thats sweet!
mine are polished but need redo...

 

Looks awesome.

 

Should have gotten black calipers with polished mazda logo. just my 2 cents

 

you do such tasteful mods, your car is absolutly beautiful man.

 

looks sick, i like it better than doing red.

 

Makes me proud to be an FD owner

 

Technically he is right about making your calipers perform worse. When you polish something you effectively reduce the surface area of the part being polished. The more surface area the better the material in reference disperses heat. So a couple of things that i never understood the purpose of polishing especially is turbo parts. Anyway i dont think you would be able to tell the difference i think is my main point. But man do those look nice. How many hours were involved in that?

Regards,

Hank

 

It's purely for looks. The amount of cooling difference is negligible at best. Looks great man! I'm actually gonna powercoat mine red.

 

I think you got this turned around. Let me explain why I say so, if you have a thick and a thin pot on the fire, the thinner one will get hotter faster, yes? Which means heat was dispersed through it faster. Seeing that material was removed from the caliper, heat is dispersed through it faster. According to the tests performed by the member in Indy, this is good 'cause you don't want the heat to stay in the caliper and boil the brake fluid.

 

thanks for clarifying. . . i for some reason was thinking the fronts were cast as well.

btw, they look great!!! maybe the polishing will help out with keeping them clean!!!

 

damn rich u truly have lost your mind.

 

Cleaning them would just be ridiculous. Second that... But they look nice

 

I've been running polished front calipers since like 2001......not sure what you mean, matto.

 

As I already posted, cleaning them isn't bad at all. I only clean the face (the portion seen through the rim spokes), and am able to get at them pretty good without removing the wheels.

 

Those look pretty sweet Rich!

 

I've been planning to do the same thing. They look great! BTW, I would think cleaning a polished surface would be easier than a matte finish... a quick swipe with a pressure washer and all the crap is off it.

I think you're both wrong about this.

First, there is not enough material being removed to change heat dispersion nor to signifantly change surface area when you polish something.

Secondly, removing a good amount of material from the caliper reduces it's mass and, in turn, reduces it's ability to hold heat. Assuming the surface area stays relatively the same (same ability to disperse heat to the air)... The less heat that the metal holds, the hotter it will get and the hotter the fluid will get.

In a word, a smaller caliper, subjected to the same amount of heat as a larger caliper, will be hotter than the larger.

Now, the caliper with a good amount of material removed may cool off more quickly because it has a smaller mass than a regular. However, it would not cool off until long after the abrupt heating caused by heavy braking.

 

oh i thought u had painted ones. just meant u have modded everything. its truly an obession at his pt.

 

How's the project going Maurice?

I'm going to have to respectfully scratch my head.... The calipers are air cooled. henceforth, one should try to maximize the external surface area available for heat energy to be dissipated. You can cool a spoon full of hot liquid with a couple outward breathes, but it would take longer to cool a pot of water. However, spread that water out into a large baking sheet, or the floor, and you will see that it cools more quickly because more surface area is exposed. This is the reason the amplifiers, resistors and other static air cooled devices of this sort require longitudinal fins or heatsinks. It is true that these fins can often double or tripple the surface area available for surface-to-air heat transfer, while the little bumps on a caliper are far less significant, but intuitively it seems that the removal of those small bumps has a more larger effect on surface area than it does on the net volume (which as you pointed out, large volumes are more difficult to cool). I would not be surprised if the total surface area was decreased by 1/32-1/16 or so through polishing (once you consider the removal all of those little bumps that you saw everywhere). I guess I forgot to calculate the bling factor....
Would you happen to have a link to the tests that you mentioned above? I'm not saying I don't believe, just caught me by surprise is all ;o) One of my flatmates is an astrophysicist; I'll run this by him if I think of it later.

Robert

Oh yeah..They look good Rich

 

Who cares about the science man? They just look cool, my hat is off to you Rich!

 

Yes Very nice i painted mine red with white text, came up pretty good,

i can even get my hand in their enough to clean the face

 

NICE NICE!
I spent a few hours with my Dremel going over my FCs front 4-pots to get a similar result but yours are truly polished with a higher degree of detail, WOWIE!
very cool.

I agree that some painting/coating of calipers just asks for heat soak and impaired performance.

 

Jesus! I didn't know we owned an F1 cars!

Who give a **** about 1-2 oz of weight we might of taken off from the surface. Most of us , and including yourself would never noticed the difference by polishing, painting, powder coating, etc... This is like people think ceramic coating is going to save engines... Give me a brake! LOL!

 

the concept of surface area here is in relation to all of the nooks and crannies that were removed from the caliper when it was polished to silky smooth finish.

now there is less surface area.

think of the lining of the digestive tract... it has undulations for more surface area compared to if it was as smooth as a silicone tube.

but I think the pitted surface is more pronounced on cast iron rear calipers than it is on the front aluminum calipers.

and any venting routed to the calipers will remove any miniscule difference the polishign made, IF this was a track car which I dont think it is.

 

Can't argue with that Phil, but it doesn't hurt to talk a little theory now and then..... ;o) I'm personally 0% concerned as I'm leaving my M2/Willwoods just the way they came. Like I said, they look nice.

 

I was just trying to prove a point about physics...

Silly aussie, put your hat back on, science built your car