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exhaust and heat wrap question

Discussion in 'A4/S4 forum(B5 Chassis)' started by boost-addict, May 25, 2012.

  1. boost-addict

    boost-addict Active Member

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    ok so as i cant find ANY decent exhuasts that dont cost circa £500 im wondering if i can use this item, and then use a 2.5" pipe from jetex to connect to the join up by the transmision were it connects from the down pipe. then buy a decat and downpipe else were,

    Audi A4 quattro 8D 2.4/2.6/2.8/2.5TDI S/Steel Jetex Exhaust Sys 42-H9PTR 94-00 | eBay

    i understand its for a v6 engine but surely the rest of the exhuast after the down pipes on the v6 is the same as the single,
    looking at the picture i get a y pipe, of course i wont need that although i might intergrat that in to use a exhaust cut out, but thats for another project/day.

    also on the question of exhaust wrap. are you able to wrap the hot side of the turbo with the normal stuff you can buy ie
    1" X 50 ft Titanium Exhaust Header Heat Wrap | eBay

    states 2000.f direct heat and 3000f radiant, what temps does the turbo get to? thinking not 2000f? as i want to try and reduce under bonnet temps alot to keep temps down as and when i remap and upgrade turbo, fuelling etc

    , is it worth wrapping the exhaust right ti the back box? and also as its 2" i was thinking split it in to two 1" strips to make it go slightly further, cheers
     
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  3. aragorn

    aragorn "Stick a V8 in it!"
    Staff Member Moderator VCDS Map User

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    TBH, by the time you've bought that Jetex, had a connecting pipe fabricated, and bought a downpipe and decat, you might as well have just taken the car to a custom exhaust fabricator, and had them made a full system to your exacting specifications.

    What you propose will work fine ofcourse. Although you didnt actually say what car you have!
     
  4. boost-addict

    boost-addict Active Member

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    i have a audi a4 1.8t 8D

    the connecting pipe is £13 from jetex, and the clamp is a audi one. or sleave it to the downpipe.

    a custom fab would cost £500 for a 3" system, that includes down pipe and decat. but i want it so i can put the cat back in mot time. would 3" be over kill, as i know on a smaller turbo to a pipe to large of a diameter decreases torque and bhp? not sure, plus thinking 3" would make it sound like a tank? i did ask for 2.75" but they said it was special order in so not sure if that means more?

    i can get a decat pipe for $149 from ecstuning and then a downpipe made.
    i have stuff to sell on ebay totalling about £250 plus a refund due worth £48 so it wont cost me alot. although io know i can take it out to the bank then do it that way, just not sure which way is the best way, becasue ive seen powerflow s/s systems and they rust as they use ****e quality stainless

    all im looking for is a real nice bark on boost, but off boost nice and quite, well i know im not going to get both but i can live with a little drone as i dont do long journeys. and as i dont want to be classed as a boy racer it cant sound like a tank. or that straight pipe sound.


    any advice on the heat wrap?
     
  5. Jason.s

    Jason.s Active Member

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    3" would be louder but you just chose the right backbox and centre box if needed to give you the sound you`re after. The larger bore would usually lose you some low end torque but you gain flow up top. Not many keep 2.75 as no one really uses it, its either 2.5 or 3 commonly so yeah they possibly might charge you more for using it.

    You could do what others have done and use a decat and have a downpipe done and use (once modified) an S4 system which is a larger diameter.
     
  6. boost-addict

    boost-addict Active Member

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    there is a s4 system on ebay, what do they sound like and what diameter is it?

    would 2.5" do for a ko4 or possiblly a gt28r/s if and when i do decide to do it
     
  7. Jason.s

    Jason.s Active Member

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    Check out byzan's build thread. It's mostly there I think
     
  8. aragorn

    aragorn "Stick a V8 in it!"
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    Is your car a quattro?

    What link pipe is 13 quid?
     
  9. Mackers

    Mackers Member

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    i've gotta 2.5tdi quatt, i've basically had my boxes cut open, pulled the cats out and the boxes welded back up,, :)
     
  10. aragorn

    aragorn "Stick a V8 in it!"
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    yeh, but its not a streight pipe thats on the car, theres a few bends in it, and fabbing it to fit isnt free.

    A decat pipe is around £100, and the downpipe part isnt really available anywhere bar OEM or cheap aftermarket replacements so that will need to be custom made too.

    Which brings me back to my previous point, it WILL be cheaper to simply have a custom system made for the car. If your looking at upto 300hp i'd say a 3" downpipe with a sport cat mounted down under the car near the gearbox, then either a 3" or 2.5" system thereafter. 2.5" will probably be fine upto 300hp i suspect, but 3" wont hurt and gives scope for more, it will however be louder and possibly a bit boomy on the motorway etc.
     

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