There's currently a thread 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.
Full Version: Converting a Vanagon TB for use with 1.8 L-Jet
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.
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.
The 1.8 plate is 43mm in diameter, the vanagon plate is 48mm.
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.
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).
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.
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).
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.
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
--DD
QUOTE(Dave_Darling @ Nov 2 2014, 10:29 PM) 
Peen or use Loctite on the throttle plate screws. You don't want one of them to fall out...
--DD
Dave - thanks for the reminder. I'll peen them.
Did you try to use the vanagon throttle switch?
QUOTE(Valy @ Nov 3 2014, 12:11 AM)
Did you try to use the vanagon throttle switch?
No. There are two terminals on the Vanagon switch, and three on the l-jet, hence the wiring harness would need work. Didn't want to open that can of worms.
Really good write up and something I would have used on a L-Jet 2.0 a few years back. Well done!
QUOTE(MrKona @ Nov 3 2014, 08:16 AM)
QUOTE(Valy @ Nov 3 2014, 12:11 AM)
Did you try to use the vanagon throttle switch?
No. There are two terminals on the Vanagon switch, and three on the l-jet, hence the wiring harness would need work. Didn't want to open that can of worms.
Thanks!
Does the bigger TB fit the rubber boot from the AFM?
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
QUOTE(Valy @ Nov 3 2014, 12:14 PM)
QUOTE(MrKona @ Nov 3 2014, 08:16 AM)
QUOTE(Valy @ Nov 3 2014, 12:11 AM)
Did you try to use the vanagon throttle switch?
No. There are two terminals on the Vanagon switch, and three on the l-jet, hence the wiring harness would need work. Didn't want to open that can of worms.
Thanks!
Does the bigger TB fit the rubber boot from the AFM?
It sure does! The beautiful thing is that the outer diameter is the same on both. Here's a picture, Vanagon TB on the left, L-Jet TB on the right.
QUOTE(pilothyer @ Nov 3 2014, 12:32 PM)
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
The p/n for the late model, 2.1 Vanagon is 025 133 067. The earlier 1.9 Vanagon TB is 45mm, the same as the 1.8 L-jet TB. I only know this from the experience of removing one from a 1.9L only to find it was 45mm diameter.
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
--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 ?
.......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.
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,,, 
QUOTE(ClayPerrine @ Oct 1 2016, 11:06 AM)
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.
Clay, DiD you use the 1.8 TPS on the Vanagon TB ?
QUOTE(jim_hoyland @ Oct 8 2016, 09:46 PM)
QUOTE(ClayPerrine @ Oct 1 2016, 11:06 AM)
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.
Clay, DiD you use the 1.8 TPS on the Vanagon TB ?
I used the 1.8L TPS (It is actually just a throttle switch). One of the screw holes matches up exactly, the other ends up inside the cover. I just made a pin out of a screw, and mounted the throttle switch with the one screw. The point on the pin marked the back of the metal where the other screw goes. So I used the drill press to carefully drill a small hole in the backing plate, and I was able to attach the throttle switch with two screws.
There are some visible external differences. The idle screw is recessed, and there are some ribs on the outside of the Vanagon throttle body. But with how far down it is buried in the engine compartment, it is really not visible.
QUOTE(ClayPerrine @ Oct 9 2016, 04:31 AM)
QUOTE(jim_hoyland @ Oct 8 2016, 09:46 PM)
QUOTE(ClayPerrine @ Oct 1 2016, 11:06 AM)
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.
Clay, DiD you use the 1.8 TPS on the Vanagon TB ?
I used the 1.8L TPS (It is actually just a throttle switch). One of the screw holes matches up exactly, the other ends up inside the cover. I just made a pin out of a screw, and mounted the throttle switch with the one screw. The point on the pin marked the back of the metal where the other screw goes. So I used the drill press to carefully drill a small hole in the backing plate, and I was able to attach the throttle switch with two screws.
Makes sense; did you use the Vanagon TB shaft and file the end or did you use the 1.8 B shaft ( as shown in this thread )
Thanks, i'm ready to start in on this....
There are some visible external differences. The idle screw is recessed, and there are some ribs on the outside of the Vanagon throttle body. But with how far down it is buried in the engine compartment, it is really not visible.
Clay,
You Da Man. Thanks for sharing this valuable information/ trick of yours. Now to source a 2.0 VW TB
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.
I have not yet, but will when the next Alfa comes in the shop.
QUOTE(aerokurt @ Oct 9 2016, 04:14 PM)
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.
Would have a part number for that unit ?
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.
A few pics sent by Phil during rebuild.
Pic of the orig 914 TB next to the Vanagon before modifying
Jim, what did you find to feel different? How was the idle?
Looks like very nice work.
Looks like very nice work.
QUOTE(Porschef @ Nov 17 2016, 09:59 AM)
Jim, what did you find to feel different? How was the idle?
Looks like very nice work.
More power! Complements the larger P & C
Idle is fine
One problem this am: the angle of the TB accelerator arm is another 10 degrees back making it had to acetate smoothly. Going to contact Mr Kona
The 1.8 plenum is only 45mm. The throttle body is 50mm. I used a tail pipe expander and opened the plenum to 51mm.
QUOTE(Geezer914 @ Feb 17 2021, 07:23 AM)
The 1.8 plenum is only 45mm. The throttle body is 50mm. I used a tail pipe expander and opened the plenum to 51mm.
I just used a dremel with a sanding disk to open it up.
Clay
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
Thanks,
Konrad
QUOTE(krazykonrad @ Feb 17 2021, 09:12 AM)
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
Nope. It won't fit. Different mounting surface.
Has anyone done a GoWesty conversion yet?
Click to view attachment
Click to view attachment
QUOTE(timothy_nd28 @ Feb 17 2021, 10:40 AM)
I sent a message yesterday to the folks at GoWesty (their "campus" is located about 0.5 miles from my house!) to see how their TPS could be adapted to work with our L-Jet system. I'll provide an update as soon as I hear back.
QUOTE(strawman @ Apr 2 2021, 12:41 PM)
QUOTE(timothy_nd28 @ Feb 17 2021, 10:40 AM)
I sent a message yesterday to the folks at GoWesty (their "campus" is located about 0.5 miles from my house!) to see how their TPS could be adapted to work with our L-Jet system. I'll provide an update as soon as I hear back.
The L-Jet is a throttle switch, not a TPS.
So a TPS fitted to it won't work. You would have to put the original L-Jet switch on it.
Clay
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.
QUOTE(timothy_nd28 @ Apr 2 2021, 04:49 PM)
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.
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.
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
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?
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. Click to view attachment Click to view attachmentClick to view attachmentClick to view attachment[attachmentid=788
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