Supra TT Big Brake Upgrade for SC400

[SC400TT]

Jibby:

My biggest concern about making the swap the way you are doing is the fact that not only have you greatly changed the dynamics of your suspension by changing wheels...(As we all do when we change wheel sizes and off-sets), but the addition of the spacer makes the effective rate of your off-sets is even more exxagerated...The further away you get from +50 mm off-sets on your Lexus, the more the scrub radius is effected. This will cause many issues with increased tramlining, and overall handling. Try to minimize the change in Off-sets as much as you can. LondonBill has commented on this in great detail, and he has much knowledge on this subject...

Ryan

 

[jibby]

Sc400T- Thanks for the heads up. The 5/16" spacers is the minumum offset that I can use to clear those calipers. 5/16" is not much, so I think I should be ok. These spacers I am having made are exactly fitted with a sleeve to squeeze into the rim hub itself, almost be coming part of the rim itself. This is not your normal spacer, hard to explain..... I don't see an issue with 5/16" spacers. This really is just an extension of the offset of the rim, that is how I can best put it into words.....In addition to that my suspension is not stock, springs, shocks, lower control arms have all been changed out so the dynamics are who knows where with this whole deal...We will soon find out, I will speed test, ABS test, etc...and give everyone the low down...

 

[stevechumo]

It's true that when changing wheels with different offset, lowered suspensions, or spacers will change the dynamics of the handling. However, if carefully done, they can greatly improve the handling of the car without any "negative effect". I'm using 1/4" spacers for front and 1/2" spacers for rear with 245/40/18 tires all around. All I can say is the car handles so great. No vibrations, tramlinings, or anything that a driver doesn't like. I guarantee it.

 

[jibby]

That is encourging news Steve, thanks....

 

[SC400TT]

It's true that when changing wheels with different offset, lowered suspensions, or spacers will change the dynamics of the handling. However, if carefully done, they can greatly improve the handling of the car without any "negative effect". I'm using 1/4" spacers for front and 1/2" spacers for rear with 245/40/18 tires all around. All I can say is the car handles so great. No vibrations, tramlinings, or anything that a driver doesn't like. I guarantee it.

Steve, that is great to hear...Please tell us more about how you have managed this...

Thanks,

Ryan

 

[xirforever]

Rear offset shouldnt really matter i dont think. The front is where you start to get "bad" feelings in the steering from improper offsets. You will always get more "positive" feel to handling the wider you go, the key is to go as wide on the inside as you do the outside so you reduce "bump steer". This is most probably what steve means by carefully choosing your offset. Your offset should be in direct relation to your width when considering which wheel to go with.

one thing to remember sc400tt, he had his wheels widened custom, so his spacer should equalize it a little.

 

[stevechumo]

Steve, that is great to hear...Please tell us more about how you have managed this...

Thanks,

Ryan

I'll try to take the pictures tomorrow if I have time. That way, my idea is more clearly presented.

 

[jibby]

Update on brake swap. As LEX mentioned there is play in the rotor to hub fit and extra holes are needed to reduce or illiminate vibration... Now I thought of two easy ways to fit these rotors tightly and securely to the hub with no play. I think either of these two options should be considered regardless of extra holes or not. (play is play).

1) I had the new spacer made to fit the rotor and eliminate any chance of play. The bigger sleeve fits into the rim and that tiny lip on the other side fits snug in the rotor. When mounted on all is snug and tight. Here are pics....

 

[jibby]

Now that the spacer sits on top of the rotor as shown above it fits in tight and does not move around...

2) My second choice as mentioned in an earlier post was to drill the new holes. I was not refering to the multiple balancing holes which Lex suggested. Even with those extra balancing holes there is still play as far as I am concerned. What I was trying to suggest is to have five smaller drilled holes in the rotor to tightly fit the wheel studs and reduce all play. Here are the pic's showing my other idea...Notice the smaller holes on the spacer and that is correct size hole which the rotors should have... I did the spacer plan instead of drilling the new holes. Why? Because I needed the new spacer anyway for caliper clearance...Here are more illustration pic's...

 

[jibby]

To finish the job I now need to purchase the longer lug nuts and the brakes will be on, I will report with final results....See ya...:nana:

 

[Lextreme II]

Good job Jibby... but.......

I am not trying to brust your excitement.... We need people like you... to drive Lextreme.com to the next level. However, there are few flaws with both method 1 and 2. Here are the reasons:

1. You will need the space for the wheel wall clearance. However, by using a spacer with smaller hole will not solve your problem. Basically you are sandwhiching the rotor to the knuckle. It will work for a while, but it will fail. It will fail as you brake hard and accelerate hard (NOS), the rotor will dance between the knuckle and the spacer. You might not noticed any virbration right now.. but you will.....


2. The drilling of the rotor will work, but you need to drill the rotor with recess. That means you bolt will be flush with the rotor. Unless u have access to a machine shop, none of the two methods will work WELL.

I admire you work and keep it up.... we need more people like you in here.

 

[jibby]

:smokin: Davey old pal, you da man but I have to disagree with you on the (spacer idea) however, you may be right on the second idea failing with the smaller drilled holes. The spacer was carefully measured against the hub and rim, when it is all combined it is a super tight fit which I already tested, infact it is almost like a pressure seal. No room for failure with the first idea as far as I can tell, unless the hub itself vibrates which I dought. The Second idea with the smaller drilled holes in the rotor may still cause some vibration only because there is not a firm fitment at the center hub area, a ring may be required in addition to the holes and that should work for sure. David, I thank you for the complement about being innovative and I do try to be creative at times and really make an effort to work thru problems, I guess that has to do with my construction back ground. Sometimes failure is not an option..

I will have you know every idea I come up with I carefully run by experienced people whom can advise me if the presented idea will work... In this case I ran the spacer idea by the old man whom owns the spacer shop for years, he knows more about fitment and vibration with brakes then most, I trust his opinion. I will be suprised if this fails.

I must say Wow, you sound so sure both ideas won't work properly, where do you base this from, experience? I am giving it a go, I will brake hard, I will brake fast, and I will report immediately if it fails.... Wanna make a side bet?:naughty:

 

[jibby]

Yet another update- First off everyone should take Lex's advise and get those little drilled rotor. I just like to sometimes do things the hard way. Anyhow the brakes are on and bled. I now have 1/16 of an inch rim to caliper clearance which is as close as it can get. I just drove it shortly did not slam the brakes yet as I want everything to work in...The feel is impressive.

The pic's show how the spacer is fitted. I had to use the lug nuts to help torque the spacer in and pull it all together with the rotor that is how tight the fit was measured. The rim fitting on the spacer is just about the same tight fit with the center hub lip. So when it was all bolted together the rotor, spacer, and rim it is in a sense all becomes one tight locking fit, there is no vibration to speak of, only smoothe tight braking. It feels like new brakes...Looks awesome.

The only concern I have at this point is that I was only able to catch 3 full turns with each lug nut on the studs of the front wheels. I may have to go with longer studs I haven't decided yet. I torqued down just about as hard as I could with the lug wrench and did not strip out the studs. What do you guys think? Three full threads grabbing on the stud enough?... Keep in mind I also have the spacer hub sleeve which helps with strength...here are the progress pic's.

 

[jibby]

That picture above shows me using the lug nuts to torque in the spacer to mesh tight with the rotor. Aluminum is a some what moldable material, like copper..When smashed into the rotor the little lip compresses at creates a tight fitting seal. This is simular to a compression washer used in plumping applications.. That is where I got the idea from. Next pic shows the minimul 1/16" caliper clearance, it's close as you can get and doesn't scrape.

 

[jibby]

These next pic's that shows the brake line hookup and bleeding of the caliper...and the last pic shows that the wheel doesn't stick out.. I would say the job is a complete success...Time will tell.. I will post a final side shot of the car and brakes tomarrow...

 

[stevechumo]

John,
Looking good. It's dangerous to have the lug nuts tightened with only 3 turns. There should be at least 7 turns as a rule of thumb. Kragen has 1/4" longer studs than stock SC stud. I forgot the part number so you should bring out one stud to them for comparison.

 

[jibby]

Thanks Steve, I hear what you are saying, and I bought those long lugs they did not work with my rims, but they did torque down hard without stripping and maybe thread catch is closer to 4 complete turns. Do you know the best way to remove those studs from the hub. Can they be hammered out or do they have to be grinded and drilled out? I will have to live dangerously for now...I think it will be ok, I just wont slam the brakes...:scared1:

 

[stevechumo]

That's true. Longer lug nuts won't help you unless you go for longer studs first. They can be hammered out with a 3 lbs or 4 lbs lead hammer/brass hammer. Or you can take out the hub and use a hydraulic press to press them out. Or I saw some shops used the electric hammer to hammer them out. That electric hammer vibrates like crazy. I guess you have that electric hammer, don't you? hah..hah..hah. Cutting & drilling take more work and might damage the hub if you strip your hands.

 

[Lextreme II]

Please drive it carefully...... you rims might not stay if you drive it hard... its a matter of time...... Just sell those damn rotors.... they hassel, money and time you spent on it.... cost more then the rotors i sell.... Secondly, it all out dangerous.....

 

[xirforever]

Do yourself a favor and buy one of these

http://www.sears.com/sr/javasr/prod...OOL&pid=00904458000&subcat=Socket+Accessories

I did a while back, and i love it, actually it works too well the the stud just refuses to come off and will break it, but thats with REALLY bad rust and whatnot.