K2RD 13" brakes!
03-08-04, 07:51 PM
#26
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Originally posted by bryantho
Look at that bridge, a single Allen bolt... Willwoods Fleeeeeeex.
Look at that bridge, a single Allen bolt... Willwoods Fleeeeeeex.
This reminds me of the when someone was bitching about the Wilwood brakes on a Miata...
Have you ever been in an FC with this particular upgrade? I bet you haven't. I'd like to see you tell the difference between the Wilwood set and a Brembo/AP caliper system?
Are people really getting a lot of fade from the Factory 4 pistons? Or are we talking mostly bling-factor?
-Ted
03-08-04, 10:41 PM
#28
I Raise Chickens
Originally posted by Cheers!
How much heavier is that setup compared to stock?
How much heavier is that setup compared to stock?
Id say its about even. The rotors are heavier, but the calipers are significantly lighter. I havent weighed them vs the stock ones personally...
03-08-04, 10:45 PM
#29
I Raise Chickens
Most people don't give the stock fc brakes a chance. We road an 86 rx7 on stock brakes. Stock rotors and used factory brake pads. They work really really well, even during prolonged periods of racing. We took 1st first place in our class at a 3 hour endurance race at Thunderhill a week ago.
-seth
-seth
Originally posted by bryantho
Brakes don't stop the car from moving forward, your tires do. Your brakes are there to slow the wheels down. In 99% of cases, you run out of tire traction before you run out of friction and clamping force in the brakes. You should be able to lock up the front tires (or engage ABS) with you stock 4 pistons.
What do good big brake kits offer in stopping distance improvement over the stock setup? It might be as little as their ability to be modulated. If it's easier to keep the tires at the very threshold of traction, you'll stop faster.
Honestly, the threshold is higher than most people realize (if their pads, lines and fluid are appropriate). You know when you're overworking your brakes on the track when they start to get hot, as you’re braking for tighter turns (or after fast straights), you'll feel the brakes get lazy (or fade). This is a sign that you're brakes are seeing too much heat and stress, and either your pads material is coming ineffective, or your fluid is starting to boil.
This is where the big brakes come in, much more rotor mass, larger surfaces and bigger hear dissipation designs. They also get stronger bridges/calipers to hold up against the stresses of repeated heavy stops and turns. They offer consistency at higher stress levels.
BTW, I absolutely love Stoptechs. They’re a great design and implementation. Modulation is awesome, very nice.
Brakes don't stop the car from moving forward, your tires do. Your brakes are there to slow the wheels down. In 99% of cases, you run out of tire traction before you run out of friction and clamping force in the brakes. You should be able to lock up the front tires (or engage ABS) with you stock 4 pistons.
What do good big brake kits offer in stopping distance improvement over the stock setup? It might be as little as their ability to be modulated. If it's easier to keep the tires at the very threshold of traction, you'll stop faster.
Honestly, the threshold is higher than most people realize (if their pads, lines and fluid are appropriate). You know when you're overworking your brakes on the track when they start to get hot, as you’re braking for tighter turns (or after fast straights), you'll feel the brakes get lazy (or fade). This is a sign that you're brakes are seeing too much heat and stress, and either your pads material is coming ineffective, or your fluid is starting to boil.
This is where the big brakes come in, much more rotor mass, larger surfaces and bigger hear dissipation designs. They also get stronger bridges/calipers to hold up against the stresses of repeated heavy stops and turns. They offer consistency at higher stress levels.
BTW, I absolutely love Stoptechs. They’re a great design and implementation. Modulation is awesome, very nice.
03-09-04, 02:13 AM
#30
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I would say the stock 4-piston brakes are more then plenty for the average joe Rx7 owner. As long as they are maintained well and serviced, they proved adequate braking in all scenerios. Even on track with proper cooling to the rotors your brakes will perform wonderfully.
Only reason you want to go with bigger brakes is for the brake modulation as mentioned above, cheaper parts, pads, rotors and cooling. Another reason I upgrade is from the jump in power I'm making now then from before. I'm actually needing to use my brakes more then before now. Also I never had any problems with my old setup but then I got sponsored so i don't complain.
Only thing you need to change or is recommend is the Master Cylinder, a 929 Master Cylinder fits perfeclty on the FC and will cure the brake pedal from the enlarge volume of pressure found within the new caliper.
Only reason you want to go with bigger brakes is for the brake modulation as mentioned above, cheaper parts, pads, rotors and cooling. Another reason I upgrade is from the jump in power I'm making now then from before. I'm actually needing to use my brakes more then before now. Also I never had any problems with my old setup but then I got sponsored so i don't complain.
Only thing you need to change or is recommend is the Master Cylinder, a 929 Master Cylinder fits perfeclty on the FC and will cure the brake pedal from the enlarge volume of pressure found within the new caliper.
03-09-04, 11:58 AM
#31
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Originally posted by RETed
There have already been replies on the reasons to go with the big brake upgrade by others.
-Ted
There have already been replies on the reasons to go with the big brake upgrade by others.
-Ted
A "budget" big brake kit is kind of a catch 22. Typically “budget” is the kind of kit purchased by someone who doesn't actually need the bigger system, and doesn't mind compromising on whatever looks big. On the other hand, a person who does actually need bigger brakes is going to go out and do research, talk to people, and read comparisons made around the different systems. They're going to try to find the system that suits their needs whilst not totally breaking the bank. Believe it or not, such systems exist beyond the price/performance offered by Willwood.
Now, I'm not saying that Willwood is total ****; because I’m sure they work well for a lot of folks. I'm just trying to get people to understand that brakes aren't something you upgrade just to upgrade. You should upgrade brakes when you find you need them, and when you do need them: you don't compromise solely on the low bidder.
03-09-04, 12:54 PM
#32
Originally posted by bryantho
Yeah, I made those replies. I'm actually willing to give my stock 4-pistons a run for their money (My TII is for 95% track use, and I track my cars hard). If they stocker work for me I won't be upgrading.
A "budget" big brake kit is kind of a catch 22. Typically “budget” is the kind of kit purchased by someone who doesn't actually need the bigger system, and doesn't mind compromising on whatever looks big. On the other hand, a person who does actually need bigger brakes is going to go out and do research, talk to people, and read comparisons made around the different systems. They're going to try to find the system that suits their needs whilst not totally breaking the bank. Believe it or not, such systems exist beyond the price/performance offered by Willwood.
Now, I'm not saying that Willwood is total ****; because I’m sure they work well for a lot of folks. I'm just trying to get people to understand that brakes aren't something you upgrade just to upgrade. You should upgrade brakes when you find you need them, and when you do need them: you don't compromise solely on the low bidder.
Yeah, I made those replies. I'm actually willing to give my stock 4-pistons a run for their money (My TII is for 95% track use, and I track my cars hard). If they stocker work for me I won't be upgrading.
A "budget" big brake kit is kind of a catch 22. Typically “budget” is the kind of kit purchased by someone who doesn't actually need the bigger system, and doesn't mind compromising on whatever looks big. On the other hand, a person who does actually need bigger brakes is going to go out and do research, talk to people, and read comparisons made around the different systems. They're going to try to find the system that suits their needs whilst not totally breaking the bank. Believe it or not, such systems exist beyond the price/performance offered by Willwood.
Now, I'm not saying that Willwood is total ****; because I’m sure they work well for a lot of folks. I'm just trying to get people to understand that brakes aren't something you upgrade just to upgrade. You should upgrade brakes when you find you need them, and when you do need them: you don't compromise solely on the low bidder.
As mentioned earlier, tires, not brakes stop the car and the threshold of the tire is primarily the limiting factor. If you have a big hp car and/or big sticky tires and run at tracks hard on brakes such as Laguna Seca, where your brakes will generate tons of heat causing fade, maybe a a big brake kit is what you need. But then again, what pads are you running? Are you providing adequate ducting to them? There are alternatives, to a point, to a big brake system and still have all the adequte braking you need.
If you want the bling factor, just get some cross-drilled power slot rotors or something and be happy with those. The money you save there you might be able to put into the car to make it faster so one day you can honestly justify the need for big brakes.
My vert will be running somewhere around 370rwhp and better ducting with good pads is adequate. On the other hand, my 20b car (if it ever moves under it's own power) has flares with giant tires that will require an upgraded braking system. Do I see 14" calipers and AP 6pot calipers in my future? Yes I do.
Btw, to see if I can't upset some people, why anyone would pay big dollars for anything but an AP sytem or maybe a Brembo system is beyond me. Wilwood is nowhere near the same class.
03-09-04, 07:20 PM
#33
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Originally posted by RX-Heven
Btw, to see if I can't upset some people, why anyone would pay big dollars for anything but an AP sytem or maybe a Brembo system is beyond me. Wilwood is nowhere near the same class.
Btw, to see if I can't upset some people, why anyone would pay big dollars for anything but an AP sytem or maybe a Brembo system is beyond me. Wilwood is nowhere near the same class.
Like C&D did a comparison for the Impreza folks:
http://www.caranddriver.com/article....rticle_id=2852
03-09-04, 07:49 PM
#34
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Originally posted by RX-Heven
Btw, to see if I can't upset some people, why anyone would pay big dollars for anything but an AP sytem or maybe a Brembo system is beyond me. Wilwood is nowhere near the same class.
Btw, to see if I can't upset some people, why anyone would pay big dollars for anything but an AP sytem or maybe a Brembo system is beyond me. Wilwood is nowhere near the same class.
I did a survey a few years ago about big brakes when I was still associated with K2RD. There was favorable response when the price started to drop under $1,000. When asked about a $1,500 price level, there was also NO interest. If we could just say "buy Brembo/AP cause that's what you should buy" and magically get people to fork over the cash, I wouldn't be arguing with you. You should ask Cork Sport how many of those KVR big brake kits they have sold over the past 10 years or so they have been in business - I know of only ONE set that's out there.
There IS a market for big brake upgrades. Is it "needed"? , No, you're right. Is there still demand? Yes, there is. It's basic economics.
-Ted
03-10-04, 09:51 AM
#35
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Nobody is going to deny there's a disparity between need and want, and no one is at fault or despised for selling to that want. It's perfectly reasonable, on the other hand, for us to inform people about the pros and cons of a particular brake system -- it's also reasonable that we might help them define the requisites of a braking "need." I'm not trying to hurt anyone's business; my sole consideration lies with helping other enthusiast.
It's good that you're filling the market with more options.
It's good that you're filling the market with more options.
03-10-04, 10:34 AM
#36
Rotary Freak
After seeing how big 13" brakes are, I think I'll opt out for the 12.1" kit. Still 6-piston, though. Also, is there any way to change out my rear brakes? I wouldn't really want to throw off brake balance, but whatever...the 5-lug vented rotors would probably do just fine.
03-10-04, 12:09 PM
#37
Lives on the Forum
Originally posted by snub disphenoid
After seeing how big 13" brakes are, I think I'll opt out for the 12.1" kit. Still 6-piston, though.
After seeing how big 13" brakes are, I think I'll opt out for the 12.1" kit. Still 6-piston, though.
-Ted
03-11-04, 12:35 AM
#40
Lives on the Forum
Originally posted by bryantho
What for, wheel clearance?
What for, wheel clearance?
Over 1" diameter on the rotor with LESS upsprung weight is always a plus.
-Ted
03-11-04, 01:12 AM
#41
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just a question
when upgrading to a front big brake kit i gather you change the front calipers the rotors and probably the lines but what do you do about the rear rotors and calipers. as you can see my knowledge on brakes is limited, but i want to learn. thanks
03-11-04, 01:42 AM
#42
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Mass is a boon to rotors.
Think about it, the rotor is a heat-sink; as heat energy is generated from friction, it is dispersed (via conduction) throughout the rotor. Mass retains heat -- the more massive the heat-sink, the more energy it can store.
When you step on the brakes, you want the resulting heat energy to have someplace to go. Temperatures build faster when there's less mass to conduct the heat, and this makes your pad material and brake fluid very unhappy.
Of course, heat energy is ultimately expelled from the brakes as it dissipates into the atmosphere (convection), but the rotor's heat-sink ability is needed most when the pressure is on. This, above unsprung weight and inertia, is pretty important.
Less unsprung weight a plus? Yeah, it is.
Less unsprung weight a plus because the brakes are much lighter? No thanks. That's kinda like taking off the seatbelts to make the car lighter.
Caveat: All of this is not to say the "lighter" system still doesn't provide adequate thermal attributes for many applications.
Think about it, the rotor is a heat-sink; as heat energy is generated from friction, it is dispersed (via conduction) throughout the rotor. Mass retains heat -- the more massive the heat-sink, the more energy it can store.
When you step on the brakes, you want the resulting heat energy to have someplace to go. Temperatures build faster when there's less mass to conduct the heat, and this makes your pad material and brake fluid very unhappy.
Of course, heat energy is ultimately expelled from the brakes as it dissipates into the atmosphere (convection), but the rotor's heat-sink ability is needed most when the pressure is on. This, above unsprung weight and inertia, is pretty important.
Less unsprung weight a plus? Yeah, it is.
Less unsprung weight a plus because the brakes are much lighter? No thanks. That's kinda like taking off the seatbelts to make the car lighter.
Caveat: All of this is not to say the "lighter" system still doesn't provide adequate thermal attributes for many applications.
03-11-04, 04:02 AM
#43
Lives on the Forum
Now, it turns into a question of thermal capacity.
Can you verify if the stock rotors cannot handle the heat capacity?
I haven't seen hard numbers on this yet.
Also, we're talking about different materials (steel rotor with aluminum rotor hat), so thermal capacity, thermal conductivity, and heat exchange capacity is not equivalent. If anything, I think aluminum is better at thermal capacity and heat exchange capacity?
Wouldn't proper brake ducting help in this case?
It would all boil down to how much heat the brake system could handle under each, unique braking event...
-Ted
Can you verify if the stock rotors cannot handle the heat capacity?
I haven't seen hard numbers on this yet.
Also, we're talking about different materials (steel rotor with aluminum rotor hat), so thermal capacity, thermal conductivity, and heat exchange capacity is not equivalent. If anything, I think aluminum is better at thermal capacity and heat exchange capacity?
Wouldn't proper brake ducting help in this case?
It would all boil down to how much heat the brake system could handle under each, unique braking event...
-Ted
03-12-04, 10:32 AM
#45
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Originally posted by RETed
If anything, I think aluminum is better at thermal capacity and heat exchange capacity?
If anything, I think aluminum is better at thermal capacity and heat exchange capacity?
Then again, at identical dimensions, a piece of steel is three times more massive than aluminum. So where you might be heating up a 2lbs aluminum hat, a 6lbs hat of steel is still going to have more capacity for heat (though, admittedly, not as efficient).
Originally posted by RETed
Wouldn't proper brake ducting help in this case?
It would all boil down to how much heat the brake system could handle under each, unique braking event...
Wouldn't proper brake ducting help in this case?
It would all boil down to how much heat the brake system could handle under each, unique braking event...
03-14-04, 10:51 AM
#47
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How about the rotora kit? Any thoughts?
Originally posted by Wormiez
I also run a big brake kit sponsored by Rotora. It is 13.2 inch two piece rotors with a 4 piston caliper. 17inch rims are a minimium in order to clear the brakes properly.
Heres a picture of it, those are 17 inch Volk Gram Lights.
I also run a big brake kit sponsored by Rotora. It is 13.2 inch two piece rotors with a 4 piston caliper. 17inch rims are a minimium in order to clear the brakes properly.
Heres a picture of it, those are 17 inch Volk Gram Lights.
03-14-04, 11:17 AM
#48
Lives on the Forum
Originally posted by error*
How about the rotora kit? Any thoughts?
How about the rotora kit? Any thoughts?
I always thought they were cheesy due to their advertising...
-Ted
