Keep cracking mani & elbow...WTF

[CMG]

Earlier this year I had some posts about the manifold and elbow. I had a Megan manifold and elbow that I was using that both cracked. It was my fault cuz I didn't have the manifold or downpipe braced. So my solution was to get a generic ebay manifold with bracket, a Tomei expreme elbow, properly brace the downpipe to the transmission and use urethane exhaust hangers. That lasted all of 3 or 4 months. Now my mani and elbow are both cracked again, in the same places. What could possibly be causing this? I only have a ltw flywheel and intake, full 3" exhaust, nismo motor and transmission mounts, not overboosting. The only thing that I can think of is when I'm bolting on the exhaust and test pipe the flanges are not 100% lined up, but I don't have to force anything. What should I do?

[CMG]

BTW, I already welded the tomei elbow and I plan on extrude honing my stock log manifold to use that.

[DrifterProdigy85]

Do you run the bracket that connects the downpipe to the trans mount? If not, thats why your sh*ts cracking. I cracked my megan manifold a while back from the same thing.

[karmakaze]

how low does your exhaust hang? do you keep hitting it on anything?

[CMG]

I have both manifold and dp to transmission brackets. My car has never bottomed out, I've never gone over a speed bump with the coilovers. Like I said only thing that comes to mind os the axhaust brackets not lining up, as in the flanges are not flat against each other, I don't force anything or torque it too much. I'm going to take off everything and bend the pipe to line it up better if necessary.

[CMG]

I started disassembling everything and think I found the problem. The exhaust system from the test pipe back is about 1/2" lower than the test pipe flange. It can be pushed up and bolted in place, it lines up good, but I think the pressure from the urethane mounts pulling downwards is too much. I think I'm going to have to readjust and weld the mounting rods so they line up perfectly cuz there is no give with the urethane.

[karmakaze]

have a flex section welded in. that 1/2" of clearance is a good thing.

[I-Fenix]

ok the brace.. you have to start the car get it up to temp.. then torque the brace down when the manifold is heated up and hung on the car. the elbow cracking and everything could do with your exhaust not being bolted up..is your downpipe bolted to your trans? what downpipe you have? if you dont have the proper hangers that weight is being held but a hot metal object not designed to be the brace for everything else. also its a universal law of aftermarket parts.. discount prices.. discount parts.

[CMG]

have a flex section welded in. that 1/2" of clearance is a good thing.

If possibly I'd prefer to not mod my dp or catback, would the flex section in place of test pipe do the trick? I'm pulling everything off and redoing it this week so I'll be figuring it out as I go. What I can't figure is why I keep having the problem. I had all my bases covered, new mani and elbow, both brackets and urethane mounts all around. I might throw in the towel and take it to my exhaust guy, he hooks me up. It was kind of a pride thing cuz I like to do it all myself.

[Initial_R90]

flex pipe is your friend =)

[Initial_R90]

http://intensepower.com/hksdossts124.html

this may help you, your welcome

[CMG]

Yes that would be awesome to get, but only after I upgrade my turbo and manifold. And it looks like that pipe doesn't have a bracket to transmission, so I'd have to mod something up, which puts me in the same situation right now.

[Initial_R90]

whats the point of flexing if its mounted to something ?

[CMG]

I'm not getting ya...brackets are for support and strength. If you used that hks flex pipe with no transmission bracket you would have nothing from elbow to the first hanger by the diff, that's like 4-5 feet, which will cause stress and probably another cracked elbow. That flex section is in the horizontal part of the dp, so how would that differ from getting a flew test pipe? Cost is an issue too.

[Initial_R90]

we'll you figure you put the word support and flex in the same sentance so what are you looking for lol?

[tiger]

the flex pipe keeps stuff from breaking..allows exhaust to flex without putting stress on important areas.. that flex prevents cracks, right? Im asking cause i'm about to get a new exhaust system and I don't want to run into this same problem;.

[CMG]

we'll you figure you put the word support and flex in the same sentance so what are you looking for lol?

My main goal is spuuort, the flex stuff was brought up by other members. Basically I was asking if anybody had similar problems. I thought I had everything taken care of this last time. I'm just gonna throw on my stock manifold tomorrow and re-align the whole exhaust. I'll see what my muffler guy can do as far as flex pipe, I have to get an A/F bung anyway.

[nwmrkt]

http://intensepower.com/hksdossts124.html

this may help you, your welcome

that pipe may not come with a flex pipe, its just a generic picture plus it doesnt mention a flex pipe anywhere.

[Red93coupe]

Thats wierd I haven't had my downpipe braced on the transmission for 8 months and I have not had any problems with cracking or any sort of things, but my test pipe lined up perfectly with my exhaust. The brand downpipe and elbow is edge motorsports it's realy nice for the price I'm using them on my CA. I also bent my hangers on the exhaust a little to pick up the slack because my exhaust kept hitting my diff and now it doesn't move at all!!

[CMG]

Thats wierd I haven't had my downpipe braced on the transmission for 8 months and I have not had any problems with cracking or any sort of things, but my test pipe lined up perfectly with my exhaust. The brand downpipe and elbow is edge motorsports it's realy nice for the price I'm using them on my CA. I also bent my hangers on the exhaust a little to pick up the slack because my exhaust kept hitting my diff and now it doesn't move at all!!

Well I got the mani and turbo off, so I'll be replacing some gaskets and putting it back on with the stock mani. When I'm done I'm gonna take it to my exhaust guy and see what he thinks about the set up. Eventually I'll be replacing the whole manifold, turbo, lines and exhaust. I've already spent around $700 or so for the system I have, so I'm gonna try to use it and spend money on other things right now.

[CMG]

Well I got the mani and turbo off, so I'll be replacing some gaskets and putting it back on with the stock mani. When I'm done I'm gonna take it to my exhaust guy and see what he thinks about the set up. Eventually I'll be replacing the whole manifold, turbo, lines and exhaust. I've already spent around $700 or so for the system I have, so I'm gonna try to use it and spend money on other things right now.

Ok, so here's the new, I pulled the mani out. The metal screw on bracket is cracked, and the first runner closest to the firewall is cracked completely around. Maybe the bracket failure caused the runner to crack? Maybe it was just a cheapo ebay mani?

[Initial_R90]

tomei mani ftw never herd of one of them breaking check it out, it has equal length runners for better boost responce, i had an e-bay typical life on them varies from like 1-2 years

[CMG]

tomei mani ftw never herd of one of them breaking check it out, it has equal length runners for better boost responce, i had an e-bay typical life on them varies from like 1-2 years

Well I've cracked a generic and a megan one so far. The tomei expreme is a good option in a year or two when I upgrade the turbo, those two alone will probably be over $1000. I have the expreme elbow (that I paid $200 for). I must say it is a piece of crap as it cracked within a couple months. And it is exactly the same thing as the generic elbow I cracked earlier, except it has a tomei tag welded on. Next time around I think I'd go Greddy divorced.

[Initial_R90]

i had the greddy one its not bad i was gonna buy a e-bay HKS style cut the one pipe off and run open WG sold the motor and car be4 i got around to it

[CMG]

Only downside to greddy if I remember correctly is that it's only a 2.5 or 2.75 outlet, and the tomei is 3".

[CMG]

So I talked to my muffler guy today, he has a real nice flex section that he took off a chevy or ford truck. It's way better than standard ss flex section. I'm thinking about him making a test pipe with that flex section, only downside is that it's only 2.75". Think that little of a restriction will make a difference on a full 3" exhaust set up?