TVT!!! You could probably benefit from purchasing a RENNTech C class Air Box and Disecting and making one like it. They claim 15-20 RWHP but when i inquire them about it they would not sell it for crossfire use cause they could not guarantee fitment. But it is 3/4" taller and they built a ram air setup into it. And it is Pretty CarbonFiber... Just an idea.... maybe you could try cutting the c class airbox up and putting spacers in it to get more volume in the box.

Just some ideas!