Exhaust problems
 

Hello, I have had multiple exhaust problems in the last few weeks. Recently on a few hundred mile trip I developed an exhaust leak between the block and the manifold. I attempted to fix it by snugging up the bolt it was leaking near. The bolt felt loose so I gave it a turn or two and it just keep going. I eventually noticed that my tightening the nut was actually pulling the stud straight out (weird I know but trust me it happened). I didn't notice for a bit because of how I was positioned and as I kept messing with it trying in and out it eventually hit the manifold. I have ignored my exhaust leak for about 2 weeks until yesterday when i had some really weird metal on metal sounds. I thought my turbo had exploded honestly. Right before I got home last night the pitch of the engine suddenly shifted and I thought it was done for. Made it home and my exhaust has actually split in half. Was this caused by the turbo pulling air in through the exhaust leak when I lift? Before I would get loads of pops and bangs but after the leak they were all muffled. I think it moved the location of the pops and bangs into the exhaust near the turbo instead of further down. I have attached picture.

I have a few questions.
Is it driveable like will the exhaust dumping there kill it or set the oil covering everything on fire? Will an exhaust shop have a t25 flange to attach to a pipe? Will it happen again if I dont fix the exhaust leak?
Attachment 221745

Uhhh..... don't drive that.

WTF kind of garbage downpipe did that?

A buddy welded a cheap t25 flange to a piece of pipe kinda downpipe. When you do a whole turbo setup for under a grand you gotta make sacrifices on literally everything lol. What do you recommend in the way of fixing it? Should I buy a flange before taking it to an exhaust shop? Should I have a piece of flex pipe put in just in case the engine roll was causing it to hit? I don't know if I could get most places to work on it in this state since they do inspections here and I don't have a cat.

I'm really not sure. If it were me and that happened to me, and there was also oil everywhere, i'd probably chalk that up as a $1000 or less lesson, and de-turbo the car.

The oil everywhere is just cause its a 27 year old miata not cause anything is gushing. I think I tossed my original manifold but I'm like 400 miles away from being able to check my garage.

You really need a new downpipe. This time one not made out of the thing junk like that. Really at this point it might be better to go back to non turbo for a while.

I would consider going back if I had the shop and my airbox/manifold. Should I have a shop fab something or get a downpipe online and have them try to make it work. I will end up paying them a bunch anyway. I really need to pay for support on the link from flying miata but I think Keith is like the only guy left with experience on the tuning to get my afr good enough to not explode the pipe again. Really old hardware is kinda sucky.

You could try FM's downpipe. An exhaust shop is going to charge you a couple hundred bucks for anything worth paying for, minimum. If you have a T25 that's side mounted between cylinder 2&3, it should fit, it has some adjustment available between the upper cast piece and the downpipe. It's $500 with a lifetime warranty.

As for the manifold stud, you'll need to remove the manifold and install a helicoil or timesert into your head, as it sounds like you've stripped the head. It most likely came loose from improper torque or a warping manifold.

I actually have a really old flying miata manifold too. That doesnt sound terrible if they have some adjustability because it could certainly make install cheaper. With the stud I will probably just take it somewhere. I dont know if I can remove the manifold with the stud pressed against it. Its a terrible situation for that. Do you know off the top of your head anyone who sells the studs?

looks totally fine to me. you should drive on it

ACE hardware has M10 exhaust studs and M8 downpipe studs.

what kind of manifold you have? is the flange to mount the turbo vertical or at an angle?
post some more pics of the turbo/manifold setup.

Manifold is basically this one
Attachment 221747
I have circled the stud that has hit the manifold

so if you have a flying Miata manifold just get their elbow and downpipe bolt it in yourself and keep on chugging

Do you happen to have a sound clip? For science.

I don't know how well you can hear it but here I guess
https://drive.google.com/file/d/1tDr...ew?usp=sharing