Changing to larger brake rotors on Miata

I did this using the brake parts from my wrecked '96 on my current '91 model. The difference is amazing.

They look and work much better than the original smaller rotors. The fronts are extremely easy to do, the backs are a lot more difficult, but not too bad if you are mechanically inclined and have the tools.

Your 1990 is so lightweight that it should never need bigger brakes than this other than possibly for racing or for looks to further fill out those 17 inch wheels. I know that seeing those tiny original 1991 rotors through my 16 inch wheels was driving me nuts.

Pat

The RX-7 has a 5-lug pattern, so you would need to replace the entire hub, possibly the entire rear end and halfshafts. The same goes for the new MX-5.

I don't even know if this is possible without major customizing, but it would be very expensive in any case, much more than a big brake kit from Flying Miata or Goodwin Racing.

Pat

The stock Mazda Miata torsen will handle as much power as I would ever want to run in the car, it is way underbuilt for 140 hp. My car has nearly double the horsepower that it did in 1991, and the

2001 torsen handles it with no problems at all.

If you are talking truly serious horsepower, and torque, I would go with the Thunderbird limited slip rear end setup that they use in the Monster Miata kits. That is going to be stronger than the rear end from an RX-7. There is also the Mazdaspeed Racing differential to consider as a direct drop-in for the miata.

Of course, if you want to drag race, just drop a 9 inch solid Ford diff. in there and forget about the handling. :-)

Finally, any 5 lug conversion will require new wheels......

Pat

Ok, does anyone have a generally accepted figure on horsepower/torque numbers where switching to more than 4 lugs becomes a good idea or even mandatory?

Pat

Not clear to me why you would need more than 3 except maybe to accommodate very weak light wheels. Fewer, thicker lugs would have an advantage in bending resistance.

Leon

I wonder why four is the minimum you ever see on typical cars, with 5 lugs being common even on low-power cars.

Of course, Formula One cars use only one in the middle.

I have seen this setup with a single center lug on a miata before as well, it was pretty nifty. The owner had lots of work space, a good floor jack, and power tools. I would think that he could swap his wheels from front to rear in about

5 minutes per side, even faster if he had a good pit crew. :-)

Pat

Because if you one of them falls off the wheel will still be secure with the other 3. Someone I knew drived for a while with one lug missing. In a car with only 3 (small French cars, specially Citroens used to have only

3), if one falls off the wheel will not be secure with only the other 2.

I suppose aesthetics reasons are part of it. Also, some manufacturers probably use 5 lugs on the smaller models so they don't need different parts for each model. But if there is a technical need it is probably related to the weight of the cars (which has increased a lot in the last

2 decades) and not the power. Power is transmited by friction between the wheel and the hub.

Thank you for the clear explanantion. Those can be rare around here at times. :-)

I looked at a couple of salvage cars that a lady was selling. One of the cars had obviously lost a front wheel and had fallen to the street. I asked her about it and she said that some (unwitnessed) kids had loosened every one of her lugnuts but had not taken the wheels. Then she mentioned that her ex-husband worked on the cars when they were married. Kids who vandalize like to immediately see the effects of their vandalism, and loosening the wheels could get an attempted murder charge. Even if they don't realize how serious it is, there just isn't much thrill to them by loosening parts and wondering if anything will happen later. It sounds to me like hubby did not want to pay for a divorce lawyer.

That is what I am guessing with the new MX-5. I am betting that they either have the same hubs as the Rx-8, Mazda 6, etc., or at least share some parts from the hub area.

Thanks!

Pat