My car came with some random SS downpipe, which WILL NOT clear the studs to install. I put brand new OE studs on the exhaust manifold before I installed the engine. I'm not taking the engine out to remove the damn studs, either. I tried to remove one of the studs in-place and it just doesn't wanna move, even though I installed anti-sieze and torqued to spec. What I would like to know is if anyone make a downpipe that will actually install on the studs, in-place, without issues. I called rx7store, asked about fitment on their downpipes, and was told that the flange should fit over the studs with the engine in-place. Can anyone confirm? If I can't get this done, I might lose it and part this car out!

 

If I understand the problem correctly, it might help to undo the engine mount to subframe bolts and jack the engine up a bit (maybe more than just a bit) to see if that buys you more clearance. It's been a while since I futzed around with my old stock downpipe, but if I remember right, that was what I needed to do...

 

I did that. This downpipe I have just doesn't want to cooperate anyway. I actually picked the engine up a little with an engine hoist and the goddamn thing still wouldn't clear all the studs! It started beating-up the stud threads, too. Short of removing even more crap off the engine, and hoisting it up even higher and pushing it over toward the driver side (which I'm not even convinced would work because the tunnel is causing clearance issues too), I can't get the flange over the studs.

 

The downpipe I have was easy to install, I don't recall having to fight with any studs or move the engine.

 

What brand downpipe was this?

 

I’m not sure, it came with the car.

 

Some downpipes you have to use 1-2 bolts instead of all studs. The aftermarket JDM downpipes usually all fit like OEM compared to the aftermarket US ones.

 

Would, say HKS, be in the JDM category? I looked around for bolts, but couldn't find anyone selling any. Do you happen to know anywhere that sell the bolts?

 

I installed a Megan Racing (maybe?) downpipe about 15 years ago, keeping a couple of the original studs and using stainless steel Allen Bolts in two or three of the locations that needed extra clearance. I'm sure I found the proper bolt thread pitch here on rx7club, you might find it by searching for 'downpipe hardware thread pitch'. It's definitely metric hardware, I don't remember if I ordered it online or found it at a local hardware shop.

 

https://www.rx7club.com/3rd-generati...wnpipe-280633/

https://www.rx7club.com/3rd-generati...wnpipe-773469/

 

The HKS downpipe is the easiest to get new that's JDM.

US downpipes are all a little different - some may fit great on the studs, some may require bolts, hard to say. Some of the cheapie Ebay downpipes just fit like garbage, period.

Dale

 

Thank you!!!

I ordered an HKS downpipe today. I'm hoping it's a more cooperative install.

 

In 2005 I put on a used HKS DP I bought here. IIRC, it was not too much of a PITA. Hope yours goes on that well.

 

this is how I got my dp on back in the day that was exactly as you describe.

Unbolt the passenger side engine mount.
Take a ratchet strap and hook it to the engine pull hook and the drivers side shock bolt(I put a nut on the bolt to keep the strap hook from coming off).
Ratchet the motor to the side till you have enough clearance. It’s not too bad at all this way. I think the hardest part was getting the motor mount undone with the heat shield around the mount.

 

Thanks to everyone who replied and PM'd! I wound-up ordering the HKS downpipe, and I'm happy to report that the flange easily slips right over the studs with no effort! Some may say that the geometry at the engine end of the Pipe is more restrictive, and that is certainly observable. I will say, however, that that does not really matter if you aren't running monster power, and also since the cat. con. is no longer there on the HKS pipe. Probably a wash at the worst.

If you are at you wit's end with getting your ebay or random pipe on with the engine in, just spend the measly $200 or so and get the HKS downpipe.

 

All JDM downpipes have that strange head to make room for the steering column (RHD). I've had different downpipes and really the difference in performance between a JDM and US-style downpipe is negligible. Having it be able to easily bolt on and have good tool access to get to it is worth it.

Dale