aluminum compared to iron

[madwilly240]

which is stronger?
which would wear quicker?

theres gotta be at least on chemistry buff on this board.

thanks

[AKADriver]

It depends on the design of the part, the grade of materials used, and the way the part is manufactured. There's really no definitive answer.

Generalizing, iron (steel) makes for a stronger, longer wearing part with less money invested in most cases.

[SaintlyCharBoy]

Originally posted by AKADriver
It depends on the design of the part, the grade of materials used, and the way the part is manufactured. There's really no definitive answer.

Generalizing, iron (steel) makes for a stronger, longer wearing part with less money invested in most cases.

all true, but keep in mind, given the same weight, and a good design, the alluminum product will likely be "stronger", though physically larger

also alluminum tends to be less forgiving when fatigue due to repetative stress comes into play

[Jeff240sx]

You're both wrong. Iron and aluminum both have their place on a car, and the question originally asked is extremely misleading. Iron would be better for a manifold, but Aluminum would be better for swaybars...
It all depends on what this metal will do as a part. What are you making? Thinking about?
And both of you are right... but there needs to be the definative "This is the part. What would be better, Al or Fe?" given, or there is no answer.
-Jeff

[madwilly240]

z32 brake calipers

[Phlip]

In an item such as a brake caliper, in my own opinion, I would say aluminum would be the way to go...
Simply by design, it will be strong enough for the function it is drawn to accomplish.
It will shed the heat quicker than steel, and that is part of what brake calipers do.
It will do both of those while weighing less than steel/iron...
I know nissan had an issue with the ROTORS that caused them to go from aluminum to steel, but that was warping, something not likely to happen with calipers. In my own opinion, I say go for aluminum, less unsprung weight.

[240 2NR]

Originally posted by PHLIP
In an item such as a brake caliper, in my own opinion, I would say aluminum would be the way to go...
Simply by design, it will be strong enough for the function it is drawn to accomplish.
It will shed the heat quicker than steel, and that is part of what brake calipers do.
It will do both of those while weighing less than steel/iron...
I know nissan had an issue with the ROTORS that caused them to go from aluminum to steel, but that was warping, something not likely to happen with calipers. In my own opinion, I say go for aluminum, less unsprung weight.

As I understand it, the issue was that since the calipers were aluminum and dissipated heat so quickly they were great while the car was moving, but when parked hot, the portion of the rotor inside the caliper cooled faster than the exposed parts (iron) and led to rotor warpage do to the uneven heat removal rates. That said I doubt it's a large issue for a street driven 240 (which weighs around 500+ lbs less) provided there is adequate cool down time after hard runs. If you park them hot you're looking for trouble (as with any brakes, though the aluminum caliper makes it more profound).

[Jeff240sx]

Originally posted by 240 2NR
As I understand it, the issue was that since the calipers were aluminum and dissipated heat so quickly they were great while the car was moving, but when parked hot, the portion of the rotor inside the caliper cooled faster than the exposed parts (iron) and led to rotor warpage do to the uneven heat removal rates. That said I doubt it's a large issue for a street driven 240 (which weighs around 500+ lbs less) provided there is adequate cool down time after hard runs. If you park them hot you're looking for trouble (as with any brakes, though the aluminum caliper makes it more profound).

I think as long as you have some wheels that give decent ventilation, and drive sanely for about a minute after the autocross, you'll be fine. I've yet to have a rotor warpage problem in the year and a half I've had the z32 brake swap.
Al all the way!
-Jeff