Before buying that huge brake upgrade, read this
- Thread starter old-git
- Start date
If your car runs a noticeable amount of downforce then big brakes will help you stop faster as higher speeds. The friction coefficient is increased, therefore you can apply more braking force into the tyres. Big brakes will be able to provide this bigger stopping power whereas smaller brakes may not be able to provide enough force for the tyres to be pushed to their limits.
If your brakes can get the wheels to lock up whatever speed you're doing then increasing brake size will not help you stop faster as the limiting factor is the tyre to road friction, not the pad to disc friction.
I think...
If your brakes can get the wheels to lock up whatever speed you're doing then increasing brake size will not help you stop faster as the limiting factor is the tyre to road friction, not the pad to disc friction.
I think...
I think that any modern car will lock up front brakes if pedal is pushed hard enough (ignoring ABS) so bigger brakes wont help to stop quicker, according to this article.
Also, downforce has very little effect as the air flow around the car quickly reduces during braking.
Also, downforce has very little effect as the air flow around the car quickly reduces during braking.
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SLEEPER
Pro Tuner
- Points
- 592
A tounge in cheek post possibly og ?
anyway i will take the bait
IMHO
There is a difference between having brakes that are " to big" for the tyres and ones that are better than the current ones and are within the tyres limits.
The article assumes that all existing brakes are efficient and often they are not .
Most Nissans for example are underbraked for standard power so are woefully inadequate for tuned cars
The article does "concede" that fitting better brakes will improve the braking at optimum braking temperatures -surely thats what better braking means after all you shoudnt be driving the cars quickly untill you have reached that.
The article is also correct when it says the bigger brakes will work consistantly and without fade ( relatively) But again surely that is stopping quicker - well it is on my car anyway.
from personal experience with standard brakes my stagea is nothing short of a deathtrap if I were to drive it at full power because sooner or later (usually sooner) I will need to stop.
With the APs on it is not only safer at speed (relatively ) but stops much quicker in all driving conditions, so much so , that I am happy to ignore any theoretical information that suggests otherwise
Obviously the writer will have sent these "pearls of wisdom" to all the entrants of the recent Le mans 24 hour race that was on recently
I cant understand why they didnt all swop back to smaller brakes.
And the way i understand abs the sytem will still stop quicker with bigger brakes because the abs maximises the amount of braking possible without locking the wheels.
The interval between off and on will remain the same whatever system is used so more braking force will be utalised and the car will stop quicker.
And if this isnt true there isnt a need for abs just fit smaller brakes.
anyway i will take the bait
IMHO
There is a difference between having brakes that are " to big" for the tyres and ones that are better than the current ones and are within the tyres limits.
The article assumes that all existing brakes are efficient and often they are not .
Most Nissans for example are underbraked for standard power so are woefully inadequate for tuned cars
The article does "concede" that fitting better brakes will improve the braking at optimum braking temperatures -surely thats what better braking means after all you shoudnt be driving the cars quickly untill you have reached that.
The article is also correct when it says the bigger brakes will work consistantly and without fade ( relatively) But again surely that is stopping quicker - well it is on my car anyway.
from personal experience with standard brakes my stagea is nothing short of a deathtrap if I were to drive it at full power because sooner or later (usually sooner) I will need to stop.
With the APs on it is not only safer at speed (relatively ) but stops much quicker in all driving conditions, so much so , that I am happy to ignore any theoretical information that suggests otherwise
Obviously the writer will have sent these "pearls of wisdom" to all the entrants of the recent Le mans 24 hour race that was on recently
I cant understand why they didnt all swop back to smaller brakes.
And the way i understand abs the sytem will still stop quicker with bigger brakes because the abs maximises the amount of braking possible without locking the wheels.
The interval between off and on will remain the same whatever system is used so more braking force will be utalised and the car will stop quicker.
And if this isnt true there isnt a need for abs just fit smaller brakes.
MasterAuron
Very Senior Member
Disagree with the article. Well, not so much disagree in that the physics etc are right BUT it's assuming you always brake into ABS? If you're driving properly and braking progressively the whole article is irrelevant bullsheet. Hands down I can brake harder and later on my AP's than the Brembo's (same pad compound too!).
Plus I can't be the only one to have seen independent tests in magazines etc that show reduction in braking distances between standard and brake kits?
It makes you wonder if whoever writes this crap has ever driven a car!
Plus I can't be the only one to have seen independent tests in magazines etc that show reduction in braking distances between standard and brake kits?
It makes you wonder if whoever writes this crap has ever driven a car!
What? Me? Tongue in cheek? Perish the thought
However, 'bigger brakes stop you quicker' is similar to 'wider tyres give you more grip'
claymore
The Torque Meister
Having had problems with my brakes overheating on track, I looked at putting even bigger brakes on, but at close to a grand I thought I might first try to improve cooling, so watch this space, (so where's that old windscreen washer pump I had lying around )
)I found a couple of lengths of 4" flexi pipe which im looking at making the most of for brake cooling. Saying that, i havent had an problems with brake fade yet. But better to be safe than sorry.
Watch this space. Or my project thread.
Watch this space. Or my project thread.
HDi fun
TC ModFather
It the standard rotors/pads are hopelessly inadequate then clearly an upgrade will help. Early Mondeos were shockingly bad at stopping, for example.
I've never had cause to fit larger brakes to any of my cars, though the point about Nissans is good - my P11 Primera had adequate brakes but no more than. An upgrade to larger discs at the front at least would probably have been a worthwhile one.
In contrast the 5 series I use currently seems near perfect with strong initial bite and good linear pedal feel. as such they're easy to modulate. This all makes for relaxed driving. Additionally, give the pedal a prod and it'll near pop your eyeballs from their sockets. In fairness the front discs are 324mm in diameter so are not exactly small anyway.
I do recommend the use of OEM discs and pads. In my experience aftermarket items never quite give the same feel and response.
I've never had cause to fit larger brakes to any of my cars, though the point about Nissans is good - my P11 Primera had adequate brakes but no more than. An upgrade to larger discs at the front at least would probably have been a worthwhile one.
In contrast the 5 series I use currently seems near perfect with strong initial bite and good linear pedal feel. as such they're easy to modulate. This all makes for relaxed driving. Additionally, give the pedal a prod and it'll near pop your eyeballs from their sockets. In fairness the front discs are 324mm in diameter so are not exactly small anyway.
I do recommend the use of OEM discs and pads. In my experience aftermarket items never quite give the same feel and response.
BIG PADS + BIG BRAKES mean more heat is generated and can be dissipated in braking, regardless of the point of "braking grip" being lost the brakes are more efficient at stopping the car and will have a more progressive feel.
HDi fun
TC ModFather
Kind of what I was driving at. If the brakes are little more than barely adequate, even though just about strong enough to lock the wheels they'll do so pretty unevenly. The idea is to keep things in their linear operating mode, not at the extremes.
geraint13
Pro Tuner
In the 3 beamers I've had the standard brakes where really good. The mondeo I just got rid of was adequate when there was just me. Add 4 blokes and tools and they were scary.
Prince
Torque King
The single piston setup in most BMWs can be improved upon quite nicely. But the ones in your 330 are actually quite good.
But in response to the link. I actually have a BBK and in comparison to the original brakes it is far better!
Pumpngo
Full member
In the last paragraph this guy does state some benifit from the upgrade. and in the second last one the thing that stood out to me was his comment on the abs not being tuned to the bigger brakes.
I have no experience with changing brakes on a car with abs, but it is logical they may not work as factory designed, which could result in less efficent braking with abs pulsing the brake at pressure and frequency designed.
Brakes are engineered by smart people that took a lot of time perfecting their system.
I like cars without the abs, it makes you work harder to get it right , not just slaming the brake pedal to the floor , so big brakes for me.
I have no experience with changing brakes on a car with abs, but it is logical they may not work as factory designed, which could result in less efficent braking with abs pulsing the brake at pressure and frequency designed.
Brakes are engineered by smart people that took a lot of time perfecting their system.
I like cars without the abs, it makes you work harder to get it right , not just slaming the brake pedal to the floor , so big brakes for me.
ABS senses the wheel locking up and that is irrespective of the size of brakes or amount of braking friction.
This is quite an interesting topic though. I think it is similar to exhausts, there is an optimum size for the application and if you go over this then the benefits become negative.
This is quite an interesting topic though. I think it is similar to exhausts, there is an optimum size for the application and if you go over this then the benefits become negative.
pgarner
TC ModFather
i know the ABS module that is in my car is the same whether its the smallest brake setup 256mm discs with a 54mm piston or the biggest 345mm 59mm piston.
all that changes is a setting within the module.
Even after upgrading my fronts i havent yet had to change the setting and its only recommended after fitting the rears as well.
all that changes is a setting within the module.
Even after upgrading my fronts i havent yet had to change the setting and its only recommended after fitting the rears as well.
SLEEPER
Pro Tuner
- Points
- 592
Presuming most systems work like mine then no brake change will affect it .
I have upgraded my brakes twice and now run 343mm 6 pot ap racing brakes with no abs issues , and these are so far removed from the standard set up that any potential abs issue would show up.
The abs sensors monitor the wheel speed which is nothing to do with the brakes . This is done electronically so you dont need to tune abs systems.
unless of course it works differently to mine.
I have upgraded my brakes twice and now run 343mm 6 pot ap racing brakes with no abs issues , and these are so far removed from the standard set up that any potential abs issue would show up.
The abs sensors monitor the wheel speed which is nothing to do with the brakes . This is done electronically so you dont need to tune abs systems.
unless of course it works differently to mine.
pgarner
TC ModFather
Not really sure tbh think the setting is just to aid the balance once the rears are upgraded head of folk running even the R8 ceramics without changing the setting. as they have left the rears as they are, could just be the sensitivity
Pumpngo
Full member
It's hard to understand Why your brakes don't need the brake bias. As it sounds like you have hugely improved the fronts and not the rears.
Plus the piston area would have been increased too.
As i said before i haven't played with this late model stuff, but i have on older cars, and it would have needed an adjustable brake bias unit fitted to tune how much pressure goes front to back.
I'd like to know what's on these newer cars that they don't need it.
Plus the piston area would have been increased too.
As i said before i haven't played with this late model stuff, but i have on older cars, and it would have needed an adjustable brake bias unit fitted to tune how much pressure goes front to back.
I'd like to know what's on these newer cars that they don't need it.
moneypit
Wrench Pro
MMMM no bodies mentioned the brake pipes!
Current toy is mx5 sport it has "big brakes" as standard they seem good
last toy FTO GPX standard are big enough but solid slightly smaller at rear but the brake bias was from memory 65% front 35% rear, woefully inadequate! So I upgraded to slotted and drilled upfront, improved somewhat, I then replaced the brake hoses all around with Goodrich ones, vast improvement.
Having also owned a Harley and even non bikers know about there lack of stopping power, easiest improvement in the world goodrich hoses! Standard hoses can and do stretch under pressure so a metal encased hose = no stretch = better braking IMO of course! with the new hoses on my bike I had on a few occasions needed to stop quickly, and on two occasions ending up with the back wheel locked (fear mainly on my part) and ending up sideways on to the car that the driver didn't see me! (both times doing 30 in a 30 just got pulled out in front of), and how anyone can not hear open pipes, and see and notice my handsome mug smiling at them!
Most cars have a brake bias to the front for obvious reasons unless your tracking the car the best option would be to upgrade the front first and try that before doing the back.
Course in an ideal world none of us would have to have ABS for emergency stops lol
well thats MHO so pull me to pieces lol
Current toy is mx5 sport it has "big brakes" as standard they seem good
last toy FTO GPX standard are big enough but solid slightly smaller at rear but the brake bias was from memory 65% front 35% rear, woefully inadequate! So I upgraded to slotted and drilled upfront, improved somewhat, I then replaced the brake hoses all around with Goodrich ones, vast improvement.
Having also owned a Harley and even non bikers know about there lack of stopping power, easiest improvement in the world goodrich hoses! Standard hoses can and do stretch under pressure so a metal encased hose = no stretch = better braking IMO of course! with the new hoses on my bike I had on a few occasions needed to stop quickly, and on two occasions ending up with the back wheel locked (fear mainly on my part) and ending up sideways on to the car that the driver didn't see me! (both times doing 30 in a 30 just got pulled out in front of), and how anyone can not hear open pipes, and see and notice my handsome mug smiling at them!
Most cars have a brake bias to the front for obvious reasons unless your tracking the car the best option would be to upgrade the front first and try that before doing the back.
Course in an ideal world none of us would have to have ABS for emergency stops lol
well thats MHO so pull me to pieces lol
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If you drive in a sporting manner , enter track days or tow/carry heavy loads then the first step is to upgrade the pads and change to approved braided lines as mentioned earlier and if you are still looking to improve the brakes then do as I have done and changed the single piston sliding calipers to 4 piston units along with larger diameter discs as the larger diameter discs not only absorb /dissipate more heat but will give more retardation with the same pedal pressure.
IMHO there are not many cars that will not benefit from an upgrade except say a Porsche GT3, as the manufacturers are always looking to maximize profits.
With the larger discs the dust covers have been discarded and I have fitted flexible hoses from the front spoiler/airdam to direct cool air to the center of the discs to improve cooling
IMHO there are not many cars that will not benefit from an upgrade except say a Porsche GT3, as the manufacturers are always looking to maximize profits.
With the larger discs the dust covers have been discarded and I have fitted flexible hoses from the front spoiler/airdam to direct cool air to the center of the discs to improve cooling
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There are a few discrepancies in the article namely
1 the wheels MUST LOCK to activate the ABS .
2 An experienced/skilled driver can stop the car in a shorter distance using threshold braking when the wheels are on the verge of locking but still rolling.
3 They will reduce the stopping distances when repeated use of stock brakes fade from continuous heavy use as the larger discs can absorb more heat and do not require the same pedal pressure to slow the car down.
Hope this makes sense to you all as there are some misunderstandings out there as ABS was initially invented to enable the car to still be steered when a panicked driver slammed on the brakes and locked up the wheels and tried to steer away from a crash but plowed straight ahead and crashed anyway.
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