I have resumed trying to get my project RX8 running, and yesterday installed the mid pipe and cat back. I've run into a problem with there being a roughly 1/4 inch gap between the 3 bolt flange between the header and mid pipe, at the top of union where the two pieces meet. I think it's because of the manzo header not fitting into the racing beat mid pipe jus right. I didn't want to buy the manzo header, but others said it didn't really matter, and the racing beat header wasn't available, and still isn't to this day.

I've finagled the exhaust every which way, the gap will not close. I don't necessarily want to just weld them together, but I'm not too worried about it considering I've heard the racing beat mid pipe is inferior to the BHR one, so if I ruin my chinesium header and the RB mid pipe when having to cut them apart in the future, I'm not that concerned. I've also read that there is exhaust sealant that sometimes works, but I know the rotary puts out a lot of heat, and this is in a high heat/pressure area. Additionally, I still have to install the radiator before firing it up so I don't know how bad the leak will be, but I'm pretty confident that it's going to leak at least some.

Appreciate any advice.

 

You could just cut the midpipe back and weld in a flex section (or have a shop do it). That way there's some room for slop if you don't get the measurements exactly right.