I'm not a fan of using foam, any kind of foam injected into a void to stiffen a structure unless you take great pains to keep moisture/water from getting into said void and/or away from any metal surface thats unprotected inside that void. I have seen where this was done, adding foam, and the foam trapped moisture against the interior metal and cause rust through!
That is a reasonable concern. My location is a pretty strong extenuating circumstance. Can't speak for anyone else!
But in theory at least, stiffer chassis means less movement you can't control, which means you can better control everything with the suspension and given good tuning, the end result should be better.
If it didn't weigh anything or require any outlay of energy/time/money, it'd be a slam dunk!
What about a roadster with a ladder-frame ... like my challenge car?
(not my pic, BTW)
Keith Tanner said:Carbon said:I really want to foam fill the commute attack car frame rails. Some production E36 M3 like tge q45 had it from the factory. Sport compact car mag did Mike Kojima's z32 and said it was a revelation, like it had a cage. Allegedly if you use automotive specific foam it doesn't cause corrosion issues.
Ask Alfa Romeo about that last bit :) Isn’t that why the Alfetta dissolved?
We foamed a couple of Miatas in our fleet back in that era. SCC may have overstated the result, but the car with the denser foam does feel like it’s on the rigid end of the Miata spectrum. The one with the lighter foam feels normal. Neither are as stiff as a caged car.
There no downside to a stiff chassis if you’re not having an accident. It gives the suspension a solid structure so it can do its job. Making the chassis into a big undamped spring is bad.
Excellent that you guys did miatas with good results. Any long term corrosion data on those cars Keith? Anyone with q45 experience to chine in and see if they (using modern 3m stuff or whatever infinity did) turn alfa on the owners?
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