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View Full Version : Aftermarket frame crush zone(s)?


samckitt
03-10-2015, 09:47 AM
For the track, everyone wants a stiffer frame with less flex, but I have always wondered if these are aftermarket stiff frames may have some safety issues build into them.

Look at alot of them & notice they all have one thing in common, straight front frame rails, parallel to the ground, parallel with the direction of the force applied to the car if hitting something head on.

On my Monte frame I noticed the front frame section is at an angle, meaning the force applied to the car if it were to hit something head on would allow the frame to bend & absorb some of the force.

I also noticed on Dale Jr's Nationwide commercial, that the front frame on his car has a arc to the front frame section. Assuming this is a crush zone that would collapse if the car were in a head on collision.

http://i242.photobucket.com/albums/ff65/samckitt/frame_image.jpg

What's your thoughts?

will69camaro
03-10-2015, 11:04 AM
http://i.imgur.com/wG8y5Pg.jpg

raustinss
03-10-2015, 11:24 AM
Couldn't agree more....moe aftermarket companies should have crush zones built in in leaving my front frame section alone but the rear I'm boxing which will have dimple die holes bigger to smaller working in from the rear of the frame. Kinda a homemade crush zone yet still providing some extra strength

mfain
03-10-2015, 11:27 AM
This is a tough problem that can open up a whole can of worms - especially for Pro-Touring cars with liability issues on the street and chassis rigidity requirements on the track. NASCAR mandated crush zones a few years back, but the chassis is full of triangulated cage tubes that restore torsional rigidity, especially at the suspension pick-up points- not that practical for a street car. My track car is VERY rigid, with no real crush zones. In a hard frontal crash, the most probable failure point is the little bungee cords (arteries) that your heart hangs on. Modern cars have extensively designed (technically complex, expensive, heavy) crush zones and air bags that absorb a lot of energy. (part of the reason a new Camaro weighs over 4000#) A good 5 or 6 point harness will hold you in place, but a lot of impact forces will be absorbed by your body. A few years ago I put a super late model stock car into a concrete inside wall head-on at over 100 mph. Luckily, I hit just enough on the RF corner that it bent the front clip to the left (2 ft., absorbed a lot of energy) and slapped me rear end first into the wall. The rear clip, with its kick-up built like a crush zone, folded and put the rear end housing 2 ft. up and forward - again absorbing a lot of energy. I still hit hard enough to detach the retina in one eye. Crush zones are a good idea, but would require a lot of expensive engineering/fabrication and would add undesirable weight. One liability issue I would worry about for the chassis shops is replacing factory "crush zones" (like bends in the front frame rails or real crush zones like those on later model cars) with more rigid structures that could result in injuries to a passenger or other involved motorist. People are nuts and will sue for any reason. My $.02 worth.

Pappy

Vince@Meanstreets
03-10-2015, 05:22 PM
This is a tough problem that can open up a whole can of worms - especially for Pro-Touring cars with liability issues on the street and chassis rigidity requirements on the track. NASCAR mandated crush zones a few years back, but the chassis is full of triangulated cage tubes that restore torsional rigidity, especially at the suspension pick-up points- not that practical for a street car. My track car is VERY rigid, with no real crush zones. In a hard frontal crash, the most probable failure point is the little bungee cords (arteries) that your heart hangs on. Modern cars have extensively designed (technically complex, expensive, heavy) crush zones and air bags that absorb a lot of energy. (part of the reason a new Camaro weighs over 4000#) A good 5 or 6 point harness will hold you in place, but a lot of impact forces will be absorbed by your body. A few years ago I put a super late model stock car into a concrete inside wall head-on at over 100 mph. Luckily, I hit just enough on the RF corner that it bent the front clip to the left (2 ft., absorbed a lot of energy) and slapped me rear end first into the wall. The rear clip, with its kick-up built like a crush zone, folded and put the rear end housing 2 ft. up and forward - again absorbing a lot of energy. I still hit hard enough to detach the retina in one eye. Crush zones are a good idea, but would require a lot of expensive engineering/fabrication and would add undesirable weight. One liability issue I would worry about for the chassis shops is replacing factory "crush zones" (like bends in the front frame rails or real crush zones like those on later model cars) with more rigid structures that could result in injuries to a passenger or other involved motorist. People are nuts and will sue for any reason. My $.02 worth.

Pappy

yep im with pap.

remember these guys putting out these affordable frames don't have the engineering or liability budget as the OEM's. You start getting into safety crumple zones and impact safety then you are looking at a very expensive unit. One of which none of us could afford.

Im waiting for that law suit from the guy going after XXX company because the frame was too ridged compared to the factory POS and caused great bodily harm when he was at a track event doing 140 in the straight.