29 replies to this topic

[dstevens]

Put the SFI stickered padding on just in case. Other forms of racing have been using the foam you have in cars that are a ) a lot heavier (like almost half again as much) and b ) that have race speeds that exceed the top speed of an SM have been doing fine with that sort of padding for years. The issue is not so much having the high density padding as it is not having it drip burning plastic into the cockpit. The first hobby stock I bought had pool toy foam on the cage and they were letting him run it at one of the local dirt tracks down here. I shit you not.... Check out the left side orange and green foam.



Lots of Work Ahead by Dave Stevens, on Flickr

[Keith Novak]

Actually the high density foam is important near your head. Why isn't the entire liner of your helmet made of squishy foam? Because a lot of force will blow right through that and you'll contact the shell of the helmet with your skull. Similarly, your helmet hitting soft padding can blow right through that too and put a small area of the helmet in contact against a small area of roll bar. Denser padding will spread the force over a much larger area and decelerate your head more before coming to a sudden stop against a steel tube.

[Killian]

Actually the high density foam is important near your head. Why isn't the entire liner of your helmet made of squishy foam? Because a lot of force will blow right through that and you'll contact the shell of the helmet with your skull. Similarly, your helmet hitting soft padding can blow right through that too and put a small area of the helmet in contact against a small area of roll bar. Denser padding will spread the force over a much larger area and decelerate your head more before coming to a sudden stop against a steel tube.

Exactly. Take a sledgehammer and lightly contact one of the padded bars. Ding. Like the padding isn't even there.
Also, is the right-side net mounted a little high?
Small things aside; that car looks great!

[Steve-O]

Wow- I really do have a POS. That's an awesome looking car!

[dstevens]

If you've been around racing a while you'll see that SFI 45.1 and 45.2 were lobbied specifically by BSCI. Just follow the money. There are plenty of high density foam cells that provide the same impact structure. Again, just as big a part of the spec is the material is fire resistant and self extinguishing, as much as impact resistance. http://www.sfifounda...45.1_081105.pdf
As for a sledge hammer test, give me a break. I've whacked my head a few times on the padding and it's not as big a deal as you guys make it out to be. It's yet another manufacturer initiated spec that SFI adopted where there are alternatives that are identical in every way to said padding, you just have to pay the tag tax for SFI and it allows BSCI to sell and license the product.

[Killian]

An impact from my head whacking a roll bar, on a jeep with that padding, landed me in the ICU for three days.

I didn't have a helmet on, though.

[dstevens]

An impact from my head whacking a roll bar, on a jeep with that padding, landed me in the ICU for three days.

I didn't have a helmet on, though.

Really? No, really? First it's a sledge hammer now it's an unhelmeted hit to a rigid structural member? Even if you had 45.1/2 padding chances are you'd still have clunked yourself into the hospital. The point is, lots of people make open cell EA urethane foam that will work. The reason for getting SFI stickered is as much for safety as it is to avoid hassles in a tech.

[Keith Novak]

If you've been around racing a while you'll see that SFI 45.1 and 45.2 were lobbied specifically by BSCI. Just follow the money. There are plenty of high density foam cells that provide the same impact structure. Again, just as big a part of the spec is the material is fire resistant and self extinguishing, as much as impact resistance.

I've been around crash testing certification for a while. The same testing and standards that SFI copied from for a number of things. I can tell you for a fact that high density foam will reduce head impact forces to your head striking something solid more than squishy foam. Flame properties are secondary when you're wearing a fire suit and you've just turned your brain to mush. You can follow the money if you want. I'll follow facts and data derived from many many years of testing.

[dstevens]

So show us the data then. You're an engineer. One of the first things they taught in ME 101 at Cal Poly was never assume.

A good example of someone not playing the SFI card is Dow Chemical. They produce a product line called Impaxx which is used extensively in passenger cars. (others have similar products, Bayer and BASF to name a couple). It's a material that is mandated by NASCAR in the body/chassis padding crash structure of the new Cup cars. Yet no SFI even though BSCI is a leading provider of these pre fitted kits for the touring series.

My apologies for the threadjack to the OP. That's a hell of a nice looking car. It motivates me to finish mine. After the current paying mini stock cage and pit wagon jobs.

[Keith Novak]

I'm guessing they never got to a discussion on protecting Intellectual Property in the freshman gee wiz engineering course. You are free to think what you will, tie a pillow around your head and call it safe and even run with scissors for all I care. I'm merely pointing out to anyone interested in what type of padding the professionals use in planes, trains, and automobiles to reduce the impact forces on the human head it is denser than the $1 a stick stuff that comes in many colors and doubles as great insulation for your hot water heater pipes at home. What you care to do with that information is entirely up to you.