ITB project, Honda VFR 800 ITBs Options

[euro911]

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

Very cool! (IMG:style_emoticons/default/thumb3d.gif)

Do the intake manifolds really get that hot?

[Dave_Darling]

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.

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. (IMG:style_emoticons/default/wink.gif) ) And the cool factor is way up there, too.

--DD

[914werke]

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 (IMG:style_emoticons/default/beerchug.gif)
Kevin

(IMG:style_emoticons/default/aktion035.gif) 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 (IMG:style_emoticons/default/smile.gif)

[aircooledtechguy]

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. (IMG:style_emoticons/default/beerchug.gif)

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. (IMG:style_emoticons/default/happy11.gif)

[aircooledtechguy]

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......?

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. (IMG:style_emoticons/default/aktion035.gif)

[kevin311]

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!
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1365611116.1.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1365611117.2.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1365611117.3.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1365611117.4.jpg)
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.

[Mark Henry]

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

[DBCooper]

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.

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. (IMG:style_emoticons/default/wink.gif) ) And the cool factor is way up there, too.

--DD

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.

[monkeyboy]

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.

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. (IMG:style_emoticons/default/wink.gif) ) And the cool factor is way up there, too.

--DD

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.

[rick 918-S]

Just purchased a set of these VFR ITB's off ebay for $ 37.50 free shipping. (IMG:style_emoticons/default/assimilate.gif)

[ThePaintedMan]

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! (IMG:style_emoticons/default/cheer.gif)

[DBCooper]

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.

[ottox914]

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

[kevin311]

Thanks everyone! (IMG:style_emoticons/default/beerchug.gif)
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.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1368374247.1.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1368374247.2.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1368374247.3.jpg)

[moparrob]

Thanks everyone! (IMG:style_emoticons/default/beerchug.gif)
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.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1368374247.1.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1368374247.2.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1368374247.3.jpg)

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

The rattle can holds up amazingly well if applied properly.

[Dr Evil]

Re-following this (IMG:style_emoticons/default/biggrin.gif)
(IMG:style_emoticons/default/popcorn[1].gif)

[kevin311]

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 (IMG:style_emoticons/default/beerchug.gif)

(IMG:http://www.914world.com/bbs2/uploads_offsite/i694.photobucket.com-11752-1373838458.1.jpg)

[billh1963]

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

[aircooledtechguy]

Looking good. . .

(IMG:style_emoticons/default/popcorn[1].gif)

[rick 918-S]

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?