Brake upgrade dilemma

Bearmw

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I am in the process of a budget backyard resto-mod of my 1/72 build Bavaria. I will be doing a B35 with Motronic manifold and the tii booster swap. I want to upgrade to vented front rotors (and keep the solid rears) and I have the original calipers with 15 mm thick pads as well as what appear to be E12 or Early E24 vented calipers with 19 mm thick pads at my disposal. I am considering just widening my E3 calipers with the 10 mm spacers and longer hardware to use the 272 x 22 rotor. My question is would it be possible to use the modified E3 calipers with an early E24 282 a 22 mm rotor as a further upgrade by simply grinding a bit of the caliper for clearance or is more entailed? My goal is to maybe have a bit larger diameter rotor and save a little on caliper and pad weight since the E24 ones are quite heavy.

Thanks
 

duct-tape

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the risk of your spacers failing would be my main concern. calipers have a ton of torsional strain on the off-center side of the pistons.
if youre doing the swap, it's best to use all the right parts, especially on brakes. really, thats the only part of the car I won't "get creative" on
 

Mike Goble

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I use the 280x22's on my Bav with the original E3 calipers and the 10mm spacers. I ground away a bit of the caliper to acquire more clearance. The ultimate indicator of sufficient clearance is to go out and get the brakes really hot and listen for interference. If you put a little Dykem on the rotor edges and the inner portion of the caliper you will get a clear indication of where things are rubbing.
 

Mike Goble

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I've had these brakes in for several years and have had no problems related to adding the spacers. I just sourced some longer high grade bolts and torqued them down. You can get new o-rings from a couple of sources.
 

Peter Coomaraswamy

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my 2 cents: Although Mike knows his way around the e3, I am thinking that if you have the e24 calipers it would be much simpler and "potentially" safer to just use them. Just sdayin' Good luck
 

Bearmw

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I am also wondering what needs to be done to the original non-vented disc backing plates/dust shields? In other words, should I attempt to put some holes in them to facilitate more airflow to the rotor center? I would rather use my plates and slightly modify them than to try and find those made specifically for vented rotors.
 

Mike Goble

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There is quite a difference between the backing plates. The originals have a full lip around and no vent holes. The later ones have no lip and vent holes.
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