The next thing I did was take a 22ga Steel sheet and start cutting out a nice gasket shape for the new midpipe. I have struggled with what I wanted to do here. When I purchased the Che Mid-pipe years ago it came with a cardboard gasket which was garbage. Years ago I also used the OEM donut gaskets, but they ended up crushing to much and I just ended up with a nice exhaust leak, so this time I decided against it and opted to make my own. Testing will show how good it will be and how well it will seal, but this is a good first attempt in my eyes. Last night I installed it and tightened it all up. It fit pretty well and looks like it made a good seal, but if it has any sort of leak, I may pull it and make a second so that there are two sandwiched together; I'm in no rush though.
Patrick, I have struggled with this gasket for a long time. No matter what you do it will leak in time either by blowing out, cool down cycles that open up a gap or by the bolts and nuts waking a little.
I finally fixed this by using high temp thread locker and making my own Rimflex gasket using a blank and exacto knife. The Rimflex gasket is brittle and you add torque in the range of 20-30ftlbs which is light, anymore and it will leak. What this does is slightly crush the gasket a little like a spring so it will add tension so it doesn't leak during cool downs. The material is made of graphite which has a much higher threshold for heat then most other materials.
If it leaks again try this gasket as it's working great for me.
The next thing I did was take a 22ga Steel sheet and start cutting out a nice gasket shape for the new midpipe. I have struggled with what I wanted to do here. When I purchased the Che Mid-pipe years ago it came with a cardboard gasket which was garbage. Years ago I also used the OEM donut gaskets, but they ended up crushing to much and I just ended up with a nice exhaust leak, so this time I decided against it and opted to make my own. Testing will show how good it will be and how well it will seal, but this is a good first attempt in my eyes. Last night I installed it and tightened it all up. It fit pretty well and looks like it made a good seal, but if it has any sort of leak, I may pull it and make a second so that there are two sandwiched together; I'm in no rush though.
Patrick, I have struggled with this gasket for a long time. No matter what you do it will leak in time either by blowing out, cool down cycles that open up a gap or by the bolts and nuts waking a little.
I finally fixed this by using high temp thread locker and making my own Rimflex gasket using a blank and exacto knife. The Rimflex gasket is brittle and you add torque in the range of 20-30ftlbs which is light, anymore and it will leak. What this does is slightly crush the gasket a little like a spring so it will add tension so it doesn't leak during cool downs. The material is made of graphite which has a much higher threshold for heat then most other materials.
If it leaks again try this gasket as it's working great for me.
Great information! I have a feeling I'll end up having a leak, it just depends on how bad it is. We'll see what the soapy water tells me when I start it up later this week.
The next thing I did was take a 22ga Steel sheet and start cutting out a nice gasket shape for the new midpipe. I have struggled with what I wanted to do here. When I purchased the Che Mid-pipe years ago it came with a cardboard gasket which was garbage. Years ago I also used the OEM donut gaskets, but they ended up crushing to much and I just ended up with a nice exhaust leak, so this time I decided against it and opted to make my own. Testing will show how good it will be and how well it will seal, but this is a good first attempt in my eyes. Last night I installed it and tightened it all up. It fit pretty well and looks like it made a good seal, but if it has any sort of leak, I may pull it and make a second so that there are two sandwiched together; I'm in no rush though.
Patrick, I have struggled with this gasket for a long time. No matter what you do it will leak in time either by blowing out, cool down cycles that open up a gap or by the bolts and nuts waking a little.
I finally fixed this by using high temp thread locker and making my own Rimflex gasket using a blank and exacto knife. The Rimflex gasket is brittle and you add torque in the range of 20-30ftlbs which is light, anymore and it will leak. What this does is slightly crush the gasket a little like a spring so it will add tension so it doesn't leak during cool downs. The material is made of graphite which has a much higher threshold for heat then most other materials.
If it leaks again try this gasket as it's working great for me.
Great information! I have a feeling I'll end up having a leak, it just depends on how bad it is. We'll see what the soapy water tells me when I start it up later this week.
It will be fine one moment and the next moment it let go and get louder. If you hold a small strip of paper or sting around the joint you can see it flapping around if there is a leak.
@dev Fingers crossed! This is why I opted for the material I did, also. A tear is HIGHLY unlikely to occur, the leak would happen because of bad surfaces.
It has been the solution to all of my exhaust gasket woes for near a decade now. In some places I've neglected to replace OEM metal gaskets at all and just use this stuff. And... I'm somewhat ashamed to admit... I have even sealed up a couple of leaks on bad gaskets without bothering to take anything apart. I just cram this stuff in with the exhaust cold, hit it with the heat gun for a little while, let it cool, hit it one more time with the gun, then give it 24hrs rest to cure. Despicable... I know...
Lol when I first installed the che midpipe i tried to use only the copper goop but it leaked like a siv because I'm inept haha. Ended up buying some gasket material from an oil and gas supplier. It's made out of layers of exfoliated graphite and stainless steel foil. They use it for exhaust gaskets on mining equipment. Rated for super high heat and tons of cycles. Reusable too. Was not fun to cut. Also cost like 80 for 1 square foot. Has passed the electronic sniffer test twice though with some dissassembly/ reassembly in between!
Could probably cut some copper to make a gasket and just reanneal it every time you disassemble.
Have y'all tried adding Permatex copper to this notious gasket problem?
Yes I have tried the copper and there is something better than the copper that I have used for years that you can pick up at Napa called acoustic seal . This stuff has fixed many leaks. If it gets on your hands its very hard to get out and if it touches your cloths throw it in the trash.
Unfortunately none of those methods worked and would blow out in a month. I also tried using what is called a Percy carbon X gasket and that eventually blew out. The problem here is three things that makes this cheap poorly designed Chinese fittings fail.
1. The nuts and bolts do not get a good bite on the polished downpipe. this causes the bolt to rotate and the nuts to walk which loosens connection and causes it to leak.
2. Once you fix it with high temp thread locker the enormous heat eventually degrades the gasket material and create a gap that causes a blow out.
3. The other issue is during the heat and cool down cycles the connection tightens and contracts, given enough time it will form a gap. This is acerbated by vibrations.
You all might be wondering how the stock set up works.
The stock uses copper ring gaskets that are contained in a counter sink on both ends so it doesn't move. When you tighten up the connection the bolts have something to grab on to because its not a polished surface and the gaskets crush to form a seal and act like a spring under tension so during cool down cycles it keeps its seal.
The Rimflex gasket material that I used is made of graphite and is rated for high heat. Its also a crush gasket that forms a seal and acts like a spring to add tension on the connection. This along with thread locker has seemed to work great. There are many people that have the cheap leaking Che 1zz header with warped flanges on the engine side that leaks and this could be what fixes it. Im sold on this gasket material.
Lol when I first installed the che midpipe i tried to use only the copper goop but it leaked like a siv because I'm inept haha. Ended up buying some gasket material from an oil and gas supplier. It's made out of layers of exfoliated graphite and stainless steel foil. They use it for exhaust gaskets on mining equipment. Rated for super high heat and tons of cycles. Reusable too. Was not fun to cut. Also cost like 80 for 1 square foot. Has passed the electronic sniffer test twice though with some dissassembly/ reassembly in between!
Could probably cut some copper to make a gasket and just reanneal it every time you disassemble.
I wonder if its the Rimflex material by the way you describe the gasket. The only difference is the Rimflex cant be reused.
Spent a bit of time last night with a grinder and a hole saw. I have a feeling i'll need to spend some more time with the grinder, but for now it looks to be big enough. It took some time bending the hangers to get them right, but I think I have them in a good place now. It visually looks even, the exhaust pipes aren't touching the bumber, and it's supporting it's own weight instead of being supported by the CHE midpipe. I haven't installed the doughnut gasket yet, or bolted it up, so that'll be next; good progress for the night though.
Spent a bit of time last night with a grinder and a hole saw. I have a feeling i'll need to spend some more time with the grinder, but for now it looks to be big enough. It took some time bending the hangers to get them right, but I think I have them in a good place now. It visually looks even, the exhaust pipes aren't touching the bumber, and it's supporting it's own weight instead of being supported by the CHE midpipe. I haven't installed the doughnut gasket yet, or bolted it up, so that'll be next; good progress for the night though.
Are you sandwiching the big donut gasket from the Che mid pipe to the exhaust?
If so this is another area where it can leak. I had to weld in a pipe like the stock downpipe so it wouldn't shift around and leak.
@dev Yeahp, sadly. I took a grinder to the inside of the Che mid pipe to create about a 3-4mm space where I can put a 2.5" pipe. I have a piece of metal to insert, but again, I'm expecting leak city and i'll have to weld it in place.
@dev Yeahp, sadly. I took a grinder to the inside of the Che mid pipe to create about a 3-4mm space where I can put a 2.5" pipe. I have a piece of metal to insert, but again, I'm expecting leak city and i'll have to weld it in place.
Welding in a pipe is what fixed everything. Before that I did the sandwich thing with gasket sealer and it held for a good while until it slipped from the vibrations. My other options was to weld in one of these newer joints they sell on Summit Racing on both ends.
HF flux core welder, grinder/cutoff tool, going to auto zone with the downpipe in hand for the right size pipe and youtube videos did the job.
With that stupid Che downpipe I was at a point of giving up and just getting a PPE header but I finally conquered that SOB.
That looks like the Rimflex material. I wonder if what you got is straight form the company and Rimflex buys large quantities and makes gaskets from them for specific applications.
