[Bassmaker]

Sorry if I appear to be a bit thick but I am a bit confused about which part of the exhaust system is the center pipe on a 99 UK S Turbo. I'm looking for a de-cat mid section and some diagrams refer to the pipe that exits the back of the turbo as the middle and/or down pipe. On other diagrams the next pipe on from that one is referred to as the silencer while on others, there is a straightish pipe about 20-24" long that goes between the first bent pipe and the silencer which some refer to as the middle pipe and others call it the back pipe. On some diagrams I can't see this long straight piece at all. If it's the long straight pipe, is diameter an issue because they seem to come in 2.5", 2.75" and 3" daimeter and the rest of my exhaust is stock. I am reliably informed that an Imprezza part, JDM or EU will fit but I don't have the year. Prices vary widely too from £80ish up to £150 plus fairly steep carriage for the long straight piece. I am Confused.com. Can anyone help please.

 

[don1952]

Here is the pre MY01 UK "Classic" "turbo back" exhaust giving the items their "OEM" names.

As its a three piece "turbo back" exhaust the three sections often get called

Downpipe - Centre pipe - Back box (Muffler)

where in fact they are........

(4)Centre exhaust pipe - (8)Rear Exhaust pipe - (18) Muffler

The Front exhaust pipe or Front joint pipe (name varies model to model) (AKA Xover pipe) joins the two manifolds and the Turbo joint pipe (AKA up pipe) links RH manifold to turbo.

The "centre pipe" (rear exhaust pipe) will have a cat under the shields, JDM version will have just a resonator or restrictor.



The complete "Classic" exhaust system (albeit having an impreza muffler :icon_biggrin

I expect that will have confused you even more :biggrin::biggrin:

 

[don1952]

Just to add, Standard exhaust from turbo back is 2.5" with possibly the muffler being 2.75".

Unless you are going big power then 3" would be overkill and may not fit unless you replace all.

A JDM classic (Forester SF or Impreza GC) "centre pipe" of similar year will fit.

 

[Bassmaker]

Nice one Don. I forgot to take into account the up pipe from the manifold to the turbo because it was on the other side of the turbo, and so I could only see three component parts. Now it's pointed out to me, it's simple enough and so perhaps I'm not going senile. Thanks. Tony.

 

[Bassmaker]

Hi Don. Based on your advice above, what do you reckon on the attached fleabay item. I know it is a 3" but it goes down to 2 1/2" at the back end. There is another similar item which is 2 1/2" all the way through on the same site. Thanks. Tony.

eBay.ie: SUBARU FORESTER SF-5 SF5 CAT DOWNPIPE EXHAUST DECAT (item 270497819852 end time 06-Apr-10 19:58:27 BST)

 

[don1952]

Have never purchased from them so difficult to give an opinion. Their feedback seems to be reasonably good although the 30BHP gain claim, i would say, is rather exaggerated. (more like 7-8)

Should go well with the TD04.

 

[Bassmaker]

Yes, I figured the +30 horse claim was amusing but I was more interested in assisting the turbo spooling up etc, although 7 HP gain is not to be sneezed at. I guess one mmust be vigilant when reading these claims as the key words are "Up to", terms and conditions apply etc. Thanks Don.