Confirmed: MS3 brakes fit under OEM MZ5 (gen 1) wheels

phunky.buddha

Booga Booga?
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DFW TX
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No mo MZ5 want MX5
I don't know that I ever saw it discussed, but here it is. I overboosted the brightness and contrast on the pictures so that you guys could hopefully see things better. Apologies for the night time pics and lack of additional clearance photos- but we were doing this outside in the snow at 1am on New Year's Day. These are OEM Mazdaspeed 3 front calipers and rotors (my brake conversion on my 5) underneath factory MZ5 wheels. No spacers. It's an extremely tight fit, but it rolled backwards and forwards several car lengths with no scraping. With my NC Miata/MX-5 wheels, it needs a 1/8" spacer to clear. If there's any wheel flex to take into account on the OEM wheels that make them scrape (doubt it, but didn't take it around the block), you could probably take care of it with a 1mm spacer.

I guess it took me getting ready to part the car out to check fitment under these wheels. One day I'll post the step-by-step on the brake install, promise. :)

mz5_wheel_ms3_brakes_1.jpg
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mz5_wheel_ms3_brakes_2.jpg
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Good deal. I've been thinking about doing this now that I have a little wave in my rotor. Thanks for the pictures!!!
 
Good deal. I've been thinking about doing this now that I have a little wave in my rotor. Thanks for the pictures!!!
Welcome!

Very nice! There was a conversion done about 10 yrs ago in a Car and Driver magazine on the Mazda5, where they swapped the drivetrain and brakes from the MS3 into the MAZDA5. I wanted that van so bad after they were done!
Yeah I remember that conversion- I'd think it would be way easier to build a turbo system for the 5 without using the Speed3 hardware and then use a piggyback ECU setup like AEM FIC to manage it. If it was my primary I would have done it already.

What's with all the rust on the calipers? That's unexpected, especially in Dallas.
I didn't expect it either- the calipers were raw out of the box, and didn't have any paint or coating on them at all. I should have painted them before installation, but didn't think to since I've never had calipers do that to me brand new. After a few days I saw the first rust spots- then didn't have time to tear everything down and have the car sit while paint dried- so I just left them. No change in functionality, and keeps it totally sleeper. ;)

I guess I've always done caliper upgrades with solid aluminum calipers and not OEM replacements, so I didn't think about it. My Stoptechs and Wilwoods were all nice shiny black enamel and powder coat out of the box. :D
 
run with the hoodride look ;)



That rust does not look right... Where did you get your calipers from? Are they branded?


Mine came off a wrecked '07 MS3, stamped FoMoCo and ATE. They are perfectly boring silver as the first day I put them on (I'm sure PA endures way more salt than TX and had them on much longer). I am using the same setup on a previous '08 Sport, which I moved to my current '08 GT. IIRC, for both cars, on one side the caliper would clear with a hair line (like your pic) but the 'other' side (I forgot which but recall it was consistent) would rub the caliper bulge against the inner spoke. I used spacers for both cars; previously 8MM on the Sport (looks nice and flush but was too much and lose hub mount) and currently 5MM on the GT. 3MM would likely be the best balance to retain hub centric mounting. I honestly would not recommend running rims that close to the caliper. I can't image if a spoke bends inward (highway pothole) and collides against the caliper.
 
run with the hoodride look ;)

That rust does not look right... Where did you get your calipers from? Are they branded?

Mine came off a wrecked '07 MS3, stamped FoMoCo and ATE. They are perfectly boring silver as the first day I put them on (I'm sure PA endures way more salt than TX and had them on much longer). I am using the same setup on a previous '08 Sport, which I moved to my current '08 GT. IIRC, for both cars, on one side the caliper would clear with a hair line (like your pic) but the 'other' side (I forgot which but recall it was consistent) would rub the caliper bulge against the inner spoke. I used spacers for both cars; previously 8MM on the Sport (looks nice and flush but was too much and lose hub mount) and currently 5MM on the GT. 3MM would likely be the best balance to retain hub centric mounting. I honestly would not recommend running rims that close to the caliper. I can't image if a spoke bends inward (highway pothole) and collides against the caliper.

They're complete Centric brand replacement caliper kits. Caliper and bracket all together, freshly built. I'm really happy with them, so if anyone does them with these calipers, they need to be cleaned and painted. I didn't care that much. Mine started to rust after just a few days, so it wasn't from salt or weather. Just bare metal.

I agree on the rubbing and minimal spacer- but Discount Tire here won't put spacers back in after you've had them on. Not allowed to torque your own wheels back on either in their lot. Liability / legal issues. I actually bought longer wheel studs to accomodate the spacers so thread engagement would be better and Discount wouldn't complain, but I never took the time to put them in before deciding to swap cars.

As far as wheel flex, if the wheel doesn't touch from normal driving and turning, it's not going to bend enough to contact the caliper in other normal driving. They're not supposed to flex. If you hit something hard enough to bend the wheel, you have bigger problems other than 3mm of clearance from wheel to caliper- it's not like you're going to decide to hit a pothole just enough to only use up 2mm of your 3mm caliper to wheel clearance. ;)
 
When I hit a pot hole, I aim for 2mm (or less) my friend :)

Joke aside, meant to imply added margin of safety.


Two other potential concerns (pure speculation based on my limited understanding) with such tight clearance might be heat soak and air turbulence. Calipers get really hot. I wonder if/how this may lead to a problem in the long run with heat affecting the rim spokes. Rims and backing plate/dust shield serve to direct air turbulence when in motion to cool brake components. I wonder if/how this may affect pad/rotor cooling.
 
Honestly? I'd expect the effect to be zero. The cooling is coming from the rotor vanes, not the air in between the spokes and the caliper. There's so much air rushing around in that area while driving that spoke spacing doesn't matter for that. The rotor is the heat sink for the heat generated by friction between the pad and the rotor, and it's designed to cool down by forced convection through the vanes, not by air flowing over smooth caliper housings or flowing over the flat surface of the rotors.
 
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