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New style of brake shim plate

So, I get bored over the long track day off-season and that gets me thinking about solving fiddly little problems that bug me when I have to deal with them. Last winter designed a hub extension for the rear hub that maintains hub-centric fit on the rims when you're using flat spacers that are too thin to be hub-centric.

This winter I solved another fiddly problem: How to make the factory GT350 front caliper pad anti-rattle springs work with Pagid and other race pads. The factory pads have a ramp for the spring to push against. That ramp's absent from most racing pads.

Here's what it looks like:

IMG_20210430_161835 Cropped Small.jpg


It's a stainless brake pad thermal shim with a ramp that enables the pad hold-down spring to work properly in the GT350 front caliper. Most racing pads, like the Pagid RSL29 in the picture, have a backing plate without the sloped shoulder on the OEM backing plate, allowing the pads to rattle around in the pocket.

IMG_20210501_114245 Cropped 2.jpg
IMG_20210501_114318 small 2.jpg


Another feature of the plate is that it has hooks on the lining side of the pad. If you've ever messed around trying to get a pad and a titanium shim both lined up so you can put the retaining pins in, these hooks anchor the plate onto the pad so the two pieces stay together. It's vastly easier to install.
IMG_20210430_162020 Cropped small.jpg


Three obvious questions:

1. Why stainless? First, surprisingly, it's about 50% better at blocking heat than titanium - I always thought titanium was the gold standard, but apparently not. Also, titanium doesn't like sharp bends - it tends to break - so it was stainless or nothing.

2. Why the slots? Stainless sheet is springy and not perfectly flat, so the slots divide the shim into three separate segments that are free to move separately. Each segment shields one piston. Dividing the plate up eliminates the risk that the natural springyness of the stainless sheet might push the pistons back. As for reducing the thermal performance, the slots are positioned to miss the piston dust shields by a wide margin.

3. Are they for sale? No. I did them just for fun - I learned CAD drafting years ago and it's a great way to while away the hours waiting for track season to start. This is the 46th revision of the design done over about two months. Maybe someone who makes stuff like this will be inspired to make these...
 
Nice! I could be mistaken but I believe the GT350 and PP pads have generally the same shape, just GT350 pads a bit taller. Just some minor trimming of these and they should work on the PP?
The PP pads are the same basic outline with a shallower pad depth. It's easy enough to adjust the design to make it work for PP brakes, but I don't have the dimensions that I need to validate the design. The reduced height is fairly easy, but verifying that the slots are in the right location requires an actual used pad to measure the marks the pistons make. The pistons are not exactly in the nice orderly row that you see on the outside of the caliper, and the slots have to positioned to take that into account.

As for selling them, I'd love to, but it's just not practical. The plates are the easy part - it's the rest of the rigmarole that's expensive and time consuming. Interestingly, from a cost perspective, even with the bending, they'd be competitive with the flat titanium plates we've all been using.
 

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