1990 LS400 Brake upgrade

gribley

New Member
I am going to upgrade the front brakes to 4 pots.
I have seen Supra kits advertised for £600.
I have priced up 95-2000 LS 400 kit at about £450 + shims + pins. but then I believe a set of lower ball joints is needed, then it will need tracking so the price difference will be negligible.
So which is the best value for money?
Which need least wheel clearance for the calipers?
I have 10 spoke GS300 wheels on and with the std discs I have 66mm clearance

Will 95-2000 LS 400 rear discs and calipers fit the 90 ls 400?
 

spf_lexus

New Member
Best value hands down is the 1995+ LS400 swap. Both have virtually the same rotor diameter. 95+ LS are very common at the junk yards, maybe $100 for both calipers used?

The only downside of the LS swap is pad options but I guess it isnt really a con.


Supra TT swap will require 17" rims with generous caliper offset. If the spokes hit on your GS wheels, im sure a 10mm spacer would fix that.
 

Spinnetti

Member
Best value hands down is the 1995+ LS400 swap. Both have virtually the same rotor diameter. 95+ LS are very common at the junk yards, maybe $100 for both calipers used?

The only downside of the LS swap is pad options but I guess it isnt really a con.


Supra TT swap will require 17" rims with generous caliper offset. If the spokes hit on your GS wheels, im sure a 10mm spacer would fix that.
so the 95+ is a straight bolt on front and rear (calipers, brackets and discs only parts needed?).... I thought even the 93 or so had bigger brakes than the 90?

I'll be racing mine soon, so good info to have.
 

gribley

New Member
As I said the cost difference is negligible. If I buy refurbished calipers, new discs, new bottom ball joints, new fitting kit and new shims it will cost be about £550. I can get a supra kit for £600.

I may be tempted to buy the supra kit if its less messing. but i need to know if the calipers will fit under my wheels. How deep is the supra caliper from the disc surface to the face thats says "supra" on it?
 

spf_lexus

New Member
so the 95+ is a straight bolt on front and rear (calipers, brackets and discs only parts needed?).... I thought even the 93 or so had bigger brakes than the 90?

I'll be racing mine soon, so good info to have.
The 93 came with better front brakes but it still did not fix the undersized braking issue. 95+ was when they stepped the front and rears up to match the heavy curb weight. And yes, 1995+ front and rear brakes bolt right up, no machining required. The older OEM brake lines fit perfect. If your still running stock rims you will need to run a 17" fit them. The rears of the 95+ have bigger diameter rotors as well as a much larger single piston slide caliper.
 

Spinnetti

Member
The 93 came with better front brakes but it still did not fix the undersized braking issue. 95+ was when they stepped the front and rears up to match the heavy curb weight. And yes, 1995+ front and rear brakes bolt right up, no machining required. The older OEM brake lines fit perfect. If your still running stock rims you will need to run a 17" fit them. The rears of the 95+ have bigger diameter rotors as well as a much larger single piston slide caliper.
Thanks... I assume the master cyl is still ok too? WIll the 93's work with stock wheels? I've got some constraints, including stock 16" wheels. I'll have the car around 3,000lb or under hopefully, but then again, I'm racing it, so the more brake the better.
 

spf_lexus

New Member
Thanks... I assume the master cyl is still ok too?
Yeah, your master cylinder will work fine with the swap. You can fit the 1993 fronts under 16" rims but your losing out on 2 spots/caliper w/o the 95 setup. I am pretty sure they are the same stock brakes that the sc400 had back in 1992. Larger rotor but 2 piston caliper.
 

Spinnetti

Member
Yeah, your master cylinder will work fine with the swap. You can fit the 1993 fronts under 16" rims but your losing out on 2 spots/caliper w/o the 95 setup. I am pretty sure they are the same stock brakes that the sc400 had back in 1992. Larger rotor but 2 piston caliper.
Sorry for so many questions.. I have to keep the 16" wheels. So if I got the 93 rotors, is variable just the caliper bracket? - For instance, could I run my stock 16" wheels, my stock 91' calipers, the 93 rotors, and the 93 caliper brackets? That would still be better than nothing..
 

spf_lexus

New Member
No prob man, this forum keeps me goin out here in smallsville CO hehe. As for the caliper bolt spacing, all versions of the LS400 brakes have the same fitment for all years (except ls430). I cannot verify that the 95+ LS calipers FOR SURE require 17's but an easy way to check would be to find if the 95 came with optional 16" rims. If so, then it must have been engineered to fit the same brakes. If it doesn't fit, you could also upgrade to the 1992+ sc400 front brakes and those will fit under 16" rims for sure. The calipers are 2 piston... but the rotors have a much larger diameter compared to the 1990-1992 ls400 so its def an upgrade.
 

Spinnetti

Member
No prob man, this forum keeps me goin out here in smallsville CO hehe. As for the caliper bolt spacing, all versions of the LS400 brakes have the same fitment for all years (except ls430). I cannot verify that the 95+ LS calipers FOR SURE require 17's but an easy way to check would be to find if the 95 came with optional 16" rims. If so, then it must have been engineered to fit the same brakes. If it doesn't fit, you could also upgrade to the 1992+ sc400 front brakes and those will fit under 16" rims for sure. The calipers are 2 piston... but the rotors have a much larger diameter compared to the 1990-1992 ls400 so its def an upgrade.

Hm so I look up online and see many different rotor diameters, and much to my surprise, different part numbers for the calipers from 91 to 93 also. I was hoping to run my existing 91 calipers with the 93 front rotors, but I just can't tell if that's possible. I was hoping I could just get different caliper brackets, but it looks like the calipers are different too. I guess I'll just have to run all stock stuff with real racing pads and see how it holds up... For reference, I put about 4 hours on a ceramic "street" pad on a race track test day, and only driving about 8/10ths, and still burned those to the backing plates...
 

spf_lexus

New Member
Interchanging rotors from one year and calipers from another year wont work. All the years will have different part #'s and also dimentions so you would need to swap an entire year over (I.E. rotors + calipers for the same year). the 1990 has VERY small rotors. For the weight of the vehicle (even stripepd out) they are under sized. They are better fit for a honda civic than a heavy luxo barge. Im confident you could grab some used sc400 fronts for $50 used at a strip yard.
 

spf_lexus

New Member
I also went through quite a few sets of pads/rotors in my 1990 LS before I upgraded mine. It seemed like all it took was one emergency stop to warp the rotors. I ended up trying drilled/slotted stock rotors + SS lines and Disc Italia Ti-Kevlar race pads and they held up pretty well but they would fade real quick when pushed for any long duration. To my surprise they never warped on me but for the cash I spent on OE 1990 upgrades.. you might as well start off with a more stout design like 1995's or sc400 brakes.

Let me ask Lex if he has some OEM SC400 fronts lying around, he has been trying to clean out his garage of used parts so he might be inclined to hook you up for a shipping charge. that way you dont have to spend any of your very limited funds for the 24 hours of lemons race. Whats the limit... $300 total or something?
 

Spinnetti

Member
I also went through quite a few sets of pads/rotors in my 1990 LS before I upgraded mine. It seemed like all it took was one emergency stop to warp the rotors. I ended up trying drilled/slotted stock rotors + SS lines and Disc Italia Ti-Kevlar race pads and they held up pretty well but they would fade real quick when pushed for any long duration. To my surprise they never warped on me but for the cash I spent on OE 1990 upgrades.. you might as well start off with a more stout design like 1995's or sc400 brakes.

Let me ask Lex if he has some OEM SC400 fronts lying around, he has been trying to clean out his garage of used parts so he might be inclined to hook you up for a shipping charge. that way you dont have to spend any of your very limited funds for the 24 hours of lemons race. Whats the limit... $300 total or something?
Cool. thanks.. yeah, its $500 TOTAL for the car and all mods not including safety stuff. Safety stuff included, its a $3500 "$500" car. I'd go for the 95 stuff, but I've already got a small fortune in new tires mounted on the stock 16" wheel, so its just not an option to go for bigger wheels (can't afford it right now anyway).

Its interesting that on the race track, the TRAC gets tired and stops working eventually... I guess with it being on all the time it probably thinks its malfunctioning.. works good for 10 laps or so though, then eventually resets..
 

spf_lexus

New Member
thats crazy about the trac system. I wonder if you could wire a 12 switch to the system to reset it on the fly? Also, another cheap mod you might want to consider is wheel spacers. You dont need billed hubs with exta studs... too expensive and not needed. A set of 10mm cast aluminum spacers run about $20 an axle set so $40 for all 4 wheels.

If you tear the splash guards out of the wheel wells, as well as the black fender trim... you can fit an extra 10mm-20mm of extra width. If you want to totally max out the fenders, take a dremel with some carbide cutting wheels and trim the 3/4" inner "lip" from each fender arch.

My 91 LS has 10" wide rear wheels with 265/35/19's and 28 offset and I have zero rubbing. Stock rims/tires would really benefit from the extra track width.
 

Spinnetti

Member
thats crazy about the trac system. I wonder if you could wire a 12 switch to the system to reset it on the fly? Also, another cheap mod you might want to consider is wheel spacers. You dont need billed hubs with exta studs... too expensive and not needed. A set of 10mm cast aluminum spacers run about $20 an axle set so $40 for all 4 wheels.

If you tear the splash guards out of the wheel wells, as well as the black fender trim... you can fit an extra 10mm-20mm of extra width. If you want to totally max out the fenders, take a dremel with some carbide cutting wheels and trim the 3/4" inner "lip" from each fender arch.

My 91 LS has 10" wide rear wheels with 265/35/19's and 28 offset and I have zero rubbing. Stock rims/tires would really benefit from the extra track width.
Where do you get spacers that cheap? so with 10mm I can still use the stock studs? If the car works well, and the team is up for it, I'll run much wider wheels in the future

I already removed the fender liners and rolled the fenders, plus I'm running shorter tires anyway, so it looks funny, but improves the gearing and has plenty of room.

Still can't get my front rotors off.. will try again tonight.
 

spf_lexus

New Member
yeah 10mm is about as big as you can get and still have solid acorn grab. I bought mine from a truck suspension shop. They had a wall with 5mm-25mm solid spacers for about $10-15/spacer. Pep boys has them but they cost a bit more. I ran these sized spacers for 2 years w/ stock studs/acorns and beat the hell out of my LS and never had any issues. You get an instant improvement in the corners
 

Spinnetti

Member
Fabbed up the cage last weekend... racing in April finally... still with stock brakes though. One disc was on so tight that we had to put a big puller on it tensioned as tight as I dared, then heated with a torch, and THEN sledge hammered off! - actually broke the rotor before it came off.
 

Attachments

Top