My VNT on an NA build thread - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• My VNT on an NA build thread by hamradio on 19 Apr, 2008 20:45
• So,
  As some may have seen, I picked up this vnt for pretty cheap at a swap.
  
  
  
  The block.
  
  
  A little mock-up of the turbo on the engine.
  
  
  
  I've got a design in my head, and some sketches in a notebook of how I'm going to control the vanes.  I'll post those up tomorrow.  
  
  I do have one question- will a normal 1.6td intake mani fit without a problem, with the tdi exhaust mani?  I'm going to fabricate an egr blockoff, too.
  
  Thanks,
  Devan
• #1 by truckinwagen on 19 Apr, 2008 21:12
• it should fit fine, the stock TD turbo sits on top of the manifold, so there should be miles of room with that setup.
• #2 by fatmobile on 20 Apr, 2008 23:32
• Lotsa room,
   Almost looks like enough room to fit a gasser intake.
   My 4 door is off the road. Going to put a vegy kit and VNT15 on it in the next couple months,... hope to have it ready for the energy fair June 20th.
   Looks like we'll be working side-by-side on this.
  
   Hey, put some covers on those injectors,... even if it's aluminum foil.
   This is going in a Rabbit right?
   I wonder how the exhaust will look near the shift linkage.
• #3 by hamradio on 21 Apr, 2008 10:30
• well, I'm planning on buying new injectors shortly, anyway.  220k on the originals; they're not doing too great.  So, I'm not really worried about dirt getting in, my shop is pretty clean and dust free, anyhow.  
  
  I just made a bung for the oil return on the lathe, will weld it on in the next few days.  I also need to order gaskets tonight; I need a tdi egr gasket (need to make a blockoff plate), a gasket for the downpipe on the vnt, oil filter flange gasket, im shaft seal, both crankshaft seals, trans seals, and appropriate gaskets to go with them.  :?   Hopefully, the engine is back together in a few days, and ready to put into the car.
  
  Also, yes, it is in an '82 rabbit.
• #4 by 71vdubturbo on 21 Apr, 2008 11:33
• Quote from: "hamradio"

  I just made a bung for the oil return on the lathe, will weld it on in the next few days.  

  
  
  Where is the bung going to be welded?  It looks like the oil return angles towards the block.  I had my oil return line brazed into the oil pan.  
  
  BTW, I love the setup
• #5 by hamradio on 21 Apr, 2008 13:19
• actually, I was going to do one of the following-
  
  buy a cheap drain fitting on ebay, just weld the bung right on the back side of the pan
  
  somehow lengthen the current return
  
  I'm leaning towards the ~$10 kit made for a t3.
  
  As for oil feed, I think I'm going to try to find some 1/4" steel line, bend it appropriately, and use compression fittings or something to hook it up.
  
  I'm still having a hell of a time trying to figure out how to control the vnt.  I scrapped my previous idea.
  
  I know there's some threads on controlling the vnt, but let me ask this-
  
  So, what I basically want to happen is the vanes are open, until I hit whatever PSI I want, or until a certain throttle position?  The designs I've seen had the vnt actuator can modified to work from boost, and had a cable to control it, from throttle position.  Would one want the vanes to be open, until full throttle?   Or design it so the cable pulls them open at WOT, but closes them at idle?  And the modified actuator overrides the throttle position, and shuts it down at whatever psi I set it at?
• #6 by OldDieselGuy on 21 Apr, 2008 18:31
• Hey there thought I would pass along a picture of my VNT setup on my 1.6TD I have tried several different ways to control the VNT and have had OK success with them. I though that I would try something different on this engine,This time as a test I installed a wastegate that I had laying around (set it at 15PSI) then use a toggle switch to control a vacuum solenoid that can cycle the VNT for normal driving or agressive driving the fuel pump is adjusted so the air fuel control kicks out more fuel when in the agressive mode. I will let you know how it all works when I get the car back on the road in a couple of weeks.
  [/img]
• #7 by hamradio on 21 Apr, 2008 18:53
• Very interesting!  A wastegate bolted right onto where the egr used to be?  I was thinking of putting a wastegate there, if nothing, for protection of my engine.  Are you using a 1.6na, or a td?  So, you have the wastegate set at 15, and the actuator still controlling it, to an extent?  
  
  Very interested in more info.  It looks very, very nice.
• #8 by jimfoo on 21 Apr, 2008 19:26
• Quote from: "hamradio"

  
  I know there's some threads on controlling the vnt, but let me ask this-
  
  So, what I basically want to happen is the vanes are open, until I hit whatever PSI I want, or until a certain throttle position?  The designs I've seen had the vnt actuator can modified to work from boost, and had a cable to control it, from throttle position.  Would one want the vanes to be open, until full throttle?   Or design it so the cable pulls them open at WOT, but closes them at idle?  And the modified actuator overrides the throttle position, and shuts it down at whatever psi I set it at?

  
  Vanes open means it isn't making a lot of boost, vanes closed accelerates the exhaust to spin it faster. The way most of our mechanical linkages work is the vanes start out open, but they are connected to the throttle through a spring. The more you push on the throttle, the more the vanes close and the more boost it makes. Then the actuator works to open the vanes when the desired boost is reached.
• #9 by shegel on 21 Apr, 2008 20:26
• very interesting. i will deffenently keep an eye out for parts around my area
• #10 by OldDieselGuy on 21 Apr, 2008 20:50
• The engine is a true turbo diesel with piston cooling nozzles, has an AAZ head that has been redrilled to accept a G60 valve cover, the intake manifold is TDI unit that has a machined adapter to accept a 2" OD pipe. The VNT turbo has no modifications except for the wastegate mounted to it. the fuel pump has been tweeked with some Dodge VE pump parts. This engine is going into my Cabriolet. I also have a Caddy that started out with a NA diesel and I ran a VNT turbo on it for a year with no problems, I built up another true 1.6TD engine and installed it the truck and traded the 1.6NA engine for a Cummins 4BT that needs a rebuild. That old 1.6NA engine is still running strong in another Caddy.  
  
  
• #11 by jtanguay on 21 Apr, 2008 22:40
• seems like a pretty complicated vnt control system... that thing will rip though  
  
  why not drill and tap the block for the return like on the AAZ & later TDI engines???  just makes sense to drain the oil above the oil level.  
• #12 by hamradio on 22 Apr, 2008 12:53
• so, anything wrong with just using throttle control on the vanes, and a wastegate?
  
  a wastegate bolted straight onto where the egr was?
• #13 by hamradio on 23 Apr, 2008 18:52
• Found an external wastegate.  From an audi 5k, need to go pick it up.  I'll have to make a little piece to adapt that wastegate to my setup, but, I have a free wastegate.  
  
  I tig welded a bung on the oil pan yesterday, today I modified the original oil drain line (read: cut off everything so I was left with a flange), welded a 1/4" npt bung on that (I made it quickly on the lathe).  
  
  I also messed around with front suspension tonight.  Ugh, what a pain, rusty old parts breaking and stuff.  Lots of dirt!  Suspension plans are: bilstein sports all around, probably h&r race springs, rocco rear sway bar, rocco front sway bar, rocco k bar.
• #14 by sprstu on 24 Apr, 2008 11:38
• hey hammy youre on here too!? looks like you have quite the project going here. I may have to ask you for some tips and hints in the future. look like a sweet project youve got in the making here.
  any thoughts on inter cooling?