R32 GTR front brake disc size upgrade!!

[saga]

does all skylines (R32/ R33/ R34) use same dimension wheel hubs?

[Oosh]

does all skylines (R32/ R33/ R34) use same dimension wheel hubs?

Hubs and stud patterns are the same, GTR's run different offsets.

[Roy]

Sorry if it's been covered here already, but I didn't quite understand the following:

Will this system (i.e adaptors and larger discs) still fit within the 16" wheel?  

Specifically thinking of factory R32 GTR wheels.

Will need 17" wheels if you are going to run the 324mm rotor with Nissan or Brembo Calipers.

generally which calipers performs better: R32GTR's(sumimotos not brembo) or R34 GTT's? assuming all other components are the same: rotors, braided lines, etc.

They all use the same piston diameter, the R32 GTST have extra ribbing which you would think is for rigidity, however the fact that new calipers were used on the GTR and R33 GTS25T would suggest they were a beter option, though it could always been a question of economics, but i doubt it.

So id say they would all do the same basic job, main difference being the rotor size you can run with them, and the bugger all difference there may be in caliper rigidity. With regards to rigidity, the newer the better as less likely to have fatigues, so go the R34, then R33, then R32 GTR...my 2c

And with regards to upgradign your brakes, forgetting whether your wheel shas the correct offset to clear the caliper (should have) then as long as you buy the caliepr with rotors off a car then it will be a bolt on option. Brake lines may need to be tweaked, as i have never seen the fitting used on the NA caliper.

So with R34GTT, 4 pot with 310mm rotor, R33 GTS25T 4 pot with 296mm rotor, same as R32 GTR, 296mm rotor with 4 pots. Only the R32 GTR used a 32mm thk rotor (others are 30) which is a good thing, but most aftermarket / replacement rotors appear to be 30mm so difference comes out in the wash:(

[williamsf1]

roy do you have any thoughts on the porsche GT3 brake setup for the R32 GTR? I am almost in possesion of my R34 GTR wheels, and will be running the RE55 tyres.....

car currently has stock sized DBA slotted (3000 I think???) and unknown pads....

I am thinking that with the newly aquired power (about 500BHP) I am going to need better brakes for some track action!

do you know a $$$$$ value on a full kit for the GTR with said above?

or anyone else?

[Ronin 09]

You mean these?

Unique AutoSports have a kit for $3,395

www.uniqueautosports.com

I believe that mr Roy is investigating them at this point...

[williamsf1]

yeah those are the ones....

has anyone done this? and how much cheaper than an AP kit are we talking?

hope Roy can post his thoughts here....

[Roy]

Basically, the std GT3 caliper has different sized pistons front to rear, so this makes them directional on the rotor. The smaller pistons are leading, the larger pistons are trailing, this helps ensure equal pad pressure against the rotor over the face of the pad, helping equalise brake temps, performance and wear.

Now thing is the std GT3 caliper when installed on a Skyline will orientate the pistons the wrong way around, so that the the larger pisotns will be leading, what this would do to pad wear i dont knwo, but cant be good.

So to remedy this you will need to swap the bleed lines with the external fluid line that joins the front and back of the caliper, effectively turning the caliper upside down. This will orientate the pisotns correctly. How that impacts the mounting of the caliper i dont know, which is what i need to find out, talk to brake places and the Porsche 6 pots are bastards to mount in the first place. So much that the cheapre caliper may ned up costinmg more installed then the CP555 6 pot APs.

If anyone can tell me what rotor thickness the GT3 Porsche runs???? I know they are a 350mm rotor, but cant find the thickness...so should work ok with a 343mm rotor to fit inside a 17" rim. But i want to be sure that the rotors are 32mm thk, and another thing is check out the pad availability and cost. From my shopping around GT3 pads aint cheap:(

Which keeps bringing me back to the CSC brake upgrades, but they doint have the :whackit: factor for me, and having had a look at their 4 pots, im still trying to work out which voice in my head i should listen to:)

[Ronin 09]

Mate if you're in Syd for a few weeks pop in to UAS? There is a 2nd hand pair of GT3 callipers on their website for $1095 or something... with new seals

[williamsf1]

I am like Roy..... assymetric pistons are great! as long as they go the right way....

If it is possible to reverse the caliper, as discussed above, I think this is easily the better way to go!

monoblock all the way!!!

oh and pads are not that hexxy.... $500 for a set of pagid's will see you bleeding from the nose soon enough!

[Roy]

But the thing is with the Monoblocs, is that i have read that the Porsche monoblocs are great, nice and rigid, but with kms and heat cycles do fatigue and in turn have more distortion under high braking pressures:(

This is only something i have read, so dont know for sure, and i wont ever know for sure as im never going to have a bunch of calipers mechanically tested. But when you look at the number of 2 year old Porsche calipers on the market, and the fact that apparantly the Carrera Cup boys life their calipers every 2nd round?!?!?!?!

Who knows where the truth lays...even if the calipers do yield a few thou more when old, they would still surely be a decent thing compared to the std calipers?

I just want a nice 343mm rotor with a good rigid caliper that works with the std master cylinder, the fact that i dont have ABS i want good feel through the pedal, so want everyhting to be as rigid as i can afford... if i had ABS i wouldnt care near as much:(

[williamsf1]

ok roy,

I am dead set needing some advice on the brakes above

1) can I run the GT3 in the correct cofig. have you priced a full kit for the R32? GTR?

2) AP racing?

I am looking at 365mm with the best caliper/rotor/lines/pad combo for value for money...

any more ideas???

[Roy]

Im just a hack that has read up a little:) If you have the budget, id be inclined to go AP 6 pots, i believe the caliper is CP555. Problem is you seem to be able to buy a pair of GT3 calipers for only a little more then a single AP caliper...best bet is to talk to John at UAS:)

[williamsf1]

yep I am just worried john boy know's less that you, as the pic's I have seen have the caliper mounted (upside down miss jane) hmmmmm

so are you going to get bigger brakes?

I wonder if snowman is reading this too! he got 365mm I hear

[Roy]

Yeh just PM him. His mechanic could be able to do another kit, i imagine the R34 and R32 setups are all the same

I did some tweaking and maintenance on my budget brake setup and yesterday at Sandown (apparantly one of the hardest tracks on brakes) the thing didnt miss a beat. It ran great. So much that im now liking the idea of getting the job done with thr std brakes...though with no ABS i would liek a bit more feel thru the pedal.

So will get some brakes, but need to get panel damage from minor accident at Eastern Creek fixed first:(

[GTR32]

Guys;

There are a lot of Brembo 8 pot calipers available overseas at the moment, specifically in the US, anyone checked them out re retro fit to a Skyline? Don't think they have dust boots and this might be a problem on a road car. Neal Bates ran them on an IS 200 at Targa a couple of years ago, I understand from one of his crew that while he got toasted uphill no one could catch him downhill

Regards

[williamsf1]

why would dust boots be an issue?

do you have any links to some prices for these second hand?

personally I can't see a big gain from 6-8 pot but if the price is right, and the pads are aval. why not???

Roy can you remember what an all up cost for the R32 (im running R34 wheels) in the GT3 package was? supply then fit?

cheers :)

and sounds like you have the brakes sussed, however I am making more power, and I'm heavier unfortunately....

[Roy]

It worked out around the $4,000-4,200k mark depending what you do with lines, pads, rotor brand/hats etc etc

And as for the 8-pot brembos, i almost had a set liend up, but before buying anything do some homework regarding not only the price, but the avalability of pad compounds. If you talking about the calipers on ebay in the US, then i think the pad related issues will scare you:(

[williamsf1]

yeah before even THINKING of getting 8 pots, my first thought was "jeeezz pads will be hexxy mate "

4k is a lot isnt it... hmmmm would be interesting to see anyone who is running this package!!

[GTR32]

yep the 8 pots on ebay are the ones I was referring to. and ditto re your comments about pad issues, I can feel the $$$ pain without having to ask further. haven't really looked into it that much because the front Brembos work just fine for a street car. still, at the price the 8 pots are available for it'd just about be worth it for a track day junkie to do a quick change to the 8 pots the night before or even trackside.