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Why Not EFI????

Old 06-25-2008, 06:06 PM
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Why Not EFI????

has anyone put any serious thought into using the rc-51 fuel injection in a superhawk. i did a search and found talk of efi but not specifically from a rc51, has anyone looked into this... or even tried it..... i'm extremely curious. to make life easier i've included two pics of the carb vs. throttle body, seems like it would fit ( although it would take the rest of the fuel injection components from a rc), let me know what u guys think.
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Old 06-25-2008, 07:40 PM
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I haven't ridden one, but I've heard and read that the RC51 dual injection is kind of glitchy for non-track riding.
On the other hand the SuperHawk's carburetion is flawless all through the rev range.
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Old 06-25-2008, 07:55 PM
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My GF's SV650S runs great on FI, but it is not as smooth as the the Carb's on the superHawk.

I much prefer the carb's, just my opinion
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Old 06-25-2008, 07:55 PM
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Fuel injection has always left me kinda' cold. If Mikuni made their HSR48s in a semi downdraft, I'd definitely have a pair of those babies installed. Here's three 42s on my car.
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Old 06-25-2008, 08:31 PM
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Old 06-25-2008, 08:47 PM
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EFI is really great until it malfunctions and then you have a dead bike. Carbs typically go bad slowly and will at least get you home or give you early warning of problems.

That said for the RC mod, I think you would need the RC's: FI bank, airbox, fuel pump, fuel tank, ECM, wiring harness, and also the..... Why not just get an RC and be done with it?

I'm not trying to dissuade you from attempting this mod, by all means go for it, but I've never thought to myself at the end of a ride on a superhawk, "man, if it only had FI this bike would be sweet". Besides the occasional carb fart is good for the digestive tract! LOL
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Old 06-25-2008, 09:45 PM
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I would be more inclined to buy a wrecked RC51 and attempt to install SuperHawk carbs on it.
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Old 06-25-2008, 09:49 PM
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Originally Posted by superbling View Post
the occasional carb fart is good for the digestive tract! LOL
AAAAHahahaha!!! I actually laughed out loud at that. Thanks!

+1 for the Carb Fart.
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Old 06-26-2008, 02:21 PM
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i work for a Very Lage used car dealer here in mass... plus i've been into cars for YEARS. and theres always been a good rule of thumb... EFI is way, way, way, better than carbs. that said, an EFI system on a car is a very simple system and way more reliable than carbs, at least on cars, also the performance and fuel economy increases. thats the only reason i'm considering it. plus a friend of mine had a wrecked rc that i might buy the efi from..... maybe............
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Old 06-26-2008, 02:44 PM
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Ten years ago when I lived in a condo with no garage, I could always bump start my BMW R100RS when the battery was low.
Can't do that with EFI...low battery volts means no fuel pump presssure and no injector pulses from the ECM.

Having said that, EFI is much more trouble free on cars than carburetors. The electronic feedback carbs of the 1980's were the worst.
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Old 07-20-2008, 02:44 AM
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Originally Posted by blackvtr View Post
i work for a Very Lage used car dealer here in mass... plus i've been into cars for YEARS. and theres always been a good rule of thumb... EFI is way, way, way, better than carbs. that said, an EFI system on a car is a very simple system and way more reliable than carbs, at least on cars, also the performance and fuel economy increases. thats the only reason i'm considering it. plus a friend of mine had a wrecked rc that i might buy the efi from..... maybe............
I am looking at doing this also, and have done some thinking about it.

If your mates RC is the early model with the 54mm throttle bodies then I might buy them if you don't want them. The later model units are 62mm, which I think would be too big for the VTR. Please let me know if they are for sale.

As for general thinking on the conversion this is what I have figured out so far. I am waiting on a workshop manual to arrive for the RC so I can study the components, so it may not be possible, but we shall see.

Use the throttle bodies and the injectors, coolant temp sensor, air temp sensor, pressure regulator, and whatever else they use. Cam sensor may be tricky to fit.

Get an aftermarket EFI fuel pump. I don't know if you can get one with an internal pressure bleed off, but I would think it unlikely, so that means you will need a return line to your tank. Fuel pump can go under the seat (I have one for the carbs there already).

A custom airbox would more then likely be needed. I think a modified VTR would would be easier.

An aftermarket ECU will be needed I think, the RC one would be too hard to use, and you would need to change the fule maps anyway. MoTec, Haltech, Microtech and EMS are all manufacturers of ECU's that could be used fo rthis application. Australia has a good market for this stuff. I have seen a small fuel only ECU from Microtech that costs under $800. Aud and USD are prety close at the moment, so the price for you guys would be similar when you added freight.

My first question wll be whether you can separate the throttle bodies. As the RC engine is different to the VTR, I doubt the spacing will be the same. If they can be separated, you would need to make up new mounting plates and linkages, and fuel lines most probably. So this is the first question to be answered. Can the throttle bodies be separated?
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Old 07-20-2008, 07:09 AM
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Microsquirt can control the VTR engine, it have dual ignition channels for our odd fire engine.
http://www.microsquirt.info/
Ain't plug and play tough, but nothing is.
You may be able to re-use most of the existing sensors and will need a one bar GM MAP sensor, the tricky part is to get the vacuum signal, but it's also possible to use a MAF unit like Ford connected to the airbox instead of the snorkel. This would eliminate the pulsing signal and get a better fuel control.
O2 sensor is a possibility as well
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Old 07-21-2008, 04:52 AM
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Originally Posted by gboezio View Post
Microsquirt can control the VTR engine, it have dual ignition channels for our odd fire engine.
http://www.microsquirt.info/
Ain't plug and play tough, but nothing is.
You may be able to re-use most of the existing sensors and will need a one bar GM MAP sensor, the tricky part is to get the vacuum signal, but it's also possible to use a MAF unit like Ford connected to the airbox instead of the snorkel. This would eliminate the pulsing signal and get a better fuel control.
O2 sensor is a possibility as well

Have you used the Microsquirt?
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Old 07-21-2008, 05:05 AM
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Originally Posted by superbling View Post
Besides the occasional carb fart is good for the digestive tract! LOL
Damn it man.. I'm at work... I laughed... You're gonna get me in trouble..
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Old 07-21-2008, 11:02 AM
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Originally Posted by shayne View Post
Have you used the Microsquirt?
Not yet, the current project is a garage buildup, I may hit it this winter, but it may be a tad too short. It may not be on a SH tough
But I even had them (with some help from the Harley guys) to modify the code for odd fire V-twin, now you can select a crank offset to trigger the second coil output.
I also need a TIG welder to make some of the stuff I need like airbox, to modify the carbs throats and prepare for one or even two injectors per throat, piping and a few other goodies.
It kills me everytime I speak of it, I was so into it and it keep delaying because of life, but garage first, it will be funnier to work into this with my asylium fully done, not laid on a pile of 2x4 with a flashlight between my teeths. with a huge and functionnal workbench, beer fridge, swimsuit calandars, proper lighting and all the construction crap off my legs.
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Old 07-29-2008, 05:25 PM
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I can make the comparison, having both a VTR and a Varadero in the shed. The main difference you feel is that the Vara is a little more touchy on the throttle at low speeds, but then mine never does the "cough...stop" at idle that the VTR sometimes does. The Vara is more economical on fuel, despite being bigger and heavier, but cams and lower power may have more to do with that than fuel delivery systems.

As I mentioned on the Varadero thread here, it should be a physically easy job to fit the EFI to the VTR, except for making space for the extra equipment. Setting the EFI would be relatively easy if you also fit a Power Commander.

Last edited by PJay; 07-29-2008 at 05:31 PM.
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Old 07-29-2008, 05:39 PM
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Fuel injection would be great. The one major drawback with carbs is the inability to adjust to altitude. I took my Hawk from Kentucky to the Blue Ridge Parkway. At that elevation the thing didn't want to run right, wouldn't idle, etc. The 919 never missed a beat, even out in Colorado at much higher elevations.

I think the swap would be a task that may not be worth the reward. You need cam timing, aftermarket ECU, etc. Good luck. Sounds good but probably a lot of frustration.
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Old 07-31-2008, 02:52 AM
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Oh, but I do love a challenge!!!!!!
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Old 08-13-2008, 12:10 PM
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ive got a nice set of 41mm throttle bodies with injectors that i was going to put on my superhawk.
i love carbed bikes but i frigin hate CV carbs.
i never got around to going FI on the VTR, too many other projects. and now i need to do something, one of the carbs on my VTR is all but shot, im looking into modding a pair of FCR carbs off of a different type of vehicle onto this.
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Old 08-14-2008, 05:00 AM
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EFI is not going to be easy, so you would need to be dedicated to the cause.

As for the FCR swap, it has been done, and you can buy the stuff to bolt straight on to the VTR. And I mean bolt straight on. A friend of mine over here bought a set from Japan. Had the right linkages and pod airfilters, the whole lot.

Sorry, I can't tell you where to look for this stuff. I did ask him myself, but have not heard from him in a while. He reckons they were bloody good though!
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