Brake Caliper Choice

[LAGWAGON]

I'm after some help from the lads in the know on brake caliper and master cylinder choice as well as rotor selection. I've been racing my sr20det datsun 1600 in the SAU vic track days and am now doing a bit of brake research. I have, and have had for a while a full set of r33 disks and calipers that are all but on the car but my interest has been sparked by the aftermarket two piece rotors and calipers. i was going to be running just standard r33gtst disks and calipers all round with DS2500 pads and motul rbf600.

after scouring the net there are many calipers 2nd hand and new available at varying costs, the car is registered and don't want to turn it into a track only beast.

what sort of piston size / master cylinder size means what.

why are wilwood calipers so cheap?

how crucial is brake rotor material?

bearing in mind the car weighs a shade under 1000kg's and makes about 180rwkw at the moment, is there any great advantage in upgrading from the r33 gear to, say some wilwood superlite calipers? they can be had for around $150 US!

[Duncan]

sounds like a fun car to drive

what tyres do you run, and are you having brake problems now?

the 33 gtst is pretty damn good and I would have thought it would be good enough for a 1000kg car. certainly the old cast volvo calipers that so many cars used to run are no bigger than the nissan setup.

all of these fat skylines with eleventy billion kw need huge brakes compared to 99% of cars out there

[LAGWAGON]

yeah its a ball, a bit of a handful at times! i have only got moderate sized disks and calipers on at the moment and so haven't tried the 33's. I don't have any brake problems as such, just want more braking power and want to keep the unsprung weight down so am trying to stick with 15 inch wheels. i am currently running dunlop formula r's on the front and advan a048's on the rear, both 205/50/15. i am probably going to go down the track of two piece rotors so i can get some brake clearance with a deep brake hat, and the wilwood calipers seemed too good to resist.

good to know that the r33 calipers are good to use though. nobody seems to run wilwood, i'm trying to find out why?

[guesty]

Wilwood seem to be more bias towards motorbike calipers. prom the comparisons i have made between them when looking for my calipers i found that the piston size was less that the standard R33 calipers and were almost too light. i personally woud stick to the stock 33 calipers. i even found that there was no real advantage on running the 33 GTR Brembos instead of mine. they are the same sized piston in the rear and the fronts are only slightly bigger, both front and rear brembo's allow a thicker rotor to be used. don't forget that you will also want to work out how much pads are going to cost and also rotors. these are usually not cheap. i found that that every 4 sets of pads i would need a new set of rotors. and at $300 a pair of pads and $1500 for a set of Harrop rotors it's not a cheap excersize. just my 2 cents. im sure ppl will probably have other opinions, but that's mine!!

[Stupid Toyota]

Wilwood seem to be more bias towards motorbike calipers. prom the comparisons i have made between them when looking for my calipers i found that the piston size was less that the standard R33 calipers and were almost too light. i personally woud stick to the stock 33 calipers. i even found that there was no real advantage on running the 33 GTR Brembos instead of mine. they are the same sized piston in the rear and the fronts are only slightly bigger, both front and rear brembo's allow a thicker rotor to be used. don't forget that you will also want to work out how much pads are going to cost and also rotors. these are usually not cheap. i found that that every 4 sets of pads i would need a new set of rotors. and at $300 a pair of pads and $1500 for a set of Harrop rotors it's not a cheap excersize. just my 2 cents. im sure ppl will probably have other opinions, but that's mine!!

Actually I think you'll find Wilwood are more dirt track oriented. Quality is moderate and naturally they sell bucketloads of calipers in the USA to the speedway guys so they can keep a cheap price. There will be no benefit at all from changing horses mid-stream with the R33 calipers you've already just about got fitted up. You can buy decent pads for those calipers plus matched rears and the original R33 mastercylinder should get you close to the mark bias wise. My vote is stay with the 33 stuff.

The only addition you may wish to consider is the 2 piece rotor but for a car thats already light, it may not be an absolute neccessity for the cost involved in doing it.

The DBA 2 piece rotors would only be a small upgrade anyway. They are lighter, but not as much as a good quality alcon rotor or similar. Of course cost can be out of the park with alcons.

As an example, a stock R34 GTt 310mm x 30mm rotor weighed in the order of 9.3kg for one only. A used Alcon rotor in 2 piece 332mm diameter and 31mm thick (originally 32mm) weighed 7.1kg each.

According to the experts, a kilo of rotational mass saved, is equivalent to 10kg static

So by saving 2.2kg per front rotor it'd be similar to removing 44kg of mass from the vehicle body weight.

As a side note, I know of a guy up here in Qld who fitted wilwood calipers to his turbo mx5 and had trouble bleeding them up. Turned out they were leaking fluid from around the piston seals, and they were new calipers...

[guesty]

The 2 piece rotors are a great set up for reducing weight, and cooling. but try to steer away from the DBA ones. they are a great rotor, BUT the internal "Kangaroo Paw' vent design confuses the air travel and doesn't allow the air to vent properly

[FranZ]

Ive heard time and time again that there is alot of caliper flex in Wilwood calipers.

[Roy]

Which model Wilwood? They make calipers that are $350 each and then they make calipers that are $4,500 each. You cant right of the expensive top of the range calipers becuase the ones they market for Lotus 7 replicas are pretty basic

[LAGWAGON]

i was looking at the 'forged billet superlite' calipers but i think it sounds now like the r33 sumitomo's should work well for me. I'm now all but sold on the two piece rotor and hat system as it will help me squeeze fifteen inch rims over the big brakes making my race tyres cheaper and easier to get second hand.

With the r33 master Cylinder, i already have a bias valve plumbed into the brake line - if i changed my current master cylinder to the stock 33 one, should i take it out?

last question - wilwood rotors of the two piece variety are about $140 US each for the ones i'm after and they sound like a good thing. any reason people know of why i chouldn't give them a go? they are 32mm wide tho, wil they fit in the r33 front caliper?

[Roy]

If you want to run 15" wheels i would be looking at R32 calipers as they are meant for 280mm rotors, where the R33 calipers are meant for 296mm rotors. The pistons in the calipers are the same size so no difference on that front..Again, i would not personally waste my momney on two piece rotors when you are running such a small diameter rotor.

The weight difference will not be great enough to justify the big dollar difference

[LAGWAGON]

I have discovered that running a three piece simmons wheel i can easily squeeze the r33 calipers and disks in diameter wise, but the caliper sticks out past the face of the disk, needing 25mm spacers on the front to fit. i could all but eliminate this with the right offset hat and disk combo. As well as the fact that the rear disks have the extra weight in them due the the drum brake handbrake which i will not be using. It also sounds like people are cracking even dba 4000 rotors, which are not cheap so i think the cost of the two piece rotors will work out cheaper for me than buying good rotors (proably the dba 4000's) and proper bolt on spacers all round. i haven't got final prices but it looks that way. also space is at a premium at the rear so deleting the 30mm spacer i would need would save me a lot of grief!

is it important to match brake pads front and rear. i want to run ds2500 pads in the front and was not going to do so in the rear but i'm not sure.