Fitting LS400 brakes to a SC400-Detailed how to do.
02-18-15, 11:19 PM
#31
We'll see if this works out as envisioned once I have everything taken apart, but my plan is to cut slits into the rolled edge of the shields and then bend it up straight behind the LS rotor, trimming only the portion that interferes with the bigger caliper. If it works, that would be less cutting and fewer jagged edges, plus a bit more shielding of brake dust, water splashing on the pads, etc.
02-19-15, 10:22 AM
#32
I've seen a few other people say they removed the dust shields instead of trimming them, since the shields serve no purpose once trimmed. However, don't the dust shields also have a cooling effect with the vent (edit: more of a scoop, actually) pulling air in from the inner edge of the wheel?
We'll see if this works out as envisioned once I have everything taken apart, but my plan is to cut slits into the rolled edge of the shields and then bend it up straight behind the LS rotor, trimming only the portion that interferes with the bigger caliper. If it works, that would be less cutting and fewer jagged edges, plus a bit more shielding of brake dust, water splashing on the pads, etc.
We'll see if this works out as envisioned once I have everything taken apart, but my plan is to cut slits into the rolled edge of the shields and then bend it up straight behind the LS rotor, trimming only the portion that interferes with the bigger caliper. If it works, that would be less cutting and fewer jagged edges, plus a bit more shielding of brake dust, water splashing on the pads, etc.
02-19-15, 12:25 PM
#33
Thanks for confirming their additional purpose. I'll try and do the slit/bend method to preserve as much of the shield as possible, with as little trimming as possible, and report back if it goes well or is an utter failure. 
I picked up some M10 x 1.0 nuts to see if I can fashion a cap for the brake lines, so as to be able to take my time with stuff like that and have minimal fluid leaking without having to clamp the lines. I matched the caliper's female thread to that size bolt but couldn't find a matching cap, so I'll have to do it by manually capping the nuts. I'm due for fresh brake fluid, anyway, but this will hopefully make for less of an initial mess.
I picked up some M10 x 1.0 nuts to see if I can fashion a cap for the brake lines, so as to be able to take my time with stuff like that and have minimal fluid leaking without having to clamp the lines. I matched the caliper's female thread to that size bolt but couldn't find a matching cap, so I'll have to do it by manually capping the nuts. I'm due for fresh brake fluid, anyway, but this will hopefully make for less of an initial mess.
02-22-15, 05:43 PM
#34
Proof of concept successful. I started trimming a couple spots I didn't need to, thinking it was rubbing on the lower right part of the dust shield when in fact it was the lower left section by the spot that has to be cut away for caliper space. The other side should go pretty quick now that I know what shape I'm after.
The only disappointment of the day was weighing the SC400 items after removal. It's been said (and repeated, thus taken as fact) that the LS setup reduces a significant amount of weight in addition to packing a bigger and better punch. Not true, as far as the weight is concerned. The difference would probably be even less favorable for the smaller SC300 brakes.
Supposed weights: LS calipers = 9.0 lb, SC calipers = 17.5 lb; LS rotors = 23.0 lb, SC rotors = 20.8 lb. Should be a difference of ~6.3 lb per side.
Actual weights: LS calipers = 8 lb 11 oz, SC calipers = 12 lb 11 oz; LS rotors = 20 lb 11 oz, SC rotors = 17 lb 10 oz (@ maybe 0.5 mm wear on each, which is probably another pound per rotor based on my LS rotors having a 2 lb discrepancy to go with each face being 1 mm thicker on one of them -- with 2mm less air space in between); LS pads = 4 lb 1 oz total, SC pads = 4 lb 0 oz total @ 75% (let's call it 5 lbs new).
So, the SC pads may be slightly heavier if comparing new to new, and the rotors are up to 3 lb lighter depending on how much metal is worn down from my old ones. The big discrepancy is the calipers, where the 17.5 lb weight is way outside the realm of accuracy. At "only" 4 lbs lighter than the SC calipers instead of 8.5 lbs, the LS combo saves a mere pound or two but does so at the expense of more rotating mass. So, performance may actually be worsened from a weight perspective. Oh well.
Edit: supposed/actual numbers updated with the weight of SC's 2nd side instead of doubling the initially measured side (made no difference), plus estimates for extra weight of pad & rotor wear on my old items -- each would seem to be right around 1 lb per side, for a total of 4 extra lbs. That brings us close to 6 lbs, after all, but only because the bigger LS pads are oddly lighter than the smaller SC ones, probably due to different compounds, and I probably got one of the lighter LS rotors to bring my average down there.
Yes, the pictured rotor exhibits a lovely combination of brake dust from handling it during repeated test fittings, along with a bit of hat overspray.
I started trimming a couple spots I didn't need to, thinking it was rubbing on the lower right part of the dust shield when in fact it was the lower left section by the spot that has to be cut away for caliper space. The other side should go pretty quick now that I know what shape I'm after.The only disappointment of the day was weighing the SC400 items after removal. It's been said (and repeated, thus taken as fact) that the LS setup reduces a significant amount of weight in addition to packing a bigger and better punch. Not true, as far as the weight is concerned. The difference would probably be even less favorable for the smaller SC300 brakes.
Supposed weights: LS calipers = 9.0 lb, SC calipers = 17.5 lb; LS rotors = 23.0 lb, SC rotors = 20.8 lb. Should be a difference of ~6.3 lb per side.
Actual weights: LS calipers = 8 lb 11 oz, SC calipers = 12 lb 11 oz; LS rotors = 20 lb 11 oz, SC rotors = 17 lb 10 oz (@ maybe 0.5 mm wear on each, which is probably another pound per rotor based on my LS rotors having a 2 lb discrepancy to go with each face being 1 mm thicker on one of them -- with 2mm less air space in between); LS pads = 4 lb 1 oz total, SC pads = 4 lb 0 oz total @ 75% (let's call it 5 lbs new).
So, the SC pads may be slightly heavier if comparing new to new, and the rotors are up to 3 lb lighter depending on how much metal is worn down from my old ones. The big discrepancy is the calipers, where the 17.5 lb weight is way outside the realm of accuracy. At "only" 4 lbs lighter than the SC calipers instead of 8.5 lbs, the LS combo saves a mere pound or two but does so at the expense of more rotating mass. So, performance may actually be worsened from a weight perspective. Oh well.
Edit: supposed/actual numbers updated with the weight of SC's 2nd side instead of doubling the initially measured side (made no difference), plus estimates for extra weight of pad & rotor wear on my old items -- each would seem to be right around 1 lb per side, for a total of 4 extra lbs. That brings us close to 6 lbs, after all, but only because the bigger LS pads are oddly lighter than the smaller SC ones, probably due to different compounds, and I probably got one of the lighter LS rotors to bring my average down there.
Yes, the pictured rotor exhibits a lovely combination of brake dust from handling it during repeated test fittings, along with a bit of hat overspray.
Last edited by t2d2; 02-25-15 at 05:11 AM.
02-24-15, 11:20 AM
#35
Interesting, I think the weight savings was in relation to TT front brakes not the stock brakes but it is still a little lighter. I think the comparison would be much different with TT brakes.
To get double the braking power for practically the same weight to the stock setup is pretty amazing really. you wouldn't notice that little bit of weight at all it would be like changing to a different wheel.
I found some numbers on the net for the weight of the tt calipers but I am not sure if it is right. I was seeing 29lbs for calipers but not sure if this if for 1 or 2, rotors are similar like 20lbs each, and I guess pads would be around 4-5lbs again.
so thats roughly like 53-54lbs for the tt front setup vs the 34-36lbs for ls400 so there is definately a significant difference.
I am happy that ebc makes pads for the ls400 so I don;t think the pad selection is that bad maybe just not as good as the supra, but at least there is one good choice and 1 is all I need to make it work.
To get double the braking power for practically the same weight to the stock setup is pretty amazing really. you wouldn't notice that little bit of weight at all it would be like changing to a different wheel.
I found some numbers on the net for the weight of the tt calipers but I am not sure if it is right. I was seeing 29lbs for calipers but not sure if this if for 1 or 2, rotors are similar like 20lbs each, and I guess pads would be around 4-5lbs again.
so thats roughly like 53-54lbs for the tt front setup vs the 34-36lbs for ls400 so there is definately a significant difference.
I am happy that ebc makes pads for the ls400 so I don;t think the pad selection is that bad maybe just not as good as the supra, but at least there is one good choice and 1 is all I need to make it work.
Last edited by Ali SC3; 02-24-15 at 11:29 AM.
02-24-15, 08:48 PM
#36
To get double the braking power for practically the same weight to the stock setup is pretty amazing really. you wouldn't notice that little bit of weight at all it would be like changing to a different wheel.
I found some numbers on the net for the weight of the tt calipers but I am not sure if it is right. I was seeing 29lbs for calipers but not sure if this if for 1 or 2, rotors are similar like 20lbs each, and I guess pads would be around 4-5lbs again.
02-25-15, 10:31 AM
#37
yeah I think its variation from different sources weighing them. for the rotors it could be some have larger ventilation channels in the middle and some have thinner channels cause they are all vented rotors. I don't think they are that different really rotor wise the savings is on the brakes themselves, the LS are aluminum and I will take those 6.5lbs weight savings, I mean there must be a reason whey all the brembo's today are aluminum and not iron like the tt supra brakes, and why toyota uses aluminum on their good brakes now.
I think on the LS it wasn't originall planned to use such good brakes, it was more of a complaing and mid design model change and then they just had to slap some really good ones on there, and at that point the ls400 was literally the flagship as in its so heavy you think its a ship (j/k LS guys), so as an engineer you can't just put heavy supra brakes on an LS400 and call it a day, I mean it already weighs so much toyota made the right choice by saving those 6-7 lbs per side, and lucky for us its bolt on.
the day will come when you need them. I used to think the stock SC had decen't braking, it would emergency stop alright... once.
if you start going again and have to emergency stop a second time, I hope there is a shoulder you can pull into cause the stock brakes suffer massive fading.
they cannot handle 2-3 80mph stops in a row, which means they have the stopping strength of a wet noodle under agressive driving conditions after the first stop.
Since the LS400 upgrade in the front, the fade is hardly noticeable and I can lock up my tt wheels and tires up front, many many stops in a row if needed, the fade does not feel threatening and is not as noticeable. you can pretty much still lock up the front if needed, which cannot be said for the stock brakes.
You don;t use it all the time to its max breaking power, but when the caliper brakes that much better/easier, the whole braking seems more confident I never worry about emergency braking anymore, in dry conditions I can stop the SC in a very short distance even when going fast with confidence, but with the stock brakes I was always nervous even with regular braking sometimes it just felt like it was barely getting the job done you know, and brakes is not somewhere you want that feeling.
alot of people have told me their first experience with the ls400 brakes was hitting the brakes too hard and face meeting steering wheel, so try to go slow at first with your better brakes =)
I think on the LS it wasn't originall planned to use such good brakes, it was more of a complaing and mid design model change and then they just had to slap some really good ones on there, and at that point the ls400 was literally the flagship as in its so heavy you think its a ship (j/k LS guys), so as an engineer you can't just put heavy supra brakes on an LS400 and call it a day, I mean it already weighs so much toyota made the right choice by saving those 6-7 lbs per side, and lucky for us its bolt on.
the day will come when you need them. I used to think the stock SC had decen't braking, it would emergency stop alright... once.
if you start going again and have to emergency stop a second time, I hope there is a shoulder you can pull into cause the stock brakes suffer massive fading.
they cannot handle 2-3 80mph stops in a row, which means they have the stopping strength of a wet noodle under agressive driving conditions after the first stop.
Since the LS400 upgrade in the front, the fade is hardly noticeable and I can lock up my tt wheels and tires up front, many many stops in a row if needed, the fade does not feel threatening and is not as noticeable. you can pretty much still lock up the front if needed, which cannot be said for the stock brakes.
You don;t use it all the time to its max breaking power, but when the caliper brakes that much better/easier, the whole braking seems more confident I never worry about emergency braking anymore, in dry conditions I can stop the SC in a very short distance even when going fast with confidence, but with the stock brakes I was always nervous even with regular braking sometimes it just felt like it was barely getting the job done you know, and brakes is not somewhere you want that feeling.
alot of people have told me their first experience with the ls400 brakes was hitting the brakes too hard and face meeting steering wheel, so try to go slow at first with your better brakes =)
Last edited by Ali SC3; 02-25-15 at 10:40 AM.
02-25-15, 04:05 PM
#38
I did have fresh fluid leaking out of the lowest bolt (that holds the two halves of the caliper together) on the driver's side. I'm completely stumped what that would indicate, as any o-ring leakage above it would be free to leak out the unsealed crack between the two halves. Traveling up the bolt's thread and out the head firmly seated against the caliper seems borderline impossible. Maybe it had just run down the back side of the caliper and pooled around the bolt head, but everything seemed dry above it... A fair bit dripped yesterday, but it's only a tiny bit moist today. I'll be keeping an eye on it, for sure.
When I took the calipers apart to inspect (three of the five rebuilds were bad) and paint them, I was surprised to see only two little o-rings for the fluid passages between the two halves. I figured some sort of tubing would pass through to form a better seal, but I guess those o-rings hold up.
03-01-15, 03:40 PM
#39
Lexus Test Driver
Hey guys I usually post in the 1GS section but it seems like more of you guys have done the LS400 BBK upgrade so hope you guys can help. I upgraded to 97 LS400 calipers (Rebuilt and power coated) and rotors with SS lines and Power Stop Z17 pads. My problem is a low/soft pedal even after bleeding the system at least ten times using various different methods include old school 2 man bleeding, brake flush machine and vaccum bleeding. There is just excessive "dead space" at the top of the pedal before I really feel anything happen. Sometimes if I double pump the pedal it seems to have full pressure but then on the next stop it feels like mush again!! Has anyone else experienced this after the upgrade? Also I read in a really old thread that members thought it might be possible to upgrade to a Supra TT or LS400 master cylinder but I never found any definitive information. Upgrade to a MC from a car that was designed for 4 piston calipers makes sense. Thanks in advance for any information!!!
03-02-15, 12:55 PM
#40
could be a master cylinder issue. did you bleed the abs also by the manual? I am assuming new pads all around. if you have worn pads in the rear and new pads up front that can cause pedal issues.
our master cylinders are not usually in need of an upgrade, probably they are similar to the supra ones. maybe check for leaks on the booster and check the line going to the intake.
our master cylinders are not usually in need of an upgrade, probably they are similar to the supra ones. maybe check for leaks on the booster and check the line going to the intake.
03-02-15, 10:11 PM
#41
Lexus Test Driver
I did bled the ABS system. I didn't bled the "TRAC" Accumulator and pump. I did not put new pads in the rear since they are at about 50% but I do agree that could be part of the problem so I just ordered a set of Power Stop Z17 pads for the rear. Thanks for the suggestion. I will install the new pads and looking into replacing the "TRAC " Accumulator and pump since its a possibility of air being trapped in there. If those 2 things do improve the pedal then it will be time to investigate MC upgrades.
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Gears12 (10-24-21)
03-12-15, 05:02 PM
#44
Hey guys I usually post in the 1GS section but it seems like more of you guys have done the LS400 BBK upgrade so hope you guys can help. I upgraded to 97 LS400 calipers (Rebuilt and power coated) and rotors with SS lines and Power Stop Z17 pads. My problem is a low/soft pedal even after bleeding the system at least ten times using various different methods include old school 2 man bleeding, brake flush machine and vaccum bleeding. There is just excessive "dead space" at the top of the pedal before I really feel anything happen. Sometimes if I double pump the pedal it seems to have full pressure but then on the next stop it feels like mush again!! Has anyone else experienced this after the upgrade? Also I read in a really old thread that members thought it might be possible to upgrade to a Supra TT or LS400 master cylinder but I never found any definitive information. Upgrade to a MC from a car that was designed for 4 piston calipers makes sense. Thanks in advance for any information!!!
Next step is ss lines and a master cylinder strut brace. If that doesn't solve it, then going to try and upgrade to the new tt master cylinder setup to see if it helps. As I have no point of reference, I am going to try and ask a guy selling his supra tt locally for a 'joy ride' to see what the difference is.
03-12-15, 06:07 PM
#45
Lexus Test Driver
I've run into the same problem and just posted about this on the supra forums yesterday looking for answers. I am starting to think that with this many people saying the same thing, that this is just how it is. I did the tt brakes instead of ls, but have same issue even after having Toyota bleed the system twice. Pads on all 4 are brand new, so didn't solve the problem like it seems it did for you per your last post. Like you, if I sit at a stop and pump the peddle it firms up, go figure...
Next step is ss lines and a master cylinder strut brace. If that doesn't solve it, then going to try and upgrade to the new tt master cylinder setup to see if it helps. As I have no point of reference, I am going to try and ask a guy selling his supra tt locally for a 'joy ride' to see what the difference is.
