Shut your mouth.

I just installed Porterfield RS4 race pads with some used (turned) rotors. I have 1.8 brakes with 1.6 calipers. It sat for a while outside in the rain before I drove it, and the rotors rusted. No biggie, I know it wears off, but the new pads haven't worn off the rust on the inside of the friction surface on the front rotors. This is exactly how the last two sets of Hawk HP+ pads wore, they came off the car in a wedge shape, with a lot of wear on the inside of the pad, with about 30-40% on the outside.

Does anyone think that maybe running the 1.6 calipers with the 1.8 rotors/pads/caliper brackets is a bad idea? Or are the calipers EXACTLY the same? it appears the little "prongs" that press on the pad might be too short, or bent. Said prongs are circled in red. Not my car, if anyone wants to see the proof of my non-derusted rotors, I can take a pictures tomorrow when its light out.

Attachment 206541

I thought that was a known issue, and that the 1.8L front calipers should be upgraded along with the brackets.

I can't believe you were treated so kindly! You ignored everyone trying to help you, seemed to refuse to do anything yourself and then came up with "anyone" when all the answers were spoonfed to you. :vash: This ain't Mnet. You'll get your peepee spanked when you are being a complete idiot.

Post up a vid on youtube of you punching yourself in the face several times and some around here might actually try to help you again. Otherwise I think you are out of luck getting help in the future.

If that's the case I'll be buying some used 1.8 calipers, I don't wanna ruin my new pads. Can anyone else varify?

Maybe I should stop posting while trying to study for finals, I promise I'm not normally this retarded!!

What I read up on was mainly about the pads sitting properly between the caliper and the bracket. I believe the larger pads have different tabs on them.

It was also noted that the 1.8L calipers have longer fingers on them.

Between the two I decided it was best to find a set of calipers with brackets to do the upgrade.

If you need 1.8 calipers let me know, a friend of mine parts out and builds spec Miatas as well as other track prepped cars, usually has 8-10 Miatas on average for parts. I actually need to head up there this week due to a cracked rear rotor and could pick some up if needed. It's almost an hour one way, so I try to not drive up too often. I think I might hit him up for some 1.8 prop valves if anyone is interested.

Unless my '94 has 1.6 calipers for some reason, I get the same wear issues if I get the brakes REALLY hot. I am able to wear street pads evenly, and I wore a set of Raybestos ST-43s and half a set of Carbotech XP12s evenly, but once I started going really fast the brakes overheated and I warped backing plates on 3 sets of pads. I need to pull the front brakes apart again (4th or 5th time in 4 weeks), replace the pads, and see how they wore at Buttonwillow.

I can't get it to load at work, but it should tell you what % of pressure goes to the rear compared to the front. The rears get less than the front, hence "front bias". With too little front bias, you risk spinning your car like a top when apply the flaps.

The calipers from the 90-97 are the same IIRC.


In it's lowest setting the Wilwood proportioning valve puts the rears at a 57% reduction, i needed more still, but it was an improvement over the stocker.

If so then there was a thread here a few months back that is misinforming folks.

I read in more than one instance that I should get the 1.8L* calipers as well as the brackets to avoid funny wear on the pads.

My '92 and '95>96 FSM show the same part number for the "body & piston"

NA75-33-71X
NA75-33-61X

Cool, thanks, I won't worry about sourcing calipers then.

So you're running the original 1.6L calipers with your Corrado rotors no problem?

This is the exact setup I'm shooting for.

correct. 1.6L calipers, 1.8L brackets & pads, and corrado rotors.

I get the angled wear at track days also. Stock 94 calipers and brackets. In my research into upgrading to bigger calipers many of the 6 piston units have varied size pistons from the front to back to prevent this. Savington had posted up a really good pic showing this wear pattern. Mines never been quite this extreme and is as much front to back as top to bottom!

Attachment 206533

There you go redeeming yourself. Good job!

I wish I took a picture of mine. i've gone to the backing plates on the track (ebc redstuff @ 170rwhp), but it was perfectly even wear.

Thanks again for the clarification.

Looks like some guys are just too hard for any Miata calipers on the track.

That's exactly how my last two sets of tracked HP+ pads have looked, there's a lot of life left in that pad if it wore evenly.