Racing Brake Caliper Rebuild Kit

[e90pilot]

I'm totally in for new rears but I have a 325 with a smaller hub and spindle. The 135 hat is too deep.

[BiscottiGelato]

Does the 350x28 rotor requires a hat change also? What kind of rotors/rings are compatible with this solution?

[Focusedintntions]

I will answer some of this stuff a bit better after I've had a decent rest....still awake from yesterday and all buzzed up on caffeine after watching all the batman's in a row and then going into work....right now my brain isn't really reading stuff correctly for interpretation haha

[Focusedintntions]

Small update from warren to share

[Focusedintntions]

Ooo OOO updates from Warren!!!



Chris,
I just finished fitment test and the adaptor mfg is released, I will expedite the first set for you in about a week - items will be up on web soon - be patient, those hardware are what take time.

What are we thinking guys??

[e90pilot]

Lookin good!

[BiscottiGelato]

I take it that's the 350 x 28, with the custom hat/hub? What kind of rings fit that hat? What kind of offset wheels fit that hat/hub? What kind of wheels clears the calliper?

[Focusedintntions]

Originally Posted by BiscottiGelato

I take it that's the 350 x 28, with the custom hat/hub? What kind of rings fit that hat? What kind of offset wheels fit that hat/hub? What kind of wheels clears the calliper?

It should be a custom hat for the rotor. The rings that fit that hat are the 350x28 ring he makes that would normally go on the rear of a 997 gt3. It should fit behind stock 18" wheels. Once i receive i'll be fitting everything and taking pictures for everybody.

[e90pilot]

Any idea on how this would affect brake proportioning?

[Focusedintntions]

I have a feeling it's going to toss a bit bias towards the front

[e90pilot]

I wonder if it's possible to do something similar to the rear or adjust the bias electronically. The F30 needs an update if you're upgrading to Msport. Maybe something like that can be programmed for these cars.

[Focusedintntions]

I don't see why not...the other solution though...and its a bit down the road too...is another bracket with a larger rotor in the rear too. There are some additional challenges there though b/c of the parking brake.

[e90pilot]

The bracket for the rear will also be a challenge. The front already has a bracket so making a new one is relatively easy. The rear is different. It has no bracket at all so I'm not sure how you could move its location away from the center of the hub. Then again I'm far from being an expert on this matter lol!

I've got my own problems with the rear brake caliper. Since I have an e90 my offset is different and I can't use a 135 rear rotor. I've been searching for a long time trying to find something that fits.

I'm also hoping it will fit my 17" style 161s. They fit a stock 335 brake with room to spare but not much.

[GaryS]

Originally Posted by e90pilot

I wonder if it's possible to do something similar to the rear or adjust the bias electronically.

The bias is already adjusted electronically by the DCS/ABS. You don't have to do anything. It will sense the difference and boost rear pressure to compensate. But there is a limit. If you increase front rotor size and use higher friction pads in front, there might not be enough margin left in the rear to compensate, and then stopping distance will increase instead of decrease.

[e90pilot]

Electronic brake balance is only adjusted when ABS is active. There's no way for the car to sense bias if the brakes aren't locking. The car will also only adjust it based on known values. This is why in the F30 you need to have the DSC updated when adding M Performance brakes. There us a very large increase in rear rotor diameter. Also, just changing the rear pad compound will adjust bias. The car does not compensate until a wheel has locked. This is one of the big reasons I try and stay out of ABS on the track. The balance profiles are all too far forward.

[GaryS]

Okay. Well that's the reply I got from a Hawk tech when I asked why Hawk recommends DTC70 in front and DTC60 in rear for 135i when it's common knowledge that BMW brakes are forward biased.

Also, you're right, I shouldn't have said it "boosts" the rear pressure. It just waits longer before it reduces the rear pressure. My understanding is that it compares front and rear wheel speeds and adjusts the rear pressure to make them balance.

[e90pilot]

Originally Posted by GaryS

Okay. Well that's the reply I got from a Hawk tech when I asked why Hawk recommends DTC70 in front and DTC60 in rear for 135i when it's common knowledge that BMW brakes are forward biased.

Also, you're right, I shouldn't have said it "boosts" the rear pressure. It just waits longer before it reduces the rear pressure. My understanding is that it compares front and rear wheel speeds and adjusts the rear pressure to make them balance.

You are correct. It's a pretty drastic change in balance when it activates. Even a very slight triggering of ABS will send the balance forward and turn the brake pedal to goo.

[amigo]

So the larger rotor is 350mm - OEM 338mm = 12mm difference in diameter.
Does this mean the caliper has to move 6mm outwards from the axle centre, and this is the adaptor's purpose. Will this effect clearances. Now I have to fiqure out what a mm is? Ok so less than a quarter inch total.
I just measured my stock wheels and my track 17" OZ alleggretta, and the 17" are actually more open inside than stock 18", just the shape of the stock wheels. Go figure.
I'm in.

[Focusedintntions]

Glad to hear you're in Amigo soon as I have the release info I'll post it up here for you guys.

[BiscottiGelato]

I guess, my question is more on what replacement rings costs. It seems to be equally difficult to find the rear rings on these Porsches from aftermarket vendors?

[e90pilot]

I just discovered something. Why didn't you guys just use the 335 front rotor? It's 348x30 vs 350x28 on the one your using and the hat depth is exactly the same and the 135's. Plus racing brake already makes that rotor. Just throwing that out there.

[BiscottiGelato]

Originally Posted by e90pilot

I just discovered something. Why didn't you guys just use the 335 front rotor? It's 348x30 vs 350x28 on the one your using and the hat depth is exactly the same and the 135's. Plus racing brake already makes that rotor. Just throwing that out there.

I think the problem is more the 30mm thickness, which doesn't fit the 135i caliper. Otherwise Focused Intension was gonna go all out and do the 360mm x 30mm rotors from the M3