Supra TT Big Brake Upgrade for SC400

[jibby]

I have been to the LEXUS and TOYOTA dealers and went thru all the studs for all cars and could not match up any longer ones. That includes the IS300, 80 seies landcruisers, supra, etc...all of them are the same length...Kragen Auto Parts in the US was the only store that had the longer studs. All thanks to Stevechumo for the find:fing02: ...They have to be ordered....Oh, the BMW studs are like $40 a piece at the dealer...Yeah right....

 

[SCV8]

NAPA Auto Parts has a picture guide for wheel studs, I had to find longer studs for another car with a custom big brake setup.

 

[jibby]

SCV8- I didn't try Napa, but I did try Autozone and Pepboys and no Cigar..... Got the studs today from Kragen and they are perfect, just need to install and finish the brake bleed and I am done.. Will post pictures and final results shortly...

 

[jibbby]

Well fellas I am ruined!!!:17: The Supra brake swap was a complete success and failure at the same time. It looked, road and braked real nice. You can definetely notice the improved power in braking by maybe 1/3..."BUT" The only problem no matter what I tried is that I had too much front end wheel scraping going on at turns.. Also didn't like the feel of the front end ride with the extended wheel base.. I simply need different rims like the Supra rims if I want to make this brake upgrade work and feel right to my liking..

The Supra calipers, rotors, custom spacers are now on lay away and off the car and back on the shelf, which is a shame.. The stock lexus calipers and after market rotors have been put back on. Needless to say I am bumbed out on this project..I just couldn't make it work.. Low profile tires would have possibly eliminated the scraping some what but then the car would ride to low..Still didn't like the steering feel...

Moving on I am may consider reselling the rebuilt Supra big brakes and rotors, but am now wondering if the LS400 4 piston calipers are lower in profile and may work out better. I don't think I will have wasted too much money on this failed mission after resale, just a lot of time and effort... Any thoughts on LS calipers?

 

[stevechumo]

John,

Sorry to hear that. The only problem is your front tires rub the fenders. It's because your Eibach springs lowered your car too much. If you can raise the height by 1/2", you may get a better clearance. The Eibach that you have advertised that it lowers 1" but it's not true. It seems like 2" from what I see.

You run 245/35/18 tires with rubbing while I run 245/40/18 tires with no rubbing. With that '40 thickness, I should have less clearance than you do. I also have 1/4" spacers. When my SC was on its original height, the tire/fender clearance was about 2". And now I lowered it to about 1/2" gap, which is 1 1/2" cut. Anyway, as far as you always want to switch to Tein coilover, I think it is time. With Tein coilover, you may raise the whole car by about another 1/2". I'm positive that you'll have no more rubbing. While you're already this far, don't give up!!!:veryhappy

 

[Lextreme II]

John,

Do you think your problem could be cause by the spacer? the spacer pushing your tires too far out and cause the rub especially during a turn or a turn with a dip or bump? I think if you eliminate the spacer might help the problem.

 

[stevechumo]

John,

Do you think your problem could be cause by the spacer? the spacer pushing your tires too far out and cause the rub especially during a turn or a turn with a dip or bump? I think if you eliminate the spacer might help the problem.

John cannot eliminate the spacers because of his rims' offset. I don't know what offset it is, but more negative offset rims might help the problem. I keep forgetting if negative offset or positive offset will push the rims out.

 

[jibbby]

Well guys the first problem is the lowered suspension and yes the flex coilovers will definetely correct that problem of tire rubbing with the raised ride height.. However, I love the way the car looks lowered and with it raised it makes the rims and tires look to small, tried that already.. I also like the improved handling capabilities with it lowered and that is with or without the coilovers.....

Second problem is not the spacers,calipers or rotors but the added wheel base expansion. Moving the wheels out 5/8" inch to clear those calipers on each side gave me a funky steering and front end suspension feel.. I tried the same setup on my stock calipers and Lex rotors, same funky feel at the wheel with the 5/8 spacers.. The solution would be to alter or widen the front rims like I did my rears, and added width of the wider rims solves the funky feel as I tested out my rear rims on the front and the ride felt nice.. Need wider rims and tires on the front to fix that problem..

I am kinda screwed at all angles and why you ask? Well, I would need the widen and altered front rims and tires for around $600 then add $1000 for the coilovers which will raise my car and down grade the look and handling of the car...I do plan on getting the coilovers, but later on down the road when the deal presents itself. To purchase those coilovers now would run me $1000 easy.. That is $1600 total just to make this brake setup work to my liking in addition to the $600 I already spent on the Supra crap.. Just too much $$$$ for brakes...that is just more then I am willing to spend for some shiney red Calipers with slightly improved braking... Oh and Steve my friend, I am not a quiter by any means but I am not a foolish spender either...I know when my ship is sunk, and when to hold up the white flag.... Maybe that better explains my troubles....

I am trying for an alternative, like to find out about the 4 piston calipers on the newer LS models, if I can eliminate the spacer the steering feel will be normal again...rather then widening or changing out my rims..

Oh, those little problems of a swap.......

 

[Lambo]

Wheel offset

hi Jibbby, have alook at this site it may help, i suspect that when you pushed the wheel out with the spacers it has increased the scrub radius beyond the manufacturers design limits. http://www.rsracing.com/tech-wheel.html#backspace

and this descriptionefinition: The distance between the extended centerline of the steering axis and the centerline of the tire where the tread contacts the road. If the steering centerline is inboard of the tire centerline, the scrub radius is positive. If the steering centerline is outboard of the tire centerline, the scrub radius is negative. Rear-wheel drive cars and trucks generally have a positive scrub radius while FWD cars usually have zero or a negative scrub radius because they have a higher SAI angle. Using wheels with different offset than stock can alter the scrub radius.

General trend is to reduce scrub to near zero, but not zero. If it is dead on zero then the point of application of longitudinal loads will wander from one side of the kingpin to the other, generating an unstable feeling under braking, in particular

the above is not my ramblings but cut from pages by techo types who know what they are about have a look at this site and ask for an opinion very helpful guys. http://www.eng-tips.com/viewthread.cfm?qid=115669
hope this helps.

Regards
Lambo

 

[jibbby]

Lambo, yeah that is exactly what the problem is "scrub radius" offset, which I was a little concerned about from the begining and was aware of... Like I said wider rims and tires extended inwards toward the center or towards the engine will correct the problem. Unfortunately to the tune tune of $600-$700 and a three week wait period..

I must get on with the headers install and my other truck build for now, so the big brakes are on lay away for the time being. I do infact plan to alter or widen the front rims to accomidate the big brakes, but later on some time. I can live without the brake upgrade for now......Thanks everyone....

 

[jibbby]

Drilled and slotted rotors...

There was some early talk in this thread about the durability of drilled and slotted rotors and how they hold up over time... I am hear to report that after 3 years of hard braking and steady use my drilled and slotted rotors on my SC400 are still like new with no ill effects to report...No cracking, warping, etc.. Braking power is still much improved over stock... I am extremely happy with the D/S rotors..

I like to update these older threads just to set the record straight.....

 

[super_red_sc]

I just totally rebuilt the suspension, brakes, and new hubs and bearings all the way around on little Red. I used PBM Pro coil overs - very nice and highly tunable. I went with P2M for the suspension parts - nice product, and for brakes I rebuilt the stock calipers and used Powerstops Z23 option with carbon ceramic pads and drilled slotted rotors. The brakes are awesome - a world of difference over stock - they perform extremely well under all conditions. High speed, hard braking not an issue - no fade and cut stopping distances by over half under all conditions. Well worth the $500 or so that they cost. Not sure the whole Supra Swap is worth the pain, seems like a lot of issues to deal with. I've used Powerstop brakes on two Raptors and they had similar performance characteristics (drastically reduce stopping distance and no fade on hard braking in long harsh desert conditions) - they just totally blow away the stock crap Ford put on those trucks.

Next mod for Red is exhaust - that forum is lengthy with a lot of stuff to consider. Since I live in AZ I'm going to take a ride out to Tempe and talk to PPE Engineering. Seems as though they do a lot of Lexus stuff and performance exhaust is their specialty.