I'd really like to get a Disc brake kit for my xB for the Rear end.

Anything out there like this yet?

__________________

 

I think its highonscion.com sells s conversion kit, but your gonna pay a hefty price for it. So pretty much its up to you if you got the cash to drop for the kit.

 

Yup, http://highonscion.com/chassisProducts.htm has um. They go for $988.

One thing that I always wondered about these rear conversions has do do with breaking distribution between the front and the rear. If you keep the same distribution wouldn't more breaking power be going to the rear on relative basis. Couldn't that screw up the distribution that was engineered into the car? So I would think that to really do it right you would need to adjust the proportioning valve to accommodate for the extra breaking power in the rear. Perhaps turn down the total breaking force and/or direct more to the front so that the stock bias is maintained. I don't know is this is possible with the stock valve or if you would need an aftermarket proportioning valve to do this. Wilwood makes a proportioning valve that I think would do the trick for like $40.

Here is description of the rear brake conversion from the highonscion site:

* OVERDOSE Scion Performance Rear Disc Brake Conversion Kit for 2004-2005 Scion Xa and Xb

* Now get Superior Braking Performance and Increased Brake Torque, Greater Heat Control, Faster and Shorter Stops with Longer Brake Life.

* This complete, High Quality bolt-on kit contains: Single Piston zinc plated Calipers with built-in Parking Brake Feature, (which hooks up to existing cable), Hi-Torque Carbon Disc Pads, Huge 285 mm “Swirl-Slotted” Gas Slotted Rotors, S/S Kevlar Hose extensions, all required Brackets and Hardware plus Step by Step Instructions.

* Utilizes OEM style Pads, which are readily available.

* Can be easily installed by anyone that's handy with normal tools.

* Typical installation time is approximately 2hrs.

* Fits stock wheels or larger.

* Cross Drilled and Gas Slotted Rotors Also Available.[/b]

 

leave the dam brake system alone some engineer spent
countless hours to make it as perfect as toyota wanted it
yes rear discs would be cool and i think the stock valve can hang but at 900 bucks they could keep it there is a spot in the tech section of someone who did it with junkyard parts and some mild fabbing but no e brake

 

I wonder if the MR-S rear disc brakes would be feasible... Things that make you go "hmmm..."

 

Well that's about twice what I was lookin' to pay, but still, it looks like a really good
product!

Thanks for the lead!

~Eric~

 

This is going to be your problem area fabbing your own. 4 wheel discs would look nice but obviously is overkill on the box and expensive to boot... I guess if I ran out of other mods, but didn't feel I was finished...

 

In Japan they sell the TRD Sports M Toyota ist. It comes with rear disk brakes standard. As the rear end of the xB and xA are near identical, it should solve your problem.

 

Actually when switching from drum to disk you need to direct more brake force to the rear tires. Drums are alot more efficient as far as force is concerned.

In the caprice/impala world they deal with both. The early caprices had drums in the back, when chevy redesigned in 94 for the LT1 engine and the impala ss they went to 4 wheel disk. Chevy, to save money, did not re-engineer the brake proportioning valve and as such rear pads would last almost 4x as long as the front since they were barely being used. Someone figured out if you took out the valve portion from the front of the brake distribution block and made some minor modifications it would work much better. Not sure if that helps much but if you want more info head to www.impalassforum.com and search for "stealth bolt" and you will find all the info you need. I would love rear disks on the xB but I would much rather spend my $1K on something more productive.

 

Maybe one of the many scion techs on the board can reply. How about the feasability of changing out the rotors, calipers drums and proportioning valve from a TC that way you can get 5 lug wheels 18" tires etc. Soon TC's will start showing up in the salvage yard. Ok now the brain is working overtime lets not stop there lets swap the entire engine cradle and put the motor trans from the TC in there Then we'll have a real reason to have 4 wheel disc setup Anybody know where there's a salvage TC

 

If you're going to all that trouble, why would you choose the tC motor???

 

Well considering that front brakes are about 80% of braking force , the front pads will last ALOT longer than rear ones , that is what's called normal. Removing the proportioning valve will make the car act very different. very prone to drifting through the brakes.

 

it is not a full removal, sorry I was in a rush on my lunch break at work, now I am in a rush before going to bed !

It is not a removal of the proportiioning valve, but replacing a vented bolt in the combination valve with a solid piece to provide more break force to the rear brakes. With drum brakes on the impala the proportioning is more like 95%/5% so getting it to 80/20 requires modifing the combi valve.


http://www.goissca.com/~gofasst/brak...ioning_mod.htm



Again, I have no idea how this pertains to the scion, this is only from my knowledge of my former car, which I had modified or upgraded all of the various systems of the car (engine, tranny, brakes, suspension etc)

 

Gotcha , makes alot more sense now.

 

I hate to admit it, but the main reason I want rear disc, is
because to me drums just scream cheap! It pains me to
see guys use caliper paint on drums, it's like screaming
"hey look at how cheap this car is!".

But that's just me...I'm spoiled by true sports cars...Hell,
even my '74 Porsche had fuel injection and disc at all
four corners...and that was a $5000 car back in '74!!

I guess I just like budget boxes...I just don't want it to LOOK budget! LOL

 

I had the rear disc kit from http://www.highonscion.com installed about 6k mikes ago. The installation was easy and took less than two hours and all required parts were supplied. The emergency brake operation is flawless. I understand that this is an upgrade kit from the JDM "Yaris"(??). No propotioning valve change was required. The car stops so fast it's scary; you actually have to be careful not to get rear ended. And the calipers take Toyota pads.

 

Cool Mark! Thanks for the info, *that's* what I wanted to hear!

So, now that you've admitted to doing what others are saying
is a pointless mod, *why* did you do it?

I love good brakes, and while the stock setup is good,
I'd like it to be better...espeically if I'm adding 10lbs to
each wheel when I go to 17" rims!!

 

rear disc conversion (done right) is big points at car shows. I've already talked to my guys and we hope to be able to get it done over winter '05.

 

I'm not sure I have the budget to do shows, but if it's
possible to do shows, I will!

 

yeah... I'm going to start out pretty small, local shows, small town parades and such. That way, I can see what the judges are looking at, maybe get a few trophies... at least get some ideas of what I need to work on.

Most of the small town shows around here cost like $10 to enter. I throw that away on lunch once a week.