Can anyone comment on how close is too close for the top-most part of the BBK to the inner barrel of the wheel? When I test fitted a peeler around my Brembo GT’s (380mm), it cleared, but just barely, maybe 1mm or 2mm clearance. Is that safe? It looks like if I wanted to run these I would need to get them re-balanced with the weights put on the innermost side of the wheel barrel instead of where Audi puts them, which is the outer most side.
Your wheels should not bend any as the tire is flexing. I had on my other car less than 1mm clearance on the spikes and the BBK and never had any issues. Yes wheel weights are an issue if they are on the inner lip.
I have pretty minimal clearance on the face of my summer wheels. Was told I should get bigger spacers in case the wheel bearing goes.
On the BMW forums there’s been a few guys who have the CCB brakes with the factory 19s complain about having pebbles stuck between the caliper and the wheel causing a scored line on the barrel. I would imagine something similar could happen in your case.
The AP racing cleared the peelers no problem. Stoptech and Stoptech Trophy seems to be fine, from other folks I see using them.
An OE+ wheel like a BBS in 19" seems to have plenty of room even for Brembo, though I have a 5mm spacer on the front.
Thanks Guys! I’ve made this car a pain to maintain (and expensive). It’s funny how I do this with every other car.
With 20’s and with the width I need, none of the tires have the right load rating, I won’t ever load the car to its maximum, but some tire shops won’t even touch my car, so I was thinking of going back down to 19s, but with these brembos, clearance will be tight. I just finished dealing with a flat tire that needed to get replaced, which was much more of a pain than usual, which is why I’m thinking about this.
I do love the feel of the brembos, and the look as well. Spacers on 19s would help with the clearance on the spokes, but like was said, I was worried about getting a pebble stuck between the top of the caliper and the barrel. I guess that would be rare. Bent wheels or wheel bearings is a concern though, but probably all of these, including the stuck pebble, would be pretty rare. Though one of my wheels is slightly bent (tech showed me today on the tire balancer), probably due to hitting some new pot holes after the last heavy down pour of rain.
oh well, got to pay to play I guess.
A friend of mine that runs the 380mm Brembo kit on his stock 19s did have a pebble get stuck. Scored his peelers and eventually it went through. I’ve also seen it happen on the track too.
I would not run with such minimal clearance on track.
Same goes with wheel to strut clearance, or in our case, wheel to wishbone.
Definitely put some spacers on there!
The people who try to squeeze an 18" wheel over a 370 or 380 BBK are crazy. Realize with heat the discs expand both in thickness and diameter, and at speed the wheel can go slightly oblate.
The wheels are going to hit the caliper, not the disc.
Went through?
Right. If you’ve got a bolted caliper it also has a tendency to bulge out when the disc expands in thickness and you apply pressure to it. No room to go up, no room to go out.
The Boxster has far better natural brake cooling from 12" rotors with 20" wheels around them. Somehow that looks ridiculous on an SUV with dubs, but looks fine on the 2900 pound Porsche.
Not sure I follow this. So you are saying that the “expanding disc” is causing the caliper to “bulge out”? Why wouldn’t the pistons just contact the disc sooner, i.e. the pedal engage sooner. Maybe if this was a floating caliper, but even then, what you are saying doesn’t make much sense.
Or are you just trying to throw in the word oblate?
So monobloc calipers don’t make sense?
Why are you answering a question with a question?
The caliper is fixed onto the suspension via a bracket. I’m not sure what all this play is that you are referring to. The pistons would engage the disc sooner if what you are saying is correct (about thermal expansion). That won’t move the caliper. It will change when the pedal engages. Not sure how to better explain this.
Here is a pic of a floating caliper:
http://s.hswstatic.com/gif/disc-brake3.jpg
Here is how disc brakes work FYI: https://www.youtube.com/watch?v=OjrY7G8o99U
A 2 piece caliper with a bolt on top can expand outward and contact the wheel spokes, if it’s already close.
Ah ok, now I think I understand where you’re coming from. However, I’m not sure that any kind of caliper flex will be a function of the disc width. Maybe indirectly because of the heat. But directly, the piston will just engage the disc sooner, which should be the same amount of force/level arm inducing the torque on the caliper.
Here, it’s stated that caliper flex isn’t just a product of mono vs 2-piece, but of the material itself. Also, steel bolts that form the bridge actually become stronger as they are heated up (said in the article):
http://stoptech.com/technical-support/technical-white-papers/monobloc-vs-2pc-calipers