I was doing some random research the other day and learned a bit about polyurethane vs fiberglass. Now in my research I learned that Ferrari typically uses fiberglass whereas porsche polyurethane.

Now my question is when building a dedicated road car where speeds easily exceed 150 mph. How would you choose? Flexibility vs rigidity. Or would you opt for cf?

 

In a perfect word everything is carbon fiber!

 

poly when not supported properly will buckle or bend, cheap FG will do the same too really. FG is easier to fix on the spot during a race weekend as well.

 

corvettes=full fiberglass

 

Fiberglas or Carbon.

 

By dedicated "road car" I'm assuming that means street car, and for street cars poly is by far and away the most durable. There is good reason it comes on nearly all street cars. Its not cheap but it still wins out in nearly all cases. However, here's the problem... its ultra expensive to mold and thus, there are very few options in poly.

 

If you're referring to a road race car Fiberglass is the most popular (cost and weight dependant).

 

If you're referring to polyurethane, majority of bumpers are not made of that. Most manufacturers use a thermoplastic polymer that has a similar chemistry to ABS plastic. Polyurethane is a polymer that contains urethane and is more expensive than the typical bumper plastic.

 

Thank you for the clarification, but I believe my assessment still stands valid. Polyurethane is expensive to mold (inject) and has very limited options due to cost (note, it generally has a substantially higher weight as well). However its street-ability is better than the more rigid fiber/composite based options. Ultimately, his choice is going to be determined by the application, cost and availibility of the bumper.

However in the case of a track car where flexibility and streetability is not a large concern, lighter-weight and rigidity are key, which favors the fiber/composites options. Note a lot of the "carbon fiber" options available are nothing more than fiberglass with the carbon fiber weave bonded on and do very little in terms of true strength.

 

Properly supported poly 100%.

Carbon and Fiberglass are great if you have the budget to constantly replace stuff two or three times a year.

 

Either material is fine if properly supported. Repairs at the track can be done with a drill, zip ties, and duct tape.