Fitting LS400 brakes to a SC400-Detailed how to do.
03-13-15, 11:04 AM
#46
I knew the rear pads would help, the travel of the cylinders is whats going to affect pedal feel, the whole system has to be setup right for perfect pedal feel.
the pedal feel wont be original feeling since the number of cylinders braking now is doubled. you could upgrade the master cylinder or in time you will forget what the stock ones felt like bevause the stock setup was ridiculous and should have never been on the car.
its unfortunate some of us get used to a large master with small breaks = awesomely perfect brake feel
but with larger brakes and the large master that we have it just feels like normal brakes to me.
some are running Z06 setups and rear setups with the stock master on it so its not a small master, but if you can find an upgrade let us know how it goes.
some years can install the supra TT master, but I dont remember if its even different I will have to visit that thread.
Kahn said his pedal feel improved when he put the rear tt's on in post 10. might help a little but I wouldn't think it would cure it.
https://www.clublexus.com/forums/sus...r-upgrade.html
this is also informative post 17 from above thread
the pedal feel wont be original feeling since the number of cylinders braking now is doubled. you could upgrade the master cylinder or in time you will forget what the stock ones felt like bevause the stock setup was ridiculous and should have never been on the car.
its unfortunate some of us get used to a large master with small breaks = awesomely perfect brake feel
but with larger brakes and the large master that we have it just feels like normal brakes to me.
some are running Z06 setups and rear setups with the stock master on it so its not a small master, but if you can find an upgrade let us know how it goes.
some years can install the supra TT master, but I dont remember if its even different I will have to visit that thread.
Kahn said his pedal feel improved when he put the rear tt's on in post 10. might help a little but I wouldn't think it would cure it.
https://www.clublexus.com/forums/sus...r-upgrade.html
this is also informative post 17 from above thread
I had the same dead space you guys are describing with LS400/stock rears and stock Master cylinder. I tired everything, bled them 100 times, etc, with the same results. I'd also experience fade after a few laps, which required pumping the brakes.
All master cylinders I've pulled from the SC's say 1 1/16th. Which is the same size as the MKIV master.
Solution to dead space was rebuilding all 4 calipers, LS400 front and TT rear with stainless brake lines and stock master/booster. I believe the issue most people have with upgrading to LS400 calipers, people buy used, which is what I did initially, and also using old worn rear calipers.
I use Castrol SRF, which is the best brake fluid I've come across. I'm still using the same fluid after 24 hours of hard track time and 150mph stops. Tried many other brands including Motul 660, and all would boil after heavy braking at tracks known to boil brakes after a lap or two.
After putting rebuilt calipers (LS400 front/TT rear) and stainless lines, the brakes bled immediately and have no dead space whatsoever. My car is a road race car so brakes are very important. I have no fading or brake issues at all with braking just as good as any car on the track I've come across. I've driven a few other high end racecars and my car brakes better, with better feel. Also had other people drive my car and their opinion was the same. My car only weighs 2500lbs dry so it's more than enough brake to lock up all four 305 slicks at any given speed. I have my ABS unplugged, but have been too lazy to run new lines to totally remove it.
Stock master has a proportioning valve, no need to add an aftermarket valve unless you are a professional driver with a racecar only.
All master cylinders I've pulled from the SC's say 1 1/16th. Which is the same size as the MKIV master.
Solution to dead space was rebuilding all 4 calipers, LS400 front and TT rear with stainless brake lines and stock master/booster. I believe the issue most people have with upgrading to LS400 calipers, people buy used, which is what I did initially, and also using old worn rear calipers.
I use Castrol SRF, which is the best brake fluid I've come across. I'm still using the same fluid after 24 hours of hard track time and 150mph stops. Tried many other brands including Motul 660, and all would boil after heavy braking at tracks known to boil brakes after a lap or two.
After putting rebuilt calipers (LS400 front/TT rear) and stainless lines, the brakes bled immediately and have no dead space whatsoever. My car is a road race car so brakes are very important. I have no fading or brake issues at all with braking just as good as any car on the track I've come across. I've driven a few other high end racecars and my car brakes better, with better feel. Also had other people drive my car and their opinion was the same. My car only weighs 2500lbs dry so it's more than enough brake to lock up all four 305 slicks at any given speed. I have my ABS unplugged, but have been too lazy to run new lines to totally remove it.
Stock master has a proportioning valve, no need to add an aftermarket valve unless you are a professional driver with a racecar only.
Last edited by Ali SC3; 03-13-15 at 11:08 AM.
03-13-15, 11:48 AM
#47
The last couple posts convinced me I should get new rear pads, given that they were estimated at 40% remaining 3k miles ago and I have a bit of the mushy pedal after the LS400 caliper upgrade and system bleeding.
I figured I might as well get Wagner ThermoQuiet PD572 rears to match the LS' QC665 fronts I went with. I'm still having a hard time believing it, but the total is $4 shipped! Only $22 to start with, minus $3 in Amazon cc credit from my front rotor/pad (LS) order, minus a $15 rebate I stumbled upon while cross-checking part numbers to be sure, and free shipping. Crazy. For that price, there won't be the slightest bit of buyer's remorse over discarding a perfectly good set of rear pads to even out piston travel.
Edit: The Wagner promotion runs through 5/31. I bought the front pads two weeks before it began. Amazon's free s/h on the rear pads is with no minimum order.
I figured I might as well get Wagner ThermoQuiet PD572 rears to match the LS' QC665 fronts I went with. I'm still having a hard time believing it, but the total is $4 shipped! Only $22 to start with, minus $3 in Amazon cc credit from my front rotor/pad (LS) order, minus a $15 rebate I stumbled upon while cross-checking part numbers to be sure, and free shipping. Crazy. For that price, there won't be the slightest bit of buyer's remorse over discarding a perfectly good set of rear pads to even out piston travel.
Edit: The Wagner promotion runs through 5/31. I bought the front pads two weeks before it began. Amazon's free s/h on the rear pads is with no minimum order.
Last edited by t2d2; 03-13-15 at 12:10 PM.
03-13-15, 12:26 PM
#48
you should generally do all 4 if you are after the best brake feel possible, that is a steal for the rear pads I think I am using the wagner thermoquiets as well on the front they are pretty decent so far and I don't get much brake dust at all. if I need more pad in the future I will try the EBC lineup, the Previous owner had the EBC greens on the stock calipers when I took them off they were pretty good pads as well. I might have to go check out if any of my cars need brakes that is a pretty good deal for those and they are a good stock replacement type pad.
Last edited by Ali SC3; 03-13-15 at 12:30 PM.
03-18-15, 12:20 PM
#50
My new rear pads are on the slow boat from Ohio, apparently, but in the mean time, I stumbled across this interesting and relevant tidbit from a Miata strut tower bar:
http://www.rspeed.net/RSpeed_Strut_T.../nab-30980.htm
Is there anything to that? Does the master cylinder move about from hydraulic pressure? Is it only certain vehicles that benefit from bracing the master cylinder?
http://www.rspeed.net/RSpeed_Strut_T.../nab-30980.htm
A really nice feature of this bar is the built in master brake cylinder stopper or movement reducer. The brake master stopper is a surefire cure for cars with soft brake pedals giving them more positive brake feel along with increased stopping power.
03-21-15, 08:13 AM
#51
My new rear pads are installed now to match the LS fronts, and it definitely firmed up the pedal feel. It's rather startling how much you have to push the single piston in to account for 50-60% pad wear x2. I haven't re-bled the system yet.
I have developed a weird noise up front the past couple days, though. Light to medium braking is quiet, but when pressing down firmly on the pedal there's a fairly noticeable grumbly noise. I'm thinking it has something to do with pad break-in, or maybe the tiny bit of surprisingly durable rotor paint over-spray being eaten into. Anyone experience something like that?
Still curious about the previous master cylinder bracing question, too...
I have developed a weird noise up front the past couple days, though. Light to medium braking is quiet, but when pressing down firmly on the pedal there's a fairly noticeable grumbly noise. I'm thinking it has something to do with pad break-in, or maybe the tiny bit of surprisingly durable rotor paint over-spray being eaten into. Anyone experience something like that?
Still curious about the previous master cylinder bracing question, too...
04-24-15, 10:57 AM
#54
lots of very high performance strut tower bars have master cylinder braces, under extreme braking they will tend to move and the brace keeps them from moving too much. I have seen them on like 900+hp supras with extreme big brake kits, but you can totally install one on your car if you like, you prob wont feel much difference though. its not very common on street cars but more so on track cars where every tiny amount counts, for example the trd strut bar does not have one so even trd didn't think it was really needed, but I have seen several aftermarket ones before on supra's and sc's.
04-24-15, 02:43 PM
#55
lots of very high performance strut tower bars have master cylinder braces, under extreme braking they will tend to move and the brace keeps them from moving too much. I have seen them on like 900+hp supras with extreme big brake kits, but you can totally install one on your car if you like, you prob wont feel much difference though. its not very common on street cars but more so on track cars where every tiny amount counts, for example the trd strut bar does not have one so even trd didn't think it was really needed, but I have seen several aftermarket ones before on supra's and sc's.
https://www.facebook.com/groups/thes...7735534948707/
No affiliation, etc.
04-24-15, 06:43 PM
#56
Interestingly, a few days after I posted that question, along came such a product from the UK, specifically for the SC, claiming 5mm of firewall flex has been observed.
https://www.facebook.com/groups/thes...7735534948707/
No affiliation, etc.
https://www.facebook.com/groups/thes...7735534948707/
No affiliation, etc.
04-24-15, 07:42 PM
#57
http://lincsdrivercom.ipage.com/Prov...ordpress/?p=18
http://www.provokedesigns.co.uk/ (in case the direct direct link sans internal redirect gets changed)
04-26-15, 04:30 PM
#58
I figured that was a public link, but maybe you have to be subscribed to the group? Here's a direct link to the seller's site; hopefully okay with the mods:
http://lincsdrivercom.ipage.com/Prov...ordpress/?p=18
http://www.provokedesigns.co.uk/ (in case the direct direct link sans internal redirect gets changed)
http://lincsdrivercom.ipage.com/Prov...ordpress/?p=18
http://www.provokedesigns.co.uk/ (in case the direct direct link sans internal redirect gets changed)
