I've been running Megasquirt II for a while now on my 71 1.7 with the stock D-jet components and it has been running well. But everything is looking tired in the engine bay and I am planning on taking out the engine to clean everything up and install SS fuel lines.

Then I remembered seeing a video youtube with an australian guy reviewing his 914 and he mentioned having GSXR ITBs on his car. Sounds like a fun project to me so I started researching and think I have found an even better solution.

The throttle bodies I found are from a 2001 Honda VFR800. The bike is a V4 so the TBs and fuel rails are already split into pairs, and have a linkage that connects both. They have 37mm throats, and came with the throttle position sensor, fuel pressure regulator , injectors and and all the wiring and connectors. Also the brackets on the sides already have a tab for throttle cable.

The injectors are high impedance so I wont have to run PWM on Megasquirt anymore and hopefully can get an even finer tune.
I'm also thinking about switching the PCs for 96mm, but I think that will wait until later, but you never know this started out as an engine cleaning...

The only things I need to figure out are the flow rate of the injectors, where I'm going to hook up the IAT sensor, and will need to build a vacuum plenum. Also these injectors run at 36 psi, can the stock fuel pump handle that or do I need to look for another solution?

Here are some pics, check out how close the spacing is for weber manifolds.
Please excuse the dirt. I still haven't cleaned them up.

This is gonna be fun.

Always interesting

I had the GSXR TB's back in the day. I actually never used them, went to a single TB because it's so much simpler, but you're right, those look better in every way, almost ideal.

The best part is the whole assembly was $60.00 shipped to my door. So if it doesn't work out its not going to break the bank. I'm excited about this project, I always liked the look and especially the sound of webers but I don't want carbs.

did you happen to get the mounting boots? looks like it wouldnt be to hard to make some adapter flanges to adapt to the manifold...

seems like i recall someone over on the type4um doing something very similar. but he was having a problem with his throttle bodies staying put. like they were coming loose and popping out of the boots. i wonder if you could fab up an aluminum flange and weld the throttle bodies directly to the flange. then bolt them to the manifold. then they would be hard mounted.

The plan is to fab up some adapter flanges to mount with rubber boots. Then make some brackets that attach between the weber manifolds and the bolts for the oem bracket in the side of the TBs to hold them solid. Unfortunately I didn't get the stock rubber boots with these, but found a set on eBay I might buy.

Love it! Easy to make an adaptor to transition that set onto the manifolds! That cast in piece between the TB's would make for a solid mount to hold them to the boots. 37mm should flow enough volume to feed a 1.7 air pump.

Looks interesting.

I don't know much about FI, but with ITBs, will it 'sound' similar to a carb'd engine? I'm already getting tired of the noise the carbs produce right behind my head

I got the ITBs mocked up on an engine today. I found some flange adapters for a Harley Davidson that are 40mm that fit perfectly on the empi manifolds. They are not bolted down in the pics.

Wow! Amazing project!

Are the Harley adapters stout enough to hold the weight of the throttle bodies, rail, filter and hoses? Or will you need to mount a stabilizing bracket to hold some of that weight?

I'm not sure how well this will work. I have to assume you have stock 1.7 internals. Cam, p&c's, heads.

If so, you had about 1.75" of throttle plate. Less actually I think. You will now have 5.8"+ throttle plate area without increasing anything else to use that volume.
You have 425cc/cylinder.

Let's compare my engine. I have 6.25" of throttle plate area but I have 608cc/cylinder, 200cfm heads, and tangerine headers. All this together produces 225hp and over 200lb/ft of torque in a table-flat curve.

I think you have to pay attention to the other parts of the engine before you can expect that to work. I love the innovation though. A few more details and you'll have a screamer!

Good luck!

To answer your questions, yes, the stock pump on mine is now set at 40psi. I used an aftermarket common plenum from Golden Eagle I think? Search my build thread for pics of it.

I had similar thoughts about the throttles when I started this project but I figured it couldn't be worse than weber 40s and I've seen those on smaller engines than mine.
So I figured what the heck, why not. I'm running megasquirt and it would be very easy to switch everything back. I think I'm into this about under $100 so it's worth it even if it doesn't wor, just for the fun/experience.
The Harley flanges are surprisingly stout. The rubber is at around 1/4 of an inch thick and the bases are reinforced. I think it should be okay but have plans for brackets if needed.
Thanks
Kevin

I thought of that too. Carbs cover their sins in many situations by running pig-rich. Really good running carbs are a real joy. I have triple DCOE's on my 240Z that now fit that description...

I just wonder if you'll be able to get EFI level control everywhere. Still, don't let me stop you. I love the critical thinking here. Prove me wrong!

Dont forget to use a phenolic spacer to soak up the heat so you dont cook your injectors.

Very cool!

Super cool looking setup but I'm concerned with your injector flow rate....might be a bit tight with 1.7l displacement vs. 0.8l on the Honda. Do you have a wideband AFR installed to watch for lean running......?

Go go go!

Love how cheap the tbs are...

A great experiment.

John

Do the intake manifolds really get that hot?

With a four-banger, you don't get one cylinder drawing from the plenum at a time. So the throttle body only has to pass enough air to fill one cylinder.

With independent throttle bodies, you only ever have the one cylinder pulling air through a single throttle body. So it needs to be able to pass enough air to fill a single cylinder...

This is one of the reasons why you do not go way, way up in throttle body size when you use a single plenum. Or conversely, why you do not have to drop to little pencil-sized throttle bores on an ITB setup.

Of course, nothing is ever that simple, especially where airflow is concerned. But we do know that 40mm throttle bodies work reasonably on a 1.7 liter 914 engine if they are carbs. So it probably won't be horrible with an EFI setup. Worth a try, certainly! (Especially since it isn't my time and money. ) And the cool factor is way up there, too.

--DD

Im following this.
& Kevin if you ever get to a place where you decide to pull it & go back, look me up..
Ive been toying with the idea of applying that 800FI kit to my 97VFR750F

I don't think you'll need to be too worried about not being able to tune this well since most folks who do this type of thing are using GSXR TBs that are 40mm. As Dave has explained, it's apples and oranges between plenum and ITBs.

I'm planning on going to ITBs with the Squarsche and had seen these same TBs on eBay but was wondering if the distance center to center for the IDF manifolds were even remotely similar. After seeing your photos in your first post, I can see that they are close enough to warrant buying a set. Thanks for posting this.

BTW, I have an aquaintance in TX that is running a 2056cc in a VW Notch with GSXR 40mm TBs and he's getting around 40-42mpg (hwy) with his MS tune and has gobs of power on tap when he wants it. So YES, MS can be tuned easily for these to work on your motor. Nothing better than making 30s technology work better than the boys in Detroit can do it on new cars.

I've been searching in vain for the injector p/n & specs specs for the early VFR800 like this one. But I did come up with the info on the '06-'09 injectors (p/n 16450-MEL-003) which are shared by the CBR1000 of the same vintage. . . They flow 294cc/min @ 43 psi / 315cc/min @ 50 psi (!) which makes them support well over 300hp(!!) TOTALLY overkill for a motorcycle but perfect for a car. If the early injectors flow even remotely close, I doubt you will have ANY problems with running lean. In fact you will have to drastically re-map your VE tables.

So the project took a back shelf for a while because my old tired engine lost oil pressure and spun a bearing just before new years. I have a rebuilt 1.7 now (Thank you Al!!).
Somewhere in the shop move I lost some of the D-jet FI parts so i figured it was a perfect time to pull these out and finish the project.

I have them mounted to the engine, started running some of the vacuum lines and fuel lines and built a linkage.

Here are some pics and a quick vid of the linkage. Sorry about the quality all I had with me was my phone.

The bottom pic is a link to the video, if that doesn't work there is a direct link below it.

Let me know what you think!




http://s694.photobucket.com/user/Kevin3118...0779db.mp4.html

The linkage is just a length of 10-32 threaded rod with heim joints and a pair of 1/8" nylon bushings between the heim and the throttle shaft arm.

Very cool, I'm about to do the same thing on my bug (see my signature) I think I'll use the GSXR though, I need at least a 40mm TB.

I'll be using SDS

Right Dave, but I think the 40mm ITB's will probably be a lot. Don't forget that those 40mm carburetors are necked down, usually to 28mm, at the venturi. No venturi in throttle bodies.

Plus with the vents and everything else in there...

From what I have read around, you can usually get twice as much airflow from a TB than a carb of the same bore size since the TB has an unimpeded airflow.

Just purchased a set of these VFR ITB's off ebay for $ 37.50 free shipping.

Kevin,
Three things.

1 - I'm glad that it's a local Tampa Bay guy who is thinking up something like this, way out of the box.
2 - It's the same guy that used to own my car! (Still hope you get to see it at some point).
3 - If this works, you might have a nice little package that you could produce for the masses! I would certainly entertain the idea of having a similar setup on my car at some point.

Can't wait to see how it runs!

Those guys wad up bikes pretty frequently, so those parts are cheap, I think I still have a set of GSXR 1000 TB's in a box somewhere. A Ducati set too, but I don't think either fit as well as those VFR's do. Activity used to be in the Type 4um of www.shoptalkforums.com if you want to look it up, but I think they've moved over to the fuel injection forum now. Good info, lots of ideas and experience over there.

That is going to be amazing when done. Keep the updates coming!

Thanks everyone!
Just a quick update, I modified some air filters to fit the tbs. I'm not sure I like the chrome... I may paint them black.
I also got a crankcase vent from the local VW store and started running some of the vacuum lines.
Next up is making a throttle cable mount and cable.

Sorry about the pic quality all I have at the moment is my phone.

Glass bead them then either rattle can or powder coat in wrinkle black.

The rattle can holds up amazingly well if applied properly.

Re-following this

Just a quick update for those interested.
I finished installing a set of stainless fuel lines, patched some rust in the hell hole, soldered all of my sensors in, mounted the engine breather box and installed the engine.
I had to make a spot for the IAT sensor on top of the air cleaner, you can see a couple of scratches on the metal on the air cleaner where the bit slipped but I'm hoping to powdercoat them black anyway.
I still have to adapt the throttle cable, finish wiring the starter, readjust my shifter, clean up my wiring and get another cheap laptop for tuning (laptops don't like being trod upon...) and i should be ready to fire it up.

Sorry I only had my phone with me again. I will get some better pics and hopefully some video of it running soon.

Let me know what you think of if you have any thoughts.

Thanks
Kevin

Really looking forward to seeing how this works out....

Looking good. . .

Excuse my ignorance I'm old so I do not know these things. But what is the IAT sensor and could you put it under the air cleaner instead of through the top?

Intake Air Temp sensor. It can be anywhere in the intake system. Wherever it fits.

Intake Air Temp sensor. Dunno why it's out the top either. Might be that there isn't enough room to put it in from underneath...

--DD

Yea I couldn't find a spot underneath that would fit without interfering with other parts. Also I figured that if there is any condensation buildup it won't pool and mess up the sensor.

I came here from another forum with a similar build. I'm very inspired.

Do you have any updates?

I have a similar thread somewhere, I need to update it as well...and get back at as the project is 98% done.
I'm done right to the airfilters, but I'm having fit issues on one side fuel rail, just because it's going into a VW bug.

Have you got a link please?

Thanks

Craig

No updates lately. This project has been shelved for the near future due to loss of the shop I was working in and a promotion at work that has been a drain on my free time.
I slapped a pair of carbs on it for now and boxed all the ITB stuff up for a later date.
I will get back around to this someday but for now I just want to get the car driving again.

Thanks for the interest and if you have any questions please ask away.

Kevin

Bummed you didnt get a chance to finish, this is exactly what I would want to do if I have a FI flat four.

do you have to use the EMPI manifolds to mount these or will any Weber manifold work? I think the spacing is the same on the weber carbs so it shouldnt have to be but I dont know for sure...

I was interested in these working at all. Fun project....understand completely time constraints.

Different set up than the MS with the D-jet components.

Here
http://www.914world.com/bbs2/index.php?sho...210004&st=0