Project Potential... variable vane turbo on 1.6l

[lord_verminaard]

Nice!  That looks sweet.  I'm jealous!  

Your craftmanship is A-1.  

I just realized that there are a lot of talented S.O.B.'s on this list- makes me feel glad to be a part of it!

So you may be ready to fire it up this weekend?  

Brendan
84 Scirocco 8v
00 Camaro L36 M49

[fspGTD]

Thanks!

Today I got the head on with a 2-notcher head gasket I picked up this morning.  I also cleaned up a 1.6lTD injection pump and bolted it up and installed the toothed pulley and timing belt, which still needs to be tensioned and cam pulley set, but the head is torqued to the block and there are a bunch of pieces ready to be installed which should all go quickly, including bolting up the turbo / exhaust manifold.  

I won't be able to work on it again until probably sunday.  After I get the turbo /exhaust manifold is bolted up, I've still got to sort out how to route the boost tube to the intake, and whether I'll install the short runner or the long runner intake manifold to start with.  Also need to determine where to put the air cleaner and how to plumb it to the turbo (so, may need to fabricate a custom air tubing adapter or two...) and also will need to install the turbo oil supply line (hopefully can just bend the stock 1.6lTD oil supply line) and make up an aeroquip line for turbo oil return (including welding an AN fitting to the oil pan.)  I'll also need to fabricate a tubular exhaust downpipe with some sort of flex joint (maybe salvaging the old flex joint that was on the exhaust system previously) and decide if I want to connect it all the way to the rest of the exhaust system myself (which is rearwards of the shifter but before the fuel tank) - in which case I'll probably need more tubing and bends, or whether I'll just drive it to a muffler shop to have them put the exhaust system together.  So it will hopefully be sometime next week when I'll be ready to fire her up.

Edit: pic of raceware head studs installed along with head gasket (coated with copper spray-a-gasket):

[Staley]

Thanks!
I'll also need to fabricate a tubular exhaust downpipe with some sort of flex joint (maybe salvaging the old flex joint that was on the exhaust system previously) .

If you guys need any stainless mandrel tubing or flex couplers..
one of my buddies owns www.ghlmotorsports.com  he sends me whatever I need tubing wise and flex coupler wise.. at a MUCH lower price than burns stainless or other companies..
let me know

later
mike

[fspGTD]

Today I got the camshaft and the injection pump timed.  I found I was able to prime the injection pump (which was previously completely drained out) by using a squeeze bulb to suck air out of the fuel return line.

With the turbo/exhaust manifold loosely installed, I bent the 1.6lTD oil supply line to make it fit with the TDI VNT turbo.  I am pleased with the result:



I will soon be fabricating a custom downpipe.  The downpipe will need to make a pretty tight bend down and toward the rear of the car in order to clear the nearby shift linkage:
(view from below, looking up:)


Also I've got the oil pan off now and will be welding a fitting to it for the turbo oil return.  It will be going back on with a windage tray oil pan gasket!  

[VWRacer]

Freakin' awesome, Jake!  

Just one question, tho...how do you plan to do this?

Just wanted to update you guys... the exhaust manifold/turbo is all ready to install with the following modifications: VNT boost pressure control conversion [emphasis added]

I couldn't find any details. Can you point me to where you covered this or expand on your plan?

Thanks!

[fspGTD]

Thanks for the encouragement Stan!  Look earlier in this "mega thread" to read about my VNT controller boost pressure conversion.  Specifically, here:
http://www.vwdiesel.net/phpBB/viewtopic.php?t=1306&postdays=0&postorder=asc&start=26

[TDIMeister]

Jake, are you timing the cam any differently from stock?  Retarding it by a few degrees will make a noticeable difference in the top-end.

[fspGTD]

Nope.  I set the cam timing right at the TDC mark, although when I was checking piston projection I found the factory TDC mark on the flywheel was off by .5 degrees (can't remember which direction, but it was a small enough variance I figured that it shouldn't matter.)

This is a daily driver application, so I opted to not compromise piston-valve clearance to bias the powerband either one way (higher RPMs) or towards lower RPMs.  Knowing my dad, he would probably prefer a broader powerband over more horsepower anyway, and it just has a 4-speed transmission (although the ratios of this "3+E" style 4-speed, with a .70 fourth gear IIRC, are practically as good for highway cruising as any five speed - and with less "gear rowing" required than a five speed, should be a GREAT setup for a torquey TD daily driver.)

I also attempted to set injection pump timing as closely as I reasonably could to the stock specs (1.00mm.)  After setting the timing and torquing the pump mounting bolts, I re-zero'ed the dial indicator and checked the timing.  Came out to 1.01mm, a variance of only .01mm... (which seemed to be a difference of only a fraction of a crank degree.)

I found that the cold start lever was *really* hard to move without any fuel being in the pump!  :?  I have my fingers crossed that it gets easier after the engine is run for a whileand the pump has time to purge all the air out of the cold start piston cavities.  If it doesn't get better, I will probably replace the cold start cable at the least (It's housing was looking kind of old and cracked...)

[MrDave]

I will soon be fabricating a custom downpipe.  The downpipe will need to make a pretty tight bend down and toward the rear of the car in order to clear the nearby shift linkage:
(view from below, looking up:)

On my TDI rabbit, I ended up putting a 1" extension onto the shifter, to elevate the swing arm, in order to clear the elbow off of the turbo.

On a, uh, let's say, enthusiastic shift, if you listen carefully, you can hear the metallic 'ting' of the shifter hitting the downpipe.

I'm also running heim joints for the shifter linkage, with a nut welded into hole on the end of the swing arm for a tad more clearance.

The TDI is a taller block than your 1.6, so you'll need a real tight elbow, and you may need to use a longer extension on the shifter piece.
Maybe you should just switch to a cable shift tranny...

-Dave

[fspGTD]

I've found that it is a much better method to make the linkage shorter by amplifying the lever of the shifter extending under the car near the driver, rather than making the relay lever arm longer.  IME, it amplified the "slop" much more when the relay lever arm is lengthened, as well as reduces the inertia of the linkage, increasing "notchiness".  For more thoughts on this topic, check out my review of the EMPI Rabbit shifter, which I installed in this car:
http://www.vwdiesel.net/phpBB/viewtopic.php?t=1146

I've already been completely through the linkage of this car, and it's totally awesome, best shifting A1 I've ever driven.  Even better than my GTD autocrosser with trick heim fittings!  I am amazed how easy it is to grab any gear, down to 1st.

Because I would rather not alter the geometry or throw of stock relay lever arm, I am planning on fabricating a very tight angled downpipe if needbe.  

I also don't think there will be a performance penalty from a very tight angle of tubing initially coming out of the turbine housing.  I understand in that area the flow frequently is in a spiraling vortex, and the reason manufacturers often have an abrupt step macined into the exducer bore of turbos is to break up this vortex.  Since laminar flow is already being broken as the air comes out of the exducer here, I don't think putting sharp kink in the passage right out of the turbine here will add a restriction.  Hugh Mackinne's "turbochargers" even shows a banjo-like tubing shape coming out of the turbo used in a really tight clearance application, and says it flows great.  I am going to see if I can make 2.5" tubing fit though!  

[MrDave]

... rather than making the relay lever arm longer.

Uh, never said anything about making the relay lever arm longer.
Just located it higher on the vertical axis, to clear the downpipe as it swings.

-Dave

[fspGTD]

Ah, gotcha.  I think that on mine, the end of the relay lever is about as high as the center of the turbine outlet.

Edit: here's another pic of this area...

[jackbombay]

Here they have a 2.5" diameter pipe mandrel bent to a 3.5" radius.

[fspGTD]

I have a stainless 4" center line radius 2.5" U-bend I will see first if I can make work.  If I need tighter, I actually do have an aluminized 3" center line radius 2.5" U-bend, although I'd prefer using stainless instead.

If I wanted a really tight bend, I could opt for a "tube doughnut", where the center line radius is equal to the tube diameter!  Anyone use one of those before?  They look pretty intriguing...


(Not exactly cheap though...
http://www.hrpworld.com/index.cfm?form_prod_id=198,55,363_1228&action=product )

[MrDave]

I extended this shaft, and moved the swing arm up enough to clear. Remember, you could always modify the shifter rod on the end of the swing arm to remedy the change in the Vertical position.

Also, and I must stress this, remember the downpipe bolts when fabbing your dp.   What kind of wrench do you want to use?  You could make a very short elbow, but find yourself not be able put one of the nuts on.
Or, find yourself using an open ended wrench and just having the rusted nut strip when you're trying to disassemble it someday.

Cable shift, my friend.   Think about it.

Plus, maybe you could install one of these:


as an aside, I'm super impressed how clean your engine bay is.    If it was in focus, I'm sure I could read the part number from the shifter bracket.

-Dave