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Having searched through a load of threads, with regards to brakes and the performance vs VFM, i was wondering what you guys would recommend.

I want some upgrades for my r33 gtr, for fast road and track. There are lots of good things being said about k-sport, D2 - 8 piston calipers.

Its beginning to hurt my head now, so could you knowledgable bunch please share your wisedom.

Price is an issue, but obviously would prefer to spend the extra bit to get a better package.

Any views or past experiance is much sought after.

Thanks
 

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Those D2/K-sport brakes are cheap for a reason. Don't think for a second they are on par with Ap/Alcon/Brembo/etc.

Rotora are pretty good for price vs performance. Better quality than the Taiwan/China stuff but still not the best (Greddy/Grex brakes are actually Rotora)

If I were you, I would buy some nice 2 piece rotors, new pads, braided lines and some good fluid to go with the factory Brembos.
 

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Alcon (which are sold under licence by Greddy), AP Racing or Brembo. The other stuff is cheaper for a reason. Most people don't even know why a caliper with 6 pistons might be a better product for their needs than a 4 piston one. Most people with 8 piston calipers are probably mentioning them about as often as they order a pint, but have no need for them at all and they are probably less efficient than a quality 4 piston product :) Whatever calipers you run they are only as good as the pads they are clamping, and their suitability to the demands placed upon them.

I wrote this little article years ago about brake upgrades, it's still meaningful today:

Brake upgrades can set out to try to achieve several objectives.
The commonest are to increase resistance to fade and or increase
braking effort for a given pedal effort. IE, the pads are
pushed against the discs harder for a given pedal effort than
before the upgrade, or the brakes will stop the car from 100 MPH,
hard, for more times before fade sets in, than previously. The feel
from the pedal, that almost intangible quality, can also be addressed
and sometimes improved upon by brake size, or pad material changes, or
brake flexi hose upgrades to something less squashy than rubber.
It's easy to get carried away by the thought of brake upgrades.
The limitation in most cars as to how short a distance they can
stop in is tyre friction. Leaving aside pedal feedback, and fade,
it is almost certain that a Supra on stock Jap spec brakes will
stop in just as short a distance as one with an AP six pot kit on
it, a Brembo kit, a KAD kit, or whatever. It may not feel to
the driver that it does, but usually such is the case if you just
nail the pedal as hard as you can. The fancy kits may *FEEL* to
stop the car faster, due to less pedal effort, and a better bite,
but in reality, if you hit the pedal as hard as you can with stock
Jap spec brakes, UK spec brakes, AP kit, KAD, whatever, the car
will stop in the same distance. Repeat this test 10 times and stock
Jap brakes may be on fire and long since faded, or the fluid boiled,
UK ones may be very hot and bothered, but the upgraded ones will
probably still be working within pad, disc and brake fluid temp
limits. Add in the intangible "feel" factor, and a desire to brake
as hard as possible, using as little skill as possible, but WITHOUT
relying on the ABS to take over, and for sure a well set up brake
upgrade may well allow more finesse.

Herein though lies the rub.

Upgrade only the fronts and the brake balance of the stock car may
well be compromised. Let's take stock brakes. You press smoothly on
the brake pedal with (say) 50 pounds force. The car stops fine. 70
pounds, the fronts are just beginning to lock (car makers ALWAYS aim
for the fronts to lock first, as rear wheel lock makes the car very
unstable and liable to swap ends). The rears are doing as much work
as the brake engineers deemed safe to prevent premature rear lock up.
The ABS cuts in, and maximum retardation has been reached. Now, take
a car with big front discs and calipers. Only 40 pounds pressure now
gives a smooth, lock free and powerful retardation. 50 pounds and the
new, more powerful, (for the same pedal pressure), fronts are locking.
The ABS cuts in. BUT, and this is the crux, those original rear
calipers and discs are still well below the caliper pressure where
they are able to achieve maximum retardation without fear of the
rears locking.

In other words the FRONT brakes are doing TOO MUCH work, albeit without
breaking into a sweat, and the rears are, to exaggerate a bit,
just along for the ride. The BEST scenario is to upgrade front AND
rear brakes, carefully ensuring the original balance of effort at any
given brake pedal pressure remains as designed, but that the more efficient
front AND rear brakes stay cooler for more hard stops, and that old
intangible "feel" from the brake pedal is improved, at lower rates of
driver effort on the pedal. The latter may or may not be good or
desirable, and can be engineered out by changing BOTH front and rear
caliper piston sizes, or pad areas. In a race car the balance would
be adjustable via 2 brake master cylinders, with a driver selectable
change in mechanical leverage effort between front and rear brake circuits,
one cylinder operating the front brake calipers, the other the rear. This
can also be achieved on road cars, but to do so is usually complex and
expensive, especially if ABS and brake circuit failure safeguards are to be
maintained. It is far easier to calculate the caliper and disc sizes, along with
pad area and compound to achieve this, as near as available off the
shelf equipment will allow.

Caveat. I said before makers engineer more effort on the front brakes to
encourage straight line stopping if the tyres are locked up . They err on
the excessive side, as, in the wet, the rear tyres can take a lot more
braking effort than in the dry, due to less weight transfer onto the front
tyres, as they will lock before as much weight is transferred when the grip
of the road surface is reduced. So adding yet more front brake effort worsens
this existing imbalance, especially in the wet. If it were not for the
ABS the front wheels would be locking up very early. On the Supra a
relatively sophisticated ABS allows some effort to be taken off JUST
the fronts, and an artificial and very inefficient balance is returned.
On cars with lesser (1 or 2 channel) ABS, or no ABS at all, a brake
upgrade on just one end of the car can be lethal.
 

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Endless and Project Mu are great choices as well.
Just remember that your brake choice should be based on where you are using them, and also which tires you will using them with. There is no point in having massive 8 piston calipers and huge rotors with run-of-the-mill tires.
 

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One simple thing to add.. I had Customers/Mates ask me about that KSport/D2 stuff before.
Just try to get spare parts for them! Brake Pads, Friction Rings, even Screws. It's a bad joke. You'll pay twice in the End.

Marc
 

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One simple thing to add.. I had Customers/Mates ask me about that KSport/D2 stuff before.
Just try to get spare parts for them! Brake Pads, Friction Rings, even Screws. It's a bad joke. You'll pay twice in the End.

Marc

Excellent point, it's trivial to get new pistons or seals for an Alcon, AP or Brembo caliper. Bleed nipples and housing through bolts likewise. See this post, the same goes for lots of Jap parts, you need to ask a few searching questions when buying expensive kit with wearing parts:

http://www.gtr.co.uk/forum/127434-why-garrett-ballbearing-turbos-best.html

Post #4
 

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These observations may be of interest, I claim no special expertise so take my musing with a pinch of salt.

People focus on calipers quite a lot which isn't necessarily the important bit. Basically the caliper has two jobs - pressing the pads on the disc and keeping the fluid below boiling point. Bigger calipers means bigger pads which means a bigger bearing surface area. More pistons spreads the load across the pad better, though the laws of diminished returns certainly apply here. You can have issues with calipers twisting out of shape but I'd be surprised if was an issue with any modern stuff.

The pads actually interface with the discs so pad material will make much more difference than the caliper (excepting perhaps bigger calipers allowing the fitment of bigger pads). Good or bad pads can make the world of difference (bit like tyres really).

Discs are the other important area to my mind. You've got the surface (ie the bit that the pad touches), the cooling and the size of the disc (ie the leverage).

Ultimately you want to be able to get to just below the lock-up point of your car quickly and consistently. That means good feel/power and not overheating/fading. Overheating/fade is partly a function of how you're driving, some people are heavy on the brakes, partly a function of where you're driving, motorway or track say. Basically a track car will need a lot more in this regard that a road car and I would suggest that discs and pads would play the biggest part of this (also things like cooling and maintenance which I've not mentioned). The feel/power side of things good discs (perhaps bigger), quality pads and maintenance (fluid, lines, working calipers) will probably result in a very good system.

As ever if you want to improve something you have to decide what you want to improve in the first place. I reckon that the stock calipers are pretty good. Four pistons is plenty. I doubt that they flex to any discernible degree. The only real benefit I can see is bigger pad area.

I should add I'm not hard on the brakes so others may have different views. There's also things like weight or master cylinders to consider.
 

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If you know anyone who is a decent machinist you *COULD* buy the brakes piecemeal and build a custom package, but it entails a knowledge of piston sizing and pad area, so you'd need help with the sizing aspects. I usually build my own brake systems to save money, looking out on the race car auction sites for suitable discs and calipers. I found some new Porsche 962 Le Mans car Brembo front calipers, and a pair of used Aston Martin DB9 rear calipers, which I mated to discs I also found on forums or had to hand. I made up suitable brackets and bells and got a nice set up for half of what a commercial package would cost. Pics are dotted around ftp://ftp.chriswilson.tv/skyline_stuff under various brake headings. I also made the bias brake set up using twin master cylinders.
 

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learning about the pitfall of just upgrading the fronts, I decided instead to keep the stock calipers, and then did the brake lines, brake fluid, pads, and rotors - in short, everything else. For the street, where time between hard stops is extended, I don't have problems.

From what I can gather from Japanese GT-R mags, it seems that a "balanced" Brembo set is the 4-pot F50 set for the fronts, and 4-pot rear F360 calipers. Am I wrong on that?
 

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As I'm doing custom sets too, I can say that Chris is absolutely right.
Some Brake Conversion Manufacturers simply take a Friction Ring, a Bell and a Caliper and slap it on with an Adapter. Et voila, there's your average chinese Big Brake Kit.

No Development, no Quality, no Spare Parts.

Marc
 

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Chris, to do this job on a budget for fast road work only would it be possible/worthwhile to retain stock calipers but fit bigger discs (19" alloys), with revised caliper mounting brackets front and rear?
 

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Not being as knowledgable as Chris on this, But my experience has been, that if of a budget I would go;

R33 Brembos with dogbones to suit bigger disks
As good a disk as you can buy with sep hats for the front (cheap ones warp or crack)
Quality pads (I like my Ferrodo 3000+, good on the street, and track days)
Quality fluid (Cheap stuff boils)
Rig up some brake ducts (Can be done with some Kiwi Inger....Cunning!)

Otherwise, If you have a little more cash, Have a look at my Wilwoods, They run a Motorsport Caliper and Disk, with floating hats.....needless to say I love them!
 

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Chris, to do this job on a budget for fast road work only would it be possible/worthwhile to retain stock calipers but fit bigger discs (19" alloys), with revised caliper mounting brackets front and rear?
Excuse me for butting in but yes you could. Bear in mind that the caliper is designed to work with a certain range of rotor/disc sizes.
 

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If you know anyone who is a decent machinist you *COULD* buy the brakes piecemeal and build a custom package, but it entails a knowledge of piston sizing and pad area, so you'd need help with the sizing aspects. I usually build my own brake systems to save money, looking out on the race car auction sites for suitable discs and calipers. I found some new Porsche 962 Le Mans car Brembo front calipers, and a pair of used Aston Martin DB9 rear calipers, which I mated to discs I also found on forums or had to hand. I made up suitable brackets and bells and got a nice set up for half of what a commercial package would cost. Pics are dotted around ftp://ftp.chriswilson.tv/skyline_stuff under various brake headings. I also made the bias brake set up using twin master cylinders.
Hey Chris,
Thought you might be keen on these, They are the matching rears to you Brembo Motorsport front Calipers you have.

Brembo Race Brake Callipers for sale - TradeMe.co.nz - New Zealand
 
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