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-   -   Radial mount caliper discussion (https://www.miataturbo.net/race-prep-75/radial-mount-caliper-discussion-54434/)

curly 02-07-2011 02:07 PM


Originally Posted by bbundy (Post 687010)
http://www.wilwood.com/Calipers/Cali...%20Low-Profile
Bias would be an issue because it only comes with small pistons however.

And only with 5.25" lug mount, unless I'm reading wrong.

bbundy 02-07-2011 02:30 PM


Originally Posted by curly (Post 687048)
And only with 5.25" lug mount, unless I'm reading wrong.

Yea but the profile of the caliper and the pad it uses looks like it would be useful for fitting in 13" wheels.

Either one of the calipers I mentioned fits in small wheels better than Dynalite.

Bob

sjmarcy 02-07-2011 02:54 PM

Look for more space for thicker front discs too…more thermal mass and cooling capacity. I should lay something out along those lines. After all I keep getting stock bits to work wonderfully with some mix & match and tuning.

bbundy 02-07-2011 05:44 PM


Originally Posted by sjmarcy (Post 687081)
Look for more space for thicker front discs too…more thermal mass and cooling capacity. I should lay something out along those lines. After all I keep getting stock bits to work wonderfully with some mix & match and tuning.

Simply won’t work well with the Dynapro Radial and 11.75" rotors in many 15" wheels. Not enough room between the tie rod end and the spokes. The DynaPro Radial 11.75" with .81" rotors is simply the best combination of parts that currently fits in 15" wheels for the high HP track junky in terms of performance and longevity. You will be giving up pad thickness to get rotor thickness and pad thickness is the better thing to have more of to reduce wear replacement costs due to pad life. Thermal capacity of an 11.75"X.81” directional vane rotor is pretty well suited to the task as it is.

Bob

sjmarcy 02-07-2011 06:15 PM


Originally Posted by bbundy (Post 687132)
Simply won’t work well with the Dynapro Radial and 11.75" rotors in many 15" wheels. Not enough room between the tie rod end and the spokes. The DynaPro Radial 11.75" with .81" rotors is simply the best combination of parts that currently fits in 15" wheels for the high HP track junky in terms of performance and longevity. You will be giving up pad thickness to get rotor thickness and pad thickness is the better thing to have more of to reduce wear replacement costs due to pad life. Thermal capacity of an 11.75"X.81” directional vane rotor is pretty well suited to the task as it is.

Bob

Except that other cars with similar space issues have solved the issue...

bbundy 02-07-2011 06:53 PM


Originally Posted by sjmarcy (Post 687151)
Except that other cars with similar space issues have solved the issue...

If you feel the need then you can work it out.

I want to see pictures and data logs of how wonderfull it is compared to the 11.75X.81" setup though.

Bob

falcon 02-07-2011 11:31 PM


Originally Posted by bbundy (Post 687010)
I think the caliper you want for that is the PowerLite. I have done a little thinking about smaller as well.

http://www.wilwood.com/Calipers/Cali...name=Powerlite

Then I just noticed this guy which looks like it could have some advantages as well.

http://www.wilwood.com/Calipers/Cali...%20Low-Profile
Bias would be an issue because it only comes with small pistons however.

The standard Dynapro Radial Mount really wants to work on 11” rotors or bigger. I'd recommend you go with the Powerlite radial mount calipers

Bob

I originally was going to use the Powerlite, but the current lack of pad choices and the smaller pad surface area made me go for the Dynapro.

According to Wilwood's schematics on a 275mm rotor (10.8'') the radius measurement from the center of the bore to the edge of the caliper is 156.2mm. Diameter being 313mm. The Panasport C8's I plan to use have a barrel diameter of 320mm. It will be tight, but it should work.

If it ends up not working out, I'll downsize to the Powerlite but I would rather give a proper caliper a go first. Going to the Powerlite would only give me an extra 6mm clearance on the overall diameter. And if the Dynapro ends up being rather tight, I noticed that have about 5mm of un used rotor surface the hub (I can tell by where the pads were biting on the old Dynalite setup). So I can turn the rotors down from 275mm to 270mm and adjust the mount as needed, hopefully allowing enough space.

Going this way will allow me to keep the larger pads, ideal piston diameter and more fluid in the caliper itself for cooling.

A local friend of mine is using Powerlites on a 10.1' rotor on his MK1 Scirocco race car under 13'' Keizers and has over an inch of barrel clearance all around.

http://www.wilwood.com/images/Calipe...ount-cm-lg.jpg

bbundy 02-27-2011 01:48 AM

1 Attachment(s)
I was digging through some old photos and I found a photo that really helps illustrate why the radial mount Dyna pro caliper fits 11.75” rotors in 15” wheels better than the popular Dynalite.

Blue backing plate is a Dynalite pad back to back with the used Dynapro radial pad. The shape and area of the friction material is Identical between the two. You can really see how much less material sticks out past the radius of the rotor with the DynaPro radial. Both calipers use just as much radial space as there respective backing plates do.

Bob

falcon 02-27-2011 03:11 AM

1 Attachment(s)
And that right there is one of the reasons I ditched my Dynalites in favour of my new Dynapros for the setup I'm having made for my Panasports. I've had a few people tell me it wont work, however I have spoked directly with Wilwood and they said with my rotor diameter (10.6'' OEM NB Sport Rotor) that I will have no issues with the C8's if the brackets are made correctly.

Same idea applies with the 11.75'' kit. Less space being taken by the caliper = more room for rotor or more room for a smaller wheel if you use the same size rotor.

Did I mention how big these things are though in comparison to my dynalites?

Attachment 190690

curly 02-27-2011 04:01 AM

1 Attachment(s)
Pads don't cause interference, the edges of the calipers do first.
Attachment 190689
And falcon, I hope you're measuring caliper clearance right behind the spoke, not the final drum diameter.

Savington 02-27-2011 05:02 AM


Originally Posted by curly (Post 694960)
Pads don't cause interference, the edges of the calipers do first.

Bob's point is that the DP4R is a slimmer caliper overall.

falcon 02-27-2011 04:31 PM


Originally Posted by curly (Post 694960)
Pads don't cause interference, the edges of the calipers do first.
http://i228.photobucket.com/albums/e.../brakewear.jpg
And falcon, I hope you're measuring caliper clearance right behind the spoke, not the final drum diameter.

Yes the caliper causes interference. I think bob was just trying to show how much slimmer the dynapros are by showing pad size.

And I already figured out I need 5mm spacers which is fine. C8s dont have a drop center.

Todd TCE 03-01-2011 09:48 AM

The DPr is simply a more compact offering for a tight fit. This is accomplished by lowering the mount height down and around the rotor edge tighter than the FBDL calipers do. They also incorporate a tighter radius at the transition around the rotor edge negating those bumps you see on the DL stuff. The DPr also does not have the pad abutments which can often contact a hat at low mounting heights on the DL also.


All of that substantiates much of what Bob has been saying since the start of the thread; for a low profile fit and max rotor fit inside a 15 this is really the best choice on the market. In fact as is the case on the Subaru and rally wheels it can even run a 12.0" rotor. The same fit for a DL will be pretty much limited to about 11.2-11.5" max depending upon wheel design.

just sayin...

bbundy 03-01-2011 01:02 PM


Originally Posted by Todd TCE (Post 695707)
The DPr is simply a more compact offering for a tight fit. This is accomplished by lowering the mount height down and around the rotor edge tighter than the FBDL calipers do. They also incorporate a tighter radius at the transition around the rotor edge negating those bumps you see on the DL stuff. The DPr also does not have the pad abutments which can often contact a hat at low mounting heights on the DL also.


All of that substantiates much of what Bob has been saying since the start of the thread; for a low profile fit and max rotor fit inside a 15 this is really the best choice on the market. In fact as is the case on the Subaru and rally wheels it can even run a 12.0" rotor. The same fit for a DL will be pretty much limited to about 11.2-11.5" max depending upon wheel design.

just sayin...

You should thank me. You might get some good business out of my ranting.

I tried this fit first and for some reason brake suppliers that make money selling these things haven't picked up on the advantages of this setup for the Miata and ran with it. Better fit stiffer caliper with significantly longer pad life due to thicker pads.

Bob

Todd TCE 03-01-2011 01:51 PM

And I have but not here. So 'thank you'.

I've actually been down this road one time before Bob and it met with some rejection due to price. But that's another story we can talk about some other time.

I think the project has some potential but I'll also state the limitation with this is going to be the installation. Few folks are going to have the tools or desire to really "drill it out" to make it work. It sounds good and seems simple enough but it requires a 1/2 drill and some moxie to do it without messing things up. Ideally I'd suggest it be done off the car in a mill. The other option is to change the bolt-up format and if there were to become some interest in it maybe I'd look deeper into that too.

Anyhow, yes a fine adaptation of the MINI kit nevertheless, just not sure it's going to be for everyone.

sjmarcy 03-01-2011 02:19 PM

Back when I used to design aftermarket braking systems, a rule of thumb was that you could generally fit a rotor about 3 inches smaller than the wheel diameter, and often a bit larger. Look at all the Nascar 12.19s in 15s fer instance. If you lay things out properly, you can fit thicker rotors than most Miata BBKs utilize. This would have various benefits.

mx5booster 03-01-2011 10:49 PM

I would like to say "Thank You" to both Bob and Todd. I order the kit from Todd with all the parts needed. It showed up in less than two weeks. I am very impressed by the service and promptness. I am hoping to find some time to do the install in the next few weeks. I will report back with the results.

Bob, thanks for blazing the trail for the rest of us.

ZX-Tex 03-01-2011 11:01 PM

Looking forward to seeing and reading more about your install.

Todd TCE 04-10-2011 07:24 PM

Been a month now...any final installed pics or result noted?

bbundy 04-12-2011 12:34 PM

I will say that with my current brake setup Radial mount Dynapro Mini 11.75” fronts 11.44” rear with sport calipers and 1.6l pads I tend to go through rear pads faster than I do the front pads. The front pad life is huge compared to any other Miata setup.

Bob.

cueball1 04-12-2011 12:45 PM

I've got a Mini Cooper kit on my car and a STUPID question/comment! Drilling the holes larger was easy. Some experimenting with a handful of thin washers, used as spacers, is all the fiddling needed. It was so easily adapted to the Miata why even mess with a Miata specific front kit? Did I miss something?

bbundy 04-12-2011 01:08 PM


Originally Posted by cueball1 (Post 713443)
I've got a Mini Cooper kit on my car and a STUPID question/comment! Drilling the holes larger was easy. Some experimenting with a handful of thin washers, used as spacers, is all the fiddling needed. It was so easily adapted to the Miata why even mess with a Miata specific front kit? Did I miss something?

I think the thing that TCE offers is a extreemly competative price and one stop shoping for the centering rings longer mounting studs spacers and hoses needed to make it Miata specific.

Bob

cueball1 04-12-2011 01:12 PM

Centering rings. That's what I forgot! Doh!

Todd TCE 04-12-2011 01:20 PM

Thanks for the updates guys.

Bob; those little calipers and pads are maybe a tad to small for realistic life? Obviously wear is related to total cubic inches...there's not much of that. An alternative to that might be to run a small four pot to pick up some pad size. There are a couple of 1.0" bore parts to pick from.

As for the holes I totally agree that it's probably 'simple to drill them out' but trust me here; selling something that requires this or modifications to that extent is tougher than you may think. People want and expect bolt-on simplicity. And to a great extent I agree; knowing my phone won't ring on Monday about how it's all jacked up for some reason. But for those who can- can.

bbundy 04-12-2011 03:40 PM


Originally Posted by Todd TCE (Post 713458)
Thanks for the updates guys.

Bob; those little calipers and pads are maybe a tad to small for realistic life? Obviously wear is related to total cubic inches...there's not much of that. An alternative to that might be to run a small four pot to pick up some pad size. There are a couple of 1.0" bore parts to pick from.

As for the holes I totally agree that it's probably 'simple to drill them out' but trust me here; selling something that requires this or modifications to that extent is tougher than you may think. People want and expect bolt-on simplicity. And to a great extent I agree; knowing my phone won't ring on Monday about how it's all jacked up for some reason. But for those who can- can.

Yea I plan on updating my rear caliper adapter brackets eventually to run Sport brake brackets and pads in the rear. The bit more pad area they offer would be good for the rear. The adapter bracket will become a bit more complicated though.

And yes the holes are very easy to drill out. It is hardly removing any material to go from the slightly oversized for 10mm bolts holes to 11.1 mm for the 7/16 bolts that mount the Mini Parts. Chasing the holes with a hand drill is easy.

Bob

bbundy 04-12-2011 03:42 PM


Originally Posted by cueball1 (Post 713455)
Centering rings. That's what I forgot! Doh!

I dont think just using the studs to center the rotors with the hub is accurate enough.

Bob

mx5booster 04-12-2011 07:32 PM

Not Yet
 

Originally Posted by Todd TCE (Post 712736)
Been a month now...any final installed pics or result noted?

I have been busy building my motor the last month. I will post some pics when it is done.

cueball1 04-12-2011 08:55 PM


Originally Posted by bbundy (Post 713508)
I dont think just using the studs to center the rotors with the hub is accurate enough.

Bob

I have centering rings with mine. Just forgot they wouldn't come with the Mini Cooper kit. Bought mine used and the rings were included.

NiklasFalk 05-04-2011 11:09 AM


Originally Posted by Todd TCE (Post 713458)
Thanks for the updates guys.

...

As for the holes I totally agree that it's probably 'simple to drill them out' but trust me here; selling something that requires this or modifications to that extent is tougher than you may think. People want and expect bolt-on simplicity. And to a great extent I agree; knowing my phone won't ring on Monday about how it's all jacked up for some reason. But for those who can- can.

Todd, do you have a complete list of items available on your side so it's easy to order when I feel the urge to be creative with my economy?
The exchange rates are good nowadays so it's tempting, but I have a racing season to manage too (and bigger brakes doesn't help if you have to stay at home).
Is XP10 as compound available from TCE or can the parts/kit be bought without pads?

The toughest part for me would be to source a 1/2" drill bit... :)

bbundy 05-04-2011 12:00 PM


Originally Posted by NiklasFalk (Post 723102)
Todd, do you have a complete list of items available on your side so it's easy to order when I feel the urge to be creative with my economy?
The exchange rates are good nowadays so it's tempting, but I have a racing season to manage too (and bigger brakes doesn't help if you have to stay at home).
Is XP10 as compound available from TCE or can the parts/kit be bought without pads?

The toughest part for me would be to source a 1/2" drill bit... :)

The bolts are 7/16" or 11.1125mm A 12mm drill would work good. The stock bolts are 10mm but existing holes are probably 10.5-10.75 mm. It dosn't take much enlarging to get the 7/16" bolts to slip through.

Bob

Todd TCE 05-06-2011 07:34 PM

As Bob points out the bolts are 7/16 SAE or roughly .437". Enlarging them to 12mm would be foolishly large in my opinion and loose. (we have sleeves for that reason...!) A 7/16 bit would be much closer to the needs of enlarging the holes from M10. Of course the fact that a drill bit does not drill a true round hole coupled with hand held use makes it nice for a bit larger hole and more "fudge factor". Metric bits in the 11.25mm range are not hard to come by. A good reamer is all anyone really needs I bet.

As for the parts....I have them noted on a build or spec sheet for production. While I'd be happy to sell you a MINI kit and all the related parts to do the conversion I think you'd find spec the entire package from me as one unit more to your liking. And less expensive. Getting a kit without pads does not pose any problems either. But I'd not jump ship on some of the pads offered by Wilwood either, there are quite a few very well proven compounds.

bbundy 05-13-2011 12:07 PM


Originally Posted by Todd TCE (Post 724302)
As Bob points out the bolts are 7/16 SAE or roughly .437". Enlarging them to 12mm would be foolishly large in my opinion and loose. (we have sleeves for that reason...!) A 7/16 bit would be much closer to the needs of enlarging the holes from M10. Of course the fact that a drill bit does not drill a true round hole coupled with hand held use makes it nice for a bit larger hole and more "fudge factor". Metric bits in the 11.25mm range are not hard to come by. A good reamer is all anyone really needs I bet.

As for the parts....I have them noted on a build or spec sheet for production. While I'd be happy to sell you a MINI kit and all the related parts to do the conversion I think you'd find spec the entire package from me as one unit more to your liking. And less expensive. Getting a kit without pads does not pose any problems either. But I'd not jump ship on some of the pads offered by Wilwood either, there are quite a few very well proven compounds.

You are correct FWIW the stock Mini Wilwood Kit comes with sleeves for the mounting holes on the Mini Knuckles I assume the Mini in stock form actually uses 12mm caliper bracket bolts where the Miata uses 10mm. A die hard American company like Wilwood apparently refuses to do metric hardware and uses 7/16"

Bob

Todd TCE 05-13-2011 11:16 PM

Oh don't sweat it....20yr dealers like myself have begun to show them the way to easier production and lower costs. Ie. brackets drilled and tapped to spec! lol


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