Idle control and maybe intake leaks, how to for swapping in a 52mm Vanagon throttle body Options

[Montreal914]

Zack, really cool writeup! Thank you for sharing. (IMG:style_emoticons/default/smile.gif)

There is some information on Shoptalkforums about the use of the 1.7 or bus plenum with the 2.0 runners and the 2.0 heads. I believe some have used this kind of setup on 2256 (2270) size engines too.

In your case, what is your plenum, runner, and head setup? Thanks!

[VaccaRabite]

Zack, really cool writeup! Thank you for sharing. (IMG:style_emoticons/default/smile.gif)

In your case, what is your plenum, runner, and head setup? Thanks!

A mishmash.
The engine is using a Bus case, 1.7 heads which have been bored out. A friend was getting rid of an entire 1.8 Ljet system so I took it for the parts (this engine used to be carbed). So my airbox, plenum and runners are 1.8. I removed the flapper box from the 1.8 and replaced it with some exhaust pipe that was the right size and put a bung in that for the ambient air temp sensor.

The 52mm throttle body is the same outside dimensions as the stock LJet unit so everything fit back together perfectly.

Zach

[Montreal914]

Zack, really cool writeup! Thank you for sharing. (IMG:style_emoticons/default/smile.gif)

In your case, what is your plenum, runner, and head setup? Thanks!

A mishmash.
The engine is using a Bus case, 1.7 heads which have been bored out. A friend was getting rid of an entire 1.8 Ljet system so I took it for the parts (this engine used to be carbed). So my airbox, plenum and runners are 1.8. I removed the flapper box from the 1.8 and replaced it with some exhaust pipe that was the right size and put a bung in that for the ambient air temp sensor.

The 52mm throttle body is the same outside dimensions as the stock LJet unit so everything fit back together perfectly.

Zach

Thank you for the info. (IMG:style_emoticons/default/beerchug.gif)

[VaccaRabite]

This topic came up again recently so I thought I'd update this thread.

After I did the swap in May, @JamesM and I did more tuning and we were able to open up new bins in the fuel map with the larger TB.

I did eventually replace the IAC with the new Hyundai unit and got that tuned in. Idle is much more even and cold starts are MUCH easier!

Ive put about 1000 miles on the car this summer, and I can say its never done as well as it had this year.


So, obviously, its time to pull that 2056 out and put in a 2.3.
Yes. Yes. I know.

But the 2056 will go into my bus, and we will see how well is does moving that around.

Zach

[DRPHIL914]

@VaccaRabite

Zach, i am not familiar with the 1.8 plenum and its orientation, so i am wondering how this would go on a 2.0 914 plenum? i am sure my new 2.1 need more air, and i think this would be a good option , but before i buy a $250 part i better make sure i will be able to use it.

Phil

This topic came up again recently so I thought I'd update this thread.

After I did the swap in May, @JamesM and I did more tuning and we were able to open up new bins in the fuel map with the larger TB.

I did eventually replace the IAC with the new Hyundai unit and got that tuned in. Idle is much more even and cold starts are MUCH easier!

Ive put about 1000 miles on the car this summer, and I can say its never done as well as it had this year.


So, obviously, its time to pull that 2056 out and put in a 2.3.
Yes. Yes. I know.

But the 2056 will go into my bus, and we will see how well is does moving that around.

Zach

[VaccaRabite]

Dunno. I did not have 2.0 induction gear to work with, and don't know its geometry well enough to say for sure.

I suspect it would work just fine, but that's really just a guess.

Googling up the different 914 plenums, looks like my mods would work on the 1.7 and 1.8. The 2.0 is different. But in the end it still need to react to a throttle cable pulling on an arm, and the cable runs from a similar place. So while the mods may be a little different, the result would be the same.

Zach

[DRPHIL914]

i am bumping this thread again for the purpose of asking if anyone has done this mod to adapt a larger throttle body onto a 2056 2.0 build using d-jet and 2.0 runners and plenum etc? or is there another way? it would be nice to get the 52mm TB ans mount it on the existing plenum, but i assume i’d have to do the same mods zach did for the TPS and the cable attachment?
any thoughts ? I think my 2.1 would benefit from the increased intake size.


Phil

[Frank S]

i am bumping this thread again for the purpose of asking if anyone has done this mod to adapt a larger throttle body onto a 2056 2.0 build using d-jet and 2.0 runners and plenum etc? or is there another way? it would be nice to get the 52mm TB ans mount it on the existing plenum, but i assume i’d have to do the same mods zach did for the TPS and the cable attachment?
any thoughts ? I think my 2.1 would benefit from the increased intake size.


Phil

I run a modified 2.0l TB with on my 2056 which is 48mm instead of the 45mm original diameter. If you stay with the D-Jet I would not go lager in diameter, as you would potentially run into trouble with your acceleration enrichment.

Cheers, Frank

[JamesM]

i am bumping this thread again for the purpose of asking if anyone has done this mod to adapt a larger throttle body onto a 2056 2.0 build using d-jet and 2.0 runners and plenum etc? or is there another way? it would be nice to get the 52mm TB ans mount it on the existing plenum, but i assume i’d have to do the same mods zach did for the TPS and the cable attachment?
any thoughts ? I think my 2.1 would benefit from the increased intake size.


Phil

If you are sticking with d-jet I would say its probably not worth the cost/effort as D-jet itself (and a d-jet compatible cam) will always be your most limiting factor.

If you wanted to I think your best bet with the 2.0 TB is just to get your existing one enlarged. The vanagon TB makes sense when using it with a 1.8 plenum as they share the same basic mounting configuration and the 1.8 plenum itself is easy to open up to match. The 2.0 throttle body is of a different style (flat bottom) and the plenum itself would be significantly more difficult to modify to a 52mm opening. Also when sticking with d-jet you would also need a TB that can handle the d-jet TPS, so your options are pretty limited.

d-jet compatible cam on a 2056 you are probably looking at best case power output in the range of ~115hp which is still within the limits of the stock TB. More of a concern when your 2056 is build to spin to 7k ~140hp

[r_towle]

This topic came up again recently so I thought I'd update this thread.

After I did the swap in May, @JamesM and I did more tuning and we were able to open up new bins in the fuel map with the larger TB.

I did eventually replace the IAC with the new Hyundai unit and got that tuned in. Idle is much more even and cold starts are MUCH easier!

Ive put about 1000 miles on the car this summer, and I can say its never done as well as it had this year.


So, obviously, its time to pull that 2056 out and put in a 2.3.
Yes. Yes. I know.

But the 2056 will go into my bus, and we will see how well is does moving that around.

Zach

2.6, just get it over with
Worth it btw .

Rich