Well, as many of you know, i recently installed a new midpipe (rx8store) on my car.

I noticed that when I tooK the stock piece off, it had a hanger on it at the end towards the 2 bolt flange where it joins with the piece that has the mufflers on it. The rx8store midpipe does not have a hanger. I THINK the stock hanger was actually pulling the midpipe over to the drivers side, helping to keep a seal in-between the flanges, so that it wouldn't do this:

http://i233.photobucket.com/albums/ee148/biblebelts/EXHAUST-1.jpg

Can anyone verify this?

If I lay under the passenger side of the car and push on the exhaust towards the drivers side, it looks like the flanges line up better and can seal better. the spring loaded nuts are on tight, so I don't know why it's doing this.

Any guesses? Fixes?

You might just take the old mid pipe and new one to a shop and have them cut the hangar off the original and weld it to the new one in the same place... Just a thought.

hm.

i would maybe thing about buying a NEW hanger...

but first i need some verification that the stock hanger actually serves this purpose.

i'll take some pictures tonight and post them up. i mean, let's all admit it... that's a pretty badass autocad drawing, but i think pictures are of the order.

it is quite impressive. I bet it took you a couple of hours eh? jp

I just put a gutted cat midpipe on my car this weekend.

I know right where you're talking about: I would say that welding a hanger on there and using the factory grommet and mount would be very useful. That is a lot of weight to just have hanging there. That puts a lot of stress on only those two bolts.

Solutions I would look at. removing the mount from your stock exhaust with a saw and welding onto your new pipe.

Or just get a cheap exhaust hanger from autozone and find a place to mount that.

I'm not an expert. But thats where I would start.

i just did it in about 6 or 7 off to the side of something else i was ACTUALLY working on.

-captain obvious steps in-

did you reinstall the donut gasket correctly and make sure it wasn't damaged?

that brings up another question....

donut gasket... is that like a regular, flat gasket that goes in between the two flanges or it is simular to what the stock exhaust has, which is a weird rubber piece around the pipe that fits inside the catback portion of the exhaust? i thought that might be it, but was unsuccessful at getting it off.

when i took it apart, it didn't have a gasket back there... not a normal, flat one at least. it wasn't leaking at all back then, either.

(this leak is much bigger than a gasket could fix)

is this the "donut gasket" you speak of?

http://i233.photobucket.com/albums/ee148/biblebelts/EXHAUST3.jpg

man you draw well---glad the header is on--out of town this w/e and didnt return your call sorry about that. I will be home tonight after 6pm.
The hanger does serve a purpose--remember also the exhaust "moves" just a little during hard driving from chassis flex etc. Get the hanger. Both my midpipes i had an rb one before i got the mazsport one--had hangers. Now with headers you dont have the exhaust stay that bolts to the header as you do with the oem making that hanger even more important.
Also you may need to get the no leak soft aluminum gaskets to have a proper seal with aftermarket pieces--bet when you cranked her it was LOUD.:)
Olddragger

it's cool man... once i figured out that i needed to take the ENTIRE motor mount off, it was clear sailing from there.

i'll see how much i can move it around later, and if i need to, i'll fab something up and weld it on there as a hanger.

i'm just hoping that it will serve some purpose to re-align it.

learning a lot arent ya!! Cussing yet?:)
yea the hanger does help to align it right.
You are going to like the hell out of this mod the 1st time you drive her.
olddragger

well, i looked at it tonight and... it's mainly the lack of donut gasket that's causing the leak.

anyone know where i can get a 2.75" internal diameter donut gasket?

^Yup at your local Mazda dealer for $40.00 :)

I was just going to say you need a gasket but come to think of it I just got my RB mid pipe installed on Monday and we reused the Donut gasket and I went out and got a new gasket for the front where the mid pipe and the exhaust header connect and my car still smells like fumes and gas lol theres just no way around it my friend :smoker:

i'm not having a problem in the front where the header connects to the midpipe, it's just in the back.

will the stock donut gasket fit? i couldn't get it off. it looked like it was bonded to the exhaust somehow,

I was able to save my Donut gasket. It was on there solid too. It took some time, but I was able to take a flat head screw driver and just tap it enough to start to loosen the donut, don't pry it or it'll start to come apart.

I'd say just get a new one. Make sure your new midpipe and stock midpipe are the same diameter.

Sorry, I just assumed that you put a donut gasket back in there.
Though I'd still look into putting the hanger on there.


My front is leaking pretty heavily right now also because I put the old stock gasket on there and its too worn out to take the shape of the new flanges.

do you have a ridge to keep the doughnut gasket in place? if not (my midpipe doesnt) then you cant use it. from the pic the doughnut is not going to solve the problem--need hanger and correct alignment. I had to use the soft aluminum gaskets like a regular exhaust gasket
ddragger

i can make a ridge on it. i'll just weld a nice thick bead on there, all the way around the pipe, after i slide it on there.

DOnt go to all that trouble--just get a Percy seal for good exhaust gasket--see Summit racing. It will work much better
olddragger

i'm not having a problem in the front where the header connects to the midpipe, it's just in the back.

will the stock donut gasket fit? i couldn't get it off. it looked like it was bonded to the exhaust somehow,

You can get it off. Trust me. You just need a paint scraper and a rubber hammer. Work around it like you would when you tune a drum or put lugs back on a wheel :)
-Gil

you guys think it would work if i slipped a bunch of regular triangular or oval exhaust gaskets on there? three maybe? and then made sure i bolted it back up real tight? i think that would close the gap for now.

no it will burn out and it will be right back to where you started. get it to fit 1st,move it all around to get it to fit right 1st.
OD.

don't go to the dealer for the gasket when i replaced my catback i went to advance auto and i think the gasket was like 11bucks or something and i would also weld the hangar back on if that's how it is stock then it is ther for a purpose of some sort

no it will burn out and it will be right back to where you started. get it to fit 1st,move it all around to get it to fit right 1st.
OD.
+1 and just reuse the OME one. I have 35K and was ok with reusing it with my OBX CAT back and my RB mid pipe :)

i got the donut gasket off, and today i'm going to buy different longer bolts that aren't spring loaded to close the gap. locking nuts and big washers as well.

and, of course, put a hanger on there.

when i installed my RB catback, i just went ahead and bought a new donut gasket. the old one was stuck on there pretty good... so i took a dremel and cut a notch in it, then used a flat head screwdriver to pry it apart which made it come off real easy. then i installed the new gasket. a tip i learned was when tightening these types of gaskets.... tighten them like they were your wheel... dont crank one all the way down then go to the second... tighten the fist one a bit, then tighten the second one a bit, then go back to the first and keep doing that until they are both tight, youl see this will help keep it all aligned as well....

i got the donut gasket off, and today i'm going to buy different longer bolts that aren't spring loaded to close the gap. locking nuts and big washers as well.

and, of course, put a hanger on there.

I'm not sure about getting rid of the spring bolts is a good thing as I believe they are there the keep a constant seal during rapid thermal expansion and contraction.

Just use the donut gasket and all will be good. I'm been running a RP Supercat with no hanger for a good 30k miles now. The main difference on why it will work without a hanger is the weight difference between the stock cat and your midpipe.

You may want to get some high temp neverseize and coat the mating surface of the donut gasket so you can easily take it off next time.

i tried it with the donut gasket and the spring loaded bolts, and it still leaked just the same. this is just a temporary fix until i get a catback in a week or two when my bonus gets here.

try the tip i gave, it usually helps seal everything evenly `

even that way, there's still a 1/4" gap.

we're not talking about something not sealing right, we're talking about something that's so off that it doesn't compress on one side at all.

do i need to draw you guys another picture on autocad? lol.

(when this is all said and done in a few weeks, it's going to be a true 3" single exit all the way back, no cat, just 2 big resonators in the midpipe.)

ok, put a floor jack under the 2 flanges and with the spring bolts loose lift up until they are both lined up.. i had to do this with the rear flange that bolts to the mufflers.. worked like a charm

tried it.

still too big of a gap.

Are you loosening the bolts on the other side of the midpipe when you try to fix the problematic side? Maybe they are holding it cocked...

well, i tried my method of buying different bolts, and it fixed about 80% of the leak. now it's just leaking out the top. it doesn't even leak after it gets warm now.

Lord ET, I didn't think of that. i'm going to give that a try here in a little while and see how it works.

any results?

you need that support--rmember that header doesnt have the support that the oem manifold has(the bolt on thingy). if you are using some other type of support for the header make sure all of that is loose when you begin to tighten. the cat back maybe off a little also. it should have some flexibility to mate up with the midpipe. get those soft aluminum gaskets man, if there is an 1/8 gap those type gaskets will take care of it--np.
OD

Other than seeing gaps or cracks with your own eyes, what other ways are there to detect exhaust leaks?

If you get soapy water on the area you suspect it will bubble. But you have to do this on metal that isn't extremely hot, otherwise it will just evaporate. This is how I found a crack in my header

you can stick your hand up in there (your GLOVED hand) and feel the exhaust pulsating out. i know exactly where it is... that's not a problem. i'm just going to have to wait until i get a catback that'll mate up better than the stock exhaust does. no biggie. i'll probably order it next week. that rx7store midpipe is just too short... bottom line.

sounds like my kind of luck--the headers etc does make it sound better doesnt it?
olddragger

I'm looking for info on the exhaust flange bolt, which I'm having trouble getting it back on. and this thread is the closest I can find.

The Spring loaded bolt and nut I'm having problem with unscrewed at the midpipe, rather than the nut itself, not really sure how to say it. The bolt came off with the nut still stuck to it. So, I'm having problem putting it back on since the spring has to be compressed so much that it will reach the midpipe hole. Am I making any sense?

Anyways I tried everything to get the nut off the bolt but its impossible. Since theres no place to clamp on the bolt, and it took a breaker bar to get the other one loose.

Is there like a mini spring compressor somewhere for this, I cant seem to find the right name for it to buy one.
Thanks

hmmm... have you tried emptying a whole can of liquid wrench in there? Also, if the nut came off, you should just be able to hit the spring part with a mallet. If that doesnt work, heat it up with a torch (or get a shop to do it) and replace the spring bolts. Charles from BHR can hook you up with new ones as he includes them with his midpipe.

Thanks for the info, I did use liquid wrench but the bolt itself is small and there isnt a good spot to grab it by to break the nut off. I'm currently trying to compress the spring with zip ties so the bolt can reach the threaded hole on the midpipe. If all goes bad I'll just get new ones.

Problem solved, borrowed a huge monkey wrench from a friend and with a breaker bar, snapped that nut out.