345 Brake Discs/rotors

[lammy426]

i don't know if its been done before,but here goes i was looking through a brake disc book and found some merc ml55 345 discs/rotors i could alter to fit a skyline,all you have to do is take the centre bore out to 68mm from 67mm skimm 1mm of each side to take them from 32mm to 30mm and redrill the mounting holes to nissan pcd,then make brackets to space the calipers out,then grind some of the caliper away where the disc runs just enough to make the pads sit right and a space between the edge of the disc and the caliper for expansion,i bought the discs for £68 in the uk the cheapest 345mm discs for a skyline in the uk is £175,quite a saving if you no somebody with a lathe

[Roy]

It has been done before, it worked with good results on an R33 GTS25t track car. But to make it worthwile you really need to use an F40 or F50 Brembo 4 pot caliper as they take the 32mm rotor to start with. All the mods required to work with a std caliper makes it a bit silly (IMO), espcialy taking 2mm off its thickness.

[lammy426]

It has been done before, it worked with good results on an R33 GTS25t track car. But to make it worthwile you really need to use an F40 or F50 Brembo 4 pot caliper as they take the 32mm rotor to start with. All the mods required to work with a std caliper makes it a bit silly (IMO), espcialy taking 2mm off its thickness.

it saves weight ,and will cool faster and the wall thickness is still as much as the gtst ones,just thought it might be an option but if its already been done it doesn't really matter

,thanks anyway

[sonoramicommando]

it saves weight ,and will cool faster and the wall thickness is still as much as the gtst ones,just thought it might be an option but if its already been done it doesn't really matter

,thanks anyway

I dont think it works that way - loss of 2mm thickness equals loss of thermal mass, in turn the brake rotor will reach its upper serviceable temperature quicker for a given brake work. If my memory serves me right, R32 GTR rotor has 32mm thickness as new and unserviceable limit as 30mm. Also, I'm told that thinner rotor is subject to warpage.

Cheers,

Sam

[Beer Baron]

that's correct. 32 GTR rotors standard are 32mm thick and wear limit is 30mm. the problem is the inner area of a thicker rotor will be larger than a thinner one. so as you take 2mm off the outside you are now closer to the inner vanes.

[Sydneykid]

I'm using 32 mm rotors with standard (Sumitomo) callipers, no problems. You just need to make sure the pistons are all the way home when installing new pads.

Cheers

Gary

[Roy]

Really? Did you modify the caliper? When i slung the GTSt caliper over some Performance Friction 340 x 32mm rotors it wasnt the divide for the piston that was the issue, it was the outer opening of the caliper where the rotor enters and leaves the caliper that had a clearance issue with the 32mm rotor.

[lammy426]

I dont think it works that way - loss of 2mm thickness equals loss of thermal mass, in turn the brake rotor will reach its upper serviceable temperature quicker for a given brake work. If my memory serves me right, R32 GTR rotor has 32mm thickness as new and unserviceable limit as 30mm. Also, I'm told that thinner rotor is subject to warpage.

Cheers,

Sam

it will reach temp quicker,but it also cools quicker,and mine are gtst calipers standard 30mm rotor but i didn't try to fit 32mm rotors in

they may warp easier but discs only warp in extreme circumstances,and the serviceable limit is set by the calipers so the pistons don't pop out if the pads go to the metal

[lammy426]

that's correct. 32 GTR rotors standard are 32mm thick and wear limit is 30mm. the problem is the inner area of a thicker rotor will be larger than a thinner one. so as you take 2mm off the outside you are now closer to the inner vanes.

i have gtst calipers not gtr,and i took 1mm of each side not 2mm off one side

[sonoramicommando]

it will reach temp quicker,but it also cools quicker,and mine are gtst calipers standard 30mm rotor but i didn't try to fit 32mm rotors in

they may warp easier but discs only warp in extreme circumstances,and the serviceable limit is set by the calipers so the pistons don't pop out if the pads go to the metal

I disagree that the minimum disc thickness is set by piston travel - I'm sure you've popped them pistons out for overhaul and they have heaps of travel before they will fall out.

I suppose your argument is valid enough for mild brake application but if you go the length of fitting larger discs, calipers adaptors and machining the disc to fit the calipers size, you might as well do it right.

Cheers,

Sam

[NZM.031]

what if you took 1 mm off each of the pads?? disc would remain untouched and all of its properties.. pads wear, i cant see a problem with it.. if it scrubs on the caliper, machine the caliper slightly... no doubt that is what nissan did to gtst calipers to fit the gtr.

[lammy426]

what if you took 1 mm off each of the pads?? disc would remain untouched and all of its properties.. pads wear, i cant see a problem with it.. if it scrubs on the caliper, machine the caliper slightly... no doubt that is what nissan did to gtst calipers to fit the gtr.

i think i'll do this next time