new user: questions about replacing downpipe on mk2 GTD - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• new user: questions about replacing downpipe on mk2 GTD by DanielAdams on 13 Dec, 2005 11:15
• Hi guys
  
  Owned a string of mk2 GTIs and just bought my first diesel VW - a mk2 GTD. Literally only owned this car a week and this is my first ever diesel vw so lots to learn. My usual stomping ground is vwvortex but as soon as I asked a question or two about diesels people pointed me to this site.
  
  My situation is that the engine seems to be in pretty good nick. Its got 120,000 miles on it and has had the head gasket changed 10,000 miles ago. Seems very strong.
  
  I want to replace the exhaust with a 2.5" from the turbo back. I've found a 2.5" downpipe and I've found a shop that can fab a 2.5" exhaust from the downpipe back. My question is:
  
  If I'm putting on a new downpipe and want to replace as many ancilliary parts as possiblewhat do I need? Is there a gasket between the turbo and downpipe? Is the downpipe bolted directly tot he turbo? If yes to both these, does anyone have the partnumbers for the bolts and the gasket (and anything else I need)??
  
  I do have a opy of ETKA but it doesn't seem to list the GTD.
  
  Thanks guys and sorry for such a long first post.  
  
  Dan
  (York, UK)
• #1 by Rat407 on 13 Dec, 2005 14:52
• I have a 91 ECO jetta and put on a custom 2.5" downpipe. There isn't any gasket between the downpipe and turbo. I have studs off the turbo and just took the nuts and lock washers off, cleaned them up and reused them with some nickle antisease.  Man my spelling is off today, sorry.  Anyway it all assemblied great with no leaks. Big difference in performance. Boost is tons better, it snaps up quick where it didn't before. I'm sure others have more advice since I'm just a beginner myself.
• #2 by GTD. on 13 Dec, 2005 17:02
• Hi, the UK MK2 GTD (91/92 SB engine) does have a square gasket between turbo outlet and down pipe, Where did you get your down pipe? as I'm in the north east (near Middlesborough) and looking for one, or even a seccond hand downpipe as mine has just split at the joint at the front box.
  
  I have American Etka so it doesnt cover the SB but it covers the similar 1.6 IDI TD engines, the gasket is part number 893253115 for the MF and 1V engine so should be the same for the RA/SB engine that the UK GTD's run
  
  I'd also replace the nuts and studs is your new manafold
  N90200201 M8 sholdered hex nut self locking
  
  If your Turbo is made by KKK (which if an SB it should be) the part number is
  N90121801 Stud m8x38
  If your turbo is made by Garret Air Research
  N90293401 Stud M8x43
  
  It will have the manufacturer markings on the compressor housing.
• #3 by DanielAdams on 13 Dec, 2005 23:33
• Thanks for the replies guys.
  
  

  Quote from: "GTD."

  Where did you get your down pipe?

  
  
  Believe it or not, I gave up loking for one in the UK and ordered one from passengerperformance in Canada. yes, the shipping is going to hurt but it looks like it will fit despite rhd/lhd differences and i couldn't find a 2.5" downpipe that would work sourced in the UK.
  
  

  Quote from: "GTD."

  
  I have American Etka so it doesnt cover the SB but it covers the similar 1.6 IDI TD engines, the gasket is part number 893253115 for the MF and 1V engine so should be the same for the RA/SB engine that the UK GTD's run.

  
  
  Thanks, I'll get this ordered from the stealer.
  
  

  Quote from: "GTD."

  
  I'd also replace the nuts and studs is your new manafold
  N90200201 M8 sholdered hex nut self locking
  
  If your Turbo is made by KKK (which if an SB it should be) the part number is
  N90121801 Stud m8x38
  If your turbo is made by Garret Air Research
  N90293401 Stud M8x43
  
  It will have the manufacturer markings on the compressor housing.

  
  
  Do you mean the studs between the turbo and downpipe? Manifold is not coming off, I'm simply replace the exhaust from turbo back, including the downpipe. Are any of those part numbers above for the bolts/studs between turbo and downpipe? Sorry, thanks for all the info but got a bit lost at the end there as to what part number was for what - just looking for the bolts/studs etc that joint he downpipe to the turbo.
  
  Thanks for an excellent and in-depth response  
• #4 by GTD. on 14 Dec, 2005 10:46
• Cheers Dan, Sorry yes there the turbo to down pipe studs/nuts x 4
• #5 by fspGTD on 14 Dec, 2005 11:53
• Hartmann motorsports out of Germany (not to be confused with the similarly named US company) makes (or at least did make at one time) a very high quality stainless steel downpipe for A2 1.6TDs.  It's a bolt on replacment that maintains the factory swivel joint and support bracketry.  The tubing is a touch under 2.5" in diameter, I'm going to guess it is 60mm OD.  It is not cheap, and I'm not even sure if it's still available.
  
  http://home.comcast.net/~vwgtd/downpipe.htm
• #6 by DanielAdams on 14 Dec, 2005 13:59
• GTD - thanks for the clarification, that's what I figured you meant but mentioning the manifold threw me! I'll have to check out the turbo tomorrow and see what make it is. I'm assuming these are identical in all but name, built to VW spec with no real differences, right? I'll get this stuff ordered this week so I'm all set for when the downpipe arrives. I've actually got a 40 quid balance witht he parts department at the minute due to a favour fromt he sales manager so I might go crazy and buy some other stuff too  
  
  fspGTD - Thanks for the info on the Hartmann downpipe, it sounds quality. However, Dave at passengerperformance has been very helpful in trying to figure out if the TD downpipe will fit in RHD and I've all bu placed the order with him so I'll stick with this part on this occasion. Hope everyone else has had positive experiences with this company because Dave seems genuinely keen to help to me.  Is that your website you linked to? Great info on there, and I just love the madness summed up by the phrase "an autocrossing mk1 turbodiesel", not something you come across every day!
  
  Thanks for all the help everyone. Very impressed with this forum. Obviously not as much general traffic as vortex but for interesting diesel-related info and on-the-money answers it seems spot on.
  
  Been prowling some of the other threads without posting. Love that crazy custom manifold design, I've actually got some AutoCAD 3D designs I put together for a replacement intake manifold myself but not the sort of thing that will ever see the light of day.
  
  See you all around the forum  
  
  Dan
• #7 by DanielAdams on 07 Feb, 2006 12:12
• OK, so an update at last. I'm not one to be rushed with my VWs (my other mk2 is a gti tht i've been buiding up slowly for about 6 year now (!).
  
  Anyway, the downpipe arrived from Passenger Performance. Quality? Well it looks the part, good gauge steel with a flex joint and good solid flanges. Welding was a little messy in parts, but just welding-with-gusto messy, not messy crappy-weld-about-to-fail messy.
  
  Anyway, I broke out the dremel to tidy it up a bit (just grinding off some of the weld spatter) and to match the flange internal bore with the pipe bore more exactly (yes, I'm anal and yes, I know it won't make a difference in performance terms).
  
  Anyway, sat on my arse for a few weeks then and forgot about it, and then sent it off last week to get ceramic coated internally and externally.
  
  Its back from the ceramic coating now and (assuming I can figure out how) I'll post up pics in an hour or so of how it currently looks.
  
  Looking to get it fitted in 2 weeks or so along with a full downpipe-back stainless system in 2.5" stainless steel. Having decided 100% but I think I will go with a 'powerflow' system (not sure if you have that company in the US/Canada). If I can get away with it noise-wise, I am looking at getting it just straight pipe all the way back, no resonators, nothing.
  
  As an aside, my (stock) exhaust currently on the car just snapped in two through rot and so I currently have a wonderful rattle and intoxicating diesel fumes in the car. Nice.
  
  Right, I'moff to snap some pics with the digital camera, will update the post shortly...
  
  Dan
  
  EDIT: Right, here are the pictures if this works...
  
  Downpipe and assorted fittings gathered to date:
  
  
  
  The mk2 GTD waiting to receive them:
  
  
• #8 by HP on 07 Feb, 2006 14:01
• Nice machine