OK full story
I built my first fuel injected engine (ver 1) back in 2004 and wanted to squeeze as much power as possible out of it in order to prove a number of people wrong (yes you know who you are) plus knock a hole in the drag challenge, in order to do that I wanted to manage air temps better (the Z engine bay gets really hot under racing conditions and hot air can contribute to detonation and reduction in power) Air boxes are nothing new, people have been putting them on engines since engines were a thing.
Originally I bought a TWM one in 2004 and ran it for a short while , after about 3 weeks it fell apart with almost disastrous results, one of the securing buckles fell apart and an internal fastener (rivet) got sucked into the engine throwing a valve, it was at that point that I thought it was time to redesign it. I had a friend who owned a molding company and they made a mold and ran off a few which I sold. I had at least one instance where I shipped a unit to a certain individual and he didn't pay and disappeared off the scene, Pete and I did some additional work improving seals and fasteners etc and sold a few more and at that point Mike offered to take it on as he was in a better position to market and sell them on.
We did extensive dyno testing at Dave Walkers rolling road emporium and produced some very interesting data, all of which favored the air box.
I have tried a number of velocity stacks and found the best result was using the adjustable ones that DW sells
When set to their shortest (around 25mm) they gave the best HP reading as it reduced the overall inlet tract length, altering the length from 25mm to 50mm didn't really alter the fueling (AF ratio) so it was a very practical solution to adjust them for the application at hand. best figure we had was around 297HP and 245ft/lbs torque with almost no torque drop at around 3500 -4000 that usually appears. Of course that's no where near what a rebello engine produces
but hey not bad for a home build.
There were a number of threads on the forum debating it, the general consensus was if you hadn't got a clue what you were talking about then they were a bad idea, conversely if you took the time to look at the empirical evidence (reduction of torque hole, reduction of hot air, filtration)......... then they were a good option.
In 2004 they weren't common, now the're all over the place.
I did see one or two in some pictures of Japanese engines of the late 90's (thanks Alan) predating my efforts but could never find where to get one.
