removing a Miata exhaust header aka manifold

I'm turboing the 93 this week and am at the exhaust header removal step.

I read about removing the driver's side front wheel to gain access. I've also read about using extensions etc to reach the 3 bolts holding it on.

Any other tips from the ones who have gone before me?

also PBblasted those bolts as best I could...

Leave the downpipe and the manifold together, and pull it out as one piece. You don't need to mess with that triangular flange on a 1990-97.

I'm going to have to separate those two at some point. I'm using a Greddy kit and the downpipe connects...at that triangular flange.

Maybe taking them out as a unit would be a lot easier than separating them while they're in the car. I could pull them together. Then attach the Greddy downpipe to the midpipe before the cat. Reinstall.

Thanks Keith..that's a thought.

Anyone else done this before?

I did. Take them out as a unit and don't forget the bracket that attaches to the bellhousing. You'll have to wiggle and cuss the assembly out but it will come out in one piece.

Once it's out, PB Blast the nuts and then use a torch to heat the nuts before you try to remove them. That makes it a LOT easier.

BTW, you're in Richmond, right? I'm in Chester. PM me if you need a hand with this.

Thanks for the suggestion CoryB. I'm at the rounded off nut stage on the Cat. :( I tried using extractor sockets on the rounded nut. It worked...for a couple of turns. Now I'm going to use a nut splitter and be done with it. Hopefully bolt #2 will come off easier. More time for the PBblaster to work on it.

I'm getting that bastard off today tho.

I'll also keep in mind what you said about heating the bolts on the downpipe. I should be able to pickup a propane torch to handle that. I don't have welder and the car is immobile at the moment due to the tear down.

..and thanks for the offer of help. This board is great.

Yeah, I've done it before as well. With that exact downpipe in fact :nice: I remember we had some issues with the triangular flange, but I had two sets of hands and all of my nuts came off (some with the stud in the case of the cat connection). I'd say you should probably pull the header and b pipe as a unit as others have suggested. Just remove the clamp holding the exhaust to the bellhousing as mentioned before. You can reach the clamp bolt with two long extensions and a socket right behind the drivers front wheel. I could even tighten/loosen it with the car on the ground.

When I last tried to do the clutch on my '97, the cat studs were all horribly corroded. So, I attacked the bolts mentioned above. PB Blaster had been applied every day for a week beforehand. I hit them with an impact wrench, and the first one didn't budge. 2nd one didn't budge. 3rd one budged, with that horrid SNAP sound that accompanies a broken stud. YAY! Darn thing still isn't on the road, though I hope to get to it soon. Got another Miata to work on first.

Thanks for the commiseration guys.

Clay, I just noticed today how you labelled all the baggies with your turbo kit you sold me. That is a serious help!

I got the cat('s) nuts off! Don't cal PETA on me. I had to use a propane torch, PBBlaster, and a hammered on bolt extractor from Sears. Remarkably, the sears bolt extractors were the same price as the Harbor Freight ones. Hmm. So now I have the downpipe and midpipe laying in my front yard marinating in PBBlaster.

As God as my witness I will never work on exhaust studs without a torch again. :nice:

You probably have done this already, but removing the intake plastic makes the job immeasurably easier. Also, if the d/s motor mount has gone to the great beyond (for some reason Miatas eat motor mounts, must be all that torque) the motor will sit at just an odd enough angle to make the job more difficult than it has to be.

Wreckerboy, sorry to read about your recent job situation. Sucks ma'man. I see you're in NJ. I'm sure if you want to move around a bit guys on here will most def'ly help you out. Thanks for the tip on the mounts too.

I'm now at the bolting things on stage so this thread is done.

Results:

I pulled the mani and mid-pipe as a unit. I unbolted the mani from the engine with No problems! PB Blaster loosened all those bolts enough so that it was cake.

The real pain was the cat bolts. Two of them. See above for the fix.

I then pulled the mani and mid-pipe out the front and unbolted them in the driveway.

Some key moments during the build.

• Baking the Greddy manifold to put it on. After slicing in the relief cuts the center bolt hole was off-center. That should've clued me in that the shape of the turbo manifold was different. It wouldn't slide on the studs pressed into the head. I then turned on the oven and baked it to expand then thing. It slipped on a bit and I nudged it further down the studs until I could use the bolts to snug it down.

• Drilling the oil pan was fun too. I used a uni-bit. It was made even more fun due to this car having AC and power steering. Needless to say I'm pretty low and forward on the oil pan with my drain hose.

• NAPA has green silicone hose that is oil resistant and supposedly high temp. The parts guy said it was good for connections to a catalytic converter. I bought two feet of it to use for my turbo drain. I may get another foot for the drivers side heater outlet as that is practically touching my Greddy downpipe.

Thanks again for all the help guys!