Wilwood Dynapro 6 Piston Calipers
#1
Wilwood Dynapro 6 Piston Calipers
I'm looking into getting some 6 piston calipers for my Miata. I was wondering if anyone has issues with the Wilwood rotor hats. Goodwin racing was claiming that their 10 bolt rotor-to-hat design was more "consistent, reliable, and stable." Is this true? They make it seem like you shouldn't trust the Wilwood design but I have a hard time believing Wilwood would sacrifice our safety just to make a few extra bucks. What are your guys' thoughts?
Last edited by ApexAddict; 04-26-2017 at 12:10 PM.
#5
Ahh gotcha. So I was having a discussion with a gentleman about the BBK and he was saying that if you don't have the 4 piston calipers on the rear, you'll have to have a heavy bias on the rear to even it out which defeats the purpose of having the big rotors on the front due to lack of heat generated. Is this true or is he full of ****?
#6
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For one. You can't increase rear bias without going to a larger rear caliper.
2: IMO 6 piston calipers are already probably more than you need. The 4 piston properly sized for the Miata has worked well at may hp levels. 6 piston just adds weight.
2: IMO 6 piston calipers are already probably more than you need. The 4 piston properly sized for the Miata has worked well at may hp levels. 6 piston just adds weight.
#7
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Ahh gotcha. So I was having a discussion with a gentleman about the BBK and he was saying that if you don't have the 4 piston calipers on the rear, you'll have to have a heavy bias on the rear to even it out which defeats the purpose of having the big rotors on the front due to lack of heat generated. Is this true or is he full of ****?
I'm not sure how the balance works out with 6 piston fronts, but a good combo is 11.75" 4 piston front, and 11" sport rotor rear (whether you use sport caliper, or non-sport caliper spaced out).
#8
He is somewhat correct. It is not advisable to do a 6 piston Wilwood in the front and leave the rears completely stock (depending on what stock is for you). The rear does need balanced out, though. The Miata is already front biased, and becomes even more front biased when putting good tires on it (I assume you'll have 200tw tires at least, if you're considering these brakes). If you make the front brakes stronger, the lockup force will be lower. But since the rear brakes have remained the same, you're now using less rear brake when the fronts lock.
I'm not sure how the balance works out with 6 piston fronts, but a good combo is 11.75" 4 piston front, and 11" sport rotor rear (whether you use sport caliper, or non-sport caliper spaced out).
I'm not sure how the balance works out with 6 piston fronts, but a good combo is 11.75" 4 piston front, and 11" sport rotor rear (whether you use sport caliper, or non-sport caliper spaced out).
Does anyone have any experience with the 6 pots?
#10
Oh wow, that's not TERRIBLE but definitely something to consider. I know I should be fine with 4 pot in the front and the 10.9" kit in the rear, but part of me just wants to say **** it and go all out. I just don't want to get 4 pot in the rear if I don't have to, although if I buy it with the kit I save 250 bucks.
#12
Oh wow, that's not TERRIBLE but definitely something to consider. I know I should be fine with 4 pot in the front and the 10.9" kit in the rear, but part of me just wants to say **** it and go all out. I just don't want to get 4 pot in the rear if I don't have to, although if I buy it with the kit I save 250 bucks.
#13
^yeah. If you want to spend more than the wilwood radial mount, just buy the top of the line stoptech, and make everyone cry and wet their pants at the same time.
On a side note, I was surprised to find out that all the options for miata are fixed rotors. I would have expected floating rotors at those pricepoints.
Oh, and if you need a handbrake, stick with oem sports rear calipers. There are no aftermarket options that have any real world practicality. Unless you custom make a handbrake, I guess.
On a side note, I was surprised to find out that all the options for miata are fixed rotors. I would have expected floating rotors at those pricepoints.
Oh, and if you need a handbrake, stick with oem sports rear calipers. There are no aftermarket options that have any real world practicality. Unless you custom make a handbrake, I guess.
Last edited by thumpetto007; 05-02-2017 at 11:27 PM.
#15
As soon as I read that last post, I knew this was you!! If your brakes arrive while you're out, don't get pissy if they end up on my car! Don't worry though - I'll let you drive it at Thunderhill...
PS I'm telling Shaun you stole his tagline
PPS Did I mention two and a half weeks to LEMONS!!
PS I'm telling Shaun you stole his tagline
PPS Did I mention two and a half weeks to LEMONS!!
Last edited by LanceMach; 05-03-2017 at 12:16 PM.
#16
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Ahh gotcha. So I was having a discussion with a gentleman about the BBK and he was saying that if you don't have the 4 piston calipers on the rear, you'll have to have a heavy bias on the rear to even it out which defeats the purpose of having the big rotors on the front due to lack of heat generated. Is this true or is he full of ****?
He is somewhat correct. It is not advisable to do a 6 piston Wilwood in the front and leave the rears completely stock (depending on what stock is for you). The rear does need balanced out, though. The Miata is already front biased, and becomes even more front biased when putting good tires on it (I assume you'll have 200tw tires at least, if you're considering these brakes). If you make the front brakes stronger, the lockup force will be lower. But since the rear brakes have remained the same, you're now using less rear brake when the fronts lock.
I'm not sure how the balance works out with 6 piston fronts, but a good combo is 11.75" 4 piston front, and 11" sport rotor rear (whether you use sport caliper, or non-sport caliper spaced out).
I'm not sure how the balance works out with 6 piston fronts, but a good combo is 11.75" 4 piston front, and 11" sport rotor rear (whether you use sport caliper, or non-sport caliper spaced out).
IOW, as you add mechanical braking grip, you need less rear brake.
Remember that a properly-spec'd 6-piston will have similar stopping power to the stock caliper or a 4-piston. All the Wilwood offerings use a 3.00" piston area, spread across either 4 or 6 pistons. The OEM caliper is a 1" bore, which gives an area of ~3.14". The OEM Sport caliper is ~3.55 (IIRC) and the Stoptech 38/36 option is somewhere in-between 3.14 and 3.55 IIRC (easy math to do for someone else).
The same is true in the rear - all the 4-piston options have the same bias as the stock 1-piston sliding caliper. You don't need to augment your 6-piston fronts with 4-piston rears, since the stock 1-piston rear provides the same or similar clamping force.
Does anyone have any experience with the 6 pots?
This is a good question.
#18
As soon as I read that last post, I knew this was you!! If you're brakes arrive while you're out, don't get pissy if they end up on my car! Don't worry though - I'll let you drive it at Thunderhill...
PS I'm telling Shaun you stole his tagline
PPS Did I mention two and a half weeks to LEMONS!!
PS I'm telling Shaun you stole his tagline
PPS Did I mention two and a half weeks to LEMONS!!
He is full of ****. If you'd like more detail than that, I can provide, but that's the short answer.
Please elaborate if you don't mind!
The Miata is front-biased from the factory, same as every car on the planet (because lawyers). As you add sticky tires, the natural bias shifts rearwards, not forward as you said. The easiest way to see this is to take the "sticky tire" to its unnatural end, where the front tires have so much grip that the car actually does a stoppie at max braking G (i.e. rear tires are completely off the ground). At that point, you need massive front bias and very low rear bias, but since your brake bias is still as-delivered from the factory, the natural bias moves rearwards.
IOW, as you add mechanical braking grip, you need less rear brake.
****. So you're saying I would've been completely fine with 6 pot up front and the stock caliper with the 10.9" rotor in the rear?
The 6-pot doesn't provide substantially more heat capacity than a 4-pot, unless you're talking about the heatsink capacity of the caliper itself. The rotor makes the biggest difference. The pads in the standard DP6 are still 12mm, and the shape is largely similar to the DP4 shape.
Remember that a properly-spec'd 6-piston will have similar stopping power to the stock caliper or a 4-piston. All the Wilwood offerings use a 3.00" piston area, spread across either 4 or 6 pistons. The OEM caliper is a 1" bore, which gives an area of ~3.14". The OEM Sport caliper is ~3.55 (IIRC) and the Stoptech 38/36 option is somewhere in-between 3.14 and 3.55 IIRC (easy math to do for someone else).
The same is true in the rear - all the 4-piston options have the same bias as the stock 1-piston sliding caliper. You don't need to augment your 6-piston fronts with 4-piston rears, since the stock 1-piston rear provides the same or similar clamping force.
I do, from years and years ago. They had slightly better pedal feel, no measurable improvement in pad life, and dramatically higher running costs. I removed them after a handful of events and went back to my DL4s.
Welp, **** me then...so in the case, what's the point of going with the 6 pots?
This is a good question.
Please elaborate if you don't mind!
The Miata is front-biased from the factory, same as every car on the planet (because lawyers). As you add sticky tires, the natural bias shifts rearwards, not forward as you said. The easiest way to see this is to take the "sticky tire" to its unnatural end, where the front tires have so much grip that the car actually does a stoppie at max braking G (i.e. rear tires are completely off the ground). At that point, you need massive front bias and very low rear bias, but since your brake bias is still as-delivered from the factory, the natural bias moves rearwards.
IOW, as you add mechanical braking grip, you need less rear brake.
****. So you're saying I would've been completely fine with 6 pot up front and the stock caliper with the 10.9" rotor in the rear?
The 6-pot doesn't provide substantially more heat capacity than a 4-pot, unless you're talking about the heatsink capacity of the caliper itself. The rotor makes the biggest difference. The pads in the standard DP6 are still 12mm, and the shape is largely similar to the DP4 shape.
Remember that a properly-spec'd 6-piston will have similar stopping power to the stock caliper or a 4-piston. All the Wilwood offerings use a 3.00" piston area, spread across either 4 or 6 pistons. The OEM caliper is a 1" bore, which gives an area of ~3.14". The OEM Sport caliper is ~3.55 (IIRC) and the Stoptech 38/36 option is somewhere in-between 3.14 and 3.55 IIRC (easy math to do for someone else).
The same is true in the rear - all the 4-piston options have the same bias as the stock 1-piston sliding caliper. You don't need to augment your 6-piston fronts with 4-piston rears, since the stock 1-piston rear provides the same or similar clamping force.
I do, from years and years ago. They had slightly better pedal feel, no measurable improvement in pad life, and dramatically higher running costs. I removed them after a handful of events and went back to my DL4s.
Welp, **** me then...so in the case, what's the point of going with the 6 pots?
This is a good question.
#19
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He's full of **** because he assumed that a 4-piston caliper will provide more bias than the OEM caliper. That's a fundamental misconception of how properly-designed BBKs work.
Then he makes it worse by claiming some crap about unused thermal capacity. Let's look closer at that. Let's say you have stock 1.6L brakes and you are having trouble with the fronts due to pad fade. The only solution is to go bigger, so you do. You buy the biggest, highest-bias BBK available, which would be a 36/38 Stoptech STR43 on an 11.75" rotor. You leave your rear brakes stock, then buy some pad combo that will actually produce proper bias (something like a full high-temp race pad in the rear and something made of foam or chewing gum in front). Physics dictates that because you have not changed the rate of deceleration (no tire change, no suspension change), the car is still generating the same amount of heat, and because you've altered the bias "properly", that heat is still being applied to the front and rear brakes in the same proportion as it was before. The only difference is that your front brakes aren't overheating, because you've substantially increased the thermal capacity of the rotor. The only way to produce LESS heat in the front brakes, as your friend claimed, is to increase rear bias beyond where it was before you added the BBK in the first place.
So dude makes a bad assumption, and then espouses some crap that wouldn't be correct even if his original assumption was correct (which it wasn't). If someone told me that story in real life, I would nod politely and never listen to another word they said.
Yes, you would have been fine with your 10.9" OEM Sport brakes. I assume you bought the FM Powerlite kit, which shifts bias slightly rearwards. That's not a bad thing, but the Powerlites are purely a weight reduction exercise. No Miata actually has thermal capacity issues in the rear, even with the stock un-vented rotor and stock caliper, so any change made should be in search of weight savings. Unless you are building a pointy-ended competition car, I wouldn't bother.
The only legitimate reason to select the 6-pot Dynapro is for the bling factor. I give the same spiel to everyone who calls asking about DP6s (they give similar pedal feel to the DP4, minimal additional thermal capacity, no improvement in pad life, added weight, more expensive pads, WAY more expensive calipers if you ever need to replace one). Almost everyone ends up with a DP4, or if they need the thermal capacity/life expectancy, the Superlites. The few who do select the DP6 after hearing my spiel counter with "I like the way they look and I'm OK with spending the extra money for the appearance", and that's 100% OK with me, because they do look pretty sweet.
Then he makes it worse by claiming some crap about unused thermal capacity. Let's look closer at that. Let's say you have stock 1.6L brakes and you are having trouble with the fronts due to pad fade. The only solution is to go bigger, so you do. You buy the biggest, highest-bias BBK available, which would be a 36/38 Stoptech STR43 on an 11.75" rotor. You leave your rear brakes stock, then buy some pad combo that will actually produce proper bias (something like a full high-temp race pad in the rear and something made of foam or chewing gum in front). Physics dictates that because you have not changed the rate of deceleration (no tire change, no suspension change), the car is still generating the same amount of heat, and because you've altered the bias "properly", that heat is still being applied to the front and rear brakes in the same proportion as it was before. The only difference is that your front brakes aren't overheating, because you've substantially increased the thermal capacity of the rotor. The only way to produce LESS heat in the front brakes, as your friend claimed, is to increase rear bias beyond where it was before you added the BBK in the first place.
So dude makes a bad assumption, and then espouses some crap that wouldn't be correct even if his original assumption was correct (which it wasn't). If someone told me that story in real life, I would nod politely and never listen to another word they said.
Yes, you would have been fine with your 10.9" OEM Sport brakes. I assume you bought the FM Powerlite kit, which shifts bias slightly rearwards. That's not a bad thing, but the Powerlites are purely a weight reduction exercise. No Miata actually has thermal capacity issues in the rear, even with the stock un-vented rotor and stock caliper, so any change made should be in search of weight savings. Unless you are building a pointy-ended competition car, I wouldn't bother.
The only legitimate reason to select the 6-pot Dynapro is for the bling factor. I give the same spiel to everyone who calls asking about DP6s (they give similar pedal feel to the DP4, minimal additional thermal capacity, no improvement in pad life, added weight, more expensive pads, WAY more expensive calipers if you ever need to replace one). Almost everyone ends up with a DP4, or if they need the thermal capacity/life expectancy, the Superlites. The few who do select the DP6 after hearing my spiel counter with "I like the way they look and I'm OK with spending the extra money for the appearance", and that's 100% OK with me, because they do look pretty sweet.