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.

This is a revolving door, my turn. The preconceptions were, rather, observations from doing a bit of research. I found them to be something that challenged my generalised preconceptions rather than reinforced them. I struggled to believe them fully, even though they were consistent comments amongst many commentators who read like they actually knew what they were writing about. I couldn't be a convert until I had some raw data to back them up, that's the science background in me still finding a way to show itself. That was a hard find, lots of hearsay where everyone has an opinion but raw data - not at all easy to track down. But when you have all the published 'experts' saying one thing and then some real and raw data comes to light (I'm going to claim a gold star for tracking that down) backing up what they are saying I'm probably going to believe it. I'm a convert, I've been educated.

LOL - I've got granddad on board stickers and glow in the dark paint, that'd help me find the car at night.

Someone PMd me earlier to say their UK brake setup is really good but also mentioned a spongy feel. I'll buy a OE UK setup ready to fit when my current brakes are no longer suited to my spirited driving or wear out. The car doesn't travel far these days so it could be a while.

I can see you haven't learned anything. As I said yesterday, its always good to have one resident expert. Hopefully you can spare some time to do a comprehensive brake write up as I suggested yesterday that I can send to the journal and article authors and maybe we can get you some feedback for you and us all because I'm not convinced, having read what I've read, that you really do know as much about the subject area as you appear to think you do.

I think its been useful, for me anyway to find out more about brakes and if anyone learns something, like me, that they didn't know or appreciate before - that's fantastic. Things I feel I've learnt or had confirmed from the viewpoint of strictly a on the Queens highway road user. 1. Bigger brakes, all things being equal, aren't going to pull you up any noticeable distance shorter than j stock brakes. 2. Bigger, wider tyres are the best way to maximise grip and through that, shorter stop distances. 3. Bigger brakes do dissipate heat much faster but that's not going to be an issue in every day road use. 4. You shouldn't just change the fronts setup without also doing corresponding changes to the rear brakes otherwise you unbalance system pressures and you deviate from the factory front to rear bias. My conclusion from having done a good amount of reading around the subject in the last 24 hours is pad choice and tyre choice are way more important that rotor size and numbers of pots in determining the braking performance of a Toyota Supra from any speed in normal road use. The report I reference mentioned after going on to do a car specific setup through trial and error they could reduce the braking distance by almost 20% but the off the shelf options only delivered a 1% to 2% improvement in stopping distance. So a bespoke system is much better than a generic system which is probably why OE bespoke systems tend to work well in the first place. Bigger brakes, especially moving to another OE setup such as the UK standard, are going to provide better endurance braking for those doing spirited road driving on winding roads. But possibly nothing that fresh brake fluid and racing pads couldn't match on the smaller j brakes. So UK brake upgrades for those still on smaller j brakes are a good way to go but probably, for me anyway, only worthwhile when the current brakes are worn out and in need of replacement and I also fancy gaining a new set of road wheels to.

Nic, you know your parts really well. Do you know what is required to perform a complete jspec brake to uk spec brake upgrade? I now know you wouldn't want to change the fronts and forget the rears as that would alter the braking bias front to back so the shopping list would start off with: 4 rotors 8 pads 4 callipers 4 dust shields potentially 4 new road wheels On other parts Are the ABS sensors the same? Is the master cylinder the same? Is the ABS ECU the same? Are the hubs the same? Are the flexible hose couplings the same? Do you have an idea roughly how much would it cost with new parts using OE pads to do the complete j to uk brake upgrade?

I think its a case of Toyota engineers probably knew something about what they were doing. The data clears up whether big brake mods have any impact in a road car which is one question I was asking myself. Seems the journal and mag threads on big brakes I have been reading are born out in reality testing. I'm sure the data will be a revelation to many, probably not you though. You will definitely see the benefit of brake mods when you take your car onto the track. Any dates planned?

Finally located real test data on a Nissan 350z using different brake and tyre combinations. Pretty much clears things up wrt actual stopping performance relative to brake setup. https://www.zeckhausen.com/catalog/index.php?cPath=6446_6565

I have cars with all sorts of brakes, mostly non assisted and lots of drums including an all drum Land Rover. So I find the Supra standard brakes pretty good by comparison. I did find one piece of science to support larger rotors and thats Force = Work X Distance. So larger rotors for the same size wheel (including tyres) will require less hydraulic pressure to achieve the same slowing force translated into friction and heat. This is presumably why people say bigger brakes have a better fell, because they require less effort to achieve the same braking performance. But, less effort doesn't invariably mean you stop or slow any quicker because even on tiny brakes you can lock the wheels with the ABS disconnected. See what little gems you find when you read into a subject. Still the biggest upside everyone zones in on is heat dissipation to reduce the potential for fluid boiling and vapour locks. Still no data though. I just cannot find any supporting data. It'd be good to see the actual figures in distance and g force deceleration for an OE jspec setup compared to UK spec compared to 6 potters on larger still rotors using the same wheel size and if possible pad materials. If I spent £1k+ on brake mods I'd want to go demonstrate it'd been money well spent so surely someone has to have the data. Then it'd be obvious what advantages there are or indeed aren't in everyday open road use, forget track that's a given.

How did you deduce a pretence? Are you our very own Mystic Meg? I actually figured its a really interesting engineering balance with potential side effects, not all good, that I for one never considered. Call me dumb if you like because maybe as a Supra owner I should know things like brakes in detail but I learned some interesting things about brakes that I never would have thought of before doing a bit of reading, so maybe now I am better educated. Or just more confused? Interesting to note though was that slightly fatter tyres could be an effective and straightforward solution for people in their road cars looking to reduce their stopping distance. Brake upgrades can be assumed as unnecessary on road cars as Supras don't have a reputation for poor brakes. The question is only are they a useful upgrade and could they impact negatively on Toyota electronic braking aids unless those are reprogrammed or isolated? I don't know the answer to that but I'm sure there must be many who do amongst those who have done brake system upgrades over the decades and know what works and what doesn't. People like me who might normally just go down Halfords and pick a cheap Chinese kit off the shelf need to be aware and if that means reading up a bit to make sure all bases are covered to end up with a system configuration operating to the max capability, that can only be a good thing. Maybe we can have someone share some actual before and afterward data. Someone must have that to hand somewhere, I couldn't track down any real life comparative data online. On a track car you would definitely want big brakes, no ABS and no traction control. Just big balls. Now that's more like it.

I didn't say anything. I'm no braking engineer. Its what others have said. I presume they are engineers who know something about what they write about. The summation is anyone considering fitting non OE brakes because they will provide better braking may not realise that expectation. It's probably like putting a big turbo on your engine because you read somewhere it'd give you 600bhp but then wondering why it doesn't because you haven't factored in the extra fuel required. Its a fascinating area and an essential safety one where any changes can have foreseen and unforeseen consequences so its good to know we may well have at least one braking systems expert amongst us.

I read reports that said the brake size doesn't appreciably impact stopping distance, its more down to how much tyre is in contact with hopefully with dry road. So fitting wider tyres would seem to be the better way to reduce stopping distance. That's probably a reason why F1 cars don't run 165's. The only benefit that consistently came from big brakes was pedal feel and heat dissipation on frequent heavy use. That's presumably why F1 cars run large disc, 6 pot brakes and split hydraulics, front and rear.

Ric, you must be a big and quite possibly painted brake man. I'm sure you took into account any side effects fitting big brakes can have before heading off on track days. As for volume and pressures having no relevance I'll leave you with an extract written by an engineer. Maybe he knows what he is writing about, maybe he doesn't. "Master Cylinders Most production cars use a single master cylinder, typically with two pistons running in two bores. Each of the pistons are sized for the stock front and rear brakes. When upgrading brake systems, the master cylinder's volume and pressure must be known and accounted for." Its possibly because pistons go in and out requiring different volumes and system pressure than the manufacturers engineers designed into the system and the electronic braking support systems. Just guessing there though. Maybe you can do a write up and I'll pass it onto the engineers writing these articles and see if we get some feedback for you.

I had a badger take out my bumper 9 years ago. The stock lip was a real hard thing to get new even back then. In the end one had to be ordered and brought in from Japan and took 2 months to arrive. Good luck!

Everyone knows big brakes are better than small brakes. The bigger the better (especially when painted) then allied to more pots the better and the bigger the material compressed on disc the better. Except there are plenty of myth buster sites that say you need to be very specific about bigger as its not always better as bigger has no respect for how the car is set up and managed by the automated ABS and traction control systems. I have a jspec on its small discs low number of pots braking and that gets up to near 160mph before the limiter cuts in and it slows down from 160mph without any real drama whenever I've done that and I've done it a lot. So tiny brakes with limited pots do work in real life, real road conditions. It seems bigger brakes come into their own predominantly to dissipate heat fade relative to smaller brakes. Stopping distance is impacted to a large extent by the area of tyre in road contact. So, reading a few sites it appears big brakes may well only be any use if you have lots of corners and chicanes to negotiate while driving as fast as you dare to around a track. There are even sites that mention big brakes can have safety concerns as they draw a lot more hydraulic fluid and DIY fitters may not have factored this into a larger reservoir. Also they can fool the ABS management into thinking things are in a different state of brake panic to where they really are, making braking assistance less effective in panic situations. So, reading between the lines non OE big brakes may well be pointless unless ragging around a track regularly and possibly a retrograde step unless allied to reprogramming or isolating the electronic braking aids. Its an interesting topic and a bit of a black arts area from the limited reading I've done into the subject area. Seems to be a few things that need to consider before just slapping big disc 6 potter on because they look good, all that looks good may not be as good as they look. Pretty key in things a critical as vehicle braking. its a fascinating area where unforeseen side effects can mitigate the perceived advantage. Think I'll do some more reading.

There are a few 220mm diffs for sale in the USA available for £1.5k to £3k. If that's in your price range I can put you in touch with someone who can arrange States side storage awaiting one of his regularly shipped sea containers over to the UK and he lands them pretty close to you so you could collect out of the container. He just takes a little contribution toward the container cost and arranges all the customs clearance which you would have to pay for of course to cover the VAT and duty. This would of course mean you wouldn't see the part for at least a month to three, dependent on when he is next scheduling to ship. PS - just checked, he is planning to schedule the next shipment end of January. On sea time and customs clearance takes about 10 days so you could have the diff via a US supplier around mid-Feb.

I'll buy your TT6 for around £16k if you want to sell. There you go, doubled your money. PM me if interested.

Complimentary sunglasses would be needed to handle that interior. Got to be around £7k assuming good underside condition and some history if the door decal is a vinyl, less if its paint.

Ill take both for £1k. PM me if acceptable.

For the mileage and no rust you are probably going to be restricted to looking at a recent Jap import. May be a good idea to register your interest with JM Imports as he may know of some already in the UK coming up for sale. Importing fresh from Japan now you'd be looking more like £20k plus since the drop in the £ for something to meet your needs, that may be the fastest route for you though to secure a car meeting your requirements. As an example JM highlighted this linked car in Japan recently which was going to cost around £23k as a UK landed and registered car. Its since sold. https://translate.google.co.uk/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.goo-net.com%2Fphp%2Fsales_records%2Fdetail.php%3Fbaitai%3Dgoo%26area_cd%3D13%26goo_car_id%3D941016081900505380001&edit-text=&act=url

Back in 2001 the car would have been worth around £12k so the damage must have been substantial to be, then, an insurance write off. That will, as it always does, have an appreciable impact upon a cars value. The absence of history prior to 2012 could put some off but if you have to old MOTs that's always a good sign the cars been catered to reasonably well throughout its life. On the door wind noise I had the same problem with the seal leaking at speeds over 65mph when my door was replaced after a car decided to park in the door. If the shut lines are good its the seal that needs sorted. I took a heat source (heat gun) to the sealing strip and plumped it up in the top corner and down the vertical length. Had to do it a few times but it settled to a good seal again. Its always difficult to price Aeros as they are so few and far between. Probably comes down to how many people are looking and that's probably going to be quite a few more come May onwards.

I used to carry 4 up regularly until the youngest daughters legs reached the end of the rear seat cushion, which took till when she was 5. Travelled as far as the Netherlands 4 up in the Supra.

If you are desperate you'd probably need to offer 30% over the 'normal' price to entice someone. There was an offer of £27k on a jspec TT6 that the owner, after some considered thought, decided not to accept. They found that offer tempting so its the old adage that anything is for sale at the right price. With such a rare car tied to a variant choice if you don't force a sale by paying over the odds then you will need time. The good news is that it appears Supra inflation has halved to around 25% this year so prices are no longer climbing at the rate they were.

If you have the Halfords Calcium HCB005 that has a capacity of 62AH. So a draw of 0.07A will drain a good battery over 37 days. So if your charge is gone in a few days either you have additional battery drain you aren't measuring or the battery is not in good condition.