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A few ramblings for anyone who's interested.


As some will know, my f-hose failed whilst the car was on Awesome's rolling road the other week. It was at full load at 5900 rpm, which clearly is not a good thing.

The sudden boost leak has overspun those tiny K03's and caused the compressor tips to get very hot indeed, they then stretched and are touching the compressor housings. Nothing has become detached and eaten by the engine so so far as we can tell.

I will replace the f-hose with a samco item as soon as I can find one. Is this good enough or does anyone have other experiences?

I didn't think my car had an f-hose (can't remember why now) or I'd have swapped it because from reading the forums, I trust them about as much as I trust the TBB which I replaced with an APR bi-pipe before the car was chipped.

Does everyone with a chipped car have a Samco TBB & f-hose ? The cost is £ 70 + fitting and boy do I wish I had been more diligent now.


Any comments appreciated.


Here is a piccy that makes me unhappy sorry


http://www.ecstuning.com/stage/edpd/pag ... mage.html#

My car has a metal F-Hose, it's an early S4 and I thought it was standard until this forum told me it wasn't.
I assume a previous owner must have fitted one of these, it's got to be the best solution............ http://www.hoppenmotorsport.com/F%20pipe.htm

60 odd quid for a bit of metal pipe and some bits of silicon tube???
I reckon I could put together something as good for far less... In fact I think I might just do that... I'll let you know how I get on....

I have the samco F-hose. It doesn't fit very well (it's a B****** of a job to be honest) but it's stronger
than the OEM item. I replaced my Samco TBB with an OEM TBB (latest pn). I think it's better than the
Samco one. It certainly fits a lot better.

David - Was that the only leak then? Got any pics of the turbos?

Doug_S2 wrote:David - Was that the only leak then? Got any pics of the turbos?

Hi Doug,

Gonna get the turbos back.


David

MTM do a metal F-hose I believe. I too have the SAMCO one, its lasted for 3 years so far.

Mik

My car has a metal F-Hose too, was on it when I got the car in 2002, I thought it theywere standard too.

I replaced my F hose and TBB before I chipped my car (Samco).

Do we reckon there is an updated Audi part then ? I seem to remember reading that the last S4's did not have an f-hose or is it just samco and MTM versions ?

I thought it was changed after the facelift (1999.5)

Bad luck David. Your case now stands as the classic example of why air leaks can be bad news!

I think the failure mode of your F-hose is the same as the original TBB: Continual flexing of the 'rubber' eventually causes cracking an ultimately rupture. I think the Samco material is a lot tougher so doesn't flex as much.

Ultimately it's the same situation as TBB and DV: Either you rely on plastic and regularly inspect/replace, or you fit and forget a metal part.

the only thing that concerns me with the metal hose is the small piece of rubber hose 2 connect it to the side of the throttle housing..again we have to rely on a rubber pipe..suppose a piece of samco will do but again its summit to keep checking..mite be worth finding a way of doing without it or moving the pick up to somewhere else..isnt it just a vaccum pick up for the engine breather??

It's the hoses which either have a large surface area (TBB) or a bend or join in them (F-hose) that are really subject to leaking. The driver's side DV vacuum pipe is also an example, it often has to be "S" shape and this causes tension and can eventually crack (mine did). If it's a short straight hose joining two metal pipes then the risks are really low.

Thanks for the comments guys.

I've got a Samco f-hose from QST (who were most helpful).

Turbo failure was a turbine blade which detached and is now embedded in the pre-cat in the downpipe

Looking forward to seeing that.