks Chris/Paul and for Terry advising on the CW pads. Quote Link to comment Share on other sites More sharing options...
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