Starting my build and it will mainly be a street car that will see autox and a trip down the 1/4 once a month when im home. Being a street car with the occasional back seat passengers. A cage is a safety issue for them.

My question is this i have a large amount of rigid 2 part structural foam (not great stuff foam) its extremely rigid. In my mind filling the b-pillar c-pillar rockers upper etc etc (anywhere that can be filled with the foam and make some sort of tube/bracing element) Should stiffen the chassis a great deal and offer alilttle more protection in a accident or roll over. Since it is no longer empty space it has a element inside to add rigidity.

Also and other seat belts other than the stock that are better for keeping you in the seat? (harness are kinda out because of no harness bar unless i fab a removable one.

And here is a interesting read about foam. http://www.plastics-car.com/plasticfoams

 

It is a sound idea, but the execution can be difficult. The good rigid foam does still expand alot, and can easily warp outside body panels.
As long as the car is not real fast, NHRA won't care. It certainly will not replace a cage, but will be better than OEM.

 

We are shooting for 500-600hp at the wheels. car is a 95 eg hatch b18 (once we get further along a build thread will be started.

And here is a interesting read about foam. http://www.plastics-car.com/plasticfoams

 

and you want to still use the back seat and dont want a full cage? might as well take 400hp off your goal, because the chassis you want and motor you want wont leave you with much you can do with the car.

 

Good read.
With that kind of power though, you will be illegal on any sanctioned track without a proper cage.

 

they will only know after the pass on the 1/4.

 

lol. one pass ftw! you got this man, just fill the whole car with foam with you in it, run a straw out the roof!

 

haha^

dont use foam. just do it right.

 

this car is mainly a street car. By putting in a cage ive put any passengers at risk.

By doing the foam in the hollow places in the chassis ive have greatly increased the strength.

once i get to the point to where the car is a track only/single occupant car (me) a full cage will go in.

 

by putting 5-600whp in a street car without a cage you are also putting the passengers at risk. what are you going to do with that much power on the street? your reasoning is not working.

 

hmm, have you ever sat in a race car? that metal CAGE around you.. deep dish steering wheel... fire system.. well maybe not but.. foam? eh, don't be silly.

just build a cage.

 

The power is irrelevant as its how you drive it. No one says you have to drive like you have 500hp the pleasure of boost average person beside me will think its stock with an exhaust and thats fine because i have no need to show my ego.

 

And you point? Either your questioning if i have ever raced which is affirmative or your implying the foam catching on fire. (which it wont)

 

i mean my friend, a cage, trust me, a cage you will enjoy far more.

 

you should email your local track...500-600whp will put you in the 10's so ask them can you run 10's with a foam "cage" and see what they say.

 

Im not concerend about being legal in a sanctioned event. The foam is just a good way to greatly increase strength in the chassis without a cage (the cage puts any passengers at risk) so the foam offers protection in daily driving without putting them at risk.

Once it becomes a race car yes it will get a cage and will no longer have passengers.

 

its not being legal in a sanctioned event. its being legal per the track because the tracks are nhra "governed"

i think what people are telling you is the foam thing is cool and will help the chassis stiffen up, but it will not be considered a roll bar/cage so if you take it to the dragstrip, and can drive decently, with your power level goal (which puts you in the et that requires a cage) your foam chassis wont matter to the track and you will get one pass and get told to leave.

 

 

Im aware of that. must have been a typo on my part.

 

silly ricer, I think you have been inhaling too much foam

 

How much does the foam weigh? It seems counter productive to a race car to be heavy with foam. I don't doubt the possibility, but it seems like something best left to engineers.

Also have you considered stitch welding the uni-body seams?

 

foam weighs 2 pounds per cubic foot.

 

Car is going to be a track car maybe a drive on the weekend. Picked up a new DD today.

 

Engineer here. Don't bother.

 

And your point is? Being a engineer doesnt make you right. and there is data to show it greatly increases strength.

Not putting you down as i work with hundreds of engineers daily, but you cant come off the hip with a opinion and be deemed right.