Injectors to match TB on bigger engines Options

[Literati914]

I know a 2.1 throttle body from a vanagon is a popular option for say a 2270 build or better... and there does not seem to be a need for upgrading the stock 2.0L fuel injectors when using it BUT, since I need a set of injectors anyway, would the following be a good option? What would be the pro's/cons? :

https://www.gowesty.com/product/made-in-usa...ctor-bundle-?v=






.

[JamesM]

What injection are you planning on running?

I wouldnt attempt to run d-jet on a 2270. You are going to want something fully programmable at which point injector sizing only becomes an issue if you are maxing them out.

That being said, on a 2270 I wouldnt run either.
Vanagon injectors have significantly less flow rate than 2.0 d-jet injectors.
2.0 d-jet injectors are old tech that run a much lower pressure than modern injectors so unless you are using them to maintain a stock looking engine bay (which you probably dont want to attempt with a 2270) you might as well run modern equipment.

Even with a larger throttle body a good 2270 will be restricted by any of the stock plenum setups.

2056 you can get away with it, on a 2270 you want to be looking at a full custom setup with ITBs

[nordfisch]

I know a 2.1 throttle body from a vanagon is a popular option for say a 2270 build or better... and there does not seem to be a need for upgrading the stock 2.0L fuel injectors when using it BUT, since I need a set of injectors anyway, would the following be a good option? What would be the pro's/cons? :

https://www.gowesty.com/product/made-in-usa...ctor-bundle-?v=

Hi,
these are no D-Jetronic-injectors and won't fit at all (besides the outer dimensions)...

The original green D-Jetronic injectors have a flow rate of 318 ccm/min at 2.0 Bar (low impedance),
the original 'Westy' injectors have a flow rate of only 167 ccm/min at 2.5 Bar (high impedance).

Regards
Norbert

[GregAmy]

The D-Jet system is only tunable if you rebuild the MPS with the screws (Tangerine Racing can do it) but that's a macro-tune.

You could also adjust your fuel pressure, but that's also a macro-tune

Even if you were to find higher-flow low-impdedance injectors (I'm sure they're out there) that's still a shot-in-the-dark that you'll be able to matchit all up for efficient running.

If you want to keep fuel injection (and I recommend it) you'll be better off going aftermarket. The Dub Shop sells a complete dual-throttle package for the Type 4.

Check out EricP's thread where he's developing a Microsquirt package.

Rumor has it Original Customs has aMicrosquirt package, but I could never get a response from them.

SDS offers various packages and parts.

[nordfisch]

Hi once more,
I forgot two things:

-You could use 'blue' D-jetronic-injectors (like in your Volvo 1800E (IMG:style_emoticons/default/biggrin.gif) ) that have a higher flow rate (380 ccm/min) than the green ones (318 ccm/min). The engine could run a little bit rich then...

- Searching for genuine 'green' injectors you could use some other Bosch part numbers (Mercedes, Jaguar, Opel, Saab) too. They all have the same flow rate - maybe with another hose, maybe with or without pintle-caps, but compatible and useable as a perfect replacement. You find the numbers here in a German posting: link to oldtimer.tips
The language will not be a problem for you.

Regards
Norbert

[Literati914]

What injection are you planning on running?

Oh forgot to mention that part - I had planned on using Microsquirt 1 with the stock 2.0 runners, plenum, filter housing.. but a 2.1 vanagon TB or... a GoWesty TB in an appropriate size. Not going for original looks - just hoped to make do really until ITBs could be afforded.

That being said, on a 2270 I wouldnt run either.

Reasons against a 2270 ?

Even with a larger throttle body a good 2270 will be restricted by any of the stock plenum setups.

Really, I didn't know that.. and didn't think every 2270 has ITBs, so what's the alternatives?

[GregAmy]

I'm not entirely convinced that the stock plenum is a big restriction for a low- to mid-range street engine. After all, the four cylinders are pulling vacuum individually, not at the same time, and the hole they're breathing through is 44mm, where the dual Webers are typically 38mm.

Sure, there's going to be a difference, especially since the plenums will be longer and less efficient than a short plenum dumping directly into the intake port. But is that a significant enough difference to mean anything for a street car?

I encourage you to review EricP's Microsquirt thread.

[914forme]

Your limited by a large number of factors. If it was me and I wanted to use a single TB, I would build my own new manifold, and then use injectors and new bungs off a more modern injector.

But that is me, and I love to fab stuff. This is for a flat -6 engine but same idea minus two intake runners and your golden.

[porschetub]

Surely the larger 1.8 L-jet plenum and runners would be a better match with the Vanagon TB ,the stock blue L-jet injectors would flow enough.
I don't think there would be much more airflow just using the T25 TB on its own,all the above parts together and the added cubic capacity it should work better.

[cgnj]

Hi,

There isn't a signifcant volume difference between a 914 1.8 plenum and a vanagon 2.1 plenum. The vanagon TB is on the wrong end of the plenum so you would have to modify it.

Look at this thread shoptalk
This was on a 2270.

Carlos

[Literati914]

So, am I understanding that the 1.8 plenum has more volume than a 2.0 plenum... and that a 2.1 vanagon plenum is a better option over either of those (in this situation, if modified to move the TB port)?

[JamesM]

I had planned on using Microsquirt 1 with the stock 2.0 runners, plenum, filter housing.. but a 2.1 vanagon TB or... a GoWesty TB in an appropriate size. Not going for original looks - just hoped to make do really until ITBs could be afforded.

^This is critical info to know. If you are going Microsquirt you can run pretty much whatever you feel like injector wise. Stock 2.0 injectors are HUGE for their application and should be able to feed ~200hp so flow wise you should be fine. They are 50 year old injectors though that run at lower pressure (poor atomization) and with microsquirt would require inline resistors. Also the connector design sort of sucks. But to your original question they will work and you wont need to go larger, in fact they are probably a bit oversized even for a 2270.

If you are looking at this as a temporary setup AND you already have the 2.0 injectors, then go for it, should be just fine. If you are going to spend money on injectors though there are better options. ITB and d-jet runners use a totally different style of injectors as well, so be prepared if you are planning on ITBs that you will need new injectors.

That being said, on a 2270 I wouldnt run either.

Reasons against a 2270 ?

I have nothing against a 2270.. they are awesome. I was against running d-jet or vanagon injectors on a 2270 as there are better options. As i said earlier though, if you already have the 2.0 injectors and are set on running a stock plenum with them go for it, I totally get it.

As a point of clarification though, if it were me I would look at going 2257 rather than 2270 as AA pistons have pretty much drop in parts to pull of that build at a much better price point. Components to do a 2270 are not as common, and the difference is minimal.

Even with a larger throttle body a good 2270 will be restricted by any of the stock plenum setups.

Really, I didn't know that.. and didn't think every 2270 has ITBs, so what's the alternatives?

I probably should clarify "good 2270", what i mean are the ~2.3L builds that i personally think are the most fun. I like my motors with a bit of a cam that wind up and breath better on the top end. If you are building one with a tame, torquey cam that doesent ever see over 5k and >140hp you might not notice to much in the way of over all power loss. Throttle response between that and an ITB setup you will almost certainly notice though. Over-sizing the throttle body helps to mask the issue some but the underlying issue is the plenum size, and there are no stock plenums designed to feed 2.3L.

Options?
1. Deal with an undersized plenum
2. Use ITBs
3. Fab a fully custom plenum

Whereever possibly I lean towards a single TB system, the larger you go the harder that gets though. It comes down to what compromises do you want to make (ITBs have their short comings too)

If you feel like running the d-jet plumbing , run the d-jet plumbing. It will run, it may even run perfectly to your liking, and even then all that stuff is bolt on and swapped easily enough later on anyways. The beauty of Megasquirt is the never ending tinkering you can do if you feel like it. Having experimented with a bunch of configurations over the last 15 years though i am familiar with the differences provided by the various options, have my personal preferences, and like to offer my experience to educate people during their decision making process. That being said, do what works for you,avent heard anthing mentioned so far that wont work, its just a questtion of how well.

[JamesM]

I'm not entirely convinced that the stock plenum is a big restriction for a low- to mid-range street engine. After all, the four cylinders are pulling vacuum individually, not at the same time, and the hole they're breathing through is 44mm, where the dual Webers are typically 38mm.

Sure, there's going to be a difference, especially since the plenums will be longer and less efficient than a short plenum dumping directly into the intake port. But is that a significant enough difference to mean anything for a street car?

I encourage you to review EricP's Microsquirt thread.

It would probably depend on the motor. For sure there would be less of a chance of it being a noticeable issue on a more mild build. Cant say for sure until you try it, but I can speak to the data that I have...

My current test bed is a fairly aggressive 2056 running a modified 1.8 plenum and runners, a 50mm throttle body, full open 3" cone air filter and headers. 2 things are noticeable 1. Throttle response has some lag to it. 2. Datalogs of WOT runs show an intake restriction noticeable in the upper RPM range of the motor, so its not just a guess, its hard data.

So, no denying it is a limiting factor, at least on my 2056, but then that is only at the top end of a motor that happily spins to 7k rpm. Would it be a problem on an even larger motor that lives at lower revs? The restriction would for sure still exist, but would it be enough to care about? IDK depends on the motor and the driver I guess.

Throttle response quality aside, My best guess butt dyno (and calculations on the intake dimensions) estimates the setup to start being an issue power wise around the 140hp range

[JamesM]

So, am I understanding that the 1.8 plenum has more volume than a 2.0 plenum... and that a 2.1 vanagon plenum is a better option over either of those (in this situation, if modified to move the TB port)?

The 1.8 plenum dosent have more volume, but it is a better layout (less turbulent) than the 2.0 914 plenum.

The 2.0 bus plenum is larger than the 1.8 and is of the same design as the 1.8 however the intake runners are narrower.

The 2.1 vanagon plenum isnt a direct fit, and requires modification. The intake runners from a vanagon wont fit on a 914 so you wind up having use 914 runners and i havent seen one done where the transition from plenum to runners winds up being at all clean. Neither one is properly sized for a 2.3 so for the small difference in volume i lean towards the 1.8 plenum for the cleaner and easier install.
The later (larger) 2.1 50mm throttle body can be adapted to the 1.8 914 plenum though.

[djway]

I have spent the past few days cleaning my stash of L Jet parts ranging from several 74 and 75 914 systems and some late Baywindow 2.0 bus systems.
The plenum's were all the same size but the late bus had the EGR tubes inside which I would assume should disrupt the air flow into the runners due to their location. If you are crafty it should be removable.
The 1.8 runners are narrower tubes until the end where they get larger for the sleeves. The 2.0 bus runners were the larger tube the entire length.
Now the difference in the brains with 6 pin not having an independent circuit for the air density resistor, although it is wired in and did affect my 74 when I cleaned the contact. The 75 7 pin does have the specific circuit wiring but I am not sure what smog programming may be in there. Then there is the 2.0 bus brain. I have read they are all interchangeable in a long thread on the samba and that the WOT circuit that is on some buses and not others does not seem to affect performance, on a bus.
I will be using the bus runners and the flat plenum, non 914 2.0. I will also adapt the 2.1 vanagon TB. Just need to decide if I should use the WOT/position switch circuit and which brain to use.

[JamesM]

The 1.8 runners are narrower tubes until the end where they get larger for the sleeves. The 2.0 bus runners were the larger tube the entire length.

1.8 914 runners are uniform the entire length and are the same diameter as 914 2.0 runners. Not sure the rest of the effort would be worth it if you are still going to be choked by skinny runners.