Supra Brake

[Lextreme II]

John is right. I just change my front brake pad on my 2001 MDX. This is the second time for this front pads. The rear still good. I would assume the next pad sets would be front and rear. Its 3:1 ratio. From what i learned, the Supra Rear will work on LS400. I dont have any issue with the heat and stickers at all.

 

[cribbj]

I just received a very interesting post from a Supra maillist, and I've copied it below. The poster is responding to another member who just mounted a set of Supra front calipers and rotors on his GS300.

"Be careful. I put a big brake kit on the front of my Supra, and it felt good, but on the track my stopping distances were actually longer. There was too much front brake bias and the rear brakes/tires weren't doing much work.

Basically when the pedal was pressed hard enough to lock the front brakes, the rear brakes were getting significantly less line pressure and not doing much work. You need to increase the brake torque on the rear as much or more
than the front to keep an effective brake system. I have the formulas somewhere, I will see if I can find them and post so you can get an idea of what's needed on the rear.

I now have a 4 wheel kit that has significantly increased the rear clamping force and to a lesser degree the front, but they work awesome."

 

[cjsupra90]

I just received a very interesting post from a Supra maillist, and I've copied it below. The poster is responding to another member who just mounted a set of Supra front calipers and rotors on his GS300.

"Be careful. I put a big brake kit on the front of my Supra, and it felt good, but on the track my stopping distances were actually longer. There was too much front brake bias and the rear brakes/tires weren't doing much work.

Basically when the pedal was pressed hard enough to lock the front brakes, the rear brakes were getting significantly less line pressure and not doing much work. You need to increase the brake torque on the rear as much or more
than the front to keep an effective brake system. I have the formulas somewhere, I will see if I can find them and post so you can get an idea of what's needed on the rear.

I now have a 4 wheel kit that has significantly increased the rear clamping force and to a lesser degree the front, but they work awesome."

This is a very common problem when buying BBK's (big brake kits) and also swaping out parts from other cars. There is a lot of design aspects that go into designing and building a BBK and making it work correctly. I am not saying that the supra swap is necessarily a bad thing, but I do think that both front and rears should be swapped together, but still might not be the greatest combination as it is designed for the Supra, now that setup on an SC400 might work very well as I would assume that the Supra and the SC have very similar weight and balance, but again staggered tire size of the supra allows for even more rear bias which may cause premature rear wheel lockup if not equiped with ABS. Now ABS is a hole nother story and is not always good to have when trying to achieve shortest braking distances and can cause problems when being used with BBK's but are not generally noticed when being used in normal everyday street use. In all reallity, BBK's are really intended for combating excessive heat. The brakes dont stop the car, the tires do. The best brakes in the world wont do sh*t if the tires cant grip the road. If you do not have ABS and you can lock up all four wheels then you have more then enough brakes. BBK's only become necessary when fade becomes an issue and when using very high grip tires that can afford more brake torque before lockup.

Bias is pretty much the most important design aspect of the system. One thing to note is that most cars in stock form can afford more rear brakes bias. The designers tend to give more front bias then needed especially if not equiped with ABS for a safety precaution as a car is more controlable if the fronts are locked then if the rears are, eventhough I disagree with this, but I understand there reason as most of the general driving public do not know how to control a car that is in an oversteer condition. I think that not enough driving technique and car control is taught, at least in the US and I sure in other areas of the world and it is too easy to get a drivers license here.

If some one can tell me the exact diameter of the stock rotors of the LS and the SC, I can tell you what the differances would be between the stock and partial (front supra) and full supra swap. I have a program that tells the final brake torque for the given compoments with in the system

 

[XxSC400xX]

The following specs were taken from www.intellexual.net

OEM Lexus SC400 Brake Specifications
caliper - 2 piston....................17.5 lbs.
rotor - 11.65 inch ..................20 lbs.
rotor thickness - 1.26 inch

OEM 95-00 LS400 Brake Upgrade ($300 to $500)
caliper - 4 piston................... 9 lbs.
rotor - 12.4 inch
rotor thickness - 1.26 inch

OEM 93-98 Supra Turbo Brake Upgrade ($500 to $1000)
caliper - 4 piston....................15 lbs.
rotor - 12.72 inch...................20 lbs.
rotor thickness - 1.26 inch

Rotora Big Brake Upgrade ($1,550.00)
caliper - 4 piston...................9.7 lbs.
rotor - 12.99 inch..................18.6 lbs.
rotor thickness - 1.26 inch

Brembo GT Big Brake Upgrade ($2800 to $3000)
caliper - 4 piston.................. 7 lbs.
rotor - 13.1 inch
piston area - 2x 1.5 inch, 2x 1.73 inch
pad area - 9.6 sq. in.
rotor thickness - 1.26 inch

AP Racing Big Brake Upgrade ($3200)
caliper - 6 piston........................6 lbs.
rotor - 13.5 inch
piston area - 2x 1.1 inch, 2x 1.6 inch, 2x 1.5 inch
pad area - 11.8 sq. in.
rotor thickness - 1.4 inch

 

[SKperformance]

Just what i was looking for XXsc
thank you so much.
I'll take a look over there for some more info as i now need to find if the rotors offset are the same for the 95-00 LS400 as the Supra as i want lightweight 2 piece oem replacement rotors.

 

[stevechumo]

For brake performance, check this technical artical out. It has all answers related to the brake. Take your time because it's alot. http://www.stoptech.com/tech_info/wp_brakesystems_upgradeselections.shtml. Upgrading to bigger brakes is good. However, I believe a good stock SC or LS brake system will be more than OK for regular driving, unless you'll do some high speed and stopping. This is when you feel the brakes fade away. With bigger brakes, the fading is greatly minimized. Many Rally cars also build the hoses directing the air to the brakes to cool them. A cheap but effective idea.

 

[jibby]

Wow I am a little worried after reading these posts, I am looking at a complete supra tt front caliper set (rebuilt) with 1/2 spacers, new pads and holding springs (that is the 4 piston calipers) I am planning to install tomarrow in my sc400 and have the car on stands now, but just found out I defenetly need to buy supra rotors, must wait now.

Is this true that I can actually loose distance braking with the supra big brakes? That would suck I just dropped $450 bucks on these babies, however they are nice looking heat painted red with a black lexus emblem on the front. Please tell me I should still go ahead with the swap? Anyone? Or should I resell on ebay?

 

[robie]

it seams like a lot of more problems to add supra brakes. is their a aftermarket bbk thats intended for the sc400 with out messing with the abs ?

 

[jibby]

robie, there is no problems with the 4 piston supra tt brake calipers mounting right on the sc400, just hook up the brake lines and bleed. The only problem is the rim clearance I had to use 1/2 spacers to clear the calipers. I have to believe 4 pistons are better then 2, right?

 

[Lambo]

Hi jibby, Have a look at this old article it does have some good info/part numbers etc in there, also quotes the braking force for Supra tt 4 pot.
http://www.planetsoarer.com/suprabrakesII/SupraBrakeUpgrade.htm

Regards
Lambo

 

[jibby]

Lambo great post, you are on it! The braking power is greater with the supra big brakes, I just read in one of the earlier posts that the back wheel braking power suffers from the big brake upgrade and the actual test stops are close, do you know what the story is on that? Also, robie- I forgot you do need the supra rotors, and the cut in the back sleeve is no biggie. The supra rebuilt calipers I got were on ebay for $400 which is more than I wanted to pay at the time, airbrushed red with black lexus on the front. I had to go to the dealer to get the pads and holding springs which did not come with the ebay purchase, most upsetting. Rotors I think sell on ebay at a good price, drill and slotted, brembo's, aftermarket etc... etc... I just hate having to use spacers on the front wheels I get rub with the 18" at full turn as it is.

 

[robie]

jibby i agree and i know that 4 is better than 2 , i was considering the economical part in getting supra TT parts compaired with the oem parts for the sc400. but you are on the money on the bbk upgrade is is well worth the money.

 

[jibby]

This is my set supra big brakes going on my sc400. I just need to pick up some Supra rotors on ebay supra and I will be good to go. What do you think of the red and black? Price $500 complete with rebuilt calipers and pads. I just figured out how to post pictures so I may be a little picture happy.

 

[robie]

good price! i would go black. but, depends on the color of you car. my sc is that dark green. so, i would do black. if i had it red i would black as well.

 

[jibby]

Right on robie, I got the tan one.

 

[stevechumo]

good price! i would go black. but, depends on the color of you car. my sc is that dark green. so, i would do black. if i had it red i would black as well.

Black calipers look fine. But red, yellow, orange, and blue are all hotter. That's why most hi-performance brake upgrades are painted so hot and become head-turners. They show you're having something special there, which also means you're having a powerful engine that needs hi-performance brakes. I've seen Porches and Ferraris having red or yellow calipers running on the freeway. I couldn't keep my eyes off them. I painted mine black but I think I'll paint them orange later.

 

[jibby]

Steve I can't agree with you more.

 

[SCV8]

Has anyone played with the proportioning valve on our cars?

After putting huge brakes on another car, I had disabled the proportioning valve and was still front biased, but a lot better off.

 

[ismo67]

Yes,,, not only that.. those are modified Supra TT Rotors

I have finally finalized my Front Supra TT brake update to my Lexus LS400 -91.
I bought my Supra Twin TT 93-98 rotors from ebay I they fit great execpt the center hole diameter is too big I think... causing vibration in high speed?

The original rotors center hole is 60mm and the Supra is 62mm?? haven't measured that but little bit bigger.

What are the modified Supra TT rotors exactly?
Is that modification that those has 60mm center hole or are there other modifications also?

 

[jibby]

This is very dissapointing news as I just recieved my supra rotors in the mail from ebay. I have my newly rebuilt Supra 4 piston calipers and pads ready for install and was thinking of giving this swap a go tomarrow. I really thought this swap was proven and tested to be successful.. How do we make this work without vibration? David is the vibration bad? Is it manageable and still makes the swap worth doing? Here are my pics to show you how ready I am...shoot!!!