jagman

Sort of , but variable IGVs require complex compressor matching

You could also say that of Dyson!! How come Hoover et al didn't develop things? There are many papers and science that never gets used , mainly due the very , very, smart originators never see applications - put 2 smart fluid dynamicists together and they end up debating mathmatics at a high level - now ask them to fix the toilet that don't flush...........

Pressure and flow are different you cannot measure pressure and then say flow is good- a blocked filter can still give good pressure but not flow!

I have had similar problems caused by fuel filter

"You're no Romeo are you?" Didnt he end up killing himself over a Girl?

Go down to the next classic car auctions with a wodge of cash , bid on someones moneypit !!! loads of good and rare cars , jensen interceptor convertible?,or Aston? , American muscle ? they are cheap now and will hold value if rare enough or good enough resto - BMW 850 CSI?

Looking good Dude! Suggest Bins!!! You cannot have enough plastic dustbins!! I had about a dozen , all over the workshop, and due some mysterious law of physics they were full every week!! 4/5 people cannot produce so much crap in a week, but there they were full- coke cans,filters, rags,gloves,pasties,fag packets,brake pads and so forth... A high bin to car ratio is needed:D

Darts, snooker, and they never hit you when they throw something at you- proof positive!!

Ordered 2 x kits , in stock, 6000 bulbs, two and a half weeks later the instock kits arrive - with 10000 bulbs??

Back in the day,They used to be called Mongrels...

Ever heard a Merlin engine in a spitfire? It has about 6 inch long exhausts- similar effect , the cops would hear you for 5 miles,and sheep would drop dead in fields as you passed by!

The reason I asked is dodgy speed converter, or loss of sensor info ie connector on gearbox , also worth checking the connector for the solenoids in the gearbox. Next I would check when in D the cable is actually selecting D at the gearbox end.

Is your speedo flickering or erratic?

Hence my perspective comment , in relation to all variables the size of the caliper almost becomes meaningless, differences with calculated bias of 1-2 % compared with 15% friction pad weight shift changes . Ultimately the best kit has the best heat removal ability and thats a job to compare ,and pad selection is a biggie . expensive BBK and cheap tyres also a bit daft!

The braking torque is the twisting action caused by the drum or disc on the shoes or caliper anchors during the application of brakes. The amount of torque is determined by the effective axle height and stopping force between the tyre and road surface. Brake torque on the front wheels is absorbed by the knuckle and suspension control arm. In rear, it is absorbed by the axle housing and the leaf spring or control arm. Braking torque during an emergency stop is much higher than accelerating torque at full throttle. Brake supporting and anchoring members must, therefore, have sufficient strength to withstand these high braking loads. http://www.the-crankshaft.info/2009/09/braking-system.html If you have a read and see what you are trying to establish is possible given the variables and fixed data -and the only data you have ie the size of the discs and area of pads to use for comparrisons Look at the brake bias bit in particular

So what is the comparrisson? simply some mathmatical size difference that becomes meaning less , some "force" difference that also becomes meaningless Toyota would have done all the calcs and based on their tyres ,caliper ,pads ,abs , wheels sizes, road surfaces etc So any changes to improve , by going bigger can only be assessed by feel , weight saved , durability,heat recovery,pad wear ,dust and even then given perfect tyre tread and pressures and compounds and becomes anecdotal rather than calculated

If there was any concentric difference , would not the valve seat be altered rather than the stem ? would there not be a greater effect at that end of the valve as the forces are higher (impact) and temps higher and the stem is the effective pivot point . Which is the harder surface, the stem of the valve or the valve guide? seems odd to me and more oil lube/seal related or clearances on the stem/guide

If a bearing got that hot it would no longer be a bearing but a brake

Perhaps a little more perspective is needed ; Even the crappiest pads/discs have the ability to lock up the wheels / reach abs limits (we are not talking about for how long or many times) The Ratio for brake pressures is fixed -ie the master cylinder The maximum retardation is locked wheel and abs , but the rate of retardation is controlled and going to be mostly due tyre selection ,compounds etc If say larger front discs/pads were fitted the maximum retardation remains the same , however the rate that this happens may be faster , this faster rate of application would move weight faster to the front of the car (and more of it) This would increase the loading /heat to the front brakes , and reduce the rear loading ( possibly lock up the rears too early?) My initial feelings are tyres are the major factor in braking ability,more than the discs /calipers/pads Discs/caliper/pads will determine "feel" ie reaction times and pedal feel , and how much load you move forewards onto them ie the point at which the rear locks up - and to work this out will give you the problem that it is tyre dependent and road surface dependent My 2 pence worth

http://www.ncs-systems.com/speedm8/

In a way the Supra has a bigger challenge than F1 , twice the weight + ,and similar top braking speeds , without the budget or ceramics. Some recent electric motors , now run astonishing Rpms compared with 2003 . Small and cheap efficient, fans for low speed and stationary cars would work I feel ,easy to do as well . I will try it , nothing ventured nothing gained !

From the link above I think it is clear that heat is the main concern, controlling the heat and keeping within limits is the single most improvement in braking 80% of the heat is in the discs themselves. Most heat is generated at high speed brake pad pressure not as important as you would think enclosed wheels don't help floating discs more heat tolerant pad compounds dictate heat range etc etc.. I maintain that electric fan cooling can only help when high speeds are used in braking . If you never go over 70 you have no worries

http://home.wanadoo.nl/this-is-me-at/brembo/brembo.html Here is a good read , especially the bit about floating discs and the advantages over solids also gives data on energy per cm so rough estimates could be made, given disc sizes larger than stock

Realy interesting thread this one, shame i dont understand everything although its probly quite simple It is very simple.... Its about energy , the car is moving and has energy built up this energy is transfered during braking 1/2 MVsq = the calculation of energy 1/2 times the mass times the velocity (speed) the car weighs say 1500 kilo multiplied by its speed (squared) so a supra going 10 miles an hour and one at 20 miles an hour does not take twice the energy to stop but 1500 x 10x10 = 150000/2 1500 x 20 x20 = 600000 /2 4 times the energy !!!! so a supra going 170 miles an hour = a shit load of energy:D All this energy is converted to heat via friction , between the pads and discs , thats a shit load of heat , can you see that no matter how big the discs and pads are its still huge amounts of heat , even with discs twice the size of stock its enough energy to get them glowing hot with a couple of high speed stops The pads at the front have a sharp edge , this gets hotter and wears more quickly ,so the multi piston calipers can have smaller pistons here to compensate a bit for that . All this heat has to go somewhere , it goes into the fluid,lines,caliper,pads ,discs,tyres and surrounding air As the various parts get hot they in turn pass their heat on , a bigger area /size dissipates heat better - but is an extra 1 inch diameter disc going to dissipate that much more heat ? to aid heat transfer the wheels can direct cooler air over the brakes/hubs/etc , so can cooling ducts in the plastic wheel arch, so can the discs themselves by the small channels between the discs that "throw" out air centrifugally between the discs. once the car stops so does the cooling !!!! But the metal parts can retain loads of heat for a long time - thats why I suggest cooling fans Its also why you take your foot off the brake after a big stop , as the pads contact only a small area of the disc and this can exchange heat to them with contact and so warp the discs with different temps across the disc

Great if you are moving , the heat energy is exactly the same whichever brakes you have ,just spread over slightly different surface areas - all the discs centrifuge the heat out and the ducts move heat away from the area while moving along with the wheels . once stopped in pits or traffic lights there aint a lot of heat being moved , so fans would help .. "I thought ducted cooling of brakes was very difficult, very easy to make matters worse" how and why ?