Okay... You asked for it...
Now who's going to build the mold to use the "resin" in eh?
No possible way to hand shape an intakes inner diameters & bends.
Even if you started with a waxed based model of the tube designs, you would have to be a near perfect sculpturer to render them exact enough to make just ONE resin manifold.
Do you get where I'm going with this?
I know there are products viable (heat resistant) to make it out off. Just how do you go about creating a mold.
I could even get my cousins company to make a computer designed one-off mold, but the cost is in the thousands. (I've checked! Trust me! :D) Even if I did the design modeling myself the machine time is astronomic (per unit) just to make one "resin" rendering.
To make an actual mold it's more so and then find a shop to actually cast the pieces from the mold...
Could you make your money back. Most likely
if it sold enough units, but like any custom project the initial cash outlay is significant!
Which brings us back to mandrel piping tubular design with silicone connectors.
I too would prefer a "resin/plastic" manifold for it's superior resistance to heat transfer. However thin wall tubing will retain much less heat then the stock thick wall (and coated) aluminum manifold.
