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Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   Suspension, Brakes, Drivetrain (https://www.miataturbo.net/suspension-brakes-drivetrain-49/)
-   -   Wilwood 4 piston rear brakes? (https://www.miataturbo.net/suspension-brakes-drivetrain-49/wilwood-4-piston-rear-brakes-68828/)

cordycord 07-04-2013 02:57 PM


Originally Posted by Leafy (Post 1028377)
I only see 2 calipers on that page, not 4.

DOH, you are correct sir. ;)

emilio700 07-04-2013 03:39 PM


Originally Posted by schmoo (Post 1028353)
Did the kits discussed here actually go into production? Can't find anything on Trackspeed or 949 that uses something other than OEM calipers on the rear.

TSE is working on a kit which I had a little input into. V8R's original 4 wheel kit had way too much rear brake bias. I dropped the rear half from our site and asked Shandelle to do a smaller rear kit just for us. I offered a few suggestions on how to configure it. We'll see how that goes.

If TSE's hits the mark, we'll add it to our webstore. If neither it nor the V8R is what we want, we'll do our own. Based on what Andrew has shared so far, I think TSE's will be the goods. Tricky part is keeping the cost down while still hitting our utility and performance criteria. Doing a fabulous $3000 lightweight rear brake is easy. Doing a functional <=$1000 rear kit is proving surprisingly difficult.

Savington 07-04-2013 04:30 PM

We're 4-6 weeks out. Wilwood Powerlite 4-pot caliper on a CNC'd bracket, custom rear rotor hat, and custom rear 10" rotor. Bias is a bit more rear than a 1.8L caliper on a 10.9" rotor. I have one kit in testing that's using production-spec brackets and an early prototype rotor hat. The production hats will be 7075-T6 and 40% lighter.

We'll play with a parking brake option at some point. Design goal #1 with this kit was to remove as much weight as possible from the rear brakes, so the parking brake got chucked immediately.

Pricing TBA, figure on it being well under $1k. Buy it with an 11.75" front kit and we'll give you a better deal. We're taking what we learned from this project and designing our own front rotor hats, so expect our front 11.75" kits to drop in price and weight as well.

Ben 07-04-2013 04:36 PM


Originally Posted by Savington (Post 1028422)
We're 4-6 weeks out. Wilwood Powerlite 4-pot caliper on a CNC'd bracket, custom rear rotor hat, and custom rear 10" rotor. Bias is a bit more rear than a 1.8L caliper on a 10.9" rotor. I have one kit in testing that's using production-spec brackets and an early prototype rotor hat. The production hats will be 7075-T6 and 40% lighter.

Replacement rear rotor required or optional?

Savington 07-04-2013 04:42 PM


Originally Posted by Ben (Post 1028425)
Replacement rear rotor required or optional?

Optional, but strongly recommended. Our rotors weigh 20% less than a factory rotor, rings will be <$100/ea to replace, and the aluminum hats transfer heat better which means the rear brakes will run cooler. Lots of benefits for only a few hundred bucks of initial outlay. If you're serious enough to swap the rear caliper, you should be running a 2-piece rotor.

We'll offer the rotor separately for racers who aren't allowed to change the rear brake caliper (PTC/D/E and a few autocross classes).

Ben 07-04-2013 05:18 PM


Originally Posted by Savington (Post 1028426)
Optional, but strongly recommended. Our rotors weigh 20% less than a factory rotor, rings will be <$100/ea to replace, and the aluminum hats transfer heat better which means the rear brakes will run cooler. Lots of benefits for only a few hundred bucks of initial outlay. If you're serious enough to swap the rear caliper, you should be running a 2-piece rotor.

We'll offer the rotor separately for racers who aren't allowed to change the rear brake caliper (PTC/D/E and a few autocross classes).

Understood. My car is going to be ~1450 lbs, so the caliper is the lower hanging fruit for me. I don't think heat will be a concern with the app. Saving ~3lbs or whatever off the caliper/bracket should be pretty huge, and OE rear brakes with intact parking brake kind of suck.

Leafy 07-04-2013 06:08 PM

I want that rear rotor. Will it fit the front as well? I've recently be talking with fast brakes to see if he can figure out something, but if this works its what I want.

Savington 07-04-2013 07:47 PM


Originally Posted by Leafy (Post 1028442)
I want that rear rotor. Will it fit the front as well? I've recently be talking with fast brakes to see if he can figure out something, but if this works its what I want.

Solid rear, vented front, so sadly it won't fit the front. If the hat offset worked for a vented front rotor, I could see doing it, but I doubt that will be the case.

Leafy 07-04-2013 10:18 PM

At least it gets me half the car.

k24madness 07-05-2013 01:34 AM


Originally Posted by Savington (Post 1028422)
Bias is a bit more rear than a 1.8L caliper on a 10.9" rotor.

Is that from the slightly larger rotor or piston volume? Will piston volume be less than rear sport brakes?

Love the pedal with the 1.8 rear calipers over the sports. That is why I am asking.

Does the caliper have a decent selection of pads? I am LOVING the Cobalts at this point and would prefer to stay with that compound.

Savington 07-05-2013 06:21 PM


Originally Posted by k24madness (Post 1028539)
Is that from the slightly larger rotor or piston volume? Will piston volume be less than rear sport brakes?

Love the pedal with the 1.8 rear calipers over the sports. That is why I am asking.

Does the caliper have a decent selection of pads? I am LOVING the Cobalts at this point and would prefer to stay with that compound.

Piston volume. Rotor is smaller than a sport rotor to hit our bias target. Expect the pedal feel to improve regardless, since you're getting rid of a flexy single-pot caliper.

Can't comment on pad availability for Cobalts, as I don't sell them.

schmoo 07-11-2013 02:35 PM

Thanks for the update gentlemen.

I'm looking at a brake kit in a serious way... my only reticence has been the large jump in rotor costs.

I'll stay tuned.

Keith@FM 07-11-2013 03:11 PM

I didn't know this discussion was going on. The FM kit is being announced in the next day or two. We'll have two options.

One, a Powerlite setup that fits over stock rotors. You can use either the 10.9" Sport (compatible with pretty much all the four-wheel BBKs on the market) or the 9.9" 1994-02 rotors. No spike in rotor costs, you can use factory parts. Billet mount, blah blah blah. Available NOW, everything is in stock. $495 for calipers, pads (Wilwood E), lines and brackets.

Two, the same Powerlite setup with a parking brake. It's the same caliper sold by Rallydesign, we got permission to use it. We've been working on these for a while and I actually had them on my car at the MRLS event. I'll admit that even when it's working well, the brake is enough to hold the car on a mild slope and not much else. Not for the drifters. But it's good enough to satisfy SCCA regulations, so you can be legal. We're waiting for more calipers (the sets we have are pre-sold), but they should be shipping in a month or two. $595 for calipers, pads (Wilwood E), brackets, lines and cables.

As far as I know, every pad manufacturer (other than Hawk) can provide pads for the Powerlite.

Oscar 07-11-2013 04:04 PM

In for e-brake powerlite groupbuy

Keith@FM 07-11-2013 04:07 PM

2 Attachment(s)
We'll do a group buy for $595, how's that for a deal?

They're now up on the site:
The Track version (no parking brake) is $495. That includes the calipers, pads (Wilwood E compound), lines and brackets. We have these in stock and ready to ship.

The Street version (with parking brake) is $595. That includes the calipers, pads (Wilwood E compound), lines, brackets and custom cables. We're waiting for some more calipers on this one, it will likely be 6 weeks before they're able to ship.

https://www.miataturbo.net/attachmen...ine=1373573402
https://www.miataturbo.net/attachmen...ine=1373573402

schmoo 07-11-2013 06:06 PM


Originally Posted by Keith@FM (Post 1030779)
One, a Powerlite setup that fits over stock rotors. You can use either the 10.9" Sport (compatible with pretty much all the four-wheel BBKs on the market) or the 9.9" 1994-02 rotors.

How is this possible? Different mounting brackets?

I'm guessing you would pair these with a BBK, not the LBBK. Right?

Leafy 07-11-2013 06:10 PM


Originally Posted by schmoo (Post 1030864)
How is this possible? Different mounting brackets?

I'm guessing you would pair these with a BBK, not the LBBK. Right?

FM is doing different mounting brackets, but since these are radial mount calipers it would be just as easy to make a mount for the 10" disks and use a spacer between the mount and the caliper for the 10.6" disks, or shit another spacer for 10.75" or 11" wilwoods (assuming the hat offset for miatas is the same front and back). But you'd need some MONSTER front brakes to end up with the correct balance with the bigger choices.

I think the killer set for anyone that requires an e-brake would be the FM setup with TSE rotors. Either the 9.9" block will fit, or it'll fit with a piece of 0.050 shim stock in between the caliper and the mount.

Keith@FM 07-11-2013 06:12 PM

Yes, we have different brackets for each rotor. Although theoretically you could add 1/2" spacers to the 10" version and use the 11" rotor - it's a radial mount caliper. Not my preferred way to do things given the choice, but it's a legitimate option.

I have mine paired with a LBBK for street use. Nice and light and compact. On the Targa Miata, I've got the 11" BBK with four-piston Dynalites in the front and the Powerlites in the back.

In other words, pair them with whatever front brakes you need, the fronts are still going to do the bulk of the work.

Note that the offset is not the same front and back. More importantly, the rear rotors are non-vented. I'm not sure we can get the parking brake calipers in a wide size for a vented rotor. We've designed brackets for front rotors on the back, but haven't put them into production because we're not convinced that there's a need for a vented rotor on the rear.

Leafy 07-11-2013 06:16 PM

Are you going to offer different piston sizes? My calcs put a 10" front and rear setup as wanting the 1 3/8" piston in the front and the 1" in back. I havent run the numbers for different sized rotors in the front, but it's going to either require a bigger bore caliper or bigger diameter rotor to keep the balance, even with a bias valve.

Keith@FM 07-11-2013 06:25 PM

Surprise surprise, those are the exact piston sizes we use. Check your factory service manual and you'll discover they're a pretty close match to stock. I would recommend similar rotor sizes front and rear. 11" front means 11" rear, 10" front means 10" rear - roughly.

Remember that if you start to monkey with piston sizes, you're also getting into effects with your hydraulic system.

Weight savings: 3.15 lbs per corner for the track version when compared to a 1994-02 stock rear caliper. That was weighed without pads, I'm assuming they'll be pretty similar. The parking brake version is ever so slightly heavier, so let's call it 3.0.


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