Big brake hype!
03-13-2001, 04:05 AM
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Hey people!
I'm somewhat concerned with the hype the big brake kits are generating lately.
What are the main reasons why people go to big brake kits?
I personally have found that the standard brake system with some slight mods (lines, ducts, pads, fluid- in general, basic maintenance) is more than adequate for all the track events that I have done with the S2000. Another thing people seem to forget is brake bias- when increasing the front's effectiveness you have to increase the rear's too, or the result wil be even more taxed front brakes.
Granted, a stock caliper with stock rotors isn't as sexy as a big 4 or 6 piston caliper with big rotors and aluminum hats, but at the same time I think the basic upgrades are already at the point of diminished returns. I think the money is better spent of getting more brake pads and fluid for replacement.
I've seen several points that some have made to justifying these kits-
1. Decreased weight. Good point. But, the savings are mostly in the aluminum hat, not a high value in changing the moment of inertia whereas adding more mass to the rotor in a higher value of moment of inertia will actually increase the need for more stopping power.
2. Ease of use. Not necessarily true. Swapping pads on the stock calipers is a single bolt affair on the front. Bleeding the brakes is a single bleed nipple for the OEM calipers. On a Brembo caliper the pads need to be removed by slipping off clips, then removing the shafts the pads ride on, taking care to not get injured by the pad retention spring that will shoot out with the removal of one of the shafts. Most four piston calipers have two bleed nipples to properly bleed both sides. Stock OEM calipers can be rebuilt with cheap OEM parts available from the local Honda dealer- esoteric brake kits require ordering parts that may or may not be in the supply chain and can also be prohibitively expensive. For what it's worth, the weight of the OEM caliper is not that much different than that of an aftermarket 4 piston caliper of similar performance. In essence, the only thing you're gaining when swapping to an aftermarket 4 piston caliper is less inboard pad flex (not caliper flex) under braking conditions, which is not a good value in my book. I also think that most multiple opposing piston designs are less stout than the fixed mount, sliding caliper design since the multi-piston type relies on the hardware that mates the two halves together for stiffness. I think a cast iron caliper is stiffer than a some grade 8 bolts to a CNC'ed aluminum caliper. The only exception to this is a monoblock design.
3. Many of you have requested a bigger heat sink as being the reason for a bigger rotor. I submit that the problem is not the size of the heat sink, but the amount of cooling air it receives.
4. Many of you think (erroneously) that a bigger rotor contributes to massively improved stopping power. In actuality the intial bite of a bigger rotor is better, but the stopping power is generally the same- a combination of coefficient of friction and force between the brake pad and rotor. A bigger rotor will be just as useless when used in combination with a crap pad. Pads make a much bigger difference- rotor size only really matter when we're talking about larger vehicle masses, like a 3400lb Porsche, or a 4500lb Tahoe, which would necessitate a bigger mass (bigger heatsink) of rotor to compensate during the braking effort.
There are companies that have produced a DOT certified stainless steel braided brake line- Earl's, Goodridge, Mugen. Check them out before making a decision. Also, check out a good performance pad and fluid. That's the most important factor in braking...
I'm somewhat concerned with the hype the big brake kits are generating lately.
What are the main reasons why people go to big brake kits?
I personally have found that the standard brake system with some slight mods (lines, ducts, pads, fluid- in general, basic maintenance) is more than adequate for all the track events that I have done with the S2000. Another thing people seem to forget is brake bias- when increasing the front's effectiveness you have to increase the rear's too, or the result wil be even more taxed front brakes.
Granted, a stock caliper with stock rotors isn't as sexy as a big 4 or 6 piston caliper with big rotors and aluminum hats, but at the same time I think the basic upgrades are already at the point of diminished returns. I think the money is better spent of getting more brake pads and fluid for replacement.
I've seen several points that some have made to justifying these kits-
1. Decreased weight. Good point. But, the savings are mostly in the aluminum hat, not a high value in changing the moment of inertia whereas adding more mass to the rotor in a higher value of moment of inertia will actually increase the need for more stopping power.
2. Ease of use. Not necessarily true. Swapping pads on the stock calipers is a single bolt affair on the front. Bleeding the brakes is a single bleed nipple for the OEM calipers. On a Brembo caliper the pads need to be removed by slipping off clips, then removing the shafts the pads ride on, taking care to not get injured by the pad retention spring that will shoot out with the removal of one of the shafts. Most four piston calipers have two bleed nipples to properly bleed both sides. Stock OEM calipers can be rebuilt with cheap OEM parts available from the local Honda dealer- esoteric brake kits require ordering parts that may or may not be in the supply chain and can also be prohibitively expensive. For what it's worth, the weight of the OEM caliper is not that much different than that of an aftermarket 4 piston caliper of similar performance. In essence, the only thing you're gaining when swapping to an aftermarket 4 piston caliper is less inboard pad flex (not caliper flex) under braking conditions, which is not a good value in my book. I also think that most multiple opposing piston designs are less stout than the fixed mount, sliding caliper design since the multi-piston type relies on the hardware that mates the two halves together for stiffness. I think a cast iron caliper is stiffer than a some grade 8 bolts to a CNC'ed aluminum caliper. The only exception to this is a monoblock design.
3. Many of you have requested a bigger heat sink as being the reason for a bigger rotor. I submit that the problem is not the size of the heat sink, but the amount of cooling air it receives.
4. Many of you think (erroneously) that a bigger rotor contributes to massively improved stopping power. In actuality the intial bite of a bigger rotor is better, but the stopping power is generally the same- a combination of coefficient of friction and force between the brake pad and rotor. A bigger rotor will be just as useless when used in combination with a crap pad. Pads make a much bigger difference- rotor size only really matter when we're talking about larger vehicle masses, like a 3400lb Porsche, or a 4500lb Tahoe, which would necessitate a bigger mass (bigger heatsink) of rotor to compensate during the braking effort.
There are companies that have produced a DOT certified stainless steel braided brake line- Earl's, Goodridge, Mugen. Check them out before making a decision. Also, check out a good performance pad and fluid. That's the most important factor in braking...
03-13-2001, 06:05 AM
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[QUOTE]Originally posted by GTRPower
[B]Hey people!
I'm somewhat concerned with the hype the big brake kits are generating lately.
What are the main reasons why people go to big brake kits?
I personally have found that the standard brake system with some slight mods (lines, ducts, pads, fluid- in general, basic maintenance) is more than adequate for all the track events that I have done with the S2000.
[B]Hey people!
I'm somewhat concerned with the hype the big brake kits are generating lately.
What are the main reasons why people go to big brake kits?
I personally have found that the standard brake system with some slight mods (lines, ducts, pads, fluid- in general, basic maintenance) is more than adequate for all the track events that I have done with the S2000.
03-13-2001, 06:41 AM
#3
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The ones Im working on, can be swapped out of stock parts, the lighter weight is all of my rotors, Im estimating about 6lbs front, down from 15lbs per rotor. The savings rear wont be as drastic. I re-designed front calipers to accept a 12.4" rotor and the calipers have a finned type surface (I dont really want to call it a heat sink even though thats what it is) to radiate heat better, and that's besides the other trick stuff. The more heat you can radiate the better. The stock front caliper is about 10lbs and the new ones may be about 6 also, maybe less. I managed to reduce the amount of material in the 12.4" rotors than the stock 11.8" rotors because of the increased stregnth of Ti, and also the vents and vanes have a special design that helps airflow but at the same time brings the major mass to the center of the hub, reducing the relative moment of inertia. I say relative because not only is the rotor (alot)lighter, but for its weight it does have a low moment.
But yeah the stock braking is really good and is mostly limited to traction, Im more worried about going faster
Im doing it for my car and for fun, but I can offset costs by selling a few extra sets.
03-13-2001, 07:49 AM
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wileecoyote-
I understand your point. However, I don't agree with your "sledge hammer solution" when all that is needed is a scalpel, and neither does Honda or BMW who use fixed mounted sliding calipers on their cars as OEM equipment. I guess even they find the money better spent elsewhere. Although you state that people go with big brake kits because of dissatisfaction with the OEM setup, I think with a little massaging, the OEM set will provide more than adequate performance. In any case, I would like to know where you can run into braking problems in your local area- with the mild upgrades I stated before, I can't see any street driving in Hong Kong that would be a problem- even my favorite South Island and Victoria Peak roads. A big key to the upgrades would be brake rotor ducts, which I assume you haven't even tried yet, since they will completely negate any need for more heat retention using bigger rotors. Almost all race teams have brake ducting as part of their basic brake design.
I'm even more surprised that you are so gung ho about modifying your car after 10 cars were very publicly towed away recently at a police road block for inspection of illegal modifications in the New Territories. FYI for those who don't know- in Hong Kong according to the interpretation of the law, virtually any modification to the car can be viewed as illegal- including shocks, brakes, exhausts, tires, etc. A bright red Porsche caliper in the front wheelwells would most likely call attention to the car, wouldn't you think?
Besides, you still haven't addressed a big problem with bigger front brakes- improper brake bias. That is a much more potentially dangerous problem than not enough front brake... Locking the brakes is generally the LAST thing you want to do- you lose 30% of your effective braking power beyond the point of threshold braking- actually INCREASING your braking distance. This is part of the reason why you never see race car drivers locking up their brakes- the other reasons are- minimising flatspotting the tires, enhancing lateral traction to actually make the turn that they're braking for, etc... Being able to lock up the brakes without effectively stopping the car only shows that the braking system hasn't been properly optimised- another demonstration of why the sledge hammer approach is not the most effective way to designing a brake system. If you are locking up your braking system, then may I suggest a stickier tire instead of bigger brakes?
The stock OEM system is good, and great when upgraded with performance lines, pads, and fluid. In fact, it's better than pretty much anything else out there and at the price of upgrades it's a steal. Find some other part of the car to work on and spend your hard earned money. You're dealing with a 2800lb car here, not a 3500lb car, with a third of the torque of the 3500lb car.
A 1000% better braking system you're proposing for a 20% extra need is not a good engineering solution- it's poor planning and development.
I think the majority of the people who install these kits do it out of fashion and not necessity. A full pad swap (front&rear), fluid and lines has been proven by me and others as being completely adequate for high performance track driving, let alone street driving. Hey- whatever floats your boat- I'm happy for you if you're happy... Remember- more is not necessarily better (see examples built by Colin Chapman for a better understanding).
As far as rebuilding calipers- I suggest rebuilding them every three years or so, or even more, depending on the system used. The OEM brakes don't need constant maintenance except for lubricant on the caliper slides. The more race oriented the caliper, the more it needs rebuilds. I would be highly suspect of any high performance brake caliper that didn't need maintenance for 10 years. Although you only need pliers to remove the pads, you also need channel locks to push the pistons back- you need two channel lock pliers, since when you push one piston in, the fluid forces the other out. I actually think the OEM single piston setup is easier to work than the 4 piston sets- pushing the pistons back is definitely easier using one C-clamp than fiddling with the channel lock pliers and poor visiblity (it's hard to see if the pistons have been pushed back far enough). I'm surprised that you think bleeding the brakes is not a high priority- I schedule brake bleeds as part of the overall maintenance of a car that goes to the track or is a high performance street car along with oil changes and general inspection- usually after every track event, or after any excessive use. If the car isn't in that category, why would it need more brake?
cmnsnse-
Interesting system...
How have you been able to overcome titanium's tendency to shear at high load and high heat stress, and the "welding" that occurs with steel under high pressure?
I understand your point. However, I don't agree with your "sledge hammer solution" when all that is needed is a scalpel, and neither does Honda or BMW who use fixed mounted sliding calipers on their cars as OEM equipment. I guess even they find the money better spent elsewhere. Although you state that people go with big brake kits because of dissatisfaction with the OEM setup, I think with a little massaging, the OEM set will provide more than adequate performance. In any case, I would like to know where you can run into braking problems in your local area- with the mild upgrades I stated before, I can't see any street driving in Hong Kong that would be a problem- even my favorite South Island and Victoria Peak roads. A big key to the upgrades would be brake rotor ducts, which I assume you haven't even tried yet, since they will completely negate any need for more heat retention using bigger rotors. Almost all race teams have brake ducting as part of their basic brake design.
I'm even more surprised that you are so gung ho about modifying your car after 10 cars were very publicly towed away recently at a police road block for inspection of illegal modifications in the New Territories. FYI for those who don't know- in Hong Kong according to the interpretation of the law, virtually any modification to the car can be viewed as illegal- including shocks, brakes, exhausts, tires, etc. A bright red Porsche caliper in the front wheelwells would most likely call attention to the car, wouldn't you think?
Besides, you still haven't addressed a big problem with bigger front brakes- improper brake bias. That is a much more potentially dangerous problem than not enough front brake... Locking the brakes is generally the LAST thing you want to do- you lose 30% of your effective braking power beyond the point of threshold braking- actually INCREASING your braking distance. This is part of the reason why you never see race car drivers locking up their brakes- the other reasons are- minimising flatspotting the tires, enhancing lateral traction to actually make the turn that they're braking for, etc... Being able to lock up the brakes without effectively stopping the car only shows that the braking system hasn't been properly optimised- another demonstration of why the sledge hammer approach is not the most effective way to designing a brake system. If you are locking up your braking system, then may I suggest a stickier tire instead of bigger brakes?
The stock OEM system is good, and great when upgraded with performance lines, pads, and fluid. In fact, it's better than pretty much anything else out there and at the price of upgrades it's a steal. Find some other part of the car to work on and spend your hard earned money. You're dealing with a 2800lb car here, not a 3500lb car, with a third of the torque of the 3500lb car.
A 1000% better braking system you're proposing for a 20% extra need is not a good engineering solution- it's poor planning and development.
I think the majority of the people who install these kits do it out of fashion and not necessity. A full pad swap (front&rear), fluid and lines has been proven by me and others as being completely adequate for high performance track driving, let alone street driving. Hey- whatever floats your boat- I'm happy for you if you're happy... Remember- more is not necessarily better (see examples built by Colin Chapman for a better understanding).
As far as rebuilding calipers- I suggest rebuilding them every three years or so, or even more, depending on the system used. The OEM brakes don't need constant maintenance except for lubricant on the caliper slides. The more race oriented the caliper, the more it needs rebuilds. I would be highly suspect of any high performance brake caliper that didn't need maintenance for 10 years. Although you only need pliers to remove the pads, you also need channel locks to push the pistons back- you need two channel lock pliers, since when you push one piston in, the fluid forces the other out. I actually think the OEM single piston setup is easier to work than the 4 piston sets- pushing the pistons back is definitely easier using one C-clamp than fiddling with the channel lock pliers and poor visiblity (it's hard to see if the pistons have been pushed back far enough). I'm surprised that you think bleeding the brakes is not a high priority- I schedule brake bleeds as part of the overall maintenance of a car that goes to the track or is a high performance street car along with oil changes and general inspection- usually after every track event, or after any excessive use. If the car isn't in that category, why would it need more brake?
cmnsnse-
Interesting system...
How have you been able to overcome titanium's tendency to shear at high load and high heat stress, and the "welding" that occurs with steel under high pressure?
03-13-2001, 08:16 AM
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Its the same ti/ceramic (at least pretty damn close) as Porsche is using.
And to comment on the other parts, I know I am spending too much time and money for a damn rotor but it "floats my boat" heh
The real problems if any will come out in testing . . .
And to comment on the other parts, I know I am spending too much time and money for a damn rotor but it "floats my boat" heh
The real problems if any will come out in testing . . .
03-13-2001, 08:20 AM
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cmnsnse-
I see- you're using a metal matrix alloy then. What kind of brake pads are used?
Sorry to hear that it's an expensive experiment- I've been there, done that!
I see- you're using a metal matrix alloy then. What kind of brake pads are used?
Sorry to hear that it's an expensive experiment- I've been there, done that!
03-13-2001, 09:16 AM
#7
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Pads are the next problem, depending on use and temp. range.
The metal matrix alloy may need to be modified one way or another. But for regular street use Im hoping stock pads will be fine and I'll work my way up from there.
The metal matrix alloy may need to be modified one way or another. But for regular street use Im hoping stock pads will be fine and I'll work my way up from there.
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03-13-2001, 11:31 AM
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GTRpower You have thought about this alot , a lot of good points . All of the items that you have talked about have come up since July .
Look at my first post and you will see all items addressed.
Caliper is forged, 3 times stonger than billet
Single bolt removes pads ( not two like stock )
don't have to remove caliper like stock ( verry hot)
Latter I will give total weight of reduction , very great compared to stock parts . Single blead screw same as stock.
Lighter
better cooling
better selection of pads
Yes I want brakes that compare with S-2000 suspension,transmission and balance of total car.
No rice!!!just quality with function at reasonable cost.
project has been fun I have learned alot.
brad 6410
Look at my first post and you will see all items addressed.
Caliper is forged, 3 times stonger than billet
Single bolt removes pads ( not two like stock )
don't have to remove caliper like stock ( verry hot)
Latter I will give total weight of reduction , very great compared to stock parts . Single blead screw same as stock.
Lighter
better cooling
better selection of pads
Yes I want brakes that compare with S-2000 suspension,transmission and balance of total car.
No rice!!!just quality with function at reasonable cost.
project has been fun I have learned alot.
brad 6410
03-13-2001, 03:00 PM
#9
I have to agree with Nick that only a few changes are needed to get fade free improved braking that is world class. Pads, fluid, lines, and cooling will give you brakes very hard to beat.
But look where the stock S2000 falls in the list of fast 60
But look where the stock S2000 falls in the list of fast 60
03-13-2001, 06:58 PM
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Read Car & Driver Aug'99 Page 98.
They did some brake analysis with Dateppli equipment.
The conlcusion is that Brake Booster Valving & Control Strategy plays the most important role in brake feel and distance. Looks like Toyota/Lexus undertsands it and get excellent braking distance from the MR2/IS300. Their newer Celica/GS400/LS400 also have excellent braking distance.
The pad material and caliper design is next. However, it is key to the ability to withstand fade after repeated use.
They did some brake analysis with Dateppli equipment.
The conlcusion is that Brake Booster Valving & Control Strategy plays the most important role in brake feel and distance. Looks like Toyota/Lexus undertsands it and get excellent braking distance from the MR2/IS300. Their newer Celica/GS400/LS400 also have excellent braking distance.
The pad material and caliper design is next. However, it is key to the ability to withstand fade after repeated use.