Best OE Size Rotor's for the Track and Other Questions

[frankiman]

this thread IS about lapping

read again

[Daryl @ RightDrive]

it won't be much of an upgrade, the BCNR33 pistons are bigger, but for street use they won't make much difference.

[frankiman]

the brembo calipers are still 4 piston calipers, BUT the pistons are staggered, meaning the first pistons are slightlly bigger then the other, producing a better force distribution than standard identical quad pistons

overall, the brembos have more contact surface with the pads (piston size) than the BNR32 sumitomo, and the pad itslef is bigger than the ones used by bnr32 calipers,

also, even if the calipers is bigger, it is the same weight, or even lighter,
another nice thing about it is, is has bleeders on the front and the back of the caliper, meaning you can bleed your brake system with the car sitting on all its 4 wheels

also the fact that the caliper is bigger means it has more contact surface with the surrounding air, so it can dissipate its heat more effectively

and by using the brembo calipers, or AMS's conversion kit, you can use the 324mm rotors;
the standard bnr32 rotors are 296mm, having rotors 10% bigger means that for the same braking force, the calipers have to produce 10% less pressure, creating 10% less friction / heat

and bigger rotors again have more contact surface with the surrounding air, cooling more effectively

i have made a big post about this way back
http://forums.gtrcanada.com/gt-r-pro...tml#post346906

basically, its the reason high end cars (mercs, porsche, ferrari, audi, etc.. etc..) use enormous brake calipers is that they can use street compound pads with its low dust and still have a very good braking force with very good cooling

[Terrh]

Those R33 brakes look great but for 2 grand I'm sure there's NEW aftermarket options available.

Evo brembos/STi brembos are probably a similar caliper (or better), way newer, and are $300-$500 a set.

I have no idea what you'd have to do for brackets or rotors but it can't be that hard, and the rotors that both of them use are the right bolt pattern.

[xcye]

I have a set of EVO brakes on my 240sx track car. They worked perfectly on race track with HP+ pads and Power slot rotors. They never faded. I agree, comparing with the R33,R34 Brembos, the EVO calipers should be stronger as they are a lot larger than R33,R34 brembos. The size of EVO rotors are 320mm x 32mm, while the R33,R34 are 324mm x 30mm. I think both calipers use the same size of pads. The relocation brackets can be easily made at about $150 a set.

Those R33 brakes look great but for 2 grand I'm sure there's NEW aftermarket options available.

Evo brembos/STi brembos are probably a similar caliper (or better), way newer, and are $300-$500 a set.

I have no idea what you'd have to do for brackets or rotors but it can't be that hard, and the rotors that both of them use are the right bolt pattern.

[frankiman]

if you search correctly, (i can't remember where) i once found a thread on another forum (might be SAU) of someone demonstrating the modifications of the application of EVO and STI Brembos to the front knuckles of R32s/S13s/Z32s

the exact spec of rotor to use was also mentionned,

all the modifications required were shown, and it was proved to be the EVO's calipers to be the best because of the bleeding system (i think) but mostly because the STI calipers needed to be grinded down to fit proper bracket

FYI, when retrofitting calipers, if you need to design and fabricate a new bracket, verify what rotor options are most easliy accessible (i.e. 350z / 370z) then have the bracket made to fit that dimension of rotor

[frankiman]

i'm currently working on a fully custom (cheap) brake ducting and deflecting system,
i should have news within a week, picking up the racing parts on saturday and the trip to canadian tire is done
should be pretty sweet

[Daryl @ RightDrive]

I wonder if you could use these in the bumper and route ducting through the fender liner somehow, they come in 50mm, 75mm and 100mm sizes:

[frankiman]

actually, i though about it, but its just way too expensive for what it is

i've ordered a set of these, made of urethane, 50$ a pair, locally

[Marke]

What size is the diameter of the exit on the funnel, Frank? Will it fit in the tunnels on the lip? What kind of ideas do you have for plumbing into the back of the wheel? I had thought about fabbing up a piece that uses the caliper mounts and directs the air on a angle into the center of the rotor. I think I will try fitting some 2" or 2.5" ducting in around the suspension.

[frankiman]

that funnel has a 5"x3" intake and 3" exit
i bought 3" aluminum dryer machine flex tubing,
and i'm having a 3" OD tube cut at 45° then welded to a thin sheatmetal plate which will be bolted to the back of the back-plate, the back plate will be cut approprietly

i though about making a small metal funnel thats mounts in between the 2 calipers bolts to direct air directly to the center of the brake disc, but to fit in that space and with the mouvement of the wheel considering its a 4wd car with front axles, i would have to be 1,5" or 2", and flex tubing of that size is harder to find than fresh T-rex dung

for my setup, i'm waiting to have the funnels in hand to choose where to mount them,
my choice #1 is directly behing the openings of the lip, where the oem ducts are, but then the huge 3" flex tube would have to be snaked through the suspension arms and axles, or go completly under the LCA, (and the fact that my front bumper/lip is on a shelf right now also doesn't help)
option #2, is to mount the funnel to the LCA (behind and underneath) via small brackets, which is the easiest option since theres a big open space there and the flex tubing wouldn't touch anything

and since i scraped the idea of the small metal funnel to the center of the earth, well, i'll be making deflectors that mounts to the tension rods, made of vey thin sheet metal, that will deflect air to the same spot

its going to be crazy !! mouahahah

and by having all this cooling apparatus, it will let me continu to run my "street/track" HP+ compound brake pads, without beeing scared of overheating them like last year, and since the brakes will be consistently cooler, less dust will be created, and the pads will last longer

its a win win situation, that doesn't cost a whole lot, as long as you are willing to design, fabricate and custom fit whatever is required

[Skym]

Look at this neat front ducting idea for the YMS HCR32 that runs 1 minute laptimes at Tsukuba -

[frankiman]

thats exactly what i was going to do

[Marke]

I would like to see more pictures of that setup from different angles.

[Skym]

It's one of those cars that's hard to find photo's of. Was lucky enough to find the above photo.