There's currently a http://www.914world.com/bbs2/index.php?showtopic=244471 about using L-jet from a 1.8L engine for a 2.0 with discussion about using bigger bore throttle body from a later Vanagon.
I tried it but ran into an issue with the orientation of the flat on the shaft that engages the throttle body switch component used with L-Jet.
Pictures are worth a thousand words, so here goes..
Here's the TPS and a picture of each TB with the plate in the throttle closed position. Original 1.8 L-jet on the right, Vanagon donor TB on the left. Notice the different orientation of the flat on the shafts. The flat engages a corresponding flat on the TPS. The flat on the Vanagon shaft is in the wrong position for the TPS.
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I didn't want to simply make a new flat on the bottom of the shaft where it engages the TPS because there is already a flat on the other side. That wouldn't leave much metal. Also, I think it would be difficult to exactly duplicate orientation of the factory flat. I put a multimeter to the TPS when it was installed on the TB and found that the switch engages pretty precisely at closed and WOT. I don't think I could duplicate that exact angle by eyeballing it on the bench grinder.
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So I decided to use the shaft from the 1.8 TB. Only problem is that the recess in the shaft is sized for the smaller TB plate.
The 1.8 plate is 43mm in diameter, the vanagon plate is 48mm.
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So I decided the way to go was to lengthen the recess on the 1.8 TB shaft to fit the vanagon TB plate. 2.5mm on each side would do it. So I measured and taped it off to guide me with the bench grinder.
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Great pictures! I just picked up a 2.1L throttle body on the Samba.
Brief intermission, and on a related note.. another one of my hobbies is vintage shop machines. My bench grinder is a 1962 Sears Craftsman that I rescued a few years ago and restored to it's former glory (and back to original colors).
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Five minutes of careful grinding on each side was all it needed. What a great thing that VW/Porsche used the same spacing between holes for both TB plates.
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And with that, I inserted the modified shaft in the Vanagon TB, attached the plate, assembled the spring mechanism... and I now have an enlarged TB that will fit the 1.8 L-jet system (for use on my 2.0 engine).
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One more note, you may have noticed already that there is a casting difference between the original TB and Vanagon TB where the TPS attaches. It feels pretty well anchored with one screw and of course the shaft that inserts into the TPS. Just for good measure, I put a zip tie around the non-screwed end and the vacuum port. I doubt it's needed, but it's just added assurance.
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Nice work. Way to think out of the box.
Peen or use Loctite on the throttle plate screws. You don't want one of them to fall out...
--DD
Did you try to use the vanagon throttle switch?
Really good write up and something I would have used on a L-Jet 2.0 a few years back. Well done!
Bryan Do you have the part number for this throttle body? also Would one from a 1.9 work or is there a difference in dimension? Thanks for a reply
I wonder what is the size of the TB for the 912E. But finding one ...
I believe that the TB for the 912E is identical to that of the 2.0 liter 914.
--DD
What about a mounting plate that picks up the TB mounting holes and has holes that match the orientation needed for the TPS?
How was the performance improved ?
All of the grinding was done with the bench grinder ? no file ?
.......and the performance improvement ?
I did this for Betty's car. I don't know if it really helped., but It makes a difference on the "butt dyno".
Easy to do too. Just about an hour to do all the work. And I fixed it so that there are two screws holding the throttle switch assembly to the body. One is inside, and one on the outside.
Bought a Vanagon TB today; gonna see how this works out with my top-end rebuild. Might have some questions later,,,
Clay,
You Da Man. Thanks for sharing this valuable information/ trick of yours. Now to source a 2.0 VW TB
How about trying one from an Alfa spider from 1982 and onwards. L-jet too and 140 hp.
I have not yet, but will when the next Alfa comes in the shop.
Just installed the modified vanagon TB; sent the TB and a TPS to Zphil in New Mexico. He did a total rebuild and it looks like new. The difference in noticeable; we just did a top end rebuild with 96mm P & Cs.
A few pics sent by Phil during rebuild.
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Pic of the orig 914 TB next to the Vanagon before modifying
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Jim, what did you find to feel different? How was the idle?
Looks like very nice work.
The 1.8 plenum is only 45mm. The throttle body is 50mm. I used a tail pipe expander and opened the plenum to 51mm.
Not to get to far off topic, but... would a Vanagon TB be an upgrade for a 2.0 D-jet set up?
Thanks,
Konrad
I purchased the GoWesty throttle body a few weeks ago, and currently in the process of modifying it to work for our Ljets. I'll post some pics of the progress soon.
I ran the go west TB for a couple years. I had ZPhill reorient it so the operating arm would fit.
It works and looks nice but it’s the long expensive way from point A to B.
It woke up the top end considerably, minor hit to the low end though.
Pay no attention to the throttle return spring.
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Beautiful! I'm going a slightly different route, but I like it. Did you open up the conic on the plenum, apparently it is bottled necked there at that opening.
There is a taper but the go westy is part fits without issue.
Call it some built in Venturi effect
I was going to buy a used Vanagon throttle body, but then realized the cost of a used throttle body and then the cost of the rebuild and modification. The GoWesty throttle body use double sealed ball bearings for the throttle shaft, which is an upgrade over the oem bushings. I can be completely wrong, but I view the GoWesty a step up from the Vanagon mod.
The one thing that confuses me is where GoWesty put their vacuum port, it's dead nuts in line of the throttle plate. So would this be manifold vacuum or ported vacuum?
I had to open up the plenum with a tail pipe expander from 45 mm to 50mm. Also the snorkel on the air cleaner box is only 45 mm. Ordered a Vanagon rubber throttle body gasket, part # 025 133 073. The air horn is on ebay, 55mm motor cycle velocity stack, unfortunately from China for $9.99 shipped. [attachmentid=788
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The GoWesty throttle body came like this, some kind of a cheap plastic cam printed from a 3d printer.
To make this work, I bought a 2nd switch, and stacked it on top. Also got rid of the 3d printed cam, and had two new ones made.
Lots of screwing around, but I'm hopeful that this setup will at least work as well as the original if not better. Bigger throttle plate, double sealed ball bearings, and the action is so much smoother than what I had.
so, if i want to do this, but not "destroy" the original parts (put them away in a box) i need the following?
aircleaner, aircleaner to throttle body duct, throttle body for mod, plenum to modify by opening up. (all of which i need to get in from the states and stockpile).
anything else?
I have its little brother
Is the 2.1l TB the one off a wasserboxer?
@http://www.914world.com/bbs2/index.php?showuser=4469
Trying to research quickly to do this mod start to finish and have it done by the end of May.
Zach
http://www.914world.com/bbs2/index.php?s=&showtopic=353039&view=findpost&p=2914136
I just did this with the 52mm throttle body from GoWesty. I think using this product is better then the 2.1L TB from the Vanagon. First off, its bigger at 52mm then 50mm. And second, the swap was WAY easer. You pretty much just use the throttle arm off the 1.8 L-jet TB. And the drilled and tapped holes at the bottom of the GoWesty unit mated perfectly with the Bosch TPS I used for Microsquirt. Simple!
The link above is how I did it.
Zach
problem is the part has been outta stock for some time.
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