1.6 vs 1.8 brakes
 

Front:
http://www.rev2red.com/images/cars/front.jpg

Rear:
http://www.rev2red.com/images/cars/rear.jpg

About 1" larger in diameter F&R, so around 1/4" all the way around. Front pads have signifigantly larger braking surface, although I dont have them yet to compare, so stay tuned.

http://www.rev2red.com/images/cars/padsize.jpg

i did the 1.8 swap a while back, i like them better, will eventually change the prop valve too when i get around to it

Prop valve is different?

I have to get my rotors turned, then my 1.8 upgrade can be finished.

i forget which one it is, there's a few different variations, but certain one is the most desirable, direct swap too, adds in a little bit more rear bias for more even braking

Hurm, I wonder what the stock bias is. I will probably just play with pad compounds in the rear.

I typically have run a race pad in front and a street pad in the rear... but I'm used to FF cars... can't wait to figure the miata out.

hey splitime, who is that dude in your avatar, he kinda looks like the guy off of the powerblocks, Trucks show.

wilwood has a cheap adjustable one.

http://www.flyinmiata.com/index.php?...umber=14-76250

See attached for diff prop valves from diff years.

I did several years ago on old 92. It was great. One of the best mod's I ever did to the car.

I have comparison shots somewhere

front rotors shot

can you tell the 1.6 from the 1.8
http://www.imagestation.com/picture/...4/fd09d5f9.jpg

Not quite clear on how to read the chart. What would non-ABS 94-97 be rear, then front? 425 rear then 840 front? or; 600 rear 840 front?

then teach us how to read shock dynos....

the straight line represents the front brake and where it branches off represents what the rear brake do at that pressure level. Under that pressure level the rears act the same as the fronts, but when pressure gets high enough pressure to rears are bled off

i never had brake balance problems. I did have a new master clynder though??

Heh, thats me... friend took the picture for an old photography class. He was doing a lighting study and had me toss on his sunglasses for the pic.

I typically get comparisons to Jason Lee in person or when I have my goatee.

Prop Valve question... those abs vs non-abs valves... all the same fittings/format? On the hondas, the abs cars use a differently designed valve, ie: its not plug/play. Are they for us?

I replaced mines about 2 months ago and its day and nite difference. I also got front steel braded lines, did flush and replaced it with DOT4 synthetic. I have colbolt blues front and EBC green rears. Great combo and stops much better. I have confidance in my brakes now! :)

OK, I'm old and dense and still can't figure out the chart.

Can someone walk me through, let's say, the '94?

They both go up together until they hit about 420?

Then they diverge?

The rear is limited to the straight line pressure from then on up; while the front goes to about 840 while the rear is reaching 600?

When the front reaches 840, is all higher pressure cut off? Front and rear?

I'm confused.:confused:

Basically, at low pedal pressures, the hydraulic pressure is evenly distributed between the front and rear brakes, but at higher pressures they skew toward the front brakes at a fixed percentage after a specific knee point. As you can see from the graph, in the earlier 90-93 they start biasing toward the front much earlier than later years.

For example, lets say you are applying 1200 (I forget the units of the graph) of total brake pressure then:

a 90-93 the prop valve sends around 700 to the front and 500 to the rear brakes

a in 94-97 car the prop valve would send around 650 to the front and 550 to the rear

a 94-97 abs car the prop valve would still have almost a 50/50 bias

So if someone wasn't going to go to an adjustable proportioning valve when they do the 1.8 upgrade, they should at least use the 1.8 valve?

Not absolutely necessary, but highly recommended from those who have done it. On my ever growing list of things to do.

In fact, as already mentioned some people even just upgrade the stock 1.6 brakes by changing out the prop valve to get less of an aggressive front bias under heavy braking. YMMV.