SC4Paulo

iTrader: (2)

supras because of a bigger rotor and caliper,

and your wheels will clear LS's and Supras perfectly fine

Kris9884

iTrader: (7)

I just put the LS4 calipers and rotors on my car but must not have bleed it enough. The pedal is a bit more squishy than it was before and there is probably no performance gain from what I can feel. Do I have to bleed the rear brakes too even though I didn't touch them?

SC4ME

thanks, im gunna do it!

INTIMAZY

iTrader: (5)

The only proper bleed is to start from the rears anyway. Do all 4 or you'll just end up bleeding the rears anyway.

Oh and in general, no car needs slotted or drilled rotors. They just crack under track use anyway so blanks are the way to go regardless of use. They definitely don't stop any quicker.

emoFTW

iTrader: (1)

Great thread! Very informative.

Murco

iTrader: (1)

I answered your post, it's directly under it!

Murco

iTrader: (1)

X2 - On street cars, and even most race cars, purely for visual effect...

SC4ME

i disagree, high quality rotors are either slotted or drilled, they produce less heat and let the brakes breathe, blanks put more pressure on the brakes causing you to replace them more often. rotors have nothing to do with stopping power, thats where your calipers come in.

bigwhite

My bad Murco, thanks for the response, the prop. valve was one of my ques. to a guy on here that has done this. He said the prop. valve was incorporated into the m. cyl.

Candela

iTrader: (1)

Quality brand rotors with the holes in them didn't get those holes from drilling, they were molded that way, so it retains all structural rigidity, same for slots. Cheap ebay rotors probably had the holes drilled and slots actually cut into them, this is probably why they then go ahead and coat them with the zinc plating to cover up all the nastiness they've done.

If you really think they're putting rotors with slots and holes in them on F1 cars and Le Mans cars purely for "looks", you should really do some reading that is outside of your automobile comfort zone.

Stopping power does not come from having holes or slots in the rotors. Those holes and slots dissipitate heat and gasses to reduce brake fade, when you reduce brake fade your brakes will work the way you want them to.

So in a sense those holes or slots prevent your braking system from losing its stopping power.

Murco

iTrader: (1)

I know, and most know, that they are not actually drilled. It is a descriptive term that has been used loosely to identify them since they were introduced...

And perhaps you could work on your reading comprehension zone...
"Brake Rotors - Again, unless you are spending a lot of time on a racetrack you do not need to go crazy with drilled, slotted, and zinc-washed rotors."


Thanks for the input but I think you have the purposes of those features mixed up. The "drilled" rotor face is designed to allow gases to escape under heavy braking on race cars. A heavy car on a road course will commonly hit 1200 degree or higher rotor temp and at that level the pads can release gases caused by chemical reactions under heat and pressure. Those gases can create enough pressure to keep the pads off the rotor and the holes allow the gas to vent out from the surfaces. The holes have little to do with cooling and everything to do with the high temperature degassing. Street cars just don't have that issue. You are seeing fewer and fewer of these rotors on race cars these days as pad compounds have mostly eliminated the gassing issues that used to plague heavier cars in the past.
Slots, or whiskers, are used to break up the hardened layer of carbon a pad face develops during hard, hot stops. That hardened face loses some friction coefficient and the slots will allow that layer to be swept away under the next hard pedal application maintaining the effectiveness of the brakes during a race.
For a street driven vehicle both are overkill and more cosmetic. I doubt you'd ever get your brakes higher than 1000 degrees for more than a second or two in daily driving, even in a panic stop, so these features would do nothing at all at the lower temperatures. If you ran on a road course regularly that would be a different story as the weight of our cars would get the pads and rotors up to around 1200 in a high speed braking zone at the end of a straight and keep it up there if you reapplied the brakes in quick succession.
That Brembo GTR brake system pic on the first page is going on a Pro-Touring car that develops over 1000hp that will see lots of track use including Maxton Mile runs and other events. It is Brembo's most extreme "street car" package and definitely leans way deep into race-car territory. Personally I make a very clear distinction between a true street car (daily driver, cruiser, show car) that may occasionally see a track 2% of the time it's driven and a race car that is occasionally driven on the street, like the Pro-touring car will be. Most complaints you hear about parts stem from someone putting a true race-oriented part on their car and not understanding why it makes their car perform worse or becomes more of an irritant in daily commutes. Huge cams, loud exhausts, and aluminum suspension bushings are all commonly installed on street cars much to the owners later dismay...

Candela

iTrader: (1)

I would suggest that the "drilled" holes would be overkill for a street car, since our cars are already ventilated anyway. The slots do look nice, but are actually very effective, granted not at our daily commuting speeds but at least we would have that extra help when one of us does a track day of some sort drifting drag circuit, or even when one of us feels the need to brake some road laws. Would you say that slots would make the spread of brake dust worse?

What say you about all these LS/Supra monoblock caliper conversions to our cars? Most end up with the spongey feeling, and they end up feeling worse than OE brakes. I've always wondered why more don't go with brand new rotors, a more aggressive pad, fresh high temp fluid, braided brake lines and a brake master cylinder stopper of some sort to make the brakes feel better.

INTIMAZY

iTrader: (5)

Be my guest. Take a drilled rotor to the track. I know the outcome. Been there, cracked that.

Even blanks develop small fine cracks. Unless you have a proper BBK setup with ducts and a legit racepad, drilled rotors are worthless besides "looking cool"

It's pretty common knowledge among the grassroot racing circles. Take a quick search on the topic.

On an unrelated note, ran an HPDE last weekend in the cold to check out new tires on my Z and bastard built Cobra. The new BFGoodrich R1S's are AMAZING. 99% of an R6 with a much more predictable breakaway. Next season will be interesting!

Murco

iTrader: (1)

Yes, much worse. The pads will also wear faster.

The Supra Turbo Master cylinder is a 1" bore, the SC400's is 11/16". That would cause a volume/pressure problem right there. Matching the bore/stroke/volume of the master cylinder with the calipers is crucial to a great, linear pedal feel. If I were to upgrade to Supra TT calipers I would definitely use a Supra TT master cylinder (that should bolt right up), make sure the pedal stroke ratio was correct and make the push-rod adjustable to reach the piston (it's .010" deeper).
My Camaro autocross car used 2004 ZO6 Calipers on the front with 14" rotors, 2000 Z28 Calipers and rotors in back with the same 2000 Z28 master cylinder and a prop valve (OEM part - class required) from a 1990 1LE Camaro. It was about the strongest, most linear OEM-sourced brake system I've ever driven and would pull fade-free 60-0 stops in 110 feet all day. No slots, no holes...
Your idea sounds good but what is a master cylinder "stopper"?

Murco

iTrader: (1)

Sweet! I run Goodguys Autocross events these days, have you run a course with the new BFG Rivals? DOT legal, great grip, and last a whole season! Just don't try to run a wet track! lol
PS - I've got a Tirerack hook-up!