rx7/corrado upgrade progress

[CBi]

D,

I had an awful feeling you put the offset in the bracket incorrectly. : (

The brackets should be completely flat. The 1mm of offset should only be in the radial plane. Your brackets (unfortunately) have 1mm of offset in the axial plane.

So, there's good news and bad news. You can salvage your brackets by simply having them machined flat to 13mm.

Great job on the bracket design! Your numbers are VERY close to mine. You could land a f**king jumbo jet with those damn things! : )

With the bracket machined flat, you can use steel shim washers to get the caliper perfectly centered to the rotor. (FYI - Brembo racing calipers use shims for precise caliper positioning)

Since the RX7 rotor is the same thickness as the Corrado rotor (22mm) you should not have any problems once the calipers are shimmed. Make sure you use same number of shims between both mounting bolts, to keep the caliper square and to avoid any binding problems with caliper mounting.

You're on the right track....keep at it.

[BigD]

I'm not sure what you mean about the shims. The 1mm axial offset is necessary. The caliper is not centered without it. (edit: in other words, the 1mm axial offset is not due to misunderstanding your advice, that's my measured offset with the test bracket to center the caliper over the rotor axially) That's separate from the radial offset, which I also have.

[BigD]

As they say, picture's worth a thousand words, here's the final design. Well mine will have the cutout on the other side still, can't fix that now, but it's still plenty thick:

[CBi]

I'm not sure what you mean about the shims. The 1mm axial offset is necessary. The caliper is not centered without it.

You are 100% correct. However, you chose to incorporate the axial offset within the bracket. Early on, I had considered incorporating the offset within the bracket, but I chose not to, because of manufacturing tolerances of the rotors, wheel bearing/hub assemblies, and calipers. Instead of incorporating the 1mm offset in the bracket, I used shims to axially center the rotor.

I used a low-quality "white box" Corrado rotor for measurement purposes, and they were almost a full millimeter out of dimension in thickness and in axial measurement in comparison to a Brembo 1-piece rotor, and the RacingBrake floating rotor. Brembo supplies mounting shims with their professional racing series calipers and rotors (which are virtually unavailable to the public, and are not the same rotors and calipers you see on Subarus/Evos, and the Brembo brake kits that Tire Rack sells) to provide precise location of the caliper in relationship to the rotor.

If you've done your homework, and you measured 1mm of axial offset for your brackets, they'll probably work. The only caveat is if you replace your rotors with another brand, they might not be perfectly centered.

In the grand scheme of things, it's not the end of the world if the rotor is not perfectly axially centered within the caliper. On production street car brakes, the tolerances are pretty loose.

I'm a bit meticulous, and I spared no expense in precision when designing my brake setup. I probably went a bit overboard, but I was happy when everything was done.

[BigD]

You are 100% correct. However, you chose to incorporate the axial offset within the bracket. Early on, I had considered incorporating the offset within the bracket, but I chose not to, because of manufacturing tolerances of the rotors, wheel bearing/hub assemblies, and calipers. Instead of incorporating the 1mm offset in the bracket, I used shims to axially center the rotor.

I used a low-quality "white box" Corrado rotor for measurement purposes, and they were almost a full millimeter out of dimension in thickness and in axial measurement in comparison to a Brembo 1-piece rotor, and the RacingBrake floating rotor. Brembo supplies mounting shims with their professional racing series calipers and rotors (which are virtually unavailable to the public, and are not the same rotors and calipers you see on Subarus/Evos, and the Brembo brake kits that Tire Rack sells) to provide precise location of the caliper in relationship to the rotor.

If you've done your homework, and you measured 1mm of axial offset for your brackets, they'll probably work. The only caveat is if you replace your rotors with another brand, they might not be perfectly centered.

In the grand scheme of things, it's not the end of the world if the rotor is not perfectly axially centered within the caliper. On production street car brakes, the tolerances are pretty loose.

I'm a bit meticulous, and I spared no expense in precision when designing my brake setup. I probably went a bit overboard, but I was happy when everything was done.

Wow, that's crazy about the rotor tolerances... well hopefully if I keep buying form the same source it won't get out of whack.

I know what you mean about being meticulous. This is why I incorporated the offset into the adapter - the spacer method bothered me because it felt like a compromise.

[BigD]

Woohoo, done. That design did it. It almost clears the wheel too, just rubs the paint on the wheel. I might grind the letters down a tad, should still be visible. I also have some 3mm spacers, maybe just use those. Note to self, need to make sure the final hose install comes from the strut side, will rub the tire this way at full lock to the inside.

[240zs30]

Nice work!

[Farbin Kaiber]

Nice bracket. I've been waiting to see one in complete form for some time now.

[mutty]

Woohoo, done. That design did it. It almost clears the wheel too, just rubs the paint on the wheel. I might grind the letters down a tad, should still be visible. I also have some 3mm spacers, maybe just use those. Note to self, need to make sure the final hose install comes from the strut side, will rub the tire this way at full lock to the inside.

Do you intend to make any of these adapters available to others who are interested in doing the swap but cannot make them?

[BigD]

Thanks guys!

Do you intend to make any of these adapters available to others who are interested in doing the swap but cannot make them?

I can ask the shop how much they'd charge to make a set for someone else. They may not work for an ABS car though, I made them as huge as I could and I think they may cover up the ABS sensor hole. And in this day and age of "nothing is my fault and my lawyer says you must pay", I would also expect a written acknowledgement from the buyer that it's just a hunk of metal as far as I'm concerned, and I never said it would work for anything.

So I guess that's a long way of saying no... (unless the shop agrees to do it again for someone else - they're not hurting for money or short on work, and someone agrees to the terms above).

[Hick]

What material are they made from?

[BigD]

What material are they made from?

I was going for 4340 but the machinist said it's a waste of money, he made them out of 4140. It's still a gun quality steel, very tough and also excellent on stress reversals - just not as good as 4340 but also not as expensive, and it doesn't need to be on either count (they make stuff for industrial assembly lines, auto and aircraft industries, so I didn't argue, plus 4140 was 2nd on my list of preferred materials).

[Brian D]

Nice job BigD, I hope you get many years of great braking with those!

As they say, picture's worth a thousand words, here's the final design. Well mine will have the cutout on the other side still, can't fix that now, but it's still plenty thick:

I could have used this info two years ago, as could a lot of other people. Too bad some people (and there were a few) treated it like a military secret. Nice to see it posted BigD, good work.

[BigD]

Nice job BigD, I hope you get many years of great braking with those!

I could have used this info two years ago, as could a lot of other people. Too bad some people (and there were a few) treated it like a military secret. Nice to see it posted BigD, good work.

Thanks dude. And that's precisely why I went to this trouble to document it - because like you I tried to piece the information together but gave up.

[Massive Lee]

Good job, Dmitry.

Lee