Honda Fuel Injection and Turbo History

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Rednaxs60

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Have been doing a lot of research and perusing of the various forums and have found a significant amount of history about Honda's foray into turbo and fuel injection. The first fuel injected Honda bike was the CX500T, released in 1982, that was also its first turbo motorcycle as well. The CX650T followed in 1983, a much better performer than the CX500T for a variety of reasons. The CX500T made a better impression in Europe than in North America, and similarly the CX650T.

The turbo project started some 6 years prior to the CX500T being put out to the general public. Over 290 patents were filed because of this bike. It is interesting to note that the turbo used on the CX500T and CX650T were custom made for the application. It was generally accepted back then that turbo technology was very much an aftermarket aspect and relegated to no smaller an engine than a 2.0 litre and a minimum of four cylinders, ergo, Honda had a lot of work to do to bring its product to market. Combining this with its revolutionary/evolutionary engine of these bikes, and its a fantastic bit of engineering put together.

The next fuel injected model(s) were of course the '85 GL1200 Anniversary Limited Edition and '86 GL1200 SE-i. Once again this was on the cutting edge, but economics and FI system expense were not in Honda's favour and fuel injection was laid to rest until the venerable GL1800 hit the streets in 2001.

These four bikes share a lot of the same attributes with regards to the fuel injection system. Many of the same parts are interchangeable, and of late, the work and testing of product by the CX500T and CX650T is applicable to the 1200 models.

There is a considerable amount of information, research and expertise regarding these fuel injected bikes on the internet and in the forums. It is because of this that I would not hesitate to recommend owning one of these fuel injected models.

Safe riding and have a wonderful fall season.

Cheers
 

joedrum

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I have thought of turbo on hooch and still do at times now ...back when I thought heat was required turbo makes a lot of sense ...it actually heats the air big time.....seems all supercharged bikes go with weber progressive 2 barrel carb ....I'm also been watching all this FI work that's getting done ...To me the best setup would be c5 powered FI combo ...so far I havnt seem the after market FI set up that tunes well as carb does... But all this work going on now on FI has got my ear and eyes keeping track ...such great work ...reminds me of the SCC work done here....great stuff
 
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Rednaxs60

Rednaxs60

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More on this issue.

Turbo and fuel injection combined are a formidable combination. The history of the development of the 4 stroke turbo fuel injected Honda CX500T and CX650T reminds me of the book I read, Stealing Speed by Mat Oxley. The innovation regarding two stroke technology that came out from behind the iron curtain back in the 50s and 60s was phenomenal, and interestingly, the Japanese had nothing comparable. The bike was also water cooled that was also a departure from the norm at that time.

The other manufacturers also had turbo bikes of the same vintage; however, these bikes were not FI models.

The CX500 non-turbo was the same engine as the turbo variant. Honda did some wise engineering with regards to the CX500 engine such that it would allow further development of this engine at higher powers.

The fuel injection system was/is of particular interest to me because of my '85 LTD FI model. It is slightly more advanced than the system on my bike because of the turbo. This system uses seven sensors, an electronic air flow meter, combined with measurements of boost pressure, throttle opening and RPM to determine injector fuel quantities. Add to this the ECU also controls timing such that the timing is retarded and advanced as required based on the input signals to the ECU.

The '85 LTD and '86 SE-i is not quite as advanced because it is a naturally aspirated engine. The FI system on my '85 LTD primarily relies on throttle opening and RPM. The CX turbo bikes are more complicated in that it also compensates for boost pressure. From what I can gather this is done with an additional PB sensor that measures the pressure in the surge tank.

CX turbo FI system schematic:
Honda-CX500-turbo FI Schematic.jpg


The CX500T and CX650T had the TRAC anti-dive braking system as well.

Here is a ride report from 2016 on the turbo bikes of the day - enjoy. https://bikereview.com.au/classic-turbos ... -v-xj650t/

Lots of history out there and I'm still finding more.

Cheers
 

desertrefugee

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I have no direct Honda experience with early Turbo/Injected bikes, but I do have fairly extensive experience with the Kawasaki 750 Turbo and a fair amount with the Yamaha 650 Seca Turbo. My best riding buddy had the Kawasaki at the same time I had my new-off-the-showroom-floor ZL900 Eliminator. We terrorized central Florida on those bikes - along with a third perpetrator (friend) with a ZX900 Ninja. These were among the fastest street bikes on the planet at the time. The Seca experience was another fellow who spent time with us. We ran frequently at Zuber, Florida. Only the locals know about this legendary piece of drag racing history. More time was spent talking (and arguing) about racing than actually racing, but still, we answered a lot of questions about who's who at that "track".

Both the Kawi 750 and the Yammy Seca were amazing machines with the Kawasaki MUCH more tractable (and fast). The Seca positioned the turbo unit well beyond the cylinder head ports and it suffered a much more noticeable lag because of this. I had lots of seat time on both - quite a bit more on the Kawasaki.

That 750 would run the 1/4" mile quicker than my Eliminator ONLY if the rider had big enough balls and skill to keep it straight and level. The Eliminator usually edged it out since it was BUILT for the quarter mile and easier to handle on the strip. Since these were new bikes and scary fast for the time, we had no compelling reason to make modifications. Those came later. The 750 Turbo is probably the one motorcycle that scared me most. You really needed to get a feel for it gradually before flogging it. The boost built quickly, but if you didn't time it right, you could get yourself into a world of hurt very quickly. Not so much at the strip, but on the road.

I apologize for interjecting alt-Honda trivia here, but the early Turbo bikes will always have a fond place in my memory because of those times we had.
 
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Rednaxs60

Rednaxs60

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Thanks for the input. The turbo bikes of the early '80s were a fantastic testament to the manufacturers. The article I posted about the road/track test of these early turbo bikes indicates that the Kawasaki 750 Turbo or ZX750E squeaked into a first choice slightly ahead of the CX650T. Hindered by the economics of the time and in my opinion, the issue of change, these bikes were in the forefront of technological advance. A following might have developed given a few more years, but a company has to decide on the cost/benefit ratio, and apparently it was not there at that time.

My son-in-law has mentioned the need for a resurgence of the turbo bike. With the insurance rates tied to CCs versus speed and HP, a turbo bike of these sizes would probably hit the interest of riders. When I read the older road reports on these bikes and what the capabilities were, an updated and modernized Kawasaki 750 Turbo/ZX750E, or CX650T could prove to be serious contenders to the bikes that are presently on the market.

Having said all this, I have gone down this path mainly because of my '85 LTD. The requirement to keep abreast of what is available to keep the old girl operating, manufacturing techniques that we all know have developed significantly since these older bikes were produced, and a host of other items/issues is extremely interesting.

Providing the collective does not overly mind my going down memory lane, I will continue to peruse the web, and when I find information that is relevant I would like to pass it on. I also need to ensure that I understand the concept - put it into layman's terms - behind the information.

Great history and information all round.

Cheers
 
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Rednaxs60

Rednaxs60

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Have to say I'm fully retired and everyone needs a reason to get up in the morning. Here is another post for this continuing saga.

Water Injection in Turbocharged Engines

Honda had another issue to overcome, that being water injection. Water injection in internal combustion engine was used as to prevent premature ignition. It was also known as Anti-detonation Injection (ADI).

This, I believe, was also why Honda determined that this new turbocharged, fuel injected bike would be water cooled as well.

Water would be injected into the air stream, or engine cylinder to effectively reduce the areas where hot spots may/might develop. It was also used to allow for higher compression ratios or even aggressive ignition timing.

From what I have read, the water injection system would use a water/alcohol mixture. The alcohol is used similar to the coolant in your car in that it protects the system (corrosion) and it burns in the cylinder. The water absorbs heat, and cools the air intake path and cylinder head allowing for a cooler intake charge allowing for more dense fuel/air mixture, increased compression ratio(s) and decreasing the possibility for engine knock.

An issue with this is the water mixture displaces some of the air required for combustion, hence the need for the turbocharger to provide an air boost so to speak.

The Honda engineers had to design a system that would compensate for the lack of a water based system while operating with 19 PSI boost on pump gas. Besides, where would the design engineers place a turbo water system on the bike in sufficient quantity to make it feasible.

To compensate for this, the Honda engineers lowered the compression ratio of the CX500T to 7.2:1 versus 10:1 for the naturally aspirated CX engine. The CX650T had a CR of 7.8:1. A reduced CR can be used because the air is being delivered under pressure and at a higher density. This can and did result in greater HP and bike performance than its naturally aspirated cousins.

The Honda engineers also found that determining fuel injection quantity by turbo boost pressure and rpm yielded best performance at low RPM, low load(s), whereas determining fuel injection quantity by RPM and throttle yielded best results at high RPM, high load(s).

As an aside, this walk down memory lane into the history of Honda motorcycle turbo and fuel injection systems is bringing up words and concepts I have not thought about for years such as the adiabatic process. I did take and learn about issues and concepts that are allowing me to further understand what I am following – who would have thought.

Cheers
 

desertrefugee

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[url=https://forum.classicgoldwings.com/viewtopic.php?p=195841#p195841:268alvj3 said:
slabghost » Wed Sep 13, 2017 4:09 am[/url]":268alvj3]
Interesting. And don't think for a second Joe hasn't considered the turbo.

Probably best to stay normally aspirated on the Oldwing. Cast crank, pistons and rods. Plus, compression is probably a touch too high for safety margin (~9.2:1) with all but the most modest of boost pressures. So, why bother?

Besides, Joe has already proven there's more than one way to skin a cat.
 

mcgovern61

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Providing the collective does not overly mind my going down memory lane, I will continue to peruse the web, and when I find information that is relevant I would like to pass it on. I also need to ensure that I understand the concept - put it into layman's terms - behind the information.

Don't mind over here! All good information as far as I am concerned!
 
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Rednaxs60

Rednaxs60

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Another installment on the fuel injection history. I give the Reader's Digest version of what I find and put in the references. It is providing me with a lot of insight and technical information. Good reason to peruse the net. Here goes.

Fuel Injection History Update

References:

a. https://shop.revzilla.com/common-tread/ ... -injection
b. https://rideapart.com/articles/motorcyc ... -injection


In 1980, Kawasaki introduced its Z1000 LTD fuel injected bike as well as its Z1000 Classic carbureted model. It increased the price by some $500.00; however , you got to ditch the engine choke and trouble with cold starts.

This electronic fuel injection system weighed in at 16.7 lbs compared to 15.7 lbs for the carburetor assembly. This fuel injector system was apparently identical in concept and design to the Bosch fuel injection system being used on Datsun cars at the time.

The motorcycling media of the time was extremely and immediately skeptical of this new development. Always easier to come up with the negative then to promote the positive, and even mentioned in a publication that fuel injection on a motorcycle was “the death knell for home maintenance and road side repairs”. So where is the downside – go figure. These journalists were also baffled by the on board computer in that it was complex. I wonder how many had started to drive fuel injected cars because of the better performance, convenience and lesser maintenance issues.

Why was fuel injection starting to be looked at by the manufactures, it was expensive, but the tightening of emission standards by the EPA would impact the motorcycling industry in the near future. Simply put, fuel injection would get a motorcycle through emission testing.

Kawasaki was the first motorcycle manufacturer past the post so to speak. This novel innovation of fuel injection on motorcycles that has come to be the expected norm on motorcycles.

Another article I have read is interesting as well.

This article explores the differences between carbureted and fuel injection motorcycles. It looks at the myths between the two systems.

No choke to be concerned with. If the carburetors are tuned and in good working order, there is generally no issue with the choke. Most of the issues with a choke are, IMHO, user issues; however, I personally like not having to be concerned with a choke and realize that there are similar issues with a fuel injected engine need to be understood.

Better fuel economy, not really. Develops more horsepower, probably not.

Carburetors were what was in vogue and available since the motorcycle was designed and put into service, besides, fuel injection was for the big boys - larger engines and different applications. Carburetors were understood by the collective and unless you were a design engineer, or backyard DIY, this is what we learned about and used. Carburetors also worked well with the inadequate electrical systems of these early bikes. Then we hit a tipping point where motorcycles were starting to be looked at as being not environmentally friendly transportation.

Carburetors are a little less emission friendly than a fuel injected motorcycle, but not by much. The real issue apparently was that the fuel in the carburetors would evaporate whereas the fuel system in a fuel injected bike is a sealed system and does not.

Another issue is a carburetor compared to a fuel injected system is less precise. It cannot be adjusted in the same way as a fuel injection system. With a carbureted system, you need to pick a fuel/air ratio that meets your requirements and area of riding. A fuel injected system is more global in that it can adjust for multiple scenarios as fitted. Modern fuel injection systems try to keep the air/fuel mixture lean when at steady speed, and enrich the ratio when the throttle opens.

Fuel injection allows for more accurate control of the air/fuel ratio, making the motorcycle operate cleaner and allowing for a catalytic converter to be installed in the exhaust system.

Carbureted motorcycles have advantages as well. Less expensive to tune and tinker with, although on older bikes the carburetor kits are getting more scarce and expensive. Fuel mapping compared to changing carburetor jets can be extremely expensive. When travelling to remote areas or even long touring trips can result in keeping the trip going because of the lesser complexity of carburetors.

Another small trip down memory lane.

Cheers
 
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Rednaxs60

Rednaxs60

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Another short snippet. Programmed Fuel Injection – PGMFI or PGM-FI is Honda's proprietary name for its fuel injection system that is now used in cars/trucks/motorcycles/outboard motors. It has its roots in the development of the CX500T – CX650T motorcycles.

Information on the net indicates that the third Honda motorcycle to have fuel injection is the 1998 VFR800FI; however, this as we know is not correct. There are the '85 GL1200 LTD and '86 GL1200 SE-i that were produced in between the CX 500T – CX650T motorcycles.

The VFR800FI and its variants have proved to be a good seller for Honda and as with all technology, the acceptance of fuel injected engines on motorcycles, this bike has a long production history, not so for the GL1200 fuel injected models.

Cheers
 

desertrefugee

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Cummins diesel springs immediately to mind. From the factory, fuel delivery is programmed VERY conservatively to meet Environmental Regulations. But, with even modest reprogramming, the Cummins becomes a beast. Upgrade the lift pump, fuel line diameter and even injectors if you're ambitions and that same factory engine is capable of ridiculous power output.

Not exactly Honda and/or motorcycle related, but Dan mentioned modern programming. The Cummins diesel line is a prime example of what software can do.
 
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Rednaxs60

Rednaxs60

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For the DIY shade tree FI enthusiast a programmable ECU would be great. This is not without its pitfalls. I would want a regular daily ride, and have a second to tinker with.
 

Ansimp

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My Bike Models
1981 GL1100 “Rats Nest”
1998 GL1500c Val
1987 CBR1000f “The Pig”
1991 CBR1000f Red
[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=196116#p196116:ohwul8dv said:
desertrefugee » Thu Sep 21, 2017 9:59 am[/url]":eek:hwul8dv]
We'll be keeping an eye on your sig line just in case such a specimen shows up there...
:popcorn: :popcorn:
:smilie_happy: :smilie_happy:
 
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Rednaxs60

Rednaxs60

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Never know; however, next installment.

Fuel Injection Fuel Systems – Return or Returnless

Reference: https://www.aa1car.com/library/returnless_efi.htm

More fuel injection history and information. This time I am commenting on the fuel system and how it has developed from a fuel return system to a returnless fuel system. I am not sure if any motorcycles have a returnless fuel system, but even so, it is good to understand the differences. It has also provided information and an understanding of why the '85 LTD and '86 SE-i system operates the way it does.

Apparently the first returnless EFI fuel system came into being back in 1993 on certain Chrysler cars and trucks. This was followed by Toyota in 1996, followed by GM, then Ford in 1999, and Honda in 2001.

How does this apply to this thread and the history of the turbo and fuel injection. Most of the time, advances in the motorcycle industry is based on the auto industry. As the auto industry changes to meet regulations/legislation, the motorcycle industry watches and eventually has to follow suit.

The fuel system schematics are:
Return Fuel System.gif
returnless fuel system.gif


As installed, the fuel system on these older fuel injected bikes is a fuel return system where the fuel pump provides more fuel than required by the engine when operating and the fuel system pressure is regulated by a vacuum operated fuel pressure regulator that maintains a fuel pressure between 34 to 38 PSI.

Fuel System Operation

A returnless fuel system keeps the fuel system at a constant pressure whereas a return fuel system varies the fuel delivery with throttle opening and vacuum changes.

A return fuel system maintains the same fuel pressure differential across the injectors when pressure drops using a vacuum operated fuel pressure regulating valve. When the vacuum drops the fuel pressure regulator increases pressure (internal spring pressure on the diaphragm) to compensate.

A returnless fuel system compensates for changes in engine load and vacuum with the ECU to regulate fuel delivery. The ECU monitors a fuel pressure sensor and when the engine load or speed increases, the ECU changes either the injector fuel delivery duration, or the operating speed of the pump. Conversely the other way.

So how does this help us with the understanding of the '85 LTD and “86 SE-i fuel systems.

The older return fuel systems circulate a lot of fuel between the engine and fuel tank. This is to keep the fuel from getting too warm/hot and boiling as it passes through the fuel rail on the engine which can cause vapour lock and hard starting, or stalling on hot days. The disadvantage is that a lot of heat is transferred back to the fuel in the tank increasing fuel vaporization in the fuel tank, ergo fuel tank becomes pressurized.

With a returnless fuel system, no fuel is returned to the fuel tank, fuel does not get heated with no increase in the fuel vapour pressure from driving the vehicle reducing the risk of excessive pressure build up in the fuel tank.

The returnless fuel system is also more environmentally friendly as it is less taxing on emission systems.

Fuel volume is just as important as fuel pressure. The pump has to push enough and more fuel to keep up with the engine operating demands. The fuel pump may still produce enough pressure to be within specifications at idle, but may not deliver enough fuel at higher RPM and load causing fuel starvation, lean misfire and a loss of power.

The fuel filtration must also be kept up to a high standard because a clogged filter, clogged fuel pump inlet filter sock, restricted fuel line, or faulty fuel pressure regulator can be the cause of low fuel pressure or volume.

Again a Reader's Digest version of information I have gathered. The reference for this truncated information is at the top, but there is much more information available. As with all my other posts, this one is to aid in my understanding of the fuel injection system on my '85 LTD.

Cheers
 

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