pros and cons of flexi exhaust pipe

[mudbitz]

need to use flexible exhaust pipe on forthcoming project
any info i need to have or is it straightforward
any type better than others
plan to fasten via u bolts
any further info appreciated

[Deleted]

its ok to use it to get the shape of an exhaust but other than that it pretty usless .
use a bit then remove it without bending it to much and copy it in a hard pipe it will look better work better and last longer

[joethefish]

I've heard the jetex stuff.. (semi flexi similar to the stuff seen in a lot of modern cars after the manifold) is not bad, and is what i'll be using as think i'll need some too.. Merlin motorsports was about cheapest online supplier I found.

[akku]

flexi pipe, from the experiance of others...

easier to get to fit than a rigid pipe
flows poorly compared to mandrel bent pipe
splits/cracks after a while.

There used to be a company called Spiralo or something like that did complete flexible "universal" exhaust systems for any car. I don't think they lasted long...

[kee]

primarily they are used to prevent the exhaust manifold from cracking as it takes up the movement in the engine, there are a lot of problems with certain manifolds on fiestas with this.
they don't flow aswell as a normal pipe but better than a cracked manifold. When i worked in the exhaust industry we used them on most the exhausts we made for the likes of Aston Martin etc. so well worth it.

[MrSpeedy]

The BZP wound stuff is bloody useless. It rusts and cracks after a short while.
We use Stainless convoluted stuff with a stainless wire overbraid, which lasts for years and years and doesn't fracture. Not the cheapest but it works and lasts ! However that is on boats !
I did use a short (6") piece when i made up the Sprintfire exhaust 8 years ago and it's still as fresh as the day i fitted it.
You get what you pay for !

[kee]

yep, go for stainless if you can. mine was put on when powerflow did my exhaust.



dunno what it looks like now, its raining so I'm staying put ;D

[joethefish]

^That looks the same as the stuff I was planning on from merlin/jetex.. think its availiable in SS too although don't quote me on that.

[kee]

that is stainless

[akku]

that stuffs the proper stuff not the naff flexi stuff a lot of places sell which reminds me of the hose off the back of a tumble dryer...

[Robinxr4i]

This stuff......





Looks like it's a quick fix kinda thing to me!

[mattblack]

Jul 17, 2009 9:03:22 GMT kee said:

yep, go for stainless if you can. mine was put on when powerflow did my exhaust.



dunno what it looks like now, its raining so I'm staying put ;D

That's just a flexi joint to allow for movement... I would think that the O/P was thinking of something longer/more bendy?

[kee]

i was worried about that when posting but it isn't quite clear to me either.

if it is long lengths of fully flexible stuff then don't bother, get some bends and then use what i have somewhere.

[dubzi]

Jul 17, 2009 11:38:16 GMT Robinxr4i said:

This stuff......





Looks like it's a quick fix kinda thing to me!

That stuff is easy to fit and is a quick fix, but as said it rusts and splits very quickly. Lasted a year on my Range Rover and about 2 months when I used it as a joining piece on my Quattro! That siad I have a piece on my Bedford CF near the back and that's still going strong after 3 years. Not so hot and not so much vibration near the back I suppose.

The stainless braided joins are better but only to take up vibration, you can't make bends.

[mudbitz]

thanks for input
only using short straight lengths

[MrSpeedy]

If it's in straight lengths then just get a length of tube.
You can make any small bends by just cutting and welding the pipe or even get some mandrel bends for welding in from somewhere like demon tweeks, ( cheaper alternatives are probably available! )
Any good motor factors will be able to supply exhaust pipe in 2m lengths in pretty much any dia you need. I got a length when i made the exhaust for my Merc. Cost me about 16 quid !

[joethefish]

How much flex is do-able with a bit like that.. not even certain I'm gonna need some yet (engine still on garage floor ) just be handy to know! (the good stuff not the washing machine pipe! ;D

[kee]

its not flexible enough to use as a bend, purely for taking up flex when the engine moves.

[joethefish]

Cool cheers.. hopefully wont be needing any then! lol