15" wheels?
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15" wheels?
I have an rX8 application where I need to use 15" wheels. Does anyone know if any of the brake kits for the RX7 (with smaller diameter rotors) or maybe the 10" brakes for the miata can be interchangeable with the RX8? Thanks.
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From: GREAT WHITE NORTH
With all due respect, I cannot imagiune why you would want to downsize the brakes on an RX8. It would be a LOT cheaper to use 17 or 18 " rims than to change rotors and calipers.
could you explain why you need smaller brakes?
could you explain why you need smaller brakes?
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I need to fit a 15" wheel and am not sure if it will fit over the 11.x" brakes, but it doesn't look like it will. I believe we'll have very adquate stopping power with 3rd gen RX7 brakes (used with 15" alloy wheels) for the application being considered. Just wondering if anyone already knows if they're interchangeable. Thanks.
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He's probably doing that to test out a low-gearing experiment. Remember Canzoomer used 17" wheels and had greater acceleration? You guys should keep your opinions to yourselves if you think 15"s don't look bling. He specifically mentioned "I have an rX8 application where I need to use 15" wheels." It's not like he's doing it for style, which most of you are after.
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I asked this same question a few days ago and received pretty much the same answers.
I am sure it can be done as this bolt pattern is very common, it will take a different rotor for sure depending on what you have now, probably some grinding in some places.
A lot of people dont understand that there are other needs out there and only think of the looks of the car or how the car came from factory.
I can see there is A need for this info ,so if someone has this solution it should be shared.
I am sure it can be done as this bolt pattern is very common, it will take a different rotor for sure depending on what you have now, probably some grinding in some places.
A lot of people dont understand that there are other needs out there and only think of the looks of the car or how the car came from factory.
I can see there is A need for this info ,so if someone has this solution it should be shared.
The rotor isn't the problem, the caliper location and size is. You may get away with rotor + caliper from an automatic base model RX8, they're just about an inch shorter.
If that doesn't do it then you're into drilling new mounting holes in the knuckle for another caliper entirely. Miata would probably be the closest match, I'd start there. If not, try Mazda 2WD trucks. Just expect custom fabrication to make it all fit, and since this is a very niche requirement, you may be the first one who actually pulls this off.
If that doesn't do it then you're into drilling new mounting holes in the knuckle for another caliper entirely. Miata would probably be the closest match, I'd start there. If not, try Mazda 2WD trucks. Just expect custom fabrication to make it all fit, and since this is a very niche requirement, you may be the first one who actually pulls this off.
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It's too niche of a question, though. Not a lot of people offroad/rally with their 8, and you are paying money and doing a lot of work for less braking. Naturally, this will go unexplored.
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Hi all.
so I have done a little bit of investigating. Solution for the front. You need to go to a smaller disc. I have used an automatic RX8 302mm brake rotor and calipers bracket and ground down part of the brake calipers on the very top which you will see is very high around 4mm has to come off to fit inside a good 15inch rally rim. You also need to run a wheel space around 10 to 15mm to so the calipers can move in and out with new pads. This is not idea but I will upgrade to a 4 pot calipers like a willwood or AP racing and make up a custom bracket.
You also need to machine the front steering knuckles down around 2-3mm on the lower ball joint mount on the nut side, machine the nut a few mm of the nut and then once back on the vehicle grind the excess thread of the ball joint until it clears the rim. I was look at replacing the front knuckles with a 2009 up Mazda MX5 one as I found a thread which said the lower ball joint mount is closer to the centre of the hub so it should clear but there are hard to get in New Zealand and expensive compared to USA.
On the rear a 15inch rally rim will clear the brakes rotor and calipers but need a 15mm spacer to miss the brake calipers bleed nipple. However it will not clear the lower control arm bush mount. The only way around this is to get and engineer to modify the lower bush mount to bring it closer to the center of the hub and then grind down excess to clear the rim about 5mm need to come off. The rear control arm outer ball joint then need to have a very small touch with the grinder to clear the rim as well.
If you haven’t areadly check out New Zealand Marcus Van Klink Rx8 rally car on YouTube. He has had the rear hub mounts modified along with other modifications to get more traction and the lower front knuckle and nuts machined but is running custom AP racing brake. The thing is a beast.
I will get some photo and add to the forum with the above info when I get a chance.
Cheers
so I have done a little bit of investigating. Solution for the front. You need to go to a smaller disc. I have used an automatic RX8 302mm brake rotor and calipers bracket and ground down part of the brake calipers on the very top which you will see is very high around 4mm has to come off to fit inside a good 15inch rally rim. You also need to run a wheel space around 10 to 15mm to so the calipers can move in and out with new pads. This is not idea but I will upgrade to a 4 pot calipers like a willwood or AP racing and make up a custom bracket.
You also need to machine the front steering knuckles down around 2-3mm on the lower ball joint mount on the nut side, machine the nut a few mm of the nut and then once back on the vehicle grind the excess thread of the ball joint until it clears the rim. I was look at replacing the front knuckles with a 2009 up Mazda MX5 one as I found a thread which said the lower ball joint mount is closer to the centre of the hub so it should clear but there are hard to get in New Zealand and expensive compared to USA.
On the rear a 15inch rally rim will clear the brakes rotor and calipers but need a 15mm spacer to miss the brake calipers bleed nipple. However it will not clear the lower control arm bush mount. The only way around this is to get and engineer to modify the lower bush mount to bring it closer to the center of the hub and then grind down excess to clear the rim about 5mm need to come off. The rear control arm outer ball joint then need to have a very small touch with the grinder to clear the rim as well.
If you haven’t areadly check out New Zealand Marcus Van Klink Rx8 rally car on YouTube. He has had the rear hub mounts modified along with other modifications to get more traction and the lower front knuckle and nuts machined but is running custom AP racing brake. The thing is a beast.
I will get some photo and add to the forum with the above info when I get a chance.
Cheers
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Congratulations on your research, this opens the door for others.
Unknown: money should not be the primary concern when building a specialty car and we are not talking in this mod for a lot of it.
As far as less braking I would have to disagree, although you will have to have a smaller rotor,a lot of these cars will weight a lot less and probably be updated to larger and better calipers, and in some cases the stock caliper will be adequate, also some grinding or changing some parts I consider that minor work VS what it takes to build a specialty car. Maybe by finding the answers to these question more of these cars will participate.
Unknown: money should not be the primary concern when building a specialty car and we are not talking in this mod for a lot of it.
As far as less braking I would have to disagree, although you will have to have a smaller rotor,a lot of these cars will weight a lot less and probably be updated to larger and better calipers, and in some cases the stock caliper will be adequate, also some grinding or changing some parts I consider that minor work VS what it takes to build a specialty car. Maybe by finding the answers to these question more of these cars will participate.
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I asked this same question a few days ago and received pretty much the same answers.
I am sure it can be done as this bolt pattern is very common, it will take a different rotor for sure depending on what you have now, probably some grinding in some places.
A lot of people dont understand that there are other needs out there and only think of the looks of the car or how the car came from factory.
I can see there is A need for this info ,so if someone has this solution it should be shared.
I am sure it can be done as this bolt pattern is very common, it will take a different rotor for sure depending on what you have now, probably some grinding in some places.
A lot of people dont understand that there are other needs out there and only think of the looks of the car or how the car came from factory.
I can see there is A need for this info ,so if someone has this solution it should be shared.
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cornrowdpantha
Series I Wheels, Tires, Brakes & Suspension
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Aug 30, 2006 10:55 PM
