Brembo Brake Caliper Upgrade

SiliconAngel

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Perth, WA
First Name
SA, Trevor
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'99 Legnum VR4 Black MT
I can see your point there (very good point) but if you have brembo's with upgraded pads and rotors then your going to stop a few meters less than the standard upgraded brakes
Sorry Emanuel, but that just isn't true.

Think about it this way - what's the most effective way to stop? If you're skidding, you have too much braking. If you're not applying enough brake, then the car isn't slowing down fast enough (room for improvement). The most effective, efficient braking is pressure that is a hair below skidding / lockup. Hence that's where ABS tries to keep the brakes if your foot is on the floor.

So if you already have brakes that can give that much pressure, how can upgraded brakes slow you down any faster? The answer is, they can't.

At that point, the only things you can improve to reduce your stopping distance are your wheels (the wider the tire, the more contact they have with the ground and thus the better your braking performance) and your tires (better compound and design will give you better braking performance, as well as handling, road holding, etc).

The same car with the same wheels, tires etc with just bigger rotors and calipers will stop in exactly the same distance given the same conditions. In fact, there's an arguement that the larger rotors and calipers will weigh more, so THAT car would have more inertia and thus would take slightly LONGER to stop!

Until a couple of weeks ago I was under the same delusions - that Brembos or other upgraded racing calipers would improve / decrease my stopping distance. But the science just doesn't add up - as good as they may be, Brembos can't re-write the laws of physics ;)
 

bradc

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New Zealand
First Name
Brad
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Facelift Manual 400hp VR-4 Legnum
yeah but if you're really in a position where you are pushing the car hard enough to care about that small difference, it probably wouldn't be the first time you had used the brakes and they would already be hot.

Ohh and the stock brakes won't get the abs kicking in until about 120kmh, even if you stand on the pedal and the brakes are fairly cold. Brembos however will do it from a much higher speed.
 
G

Guest

Unregistered
Picked up the brake lines today. Will be doing the brembo upgrade tomorrow night.
At first these lines look very confusing (the rears) with the size and fittings but after looking at the car and making sure they fit on the brembo's it all looks good.
These rears do not need to be longer like evo8's one's are, as the fitting on the brembo end is a different style and more like our original ones and screw straight into the brembo's so its all good.
Thanks Paul.



Brakelines.jpg
 

VR-04-TT

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Location
NSW
First Name
Paul
Drive
2005 Liberty 3.0R Spec B
Good stuff Emanuel! Good to see it's all happening :D

Dibs shotgun for the first ride :D
 
G

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Unregistered
I’ll have to wear them in properly first then you can be co-pilot for some high G-force stopes. :D These will kick ass over the poo stock ones.
 

VR-04-TT

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Location
NSW
First Name
Paul
Drive
2005 Liberty 3.0R Spec B
Swweeeeet! I'm looking forward to the seat belt welts already :p
 

VR-04-TT

1 AYC Bar
Location
NSW
First Name
Paul
Drive
2005 Liberty 3.0R Spec B
Sorry Emanuel, but that just isn't true.

Think about it this way - what's the most effective way to stop? If you're skidding, you have too much braking. If you're not applying enough brake, then the car isn't slowing down fast enough (room for improvement). The most effective, efficient braking is pressure that is a hair below skidding / lockup. Hence that's where ABS tries to keep the brakes if your foot is on the floor.

So if you already have brakes that can give that much pressure, how can upgraded brakes slow you down any faster? The answer is, they can't.

At that point, the only things you can improve to reduce your stopping distance are your wheels (the wider the tire, the more contact they have with the ground and thus the better your braking performance) and your tires (better compound and design will give you better braking performance, as well as handling, road holding, etc).

The same car with the same wheels, tires etc with just bigger rotors and calipers will stop in exactly the same distance given the same conditions. In fact, there's an arguement that the larger rotors and calipers will weigh more, so THAT car would have more inertia and thus would take slightly LONGER to stop!

Until a couple of weeks ago I was under the same delusions - that Brembos or other upgraded racing calipers would improve / decrease my stopping distance. But the science just doesn't add up - as good as they may be, Brembos can't re-write the laws of physics ;)

I see what you're saying and while it's true to an extent you still need to consider that larger rotors and larger contact area will provide stronger stopping force before lockup (I don't mean that the pad pushes the rotor any harder...I mean it can slow the rotor quicker at the same pressure as before). As it's akin to stopping a bike wheel from the furthest point or stopping it from the centre. Much less pressure is needed to stop it from the furthest point, so a larger rotor acts the same.

If this isn't the case and brembos are such a waste of time...why do they use them at all on any cars? There's a bucketload of rally/race cars that upgrade their brakes to larger rotors and brembo calipers. And it's done by people who know their stuff...I just can't see your explanation being correct. Noone is re-writing the laws of physics...they're adhering to them...

Ultimately though, your tyres dictate how hard/fast you can brake. But we're talking about braking from speed to lesser speed, not to a halt.
 
G

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I see what you're saying and while it's true to an extent you still need to consider that larger rotors and larger contact area will provide stronger stopping force before lockup (I don't mean that the pad pushes the rotor any harder...I mean it can slow the rotor quicker at the same pressure as before). As it's akin to stopping a bike wheel from the furthest point or stopping it from the centre. Much less pressure is needed to stop it from the furthest point, so a larger rotor acts the same.

If this isn't the case and brembos are such a waste of time...why do they use them at all on any cars? There's a bucketload of rally/race cars that upgrade their brakes to larger rotors and brembo calipers. And it's done by people who know their stuff...I just can't see your explanation being correct. Noone is re-writing the laws of physics...they're adhering to them...

Ultimately though, your tyres dictate how hard/fast you can brake. But we're talking about braking from speed to lesser speed, not to a halt.

i agree with you paul.... why the hell would people use bigger brakes if a cheap, small setup did exactly the same?

the brakes are not stopping the momentum of the car, they are stopping the wheels rotating, thus a larger rotor, with a larger pad, will slowing the rotating speed of the wheel alot quicker than a smaller rotor with a smaller pad.

the reason cars skid under braking is because the momentum force of the car plus the force braking applies, exceeds the gripping force the tyres.

i've been in a stagea with stock 2 piston/1 piston callipers on 280mm rotors, a stagea with 4 piston/2 piston sumitomo calipers on 300mm rotors, and then another stagea with 4 piston/2 piston R34 GTR brembo's on 320mm rotors, and i can GUARANTEE you the larger brakes pulled the car up alot quicker, especially the brembo's.

tyres/rims, etc can affect braking, especially as grippier tyres can take harder braking, and lighter rims lower the rotating mass, however assuming these all stay the same, and only the rotor/calliper is upgraded, there will be a noticeable difference.
 

SiliconAngel

1 AYC Bar
Location
Perth, WA
First Name
SA, Trevor
Drive
'99 Legnum VR4 Black MT
If this isn't the case and brembos are such a waste of time...why do they use them at all on any cars?
As mentioned, the reason you'd want larger calipers and rotors in a racing application are heat dissipation, lower pressure (more 'responsive' braking) and more consistent pressure across the pad. The larger your rotor, the faster it will dissipate heat. The more pistons in the caliper, the more consistently distributed the braking force and the less pressure you need to apply to the pedal. In an application where everything is pushed to its limits, all this makes sense. But in a road car is it worth it? Is there a real and measurable benefit?

larger rotors and larger contact area will provide stronger stopping force before lockup (I don't mean that the pad pushes the rotor any harder...I mean it can slow the rotor quicker at the same pressure as before). As it's akin to stopping a bike wheel from the furthest point or stopping it from the centre. Much less pressure is needed to stop it from the furthest point, so a larger rotor acts the same.
Yep, absolutely, don't disagree in the slightest. Less pressure required means more responsive braking, the result of which means you don't need to press as hard on the pedal. But will it stop you any faster? If the pressure applied is slowing the vehicle a hair below tyre lockup with EITHER application, then the answer is no. As both applications (with good rotors and pads) will be able to exhert this same pressure then you can't consider that one will reduce stopping distance over another.

HOWEVER, as you increase the size of your pads and rotors and you increase their responsiveness, the difference between not-quite-enough-pressure and oh-shit-too-much-and-now-I'm-sliding wheel lockup will be extended, making that perfect balance ultimate braking point easier to achieve, so there is a benefit there which could translate to slightly decreased stopping distance (although as a factor of overall surface area compared between the two alternatives, indexed to external variables such as driver response time, tyres, road conditions etc I think you'll find this difference is marginal).

i've been in a stagea with stock 2 piston/1 piston callipers on 280mm rotors, a stagea with 4 piston/2 piston sumitomo calipers on 300mm rotors, and then another stagea with 4 piston/2 piston R34 GTR brembo's on 320mm rotors, and i can GUARANTEE you the larger brakes pulled the car up alot quicker, especially the brembo's.
With exactly the same rims and tyres? And the same quality (albeit smaller) rotors? Exactly the same model (again, if slightly smaller) pads with the same amount of wear-in and heat? You'd get improved braking from altering any one of these variables, so unless you're being very careful to compare apples to apples, instead you're comparing apples to fruit salad... And while I do love a fruit salad its hardly a fair comparison ;)

Look, I'm not saying Brembo's aren't better. Clearly they are. My point is for those of us not thrashing our cars around a track every weekend upgraded rotors and pads will get you 98% of what Brembo's would give you with the same spec rotors and pads, without the additional $1,000 outlay (if you can find a good set second hand) and effort on installing new calipers.
 

VR-04-TT

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Location
NSW
First Name
Paul
Drive
2005 Liberty 3.0R Spec B
HOWEVER, as you increase the size of your pads and rotors and you increase their responsiveness, the difference between not-quite-enough-pressure and oh-shit-too-much-and-now-I'm-sliding wheel lockup will be extended, making that perfect balance ultimate braking point easier to achieve, so there is a benefit there which could translate to slightly decreased stopping distance (although as a factor of overall surface area compared between the two alternatives, indexed to external variables such as driver response time, tyres, road conditions etc I think you'll find this difference is marginal).

Cool, that's the part I was getting at, but couldn't explain it properly :D And I agree that if you're not planning to track the car that Brembos are an expensive outlay and that the slotted rotors and better pads will be fantastic for the every day driver. I do plan to track mine though as much as affordable lol, so that's why I'm doing it. :D

btw SA, wasn't arguing, I was just confused by your point, but I see it clearer now :D
 

SiliconAngel

1 AYC Bar
Location
Perth, WA
First Name
SA, Trevor
Drive
'99 Legnum VR4 Black MT
Paul friendly, intelligent arguement is how we learn and develop, and I welcome it :) All I ever hope for in discussions like this is improvement in my understanding, or that of others. The only thing I take personally is a personal attack, and I just ignore idiots like that 'cause they're just showing their inability to follow a mature conversation ;)
 
G

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Unregistered
Brembo's are on but the lines need to be changed slightly.

The front sheilds, well I didn't need the evo ones, just use the stock ones as they do not get in the way.

The rear shelds do not come off like the fronts and had to be removed with a hammer and chissel as the new rotors won't fit with them on.
So without the rear brake sheilds no rally drving or offroad. Tryed bending the rear sheilds back but they were too rustly and split a few places. Maybe might be able to get some new ones made up and weilded on if ever needed.

The rear evo brembo bolts were too long and had to be cut down.
I'm going to go and buy the right sized ones and re-fit them, but the re-sized ones are working fine for now.
 
G

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Another interesting thing I noticed was our rear brake rotor acts as a drum brake for the hand brake on the inside on the inner rotor.

So our hand brake has separate pads (like a drum brake) as well as the normal rear pads for stopping.

Yea so 2 different systems on the rears.

 
G

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Unregistered
thats how most hand brakes work, i know my R33, stagea, and pintara are the same.
 
G

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Just over 2 hours, but I was't the one doing it.
If I was to do it more like 4 hours.
 

jungle

3 AYC Bars
Lifetime Member
Location
QLD
First Name
Simon
Drive
1 PFL & 1 FL Legnum
At that point, the only things you can improve to reduce your stopping distance are your wheels (the wider the tire, the more contact they have with the ground and thus the better your braking performance) and your tires (better compound and design will give you better braking performance, as well as handling, road holding, etc).

Hi Trevor,

Regarding wider tyre, more contract area, that's incorrect and a common misconception.

It will actually have the same contact area- just the shape on the contact patch will be different, it will be wider but shorter.

This actually can upset the balance of the car and can decrease longitudinal grip but generally the wider tyre is a softer compound and will have better overall grip via better compound and stiffer sidewalls.

Reference- Julian Edgar, 21st Century Performance
 

SiliconAngel

1 AYC Bar
Location
Perth, WA
First Name
SA, Trevor
Drive
'99 Legnum VR4 Black MT
That's definitely interesting Simon - I would have thought keeping circumference equal and widening the tire would naturally give you greater surface area?

I just Googled your reference and it sounds like a good read - I'll see if I can find a copy.
 
G

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Unregistered
Just to let everone know my set of Legnum to brembo custom lines cost under $200.
I have the original ones so if anyone wants the brembo ones made up or the original ones made up I can take them in so they can make you a set.
 
G

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Unregistered
Here are some more pics with the brembo's and new lines installed.
The red looks a bit off colour from the flash.

06.jpg


01.jpg


3.jpg


029.jpg


It has made a massive difference in brake performace. Can pull up so much shorter and harder.
From high speed stops to normal stops its made a big difference. :D

I was also told cusco brake stop are another great upgrade.
(an adjustable stopper to keep pressure against the master cylinder so it doesnt move when the pedal is depressed)
 
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