OK I understand what you mean by plenum now. It looks like a pretty tight bend where the cast section comes over the top of the throttle body. I did consider making up something but I met a guy that had fitted a large diameter rubber pipe with a good sized bend. He didn't notice any difference and looking at it the entry to the throttle body is much larger than the effective hole through it. I did consider removing the injector and boring out the bottom of the throttle body to allow it to flow more. I was then going to fit two smaller injectors in a throttle body spacer. Then I would have had to replace the alloy cross pipe and then my snorkel would have been the restriction. I decided that it would to too much work for too little potential gain. I'm going to be doing some dyno work in a couple of months testing out some ECU mods. I'll try a run with the pipe off to see if there are any gains to be had.
