Serious Brakes

[Roy]

Yeah but i'd like to see those stopping distance figures, in a "best of 3".

If you did three massive "up to 150 kph - back to 0" stops, in a row, downhill to make it even harder, you'd start to see much bigger differences, i think.

For the street though, no doubting its all a bit of wank

Well 24 hard stops from 100mph is a far more demanding ask of a brake setup then 3 stops

Brembo F50; _____________ 299 / 288 (Average / Best)

Brembo Lotus; ______________305 / 294

Prodrive; __________________ 308 / 295

StopTech;__________________ 297 / 290

Stock;_____________________ 340/317

Stck with pads and fluid;_____316/299

So how long is a car? On avergae the tweaked std brakes were only 16ft worse off then the F50 with its best only being 11ft worse.

The real test for the brakes would be to give them good tyres and really tax those brakes On street tyres you just dont have the grip to perhaps make use of the bigger brakes improved braking torque and feel

[Merli]

The real test for the brakes would be to give them good tyres and really tax those brakes On street tyres you just dont have the grip to perhaps make use of the bigger brakes improved braking torque and feel

Exactly. This test (although interesting), is next to useless.

We all know (or should know, if we're looking at spending mulitple thousands on new brakes), that braking is mostly a function of tyre grip. Throw 50" brakes and 80 piston calipers on a car, and it'll still lock up the wheels or engage ABS at the exact same point as your stock brake setup. If you can lock up your brakes with your stock calipers, pads and tyres, what improvement is putting MORE braking effort into the system? The tyres are still going to lock up at the same point and stop you braking any harder.

For all intents and purposes (discounting pedal feel, etc), big brakes of any brand or size, will not improve your braking effort noticeably in the one-stop test on street tyres.

What DOES change, is if we alter TWO factors in this equation?

1. What if we increase NUMBER of stops? As you can see in the test, larger brakes are able to dissipate more heat, more efficiently... resulting in more consistent braking, and resistance to brake fade.

2. What if we increase TYRE GRIP? Throw a set of semi-slicks onto the car, and the level of braking you are able to achieve before locking up the brakes is massively increased. This means that you're introducing a MASSIVE amount of extra heat into the brakes, and at a MUCH faster rate than you would ever ever ever see on street tyres. That means that the heat dissipation abilities of your brakes really comes into play now. They need to shed that extra heat much more efficiently, otherwise meet my little friend "brake fade".

Now to REALLY make those big, expensive, shiny, brakes earn their keep, lets combine both of those above factors and do lots of stops on semi slicks. Aha! Now we are accurately testing the difference between stock brakes and big brakes, in an environment that we would be applying them in.

[Roy]

2. What if we increase TYRE GRIP? Throw a set of semi-slicks onto the car, and the level of braking you are able to achieve before locking up the brakes is massively increased. This means that you're introducing a MASSIVE amount of extra heat into the brakes, and at a MUCH faster rate than you would ever ever ever see on street tyres. That means that the heat dissipation abilities of your brakes really comes into play now. They need to shed that extra heat much more efficiently, otherwise meet my little friend "brake fade".

Now to REALLY make those big, expensive, shiny, brakes earn their keep, lets combine both of those above factors and do lots of stops on semi slicks. Aha! Now we are accurately testing the difference between stock brakes and big brakes, in an environment that we would be applying them in.

And people also forget that tyre grip is one thing, but mechanical grip is almost as important. If you are going to go to semi slick tyres you will often find that the car handles differently. More squuat under accleration, more roll in corners and more pitch under brakes. So if you are increasign grip and you have brakes that will take a hammering, then remember that there is gains to be had from having well adjusted/tuned suspension as well. Stability under brakes comes largely from suspension and more then the rotors and calipers you are running will allow you to dive up the inside of otehr cars under brakes.

But i will say again, the test posted earlier with teh WRX comparison was on a US Spec car that runs sliding calipers etc. Not the alloy 4 pot calipers that Aus spec WRXs run which are similar to R32/R33/34 calipers. So the std Nissan gear is much better then the US WRX with larger rotors, 4 piston front, 2 piston rear calipers all on larger vented rotors....so Nissan give the Skyline good brakes to start with...so the gap could very well be less if the test car was something like an R33

[Merli]

Of course... But I would hazard a guess to say that whoever is looking at spending $4000-10000 on their brakes have their suspension sorted already

In any case, this thread was going in the direction of arguing the merits of big brake setups, so the same could be said about improving the suspension to accurately control the application of standard brakes OR big brake kits, so is irrelevant in this discussion...

[Beer Baron]

Yeah I thought we were just here to talk crap about big brakes!

I liked the endless 16 piston ones I saw about 3 years ago when they came out. also saw some cool Group A brakes at fuji speedway in november. Carbon rotors (about 380mm) and carbon pads of course. sadly for AP that made the gear the rules were amended to outlaw Carbon brakes in Group, so they have a shitload left over if anyone wants some. from memory they said each rotor cost about $5,000. They also used titanium pistons in their calipers which was pretty cool.

and all of the above is absolutely useless for anything really, but they sure are cool.

we already have plenty of serious threads on brakes. this is a non-serious thread, about serious brakes.

[Roy]

Alcan made 12 pot calipers that were used on 2L Super Tourers by Peugot etc

Some fruit loops like running them on street cars

[BLK33T]

Don't you get a much greater result in braking performance by increasing the rotor size over increasing the caliper size? As well as more initial bite by reducing the pad surface area?

Also I thought stop tech match the amount of fluid that your stock BMC could flow? This is important because it retains that feel in the pedal and even braking pressure accross the pads correct? Thats what makes them a good light track car upgrade?

[Roy]

The likes of AP actually run all up smaller diam pistons then the std Niisan Brembo, which is why AP 6 pots work well with std BMC etc. Stoptech run the same sized pistons as the Brembo F40 and F50s as theyare essentially re-engineered Brembos

[BLK33T]

ahhh i c ...

[badkarma85]

How's this for a serious BBK?

[BLK33T]

what car is that ...

[sh@un]

R35 GT-R

[badkarma85]

Or if you're really hardcore...

or maybe,

[SKYPER]

I noticed bigger diameter brakes help with pulling up cars that weigh

alot.

Look at the weight of the R35 GTR and weight of R34 GTR, R33 GTR,

R32 GTR.

You'll notice they weigh more with each generation and the brakes

have bigger diameter rotors, bigger calipers (R35 GTR) to suit.

Edited February 10, 2008 by SKYPER

[Stock GTR]

Hey guys, great to see this topic actually took off. I was after some proper advise. Thank-you all.

A few months ago I knew nothing about brake upgrades for GTR's.

Although no-one actually said it, I agree that stock Brembo's are more than adequate for the street. However, I am building a car that will be used for the ocassional track day. I can't think of anything worse than running out of stopping power at 300 clicks.

I have seen some interesting upgrades available, including the alcon's and a neat brembo kit from UA. Harrop's seem to be the ultimate, but i've also been told not to go with a brake disc larger than 365 MM at the front. Wheels will most likely be 18 inch LM GT4's. Any advise will always welcome.

[NISMO]

There are plenty of seriously quick street/track cars which still have OEM Brembo's and do fine for the "occasional track day".

It really sounds like your going for way overkill. If you're only interested in the occasional track day, a $10k brake kit would not be at the top of my list. Unless of course that money tree i planted 10 years ago, finally gets its sh!t together and starts growing! :-)

300 clicks, what track would this be at?

[gts-4 dreamer]

I noticed bigger diameter brakes help with pulling up cars that weigh

alot.

Look at the weight of the R35 GTR and weight of R34 GTR, R33 GTR,

R32 GTR.

You'll notice they weigh more with each generation and the brakes

have bigger diameter rotors, bigger calipers (R35 GTR) to suit.

more wieght = more force = more heat = more wear + the condition known as fade.

I have never come across brakes that didnt give you SOME warning before they are useless... Im not saying it's impossible.. ie... really short ammount of chomp before your foot hits the floor.. but usually you start to notice that pedal is sinking deeper... some brakes... the travel is that far that you just notice.. im pushing the same ammount but she isnt slowing down as fast...

How competitive do you want to be on your occasional track day... how occasional is your track day and how many laps are you chasing before she starts to fail... because there are many systems that will all fail at different rates...

Ever felt your power steering start to go coming into a long corner with a tight end chaser... re turn 1 + turn 2 @ ec? Fun times + sand/mud/grass to ensue depending how much you manage to turn.

most frustrating... fugn clutch gets to hot and starts to slip... not even a hard launch coming out of pits... 3k just before your turby thinks about turning... an walla... free spin not 3m infront of the official... still remember turning red as with the bastard laughing his ass off... no oil dropped.. no worries!

decide whether you want a car that will stand up to 3 laps or 9 laps... forget 45 minute sprints at full tilt too... unless you wana pay/play... (interchangeable here).

Edited August 14, 2008 by gts-4 dreamer

[maccattack]

Having gone down a similar route a while ago (I need really big brakes - then going Oh shit! they cost how much???) I spoke to a number of people

(there is already a sizable thread under "Suspension, brakes and tyres") I was advised to look at the problem progressively.

Generally a big brake upgrade is not always the best answer.

Look at what they are to be used for - stopping from 300k's can be done with your standard Brembo's.

Doing it repeatedly may require more.

Brake failure in nearly all situations is due to the inability to disburse heat.

Have you taken off the stone shields?

Change the rotors to a full veined rotor?

Change the lines to braid?

Upgrade the fluid and pads?

Is more ducting required?

If you did all of the above (which I must say will cost you a shitload less than what you are talking about) then start looking at the bigger brakes.

I would be surprised if this did not sort out most weekend warriors (such as myself).

Just make sure that when you do you take into account your master cylinders as well to make up for the additional capacity.

[Stock GTR]

Thanks for the advise guys. Yes I have done some simple upgrades like pads and fluids. For the street and some windy hills they work a treat.

I've had a couple of bad experiences (when I was younger!) with brakes overheating at high speed. Its not a great feeling at 200+km, having brakes heat up and not work. The corners come up much faster than you would like.

I've seen this Brembo packaged adverdised. The price looks respectable (for decent track brakes) but i havn't heard much about them. Size is good, 380 front and 355 rear. 8 piston front and 4 piston rear.

It would be nice to keep a set of brembo's on the car. Does anyone have any experience with this setup?