A little background on one of Ronin's longer running projects and then a request for the forum...
In the last couple months I actually made a great deal of progress on the Ronin FD Mandeville big brake kit. We didn't advertise this because I didn't want folks getting super excited before we were truly ready to go. It got as far as cutting the first full batch of caliper spacers and getting permission from Roger Mandeville to order the proprietary hats and rotors he used to provide back when (better offset than anything else we'd found).
Then we hit a fairly substantial snag. Because this is a relatively smaller diameter gain than the FC kit I discovering that the bolt pattern wants to be closer together than we can actually package while leaving any meat left for the hardware to engage. The only other alternative is to move the caliper further out than I want and live with significant pad overhang (give or take 3/16") and/or the rotor not being centered in the caliper slot (both were compromises that existed in the original Mandeville kit that I assumed I could improve on; I'm not so sure it's possible anymore). We've looked at rotating the caliper around the radius and some other tricks and the small(ish) diameter gain is just a pain in the ass. Plus if we users had to jump directly to the hardcore two piece rotors this kit would end up being dramatically more expensive than the FC version so living with design compromises makes this a less compelling offering than we'd like.
Basically what needs to happen now is that we try to find a bigger rotor such that we can use the type of bolt to bolt spacing we want for the adaptor bracket. It needs to be a 13.25" diameter rotor minimum (13.5 would be better), however we really can't get much larger than that or the caliper body becomes the limiting factor. If at all possible we'd like to keep this capable of working with most 17" wheels. A fairly deep rotor hat would be a big bonus in helping these fit like OEM. 26 to 30 mm thickness would be acceptable. We have enought irons in the fire right now that I'd rather not have this one languish indefinitely so I'm throwing out a request for assistance. Rotor suggestions? Sources for custom 13.5" rotors and/or hats?
Oh, BTW, if you think you're a hotshot and can solve our bracket conundrum shot me and line and we'll hook you up with caliper spacers inexpensively to let you try (provided Ronin is given rights to the design if it works.) We cut 5 sets of the caliper spacers to try them out since I was already confident in the CAD work for those.
-Joel
Got any pictures of the bracket conundrum? Having a hard time picturing it.
Weren't 305Z rotors what some people used with the brembo caliper swap?
Oh and btw, I'm happy to hear ya'll are trying this.
Got any pictures of the bracket conundrum? Having a hard time picturing it.
I'm on the road this week but I'll see if I can do a Cad sketch. In the meantime let me try another description. Picture the caliper to mount point interface but with no bolts so you're just holding the parts in place... If you wanted to run a bigger rotor you'd need to slide the caliper out radially while keeping the mount to caliper interface in the same plane. If the upsize rotor was only a 1/4" bigger clearly this wouldn't work because the bolt holes still overlap. In my case I want to slide the caliper out to a position where the caliper hole is just barely clearing the mount point but I can't because there's nothing for the threads to engage on the backside since the surface of the bolt protruding through to where the bracket must land is already in line contact with the knuckle mount point. This means I have to move out more than I want (and pad overhang goes to hell.)
Weren't 305Z rotors what some people used with the brembo caliper swap?
Works great on FC. Diameter is too small and offset is terrible when you look at FDs.
As to the rotor recommendations, I'd prefer to avoid using a rear rotor in front sice most of them use integral e-brake drums. 13.75 its getting too big sure the caliper body and unlikely to work with 17" wheels.
Is the offset too low for the 3rd brake rotor listed?
Personally what I would like to see happen over another Front FD kit is a solid rear kit. That would work with the FD fronts that are already out there.
I have seen Brembo say they will make a kit for the rear thats in the 3K range. Also hear that Performance friction is doing the same but they want a car for mock up and want 3K too. The fronts have the been there done that got the T-shirt feel. I need rears that are up to the task of the big fronts.
I know what your going to say why not look at the Racing Brake rear. Sorry but its not that great. The fact is you are still using the factory rear caliper and its not enough.
That makes more sense now Joel. It sounds like clocking the caliper to another location could be the best solution. I wonder if the caliper is too heavy to hang off a bracket like that semi-unsupported.
It'll be difficult to clock the caliper because of the configuration of the knuckle and the caliper body wanting to be in the same plane. It's a 3D problem so harder to describe but it's not at all a slam dunk.
To bring this back from the grave:
I am glad to see there was more movement at one point to use the stock front calipers. Was anymore work done on this?
Some images of the Mandeville kit are here:
https://robrobinette.com/bigbrake.htm
