Hello RX7 Folks,


I don't have an RX7, but I do have FD calipers on my car (they work great).

Here's the issue:

According to Mazdatrix, there are different part numbers for FC (4-pot) and FD calipers:

33-28ZD-FB71

33-28ZA-FDZ3

Now, track pads like Hawk, Porterfield and Carbotech all have one part number for both calipers. When I designed my setup, I used 4 sets of pad to determine radial caliper positioning. The setup was perfect. When I ordered a set of R4s from Porterfield, the top 2mm of the rotor ended up being unused. I called Porterfield and explained the situation, and they said their mold may have shifted, and they'd look into the problem (they even offered to replace the pads). This was last fall.

I recently purchased a used set of calipers on Ebay, and they came with some used pads, that actually match the size of the R4s perfectly. Upon further inspection, I can clearly identify the different pad sizes based on the pictures on the Mazdatrix website.

The measurement of the "original" pad I used had a pad height of 52mm. The R4 pad height is 49.5mm. I'm speaking of the actual pad surface, not the backing plate.

I really want that 2.5mm of pad!

What I'm hoping is that someone on this board has some input here, or can possibly measure a Hawk pad (Blue, Black, HT-10, whatever) they have lying around?


Thanks!

 

You're talking about HB155 in front and HB158 in back, right?
(Industry numbering standard for brake pads)


-Ted

 

Yessir, HB155.

A.K.A. D-463.


If someone has a set of HT-10's or Blues that they could measure, that's really what I'm looking for. Actually, any Hawk pad will do.

 

I can say that with Hawks I end up with something near 2mm of rotor that is uncovered by the pad. Wears a nice lip around the OD of the rotor.

 

I got HP+ pads for4 POT on a FC and they cover the whole rotor. Not sure if there are any size difference in the rotors between FC's and FD's though.

 

Should added that this is on an FC with 4-pot brakes.

 

Thanks for input, guys.

The FC and FD calipers share identical mounting dimensions.

I spoke to a guy at Porterfield the other day about the issue, and he didn't have much to offer, other picking through their stock and finding something that fits my measurement. Yeah, great help. Just what I want to do every time I need a set of pads.

I ordered a set of HT-10s. Hopefully they fit correctly.

If not, I suppose I'll have to make another set of caliper brackets to move the calipers out 2mm.