So, I bought my RX-8 with the specific purpose to eventually REW swap it in the future. I plan on eventually shooting for 450-500hp, but I'm still doing a lot more research on the swap and what I'll need.

What I'm having trouble finding is, if I do a BHR midpipe and HKS Hi Power catback, will they be large to accommodate the exhaust needs of an REW single turbo or will I have to replace them afterwards? I know I'll likely need a custom downpipe, but I don't want to spend money on an exhaust system I'll have to replace in the future, even if it's going to be a few years before I swap.

Also, if I upgrade the radiator with an aftermarket for the renesis, will I need to replace it or will it need to be changed again to make room for the intercooler and various parts for the REW swap?

Thanks

 

Yes a true 3" from the manifold back will be fine.

 

Awesome. I figured it would be ok. 3" seems to be the standard, just wanted to be 100% before I start spending money.

 

The flanges on those are not 3". You could use that as a base and have the flanges redone in say 3" v-band connections. Or if you have the wastegate dumped to atmosphere that would work instead as well.

 

Cool. V-band would be my preferred way to go anyways. Probably still cheaper to have them modified than to replace them.

 

A 3" exhaust will be fine. I've got the HKS Hi-Flow Catback on my car; it works, is fairly cheap and is pretty noisy (beware of noise limits on trackdays!).

I used an upgraded (3-row aluminium) RX7 FD rad in a location different to the original RX8's rad. I
recommend that you save your money for a rad until you do your swap.