1990 LS400 Brake upgrade

Spinnetti

Member
Since I have the UCF10, 11 and 21 brakes right now i thought i'd measure them up to see the differences.

UCF21:
Front piston: 1.54"
Hub to Piston: 5.0625"
Rear piston: 1.48"

UCF11:
Front piston: 1.38"
Hub to Piston: 5.0625"
Rear piston: 1.48"

UCF10:
Front piston: 1.38"
Hub to Piston: 4.625"
Rear piston: 1.48"

The only thing that changed between the UCF10 and 11 brakes is the distance the caliper is from the hub center. This can be seen in the carrier bracket. Which would mean a higher Force x Length for the UCF11.
You have disc diameters too? So I could buy just the discs and brackets to upgrade my 91' rears to the later model? that's good to know. I did the 95 front upgrade (really should do the front hubs too), but nothing to the rears yet, and I'm working them hard. I go through $400-500 in brakes every weekend I drive it!
 

spf_lexus

New Member
Spinetti,

Why not run 98 LS400 calipers + rotors all around with a good ceramic pad? They would hold up to the abuse leagues better the OE. I ran the 98's all aroung at one point. Ended up swapping supra brakes in the front later on and this was also on a 1991. The 98 (and 95 i believe) has a larger diameter rotor and larger diameter piston.

These days a complete 98 brake sway from a junk yard would be very cheap.
 
Doesnt seem to be any options for the rears on these. Theyre the same from the UCF11 up, a 1.48" single piston. Again the UCF10 has a slightly smaller hub center to piston on the rear than the UCF11 and up. Only difference being the carrier bracket.

UCF10 front:



UCF10 rear:



UCF11 front:



UCF11 rear:



UCF21 front:



UCF21 rear:

 

Spinnetti

Member
Spinetti,

Why not run 98 LS400 calipers + rotors all around with a good ceramic pad? They would hold up to the abuse leagues better the OE. I ran the 98's all aroung at one point. Ended up swapping supra brakes in the front later on and this was also on a 1991. The 98 (and 95 i believe) has a larger diameter rotor and larger diameter piston.

These days a complete 98 brake sway from a junk yard would be very cheap.
95=98, so already running the fronts. Looks like calipers and pads are same for rear, just larger rotor diameter. Will run those eventually. Ceramic pads would evaporate in minutes in my usage! (I use them on the street on other cars though.)... Already running $300 indy car pads.. they are great, but am just about using them up in a weekend.
 

spf_lexus

New Member
I can vouch that the ucf11 and up rear caliper is larger than the ucf10. Its still a single piston but its a larger diameter piston. Overall caliper size is larger as well. As Hammered's spec sheet shows, the rear rotor diameter is larger as well. Not technically a big brake upgrade but an upgrade nonetheless.
 

Spinnetti

Member
After much research, Here's my "ultimate" brake rotor. I'll custom CNC machine these, and use them at my next endurance race in October. Will be a bit spendy, but absolutely nobody will have them.... Anybody interested in a group buy? I should have them made and on the car within a couple weeks.
 

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Spinnetti

Member
Why not just buy the r1concepts D/S rotors, be cheaper than making them. I just threw on the same set, haven't tracked the car yet but they feel good so far.
http://www.r1concepts.com/lexus-ls400-1995-brakes-PDS.44107.htm
I'm pushing these harder than any street car or even a sprint race car could possibly do with races lasting up to 24 hours of full out racing on one set of rotors. Just my brake pads cost over $250 per axle, and don't last past one event. The wave external profile puts more surface area in the airstream for better cooling, weighs less and looks sweet :). Only Audi on their top models has started to do this. On the street, will make for a unique look too, though my Lex is track only. Sometimes, only the best will do :)
 

Spinnetti

Member
First parts off the CNC machine... After much research, will do drilled and slotted too, and then test them under the hardest conditions I can - 15-24 hr endurance race... At the last race, I used up race pads and even ate through the rear backing pads, so its quite a test.
 

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Lambo

Moderator
Supra brake upgrade

Hi guys, I am still beavering away on my Countach project, can any one tell me the dimensions for the supra jza80 alloy callipers, I believe they are the ones to use. I have a Sc400 91 suspension to fit them too, I have wheels with a 25 pos offset and I will need adaptors to go from the sc400 to the bmw/lambo Countach pattern anyway. I am looking at a 25mm pos adaptor so that brings me back to the 50mm offset of the original Soarer wheels, I have read how Jibby had issues with the handling due to incorrect offset, and ended up removing the upgrade and returning to stock. But a sc400 single pot on a lambo I don't think so.
I do have a set of the old ma70 supra 2 pot, they bolt straight on but they are made of cast iron they are very very heavy, and are a little two big to fit inside the 15" lambo wheels, its only 2-3mm two much, so if I had to perhaps could skim that much off them, but would rather not.
I also have a set of Nissan R32 4 pot and they are very light and would miss the wheels rim but need serious work to adapt to the sc400 upright, so if any one can give me some dimensions that would be great, I really need a centre of wheel to edge of calliper, and also how much they stand out from the disk, I have about 350mm inside the Rims so at 175 it is going to be close. And with a mock up adapter I have about 30mm disk to rear of wheel.
any help much appreciated
lambo
 
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Lambo

Moderator
Supra brakes

Guys, Nobody out there got a set they can throw a tape over for me.

Regards
Lambo
 
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