Was ITB size for 2270 motor Now Single plenum 2270 Options

[aircooledtechguy]

A plenum based system is easier to tune and will net you more hp & torque down low on the RPM range. Plus they are just easier to set-up and tune to some extent. A 75mm TB on a factory 2.0L plenum is absolutely HUGE and I would expect tip-in tuning issues going that large. I would look into a Jeep straight-6 TB since they are around 60mm (up from the factory 50mm for the 2.0L) and have an integrated IAC valve.

Then get a pair of these ends and make your own runners with mandrel bent tubing.

(IMG:http://www.914world.com/bbs2/uploads_offsite/images.thesamba.com-9730-1458164598.1.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/images.thesamba.com-9730-1458164598.2.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/images.thesamba.com-9730-1458164598.3.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/images.thesamba.com-9730-1458164598.4.jpg)

Use 1.625" tubing and you've got one hell of an intake system.

[Mark Henry]

A plenum based system is easier to tune and will net you more hp & torque down low on the RPM range. Plus they are just easier to set-up and tune to some extent. A 75mm TB on a factory 2.0L plenum is absolutely HUGE and I would expect tip-in tuning issues going that large. I would look into a Jeep straight-6 TB since they are around 60mm (up from the factory 50mm for the 2.0L) and have an integrated IAC valve.

Then get a pair of these ends and make your own runners with mandrel bent tubing.

(IMG:http://www.914world.com/bbs2/uploads_offsite/images.thesamba.com-9730-1458164598.1.jpg)

Use 1.625" tubing and you've got one hell of an intake system.

You right 75mm is too big my bad. It's been a few years since I looked into it last, so I was working from memory.
How I got the figure is Ford performance guys are removing stock TB's and replacing them with aftermarket 75mm TB's, Thus stock mustang TB's can be had for cheap.
The stock Mustang TB I have in front of me and pictured below is 60mm.

If you used a pair of those ends you could do a DIY intake like Nate said.
Here are a couple of how to's, first one is a subi so it's actually close to what you would need.

http://www.sdsefi.com/air12.html
http://www.sdsefi.com/techinta.htm

[cgnj]

I decided to back burner ITBs. I did a little bit of math, went through my boxes and this is my plan. Based on this math.

My cam is all in @7200 rpm. displacement=2270cc ( 138.52 ci)+10%
Math says (((7200/2)*138.52)/1728)*1.1=318 cfm. That puts me in the 944 throttle body range and I have a box of 4. (Good thig I paid 130k for the BSCE @ private college for my son. How is that for ROI?)

The advantage is that it is much easier to bore the plenum out more if I'm not making the required air. If that is still not enough, it will be time to fab a custom plenum and runners.


2.1 liter waterboxer plenum( in the mail), 944 tb in hand. Stock intake runners. MS in hand, trigger wheel in hand. I dropped my motor over the weekend and and expect to have this ready for MS Sunday night. I have a shot at having it ready to go for Hershey, otherwise would it be OK for me to park a 928 in the 914 area?

Even if it is not perfect, I think I'm on the right track. I think that all of these tb sizies are overblown. My personal experenice with dellorttos is that I had to swap vwnts from 38 to 34. My other experience is the long a project sits, the less likely it ever get finished.

If I'm wrong it won't be the first time. Ask my ex.


Carlos

[Mark Henry]

How big is the vanagon plenum?
As a rule of thumb for performance you want your plenum to have the same volume as the engine, so in your case about 2.25L.
Just a little bigger than two quart bottles of oil put together.

[Krieger]

I think the stock bore for a 2.0 throttle body is 45mm. I run a modified volvo throttle body. It is 55mm. The engine size on the 90s Volvo it came from is 2270. I figured it would be a good choice and it was. The Volvo TB requires some mods. it turns the opposite direction and also required me to drill and add a vacuum advance or retard port. I can remember which. I made an adapter plate to fit the stock plenum out of a chunk of 1/2" aluminum plate to test it out. It worked for a couple of years until a machinest I met saw it and modified another plenum properly. I run a modified Djet system. Web cam fuel injection grind. Torquey SOB!

[Mark Henry]

I think the stock bore for a 2.0 throttle body is 45mm. I run a modified volvo throttle body. It is 55mm. The engine size on the 90s Volvo it came from is 2270. I figured it would be a good choice and it was. The Volvo TB requires some mods. it turns the opposite direction and also required me to drill and add a vacuum advance or retard port. I can remember which. I made an adapter plate to fit the stock plenum out of a chunk of 1/2" aluminum plate to test it out. It worked for a couple of years until a machinest I met saw it and modified another plenum properly. I run a modified Djet system. Web cam fuel injection grind. Torquey SOB!

What system are you running?

The D-jet plenum is up somewhere around 2.5L IIRC

[r_towle]

Djet works up to 2.4 tested.....not sure of anything higher.
I did 2.4 because I could not find any factual cars, just urban myths.

I will say that I did a lot of research and stuck with the stock stroke crank, and fairly stock camshaft....a little change there, but typical early ramp up on the lobs.

I recall, but it's foggy, that the longer stroke does some funky things to the air in the plenum and the djet did not like it...
At 2.4 which was 71/103 it works fine using the maps from a 411 which removes one of the diaphragms and gave me a simple fixed external adjustment....made tuning fairly straight forward.

Rich

[Krieger]

It is nearly stock Djet. Early 2.0 injectors and MPS. 425 ohm resistor in line with the head sensor. I bumped the fuel pressure up to 36 psi

[cgnj]

Update.

Junkyard shopping list
55 mm throttlebody with angular tps and heated wire MAF.
vanagon 2.1 plenum arrives Monday.
Motor is down and out and on engine stand.
MS arrives this evening.
Runners, injectors, triggerwheel gaskets, seals in hand.

Looking for location tips for MS. Inside cabin or in engine bay. In either case, I am looking to get some type of single weather proof connection to ECU to make engine drops less complicated.

Why am I using 2.1 bus plenum? I have just one 2.0 plenum left, this is the biggest reason. I also read on STF a while ago that there is something different about a this waterboxer plenum that makes it more efficent than a 2.0 plenum. STF is down, otherwise I would post a link. I need the throotle body to exit the side of the plenum so I have room to add a heated wire MAF. I'm thinking that I will be half way to a forced induction system.

Im planning to run my Unilite in the beginning so that I can log the advance curve and use that as my starting point to build the spark advance table.

Time to see . Junkyard Barbie

[cgnj]

Progess to date.

Vanagon 2.1 plenum is a dead end I think. Volome is approximately 1600 cc. Also the throttle body is at one end so there are two favored and two disadvantataged runners. Although it comes with a 50mm tb, there doesn't seem to be enough rom for a 55-58 mm tb.

So, I pulled my last 2.0 plenum out of the box. First advantage, tb is more centrally located, runners should be appear to be the same. Volume is approx 2350 cc min., (+- measurement losses).
I wanted to avoid using a 2.0 plenum because I expect that i will need a MAF to since I am currently on a split durarion 163/86b cam. (plus it was the last one in the box). I'm married to 2.0 plenum now.

Motor is on stand, I will do leakdown, plenum packed for trip to machine shop. Need to puzzle out the volvo tb. It pulls in the wrong direction. Prepped the runners for powder. Prepped headers for paint. Pulled out heat exchangers and triad. I am going to test this with headers and heat exchangers.

At this point, Im going with 2.0 green injectors. I have them. I am looking for a 2270 MSQ file if someone can pm one to me great.

I'm hoping to fire this up next weekend.

[Mark Henry]

Progess to date.

Vanagon 2.1 plenum is a dead end I think. Volome is approximately 1600 cc. Also the throttle body is at one end so there are two favored and two disadvantataged runners. Although it comes with a 50mm tb, there doesn't seem to be enough rom for a 55-58 mm tb.

So, I pulled my last 2.0 plenum out of the box. First advantage, tb is more centrally located, runners should be appear to be the same. Volume is approx 2350 cc min., (+- measurement losses).
I wanted to avoid using a 2.0 plenum because I expect that i will need a MAF to since I am currently on a split durarion 163/86b cam. (plus it was the last one in the box). I'm married to 2.0 plenum now.

Motor is on stand, I will do leakdown, plenum packed for trip to machine shop. Need to puzzle out the volvo tb. It pulls in the wrong direction. Prepped the runners for powder. Prepped headers for paint. Pulled out heat exchangers and triad. I am going to test this with headers and heat exchangers.

At this point, Im going with 2.0 green injectors. I have them. I am looking for a 2270 MSQ file if someone can pm one to me great.

I'm hoping to fire this up next weekend.

The 914 injectors are low impedance so you will have to run a resistor pack.

The factory D-jet plenum will work and you can find a used one cheap to replace it if needed.
Personally I would use the d-jet so you can drive now, but build a SDS style intake along the lines in the link below. They do state "Velocity stacks to go on the end of the runners were shown to improve airflow by 19% on the flow bench over straight tubes."
With that kind of improvement I'd be giving it a go.

http://www.sdsefi.com/air12.html

[cgnj]

The 914 injectors are low impedance so you will have to run a resistor pack.

The factory D-jet plenum will work and you can find a used one cheap to replace it if needed.
Personally I would use the d-jet so you can drive now, but build a SDS style intake along the lines in the link below. They do state "Velocity stacks to go on the end of the runners were shown to improve airflow by 19% on the flow bench over straight tubes."
With that kind of improvement I'd be giving it a go.

http://www.sdsefi.com/air12.html

The vanagon plenum won't be a complete waste I don't have the tooling to make a velocity stack. I expect to cut it up and use the stacks if a custom plenum is needed.
Carlos

[cgnj]

As I am still waiting for the machinist, I need to decide on temp sensor. I see two part numbers available.

0 280 130 003 1.7
0 280 130 012 2.0.

I'm guessing that I can use either one,

[Larmo63]

I'm thinking this is going to sit on my 2.3 /6 911 motor that we are building.

Has anybody here looked at this stuff?

http://www.jenvey.co.uk

[McMark]

Also the throttle body is at one end so there are two favored and two disadvantataged runners.

Not trying to change your mind, but I think this is wrong. Or rather, I think that the side inlet plenum has a huge advantage in smoother air flow. The 2.0 plenum forces the air directly into a wall/floor which means you have no velocity. The side inlet plenums allow air to smoothly enter the chamber.

Just my armchair engineering at work. (IMG:style_emoticons/default/drunk.gif)

[aircooledtechguy]

I'm thinking this is going to sit on my 2.3 /6 911 motor that we are building.

Has anybody here looked at this stuff?

http://www.jenvey.co.uk

Mario from thedubshop.net builds 911 kits with Jenvey ITBs.

Also the throttle body is at one end so there are two favored and two disadvantataged runners.

Not trying to change your mind, but I think this is wrong. Or rather, I think that the side inlet plenum has a huge advantage in smoother air flow. The 2.0 plenum forces the air directly into a wall/floor which means you have no velocity. The side inlet plenums allow air to smoothly enter the chamber.

Just my armchair engineering at work. (IMG:style_emoticons/default/drunk.gif)

(IMG:style_emoticons/default/agree.gif)

With a carb where that air also has heavy fuel dispersed in the air charge, that will be true, and charge robbing occurrs. With an EFI plenum, you are only moving the air. The bus/Vanagon/1.8L Porsche plenums work very well on bigger displacement motors over the stock 2.0L plenum.

[Mark Henry]

Also the throttle body is at one end so there are two favored and two disadvantataged runners.

Not trying to change your mind, but I think this is wrong. Or rather, I think that the side inlet plenum has a huge advantage in smoother air flow. The 2.0 plenum forces the air directly into a wall/floor which means you have no velocity. The side inlet plenums allow air to smoothly enter the chamber.

Just my armchair engineering at work. (IMG:style_emoticons/default/drunk.gif)

(IMG:style_emoticons/default/agree.gif) The D-jet intake would be ok to get thinks up and running quickly, but I'd still look at the SDS intake I linked to in my last post.

That link is a subaru plenum so of course you would have to tweak the design.
Note how it feeds direct across the runners and that the runner inlets are shaped like velocity stacks.
Long known fact that the velocity stack shape increases airflow and thus power.

If you have 2.0 914 heads you likely could mod D-jet runners and build a custom plenum.

[cgnj]

Hi,

This is an update to explain where I am at currently and how I intend to go forward.

I'm married to water over plenum at the moment. Forgot that my big valve heads are built on a 1.8 casting. 1.8 runners won't fit with a 2.0 plenum. I'm not cutting any parts yet.

After careful measurement of 1.8 runners, the intake flange from the dubshop is backseated. I can get the same runner ID with the stock 1.8 runners. At the moment, just waiting on the powder coater.

Carlos

[Jake Raby]

I played around with this a good bit in 2003-05. I found that unless the plenum capacity was at least 75% of the swept volume of the engine, that you'd lose big power with a plenum. This was despite the size of the TB thats used.

I also found that the plenums radically effect camshaft selection. Idle and low speed performance were greatly impacted when using the cams that work best with ITBs and carbs for us. I had to alter lobe separation to increase the vacuum signal, and make the engine run down low.

I was never pleased with it, way too many compromises for me.

[cgnj]

Hi,

Just wanted to update this thread with what I know at the moment.

I don't think there is any measurable difference in volume between a 1.8 and a 2.1 waterboxer plenum, except the throttlebody mount. waterboxer is bigger, but not big enough for my volvo TB. I am going to setup for the 2.1 waterboxer plenum.

I think the overall volume is too small for 2270, but I am prepared to live with it while I cobble everything together. I always expected that I will have to do a custom plenum similar to what Mark Henry has posted on this thread.

If you want to post some empirical data regarding plenum volume and performance feel free.

Dont post internet heresay.I have cc'ed all of these plenums. I am willing to discuss "informed opinions". I'm trying to learn something.

Carlos