MikeySC

iTrader: (1)

Hi, so i bought the stoptech st40 BBK made for the IS300, the bracket obviously didn't fit.. My cousin got the ST40 made for the sc, we test fitted the caliper and it bolts onto his bracket to his kit, now the question is, if i buy the bracket to make this kit fit onto my car, will this kit function propertly? would i have trouble stopping? would it b safe being that the piston sizing on the IS300 kit compare to the one made the SC is differ? Thanks...

camberSC

iTrader: (17)

Yes it will work... The caliper is the same, ST40. Just like you said buy the bracket and you are good. Stoptech doesn't sell them directly but you can call them and they will direct you to a retailer.
GL

PS I miss my stoptechs!!!

5sp_jzz30

iTrader: (2)

just because it is an st40 caliper doesnt mean it is the same for every car. piston sizing will vary due to wheel size, rotor size, car weight, and master cylinder used.

i have called stoptech before and asked for pricing on rotors and such. my buddy was selling a set of stoptechs off a wrx. i called and said i needed the brackets and rotors to work with a supra. the guy told me not to do it. he said the brake bias will be off and they have a dozen or more piston size combinations that can work with that caliper for different cars.

they only real way to make a set of calipers made for another car work properly on ours is to match up the master cylinder size or go dual master setup. that would be really expensive for a regular person anyways and too much work.

basically sell those IS3 brakes and get the ones that will work as a bolt in upgrade. even if you get the brackets and they fit doesnt mean anything. you will be able to lock up the fronts driving 80mph and the back wouldnt do anything.

camberSC

iTrader: (17)

Makes sense, but then again you can say that about everyone running LS or Supra brakes. My stoptechs were originally for my old Camry, so I bought the brackets for my sc and never had a problem....

5sp_jzz30

iTrader: (2)

on a street car having only front brakes will suffice in 90% of the situations.

supra tt brake upgrade is only complete and 100% functional if you swap over a supra tt master cylinder. the NA and TT one look the same by the proportioning valve inside is different.

JohnEd

iTrader: (1)

Camber,

Your logic about the LS upgrade holds. As I said before: the limiting factor is the tire on the road. The ABS "should" prevent you from locking up any wheel or end. Isn't going to be enjoyable if you are engaging the ABS at every stop. Panic stops are ok and we see them rarely....I hope.

You bring up a good point though: does the LS upgrade induce premature ABS engagement? Excellent point! I'll tell ya in a few days. My test drive is postponed till Tues. Sure would like to hear other's take on this.

Are the rear LS calipers and rotors compatible with the SC or are they the same as ours? If they are the same we need to install the proportioning valve wherever that is housed.



Thank you,

John

RyanV

iTrader: (9)

John, the proportioning/bypass valve is built into the master cylinder. You might be able to pop the end off and remove it, but I don't think you can actually buy the valve by itself.

JohnEd

iTrader: (1)

Ryan,

The actual proportioning is done by a spring. You can preload the spring with washerlike slugs or shorten the spring or buy a softer one. The ABS is the fly in the ointment...no idea how to deal with that.

Thanks for your info.

John

5sp_jzz30

iTrader: (2)

disable your abs either way. its a waste. if you are going with bigger wheels your abs wont work properly anyways. the rolling diameter is most likely going to be bigger with bigger wheels even if you get a much smaller side wall tire. the car will read one speed but it will still be off a bit. if you are going 45 and it actually shows 40 and the abs goes off it wont react at the proper rate. i had my abs disabled for two years. driving without it for the 3rd winter too. its not that big of a deal. i think i can count on one hand how many times i locked up my brakes in almost 3 years of owning the car

ls400 rears are also single piston like our stock brakes. they dont bolt up. the pistons on the ls400 are either bigger to compensate for bigger fronts or most likely the proportioning valve in the master is set up different to make up for it.

JohnEd

iTrader: (1)

5,

Thank you for that info. Word I got was that the ABS doesn't see tire size but only relative tire speeds. You sound much more knowledgeable than most and I hope you will elaborate.

It isn't that you can't stop without ABS....its that you can stop with all 4 wheels in lock up, effectively, and continue in a straight line or even turn a little. One dark night in mid Idaho I locked at 90+ and she, SC400, stayed true and straight to 25. There was a HERD, I kid you not, of deer in the center of my lanes and they were spread out. Maybe 10 deer. I got her slowed down to maybe 70 when I flashed thru the middle of them and luckily I had a line and the car held it. I am way big fan of ABS. Yes, deer me, I am.

When these things first came out ( long before your time I assume) they were for formula 3 and Pro Stock and such. The formula guys said they could stop in a shorter distance without ABS but only by a few feet and not every time. The ABS science has improved hugely since then and the important thing is the sample rate. I don't think the pro's can beat it now but I didn't follow such things specifically. Maybe you know?

Thank you for your comments...sincerely,

John