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BiKenG

RC36.2 (4th Gen) Fuel Injection discussion

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1 hour ago, JZH said:

I sense another trip down the garden to my shed is imminent!

 

The throttle bodies pictured were acquired solely to harvest their injectors, which were then professionally cleaned and used on my yellow 5th gen in California, so these TBs have no injectors.  If you want to try them with 6th gen injectors, feel free; I have no use for them, so you're welcome to them.  I'm happy to help your projects in any way I can.  Some of my spare parts made their way into lovely Rick Oliver's RC30/36 some years ago, so no pressure there!  (The bike's original injectors are still in California, sorry.)

 

ISTR Dan from A&A Performance experimenting with 6th gen injectors on the Torocharger bike, but ultimately he decided the 5th gen injectors were fine.  That suggests that they can swap, but I don't remember the details, really.

 

Btw, the RC36 carbs in that picture are from my FL; FR-V carbs are 2mm smaller, I think--and they are definitely different in many other ways (I had not realised that until I compared the set I have here with that picture.

 

Ciao,

 

Aha, first of all, yes those TBs will be perfect to try and fit, thanks, much appreciated.

 

Secondly, very interested to hear what you say about the 3rd Gen carbs being bigger - music to my ears. Since 4th Gen rubbers are too small to accept the TBs, there's hope that 3rd Gen rubbers may be better, i.e. actually fit.

 

I need to find a good (i.e. flexible) set of 3rd Gen rubbers and try to squeeze those TBs in.

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I've been building and riding Do-It-Yourself Fuel Injected motorcycles for about 10 years now.  One of my best efforts is my 1993 Suzuki GSF400.  Instead of trying to retrofit/modify a set of throttle bodies from another motorcycle I simply turned the GSF400's rack of Mikuni BST32SS carbs into fuel injection throttle bodies.  This keeps the fit and serviceability of the original setup which really helps in the areas of long-term ownership and maintenance.

 

I did a little searching and found that the secondary injectors from a Kawasaki ZX-6R (the set that's mounted on the intake airbox) were a perfect match for the fueling needs of my GSF400's little 100cc displacement pistons.  So all I had to do was remove all of the excess plumbing and metal from the float bowl area of the Mikuni BST32SS carbs and get a receiving pocket machined into each of the four carb bodies (with the tip of each injector aiming up into the carb bore just beyond the throttle butterfly.  After some experimentation I removed the carbs vacuum operated diaphragms because performance was unaffected.

 

I fabricated the necessary bracing to locate and secure the ZX-6R injector array into the newly machined injector pockets.  And I added a Throttle Position Sensor that was parted-out from a Triumph Speed Triple.

 

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Just an example of one possible pathway to a successful Fuel Injection project (I use the Microsquirt V3 ECU).

 

Why try to stick with the Honda ECU when the Microsquirt V3 ECU offers you almost unlimited user-control over every input and output parameter?  You'll be able to fine tune every single aspect of your 4th Gen's fueling and ignition.  There are moments when you feel like a mad scientist (when it's your fabrication and tuning that make is happen).

 

There's even a way to achieve Full Sequential Injection Control without a camshaft position sensor (using the Manifold Absolute Pressure signal from cylinder #1, which is just as reliable as a camshaft position sensor).

 

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7 hours ago, GreginDenver said:

I've been building and riding Do-It-Yourself Fuel Injected motorcycles for about 10 years now.  One of my best efforts is my 1993 Suzuki GSF400.  Instead of trying to retrofit/modify a set of throttle bodies from another motorcycle I simply turned the GSF400's rack of Mikuni BST32SS carbs into fuel injection throttle bodies.  This keeps the fit and serviceability of the original setup which really helps in the areas of long-term ownership and maintenance.

 

I did a little searching and found that the secondary injectors from a Kawasaki ZX-6R (the set that's mounted on the intake airbox) were a perfect match for the fueling needs of my GSF400's little 100cc displacement pistons.  So all I had to do was remove all of the excess plumbing and metal from the float bowl area of the Mikuni BST32SS carbs and get a receiving pocket machined into each of the four carb bodies (with the tip of each injector aiming up into the carb bore just beyond the throttle butterfly.  After some experimentation I removed the carbs vacuum operated diaphragms because performance was unaffected.

...

 

Aha, I've been thinking along those lines too, using the VFR750's carbs and I believe an early Kawasaki 900/1000 (I forget which) had a similar injector rail with suitable injectors. I've not discounted it and will be looking into that and the MicroSquirt for a similar project to inject a CBX1000 (6 cylinder), but that's further down the line. For this VFR750 I kinda want to make it as Honda as possible, so priority will be to see if I can use the 800 parts. If I can't use those TBs, I'll look for alternative TBs and if that fails, then it's modify carb time and a different ECU.

 

But it's always interesting to see what others are doing to inject their bikes, even more so with regard to my CBX project.

 

How does the MS use MAP sensor output to detect engine position? If the MAP sensor is connected to all intakes, how does it know which pulse is for which cylinder?

 

BTW, why did you choose the MS over say Motec?.

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7 hours ago, BiKenG said:

How does the MS use MAP sensor output to detect engine position? If the MAP sensor is connected to all intakes, how does it know which pulse is for which cylinder?

 

BTW, why did you choose the MS over say Motec?.

 

The Firmware load that the MegaSquirt and MicroSquirt use is Open Source, so guys are free to be creative. 

 

Your question about the MAP sensor is a perfect example: One of the problems with fuel injecting motorcycle engines is that they are always configured with Individual Throttle Body arrays (both carbs and throttle bodies count).  Individual Throttle Bodies are great for high-revving performance applications (most motorcycles) but they produce a very poor and messy vacuum signal to a MAP sensor.  So running a single MAP sensor is always a bit of a problem.  A guy in Germany has developed a build-it-yourself, advanced Multiple-MAP-sensor unit that uses an Arduino Nano to monitor four MAP sensors (one for each cylinder on his ZX-7R).  The code loaded into the Arduino Nano looks at all four MAP sensor signals and determines which is pulling the most vacuum at any given microsecond.  Then the Nano forwards that signal to a Digital-to-Analog converter which is wired into the MicroSquirt's main MAP sensor input.  Also, the Nano knows which of the four MAP sensors is connected to cylinder #1, so whenever it sees that particular MAP sensor pull its highest vacuum it (the Nano) generates another digital output that mimics a camshaft position sensor (again out of the Nano as a digital signal, then through a DAC and on to the input on the MicroSquirt for camshaft position).

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I see, so there's a MAP sensor for each cylinder. I have a funny feeling Honda MAP sensors are rather expensive, but I guess he's using a more cost effective sensor.

 

All food for thought re the CBX, but is another reason for grafting the 800s injection onto the 750 as provided it can physically be done, then it's relatively simple as there's a ready made wiring harness with all the required sensors and just the one ECU module. No other ancillary electronics required. Well, apart from a Power Commander or equivalent. At least I assume it will need some tweaking, although just have to see on that once it's running.

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1 minute ago, BiKenG said:

I see, so there's a MAP sensor for each cylinder. I have a funny feeling Honda MAP sensors are rather expensive, but I guess he's using a more cost effective sensor.

 

All food for thought re the CBX, but is another reason for grafting the 800s injection onto the 750 as provided it can physically be done, then it's relatively simple as there's a ready made wiring harness with all the required sensors and just the one ECU module. No other ancillary electronics required. Well, apart from a Power Commander or equivalent. At least I assume it will need some tweaking, although just have to see on that once it's running.

 

Did you go to Patrik's NC30 Fuel Injection project blog (as was suggested on page 1 of this thread)?  If "simplification" is your overall aim it's important to realize there are different areas of a motorcycle fuel injection project that can present as very, very complex.  If you take the time to read Patrik's NC30 blog you'll see how complex it was for him to adapt throttle bodies to the bike.  He has skills and equipment that I will never have (CNC machining, for one example, and he's highly mathematical). 

 

So I choose to simplify by not attacking areas like the mechanical aspects of the throttle body (especially a throttle body assembly as complex as a Honda V4!), and instead I'm willing to suck up the punishment of lots and lots and lots of wiring and soldering.

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11 minutes ago, BiKenG said:

I see, so there's a MAP sensor for each cylinder. I have a funny feeling Honda MAP sensors are rather expensive, but I guess he's using a more cost effective sensor.

 

Motorola MPX4115 MAP sensors are pretty cheap.  I always use the MPX4115 because it is their basic atmosphere model (as opposed to other MAP units designed to handle turbo or supercharger boosted engine MAP signals), they sense in a range from 115 kPa down to around 9 kPa.

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2 hours ago, GreginDenver said:

 

Did you go to Patrik's NC30 Fuel Injection project blog (as was suggested on page 1 of this thread)?  If "simplification" is your overall aim it's important to realize there are different areas of a motorcycle fuel injection project that can present as very, very complex.  If you take the time to read Patrik's NC30 blog you'll see how complex it was for him to adapt throttle bodies to the bike.  He has skills and equipment that I will never have (CNC machining, for one example, and he's highly mathematical). 

 

So I choose to simplify by not attacking areas like the mechanical aspects of the throttle body (especially a throttle body assembly as complex as a Honda V4!), and instead I'm willing to suck up the punishment of lots and lots and lots of wiring and soldering.

 

Yes, I've read most of it, but a power cut here prevented me from finishing it. I will go back and read the rest though. It has encouraged me to start looking again at adding CNC capability to my mill. That would be enormously helpful in so many ways. But I digress...

 

I understand that modifying the TBs to suit won't be trivial, but Patrik and Durbahn both use the TBs from a totally different bike and then had to totally create their own maps etc. from scratch. I am currently of the opinion that using 5th Gen TBs will not actually be as difficult although I may change my mind once I start hacking them. :biggrin:

 

However, if I can get the TBs to fit, the rest of the system is essentially off-the-shelf, just by using the 800 parts and it should even run like that with just minor tuning required with a PC. All that is a BIG advantage by using the VFR800 parts. I do have to add a Cam sensor, but that's been done before.

 

Of course the first requirement is that I can get the TBs to fit and I'm waiting on a set of 5th Gens I can start work on. Currently I'm firmly of the opinion that it will be easier than modifying the carbs, but I guess I'll soon be finding out if I'm right or wrong on that. It's all good clean fun though.

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2 hours ago, GreginDenver said:

 

Motorola MPX4115 MAP sensors are pretty cheap.  I always use the MPX4115 because it is their basic atmosphere model (as opposed to other MAP units designed to handle turbo or supercharger boosted engine MAP signals), they sense in a range from 115 kPa down to around 9 kPa.

 

Good to know. Thanks for that. A typical Honda MAP sensor (I just checked for the RVT1000) is £256. So for the CBX, that would be prohibitive.

 

I also have a VTR1000F FireStorm (er, Super Hawk in the US?) that I'd like to inject. So another project to keep me busy. Possibly do that before the CBX. Just see how everything else pans out.

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Late to the party but I'm considering adding EFI to my project RC24 VFR (which is planned to be a 840cc '88 FJ engine in an '86 FG frame). I have the '86 FG engine but the '88 FJ engine is a better starting point with the *one* exception of the '86 having a cam sensor already (but smaller valves, different cams etc etc). 

 

'86 has a cam sensor *but* the crank sensor is useless for EFI. It is merely a single tooth trigger.

'87+ RC24/RC36 has a 12-1 tooth wheel (11 teeth at 12 tooth spacing with one 'missing') but no cam sensor.

'98+ RC46 (and the RC45) has a 12 tooth wheel & a cam sensor. 

 

The '86 runs non-wasted spark, all the others run wasted spark but single cylinder wasted spark (not sure about the RC46, it's probably non-wasted as the ECU knows where it is in the cycle). Any aftermarket ECU needs to have 4 separate IGN outputs. 

 

It doesn't look possible to fit a '86 cam sensor into later RC24 let alone an RC36 as the castings are different, it appears to be a small VR sensor slightly to the left of the front intake cam and picks up off a single "tab" off the cam gear. Although you could I think fit something in the same place and add a sensor in the cam cover. In comparison it is trivial to add the later 12-1 toothed wheel to the '86 and it looks like you should be able to fit the 12-tooth wheel to the RC24 and RC36.

 

RC46 TB's are IMO more trouble than they're worth, the spacing is wrong, the angle is wrong and they're small. IMO you'd spend more time trying to adapt them than something else entirely. 

 

I'm not sure about the later RC36's etc but the 88/89 RC24 has 36mm carbs which are 44mm OD where they fit into the inlet rubbers. 

 

So I'm looking to use 2001-2 GSX-R600 TB's, these are only 2mm larger at 38mm ID and more importantly 44mm OD, ie the same as the original.  They split apart and the plan is to sacrifice a set of old carbs for the linkages and top plate. Then use those to work them into the original airbox. 

 

Fuel rails will need to be custom, I have seen  GSX-R1000K1/2 TB's which have a nice fuel rail that splits into multiple parts....but the TB's are too big and you'd need two sets to give enough "pieces" off the rails to work (and still need to fabricate additional lengths).

 

I have one issue at the moment in that I'm not sure if Microsquirt is enough for the VFR. It only has two injector outputs and the 180° crank means even with a cam sensor you couldn't do sequential injection as the second cylinder would always be at the wrong point of the cycle so it would be batch-injection only. To do things properly would need duel Microsquirts or an MS3.

 

Interesting about the multi-MAP though, I'll have to take a look at that. 

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On 12/8/2017 at 8:26 PM, BiKenG said:

I do have to add a Cam sensor, but that's been done before.

 

You don't need a cam sensor, you can have EFI without it but it limits you to wasted spark and either batch injection (ie random all cylinders squirt at once) or semi-sequential injection (one half squirt per cylinder every 360°, ie one squirt is correct, the other isn't) rather than fully sequential injection (ie one squirt per cylinder every 720°). 

 

Again note that the Microsquirt cannot do either semi or full sequential on the VFR750F or VFR800F (it could do semi-sequential on the VFR750R or RVF750R) as it does not have enough injector outputs. 

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since fi has so few actual benefits over carbs, and since so many fi bikes are available now, it seems impossibly difficult and senseless to try a conversion.  anyone who can't get their carbs working and tuned to 100% of their potential hasn't got a chance with a complicated, computer- and sensor-driven fi system that was never designed for their bike.

 

 

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This is a technical discussion rather than a justification of if it is at all advisable!

 

I'm largely in agreement...but

 

17 minutes ago, squirrelman said:

since fi has so few actual benefits over carbs

 

 

EFI has a massive number of advantages over Carbs. It is more efficient, gives better starting, better emissions, it adjusts to altitude and pressure differences better. It is massively easier to tune and does not suffer as badly from wear or from alcohol (eg e85). 

 

17 minutes ago, squirrelman said:

and since so many fi bikes are available now,

 

 

But none of the more modern bikes are substantially better. 32 years after the introduction of the VFR750F and and the very latest VFR800 manages to be 10Kg heavier with the same amount of power and while I've not ridden the RC79 the VTEC of the RC46 was horrible and the engine uninteresting. 

 

Objectively it is a better bike in every way. 

Subjectively...it's a poor relation to the earlier models. 

I have zero desire for one and so the argument that it isn't worth it because there are new FI models is a poor one. 

 

17 minutes ago, squirrelman said:

anyone who can't get their carbs working and tuned to 100% of their potential hasn't got a chance with a complicated, computer- and sensor-driven fi system that was never designed for their bike.

 

I'm 98% in agreement if we're talking about stock bikes. Where it makes a difference is when you have modified it, the ability to tune with a laptop rather than spend a fortune on jets/needles and hours taking it apart and putting it back together again (and I *hate* taking the carbs on and putting them back on again).  Still, even with modified bikes its more something to be done for it's own sake rather than because of any real advantage.  So again I'm largely in agreement. 

 

 

 

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Fastdruid, I'm curious about your special note of E85.

Have you run such?

If so, I realize this is a carburetion discussion, but did you make any other optimization changes (higher compression/boost)?

VERY interesting topic (retrofitting FI to older VFR's) and I agree that it is probably the better way to go for those with increasingly complex modifications (E85).

Please, keep this thread going !

-Smack-

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13 hours ago, Smack said:

Fastdruid, I'm curious about your special note of E85.

Have you run such?

If so, I realize this is a carburetion discussion, but did you make any other optimization changes (higher compression/boost)?

VERY interesting topic (retrofitting FI to older VFR's) and I agree that it is probably the better way to go for those with increasingly complex modifications (E85).

 

Ah no, not personally and I'm not intended to.  I mean in theory you could get something like 20% more torque on E85 (or potentially more, up to 40%) but you'd need to replace all the aluminium and rubber parts in the fuel system along with tuning to make the most of it....  

 

E5 / E10 is likely to be more realistic which has issues already on older carb bikes with "carb jelly" not to mention eating unobtainium rubber carb parts (seals you can replace and some are available in E5/E10 proof but diaphragms etc are NLA) and then you have the rusting tanks... (although that is still a problem with EFI). 

 

I'm "just" planning on a big bore (837cc) + EFI which should see about 120hp (based on others who have done the same) running on "normal" pump fuel. 

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I have -by mistake- run my 4th gen on E85 and it ran

 

utter,

 

 

utter,

 

 

utter,

 

 

 

utter

 

 

SHYTE!!! :goofy:

  • Haha 1

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GSX-R600 throttle body on VFR750F (RC24) carb rubber. 

 

It is a perfect fit. No pissing about with different adaptors etc. Bodies split easily (with the loss of the secondary throttle valve) although its going to be a pain to forge the linkages. 

 

I know the RC36 carb rubbers have a different p/n and I don't know if the carbs are the same diameter there. 

 

 

CY4Lcnxpy0fq77V1LS50rpzsBfCEvHUGgyieElaSvRqZ37ZaT7OqCjj_uOkFl-64-No4TYtlWbd-2QSw0YgB-KRdKE6gVs8w8oc6PYNFQUZ0npY7sBFip7ThVaCpFZ-YjWkyrGQwSlTWbqN56yQorlkZqRHUuKZBCfEXtkrgS-PSecSBOl3ZskGbw2G3dPx0rB7PMQdScy_Wmf7HZJiRnACsDGWx5CG2t__stNwkR5Glw-0fTL5cPvLSZUOtbZgp-0sXlTvQe670qBJp9YYs8JGRjtmoWY14UtOgRskMryOfyBdpdDO_TIS6ozojI0if_bJXlZdlTXi_1xqJUdL_clU-6G30gIMr4W4eHjN76r8xnrgPVTfMYIZhKk4JvXRhEftWAuMMOoy35ys5HD_6O2hME_Ku4iFv5gIUSbU9BFv9Y88v5IR85fnjW-paJ6bJg0pUlRxuQ7CdWHUzue-LQLQppI4ioKwj90V0tvEnvfpZ-eNiz33nuIw7v65aNfg2FMoYaJ_xQvgHqXLWkmrPk6CY4m-SJTZ9-U4HO0DagVxsoFHg4xW2P8gwPSjsntp_Ak7NQavccnXXB58QmvoXWuyfsBl_14Qfx4c1YuYoLlwCjWuBK6N2dhtVQyCr-UwjXspit4wSjmFQRu36nj5BW87lSQ=w1186-h889-no

 

(I'd have put it on the spare engine but its cold outside and the old rubbers are rock solid, I utterly failed to get it on out there)

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Hi guys, i thought i would add my 2 cents for what it is worth.  I am wondering if you have got any further with your efforts yet? Just to spurr you on I have done this project on a ZXR 900 engine currently in a 7R frame and i can say that yes it was worth all the blood sweat and tears! Yes there lots of head scratching moments but nothing that someone else has already done, so just google it! I have learned so much from that project that I am now currently gathering all the nessasary components to do the same to a vfr750 gen4. I will also be adding a zx10r front end for the usd forks and radial calipers also adding an RVF body kit for the RC45 look.  Iwill be using a microsquirt v3 ecu, triumph 675 throttle bodies and also going to a coil on plug system to save a little space. for what it is worth i think it will be hard work to adapt the vfr800 system/ecu to run with the 750. I am willing to share any info and help others where i can. It is good to find other people with a similar mind-set and the same "I want to do it just because i can". Dont loose heart cheers Nick.

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