Since the HKS down pipes have dried up, what is the best option for one to replace the stock one, and where is the best place to get one?

 

I'd say RX7.com or Pettit.

 

I still think the HKS is the best option. It is easy to install without moving the engine around. They pop up used every once in a while. Get a used one, no matter the condition and send it off to be ceramic coated with either Calico Coating or Jet Hot. They will have to sand blast it before coating which will clean up any rust and the ceramic coating will significantly lower your underhood temps.

SMB in Australia makes beefy downpipes.

Otherwise, just looking at RHD Japan's website they sell a Greddy downpipe.

 

What about the Bonez at RX7.com?

 

 

Its not a bad product, just understand it will be harder to install. It would theoretically give you better flow. I personally do not have any experience installing a LHD downpipe, but those who have, had to either remove the studs or hoist the engine some to clear it. It will be difficult to remove the stock nuts and studs. I would order some studs and copper washers, because your stock ones will most likely get damaged, when installing. With either product you go with, I would also recommend ceramic coating.

 

I have never had to use a hoist to remove/install a downpipe. The hardware doesn't get damaged upon install. I agree with gracer-7. Pettit or rx7.com for the downpipe.

 

SMB 3 or 3.5" if you can find it (Marcus Read or RX7 FD Specialist on FB sells them)

FD Motorsports 3 or 3.5" from Raceonly

 

As Steve mentioned, the OEM JDM dp and HKS JDM dp are probably easier to install due to them being smaller near the turbo and having more room to access to the fasteners. I haven't installed one in decades so I'm rusty about how much of a pita it might be. I do vaguely remember certain kits using a bolt instead of a stud and nut on one corner due to clearances. Check the FAQ for old install threads - or call the vendors and ask.

Good luck.

 

I've got 2 twin tube autoexe/Mazdaspeed downpipes available

 

I got lucky, found a used HKS on Marketplace, and I have been looking for awhile, wasnt cheap but I feel good about getting what most say is the best.

 

I bought maybe of the the few left bonez downpipes from rx7.com.

Had to remove the studs as other poster mentioned to fit it to the turboes but luckily after soaking it with pb blaster it wasn't bad. Replaced studs with new too.