What do you guys use for exhaust flex?

[PMan_S13]

I'm putting together my own 3" exhuast from the turbo back. No one around here has the balls to make one, so I was somewhat forced to make at least the downpipe all on my own.

Anyway, I have the downpipe all finished and I pretty well have the rest of the exhaust back to the muffler finished. But so far it is all straight pipe. It has no flex whatsoever besides what the pipe (and my gorilla welds) allow.

I wanted to use 3" flex pipe to be welded in right after the downpipe. But no one around here carries the stuff. Speedy muffler can get it for 105 plus shipping for a 10" section. (Yeah, the're out of their freakin' minds) If someone knows an online retailer that would be sweet.. I can't find anything. Ebay has some for 34 plus 15 shipped.

Does anyone have some pointers on what I can use to assure my exhuast won't shake itself crazy?

[bruinbear714]

I'm putting together my own 3" exhuast from the turbo back. No one around here has the balls to make one, so I was somewhat forced to make at least the downpipe all on my own.

Anyway, I have the downpipe all finished and I pretty well have the rest of the exhaust back to the muffler finished. But so far it is all straight pipe. It has no flex whatsoever besides what the pipe (and my gorilla welds) allow.

I wanted to use 3" flex pipe to be welded in right after the downpipe. But no one around here carries the stuff. Speedy muffler can get it for 105 plus shipping for a 10" section. (Yeah, the're out of their freakin' minds) If someone knows an online retailer that would be sweet.. I can't find anything. Ebay has some for 34 plus 15 shipped.

Does anyone have some pointers on what I can use to assure my exhuast won't shake itself crazy?

I'm using the 3" flex section from atpturbo.com.

[ziggy682]

Flex pipes are generally for front wheel drive cars, because when the engine torques, it will pull and push the exhaust. In a rear wheel drive application, the engine will twist the exhaust, and there should be enough play in the rubber exhaust hangers so you wouldn't need a flex pipe.

I know my S13 didn't have a flex pipe stock, and now I have a custom downpipe, and Apexi N1 exhaust, and it's just fine with no flex pipe.

[Soulja]

I would rather have a section of flex pipe, than shaking in the exhaust over time causing the welds in my manifold to crack. Anything that you can do to make a tubular manifold last longer, is a good investment in my opinion.

[red240ne]

ebay flex pipe. I personallly don't run flex pipe either tho

[PMan_S13]

I know they generally are for FWD, just thought it would help me sleep better knowing some of the flexing is done by something deesigned to handle it.

But I suppose you are right about the rubber bushings...

[huguetpj]

I would rather have a section of flex pipe, than shaking in the exhaust over time causing the welds in my manifold to crack. Anything that you can do to make a tubular manifold last longer, is a good investment in my opinion.

Well a good manifold with good welds should not crack anywhere.... mine hasn't and I have no flex pipe. I even ran the car up to 1600°F+ EGT while running track a couple of times. Fortunately nothing burned nor failed. I'm pretty confident my mani won't fail me now :pface

[Soulja]

Well a good manifold with good welds should not crack anywhere.... mine hasn't and I have no flex pipe. I even ran the car up to 1600°F+ EGT while running track a couple of times. Fortunately nothing burned nor failed. I'm pretty confident my mani won't fail me now :pface

alot tubular manifolds will eventually crack, some are know for it more than others. The flex pipe is a cheap peice of insurance, to help with the problem.

[huguetpj]

alot tubular manifolds will eventually crack

Not if they are WELL made... and mine was custom made by my muffler shop, no fancy name high price mani here :pface

Quote »The flex pipe is a cheap peice of insurance, to help with the problem. [/quote]

I do agree on that. I just forgot to put that on the last post. But it is not as important as with a FWD car. As someone said, the rubber hangers should be enough.

[sil80drifter]

http://cgi.ebay.com/ebaymotors...=WDVW

this is what i got for my downpipe (but 2.5" instead of 3"), i am going to build it in right before the cat.

sil80

[PMan_S13]

I went ahead and just finished welding up the 3" exhaust. Seems to be working fine so far. I've driven it like this all week and put it through it's paces.

Only small issue now is I'm having trouble keeping the bolts holding the downpipe to the turbo tight. I guess I'll have to find some very high temp lock-tite