Aluminum,Titanium or Carbon Fiber

[SprintCar_Racer]

What kind of aftermarket parts would work the best, like the lightest, most durable and i dont want it to cost an arm and a leg.

[AudiTT-Quattro]

Carbon Fiber is by far the lightest of the three...

Durability? It would have to depend on the application.

[Mr. Constructor]

in very stressed areas: titanium, in lightweight (where it only acts as a servo holder you could use light alu (around 20% lighter than titanium wich is around 45% lighter than steel but twice the time stiffer !!) or even maybe the use of carbon, normally it is used in chassis, there it will make shure that the stiffenes is guaranteed, but in stressed areas it might be better to use alu or ti (shock towers on 8th buggys or steering plates in those cars !!

but the chassis (if electric is your way) could be done out of carbon, if you use gas, ONLY alu comes in !! (as ti reacts around 200° celsius with the surrounding air and might start to burn !! (and you really can work very hard on ti, this material IS the strongest i´ve had so far (a totally 8th titanium buggy was the result, everything that was round or a plate was made out of it !!

so it will be mostly carbon and alu you might need (and your wallet won´t be killed either !!)
try to search at ebay for a sheet of carbon, in germany there are often some parts offered !! (should be the same in the us)

[crank throw wei]

In almost all cases,aluminum is the choice,especially if you are cost conscience.

[Mr. Constructor]

on 8th buggies the shock towers might be better out of titanium, they´re much stronger (i haven´t bend my 3mm ones at any time !!) and sometimes (in 10th racing the carbon is better, but for general cheap use, and easier to manufacture alu IS the way to go !!