I'm using a set of Suzuki GSXR 750 throttle bodies on my racecar. What I need is an alternative to the expensive TWM air box. Its a nice piece but $250 is a bit much for my budget. There has to be something with a lid that I could modify and use. Any suggestions?

http://www.twminduction.com/airbox.htm

 

Did you re-space the throttle bodies or just use them stock? Because you may be able to get away with a hacked-up stock GSXR box. Or you could make one up out of aluminum with the airhorn incorporated into it.
Have you considered just going with inidividual filters or is this a turbo app?
Grant

 

I'm not respacing the throttle bodies. The intake manifold was made to fit. I'm using silicone hose to attach the TB to the manifold. I thought about a stock GSXR box but wanted something less odd shaped. A basic rectangle type box(shoe box sized) would be idea. I'll probably attempt a riveted aluminum box with some type of clip to secure the lid. If it comes out usable will probably make a second box and have it welded up nice an pretty. If thats not cost effective I guess I'll end up with that nice TWM piece. the velocity stacks will be attached with silicone hose also directly to the TB. Standard K&N airfilter inside the front bumper cover with the needed piping to the air box.

 

It might be kinda crude, but have you thought of using a large piece of PVC pipe with one end capped off? It would also form part of the intake path. You could glue the velocity stacks to it with epoxy and then just connect to the part that hangs out. It wouldn't look good but it would be simple and probably would insulate very well. Or you could make one out of fiberglass using a lost foam method.
Grant