I have a 1996 miata and am going to turbo it soon. The only thing I would need is a downpipe but I plan on just having an exhaust shop make a full 2.5" exhaust. My setup is an ebay cast manifold and an SR20 2554, i've heard that I would need to cut a bit of the shelf under the heater core hoses for a downpipe to fit. Would that be necessary? Are there any downpipes that are sold that will fit fine?

 

The MKTurbo downpipes only require slight hammering of the shelf you speak of to get it to fit. No cutting. His DP's won't fit your manifold/turbo but perhaps he could make you one? I'd shoot him an email. His kits come with a 2.5" to 3" DP to a full 3" exhaust.

Also, it's been proven that 2.5" exhausts choke turbo miatas. Go 3".

 

Alright thanks for letting me know! Definitely going to get in contact with him.