HI,

i am a senior at old dominion university and am beginning on my senior design project.
the project my group has chosen is to design and build a hybrid powertrain.

the plan so far is to use a single cylinder small gasoline engine mated to an electric motor.

part of my duty is to create the fuel injection system from scratch.
SOOOOOOO
looks like i will be jumping into this head first lol!

aside from the details of designing the manifold (which i would like input on as well) i will need to either start with an OEM computer or create my own.
i am thinking that starting with a computer would be much easier.


the question i have is:
does anyone know of a car computer that is easy to program?
i would love to be able to plug it in to my computer and make changes on the fly, as well as be able to read data live.

one member of our group has access to pretty much any computer we would need, so if any car computer is more easily programmed than others, i would love to know.

if not, i will probably try and get a megasquirt or something aftermarket.



edit:
another thing
i have heard of plugging the ports on a carb and using it as a throttle body... is this possible?

 

Try to locate a single barrell TBI unit with injector that was used I will suggest on a 1990-1992 Cavalier/Sunbird. Junkyard. Make sure it has the wire harness. you need a smalll venturi TB so large will make the tune more difficult. Single barrel was used also on larger engines. Not much is said here as most of us have V8. T
asht engine used a 1227730 ECU. Again the chipp will need to be for the smallest engine so keep in mind for donor vehicle from JY. eprom style(not .bin) is a 27C256.

For datalogging you can use winALDL or TunerproRT. Both are free. you need to construct a cable. That remins me you need an ALDL connector. Junkyard. And I suspect appropriate sensors. What will you use to provide spark?

 

currently i am waiting to get the engine before i settle on too many details.
ideally, i would use a coil instead of a magneto.
there are still a lot of details up in the air lol.

is there a reason i cant use just any computer and set the number of cylinders to 1?
keep in mind ive never done any of this before

 

if/when you get to needing a wiring diagram, let me know the donor vehicle and i'll see what i can scrounge up.

 

awesome thanks!

 

If you go with gm ecm stay with OBD1 type computers much cheaper to tune due to all the support. Check moates.net for tuning tools, burner, emulators, etc. Will you need alpha n or speed density? I figure speed density won't work on a single cylinder due to the pressure fluctuations. So check with the forum for an alpha n solution if needed, the guys here will most likely have a solution for it.

 

thats what i figured.

 

I would suggest a 730 ECM, as you will need to do some patching to control a 1 cylinder engine properly.

There will be very strong pulsing of the air flow through the system. I would go into the MAP value routine and modify the dampening filter.

IMO, Open-Loop operation would be the best way to control the engine.

A 1 cylinder engine will need to have a very high static compression ratio to get any real efficiency out of it.

I would pick an engine with a relatively long rod and stroke, then try to bring the static compression up to 14 or 15:1.

In some applications such as hooking a small engine to a generator, it often helps to add significant flywheel weight to store energy. Otherwise the pulsing of power vs load will be too much for smooth operation.

I would use a thermocouple near the exhaust valve to monitor combustion temp. Depending on your final compression and how exactly you want to go with this project, I would consider mixing my own ratio of Ethanol into some 87 octane gasoline.

HTH

 

great suggestions!
how would i go about raising the compression?
i can measure a few parameters like cylinder pressure, V1-V2 (piston down volume w/o head minus piston up volume w/o head, and stroke, to get a good idea, but without a true head volume measurement i will only be approximating.

i could have the head milled down i suppose. new pistons are out of the question...

so say i put on a 5lb flywheel, which is enormous for that engine considering honda guys use 8lb flywheels, that will help smooth out the RPM significantly, but my understanding is that i will still have pulses in the intake.

now i could be misunderstanding this, but my thinking is that to rectify this, i would want a short runner intake with as large a plenum as is reasonable.
the large plenum will give a 'cushion' to the intake pulses, the short runner will negate any real 'tuned' effect, especially since we want it to be effective through a wide range of throttle and rpm.

would the airflow even be enough to read with a camaro MAP sensor?
we are looking at a MAX of 10 hp at WOT... a SBC beats that at idle.

this is really helpful information though. i might go junkyard hunting tomorrow for engines!
wish me luck.
anything in specific i should be looking for?

 

The MAP sensor doesn't care what volume the engine has, all it looks for is pressure changes. All engines be it a 20cc RC car motor to a 600+ cube mountain motor all has relativily the same effect on presure changes within the plenumcoupled to an intake runner. The benefit to more cylinders is that there will be less time between each intake stroke, lessening any real intake pulsing between intake strokes.

I think for this I would take the suggestion of running Alpha-N, and that means that I would likely look at that aftermarket ECU that will remain un-named in this forum. It has a true Alpha-N setting, where as the GM ECM doesn't seem to have a true Alpha-n ability. There has been talk about tieing the MAP sensor input to the TPS sensor, and in theory it will give an Alpha-n like tuning and running ability, but there are other things that would have to be changed in the instructional code, to do away with or change the way the baro corrections work at key on.

 

ok.
i would LOVE to have EBL, but unless it was donated, its out of my budget.
could someone please explain alpha-n in more or less laymans terms?

 

alpha-N means the ECM assumes how much air the engine is consuming based on throttle position and engine speed alone.

 

and what are the benifits?

 

compared to trying to run speed-density?

you won't have to try and filter the MAP due to the intake pulses.

 

Why? I guess I misunderstood. I thought the engine was just going to be turning the generator.

I suggested the 730 ECM because it has lots of area in memory to use for patching. There is a filter routine for the MAP output depending on which other routine is using that output. You would need to rewrite the filter routine to condition the MAP output to something you could easily manage.

If your intake tract is large enough to dampen the pressure pulses, then it's WAY too big, and will have trouble with any sort of loading.
Engines that turn generators are generally low RPM, run in a fairly narrow range, need a richer than stoich AFR, and do well with longer intake tracts with relatively small cross-section. If you're going to use an injector near the valve, then the air intake can be as long as you want to boost power output. You're only looking for solid torque. 5000 RPM is far too much for turning a generator.

Sorry if I'm still misunderstanding your project.

 

its a parallel hybrid. like a prius.
the electric motor and gas engine are working in parallel. the electric motor starts off from a stop, and the gas motor takes over when you get moving

 

ok, alpha-n sounds great then.
so as far as i understand, i need a 730 ecm, a MAP sensor, and TPS to get alpha-n simulated correctly

really, i would think that a bigger engine would make the tuning easier, but it will make the rest of the project a nightmare!
we have to basically build a coupler to mate the powertrains together, and if we have a 40hp gas motor, then a 5hp electric motor will not work... not to mention needing bigger, more expensive shafts and couplers to mate everything

 

erm..... the MAP wouldn't be necessary, or even used for alpha-N.... if it was, it would be speed-density.

 

Actually you would use the map for barometric pressure compensation, vented directly to atmosphere so it can measure pressure change. What if you were driving from a valley up over some hills??? And your elevation rose to 3000 ft, hmmmm do you think the fueling would still be correct??? It wouldn't be. Also what are you using to transition from electric to gas? Are you starting and stopping the gas motor everytime during these transitions?

 

It wasn't the EBL that I was thinking of, though I'm sure RBob has ideas on how to run Alpha-N in the C3 type ECM.

I'm interested in how this works, since I'd love to do a hybrid, but with larger motors.

 

me too, thats why i am giving it a try... it probably wont work perfectly, but who cares!

not 100% sure, but ideally, the motor would cut out when the brake is pressed for a certain amount of time, or when the vehicle is coming to a stop. when the gas pedal is hit, the electric motor gets you up to a certain speed (possibly a certain RPM of the gas motor) then the gas motor is turned back on and you continue on your way.

i am thinking that we will need a more powerful starter than you would typically use on a motor that size, in order to get it to fire quickly, but a car starter, even one from a small honda will be more than sufficient IMO

:-)

im excited to go hunting for stuff tomorrow.
wish us luck

 

IMO it would be MUCH easier to use a bigger engine with more cylinders.
Between a governor and control of the tune it would be very easy to reduce the max power output of the engine to match your other equipment.
In fact a governor would be a perfect match for running a very high mechanical compression ratio.

 

Red Dragon get some ideas together on possible engines, load/torque requirements etc. There is just too much guessing going on. Multi cyl engines simplify things but also cause more difficulty also. When the team I was on for the shell eco challenge decided to try a single cylinder diesel in the car we had all sorts of trouble. Mainly shearing and breaking drive train components because the diesel was so lumpy off idle do to the impulse of torque because it was a single cylinder.

What is your budget by the way??

Now gas won't do that. Also you should look at some efi on atv's and motorcycles. That might give you some ideas also. You may want to try to find a forum where guys are tweaking there injected bikes/atvs because they will no doubt be more yourself if you decide to go single cyl. I have 2 suzuki king quad 700 efi single cyl. They are very smooth running engine. If you are thinking about a single you may think about searching your area for a motorcycle/atv engine tuner/builder. Theres a wealth of knowledge in those poeple when it comes the specifics of single cyl engines and dynamics of the cycles.

What I am really saying is that at the end of the day you will have to pick something form your list.
Try to apply it for what you need.
If it doesn't work try again.
You are doing research which is good.
But at some point the rubber needs to meet the road to finalize project direction whether good or bad!!
That is being an Engineer in a nutshell.

Goodluck

 

well we have an engine and electric motor.
the engine is a single cylinder generator motor. we picked it because it is a horizontal shaft motor as opposed to a riding mower which has a horizontal shaft...
i dont know the exact power, but the generator is a pretty hefty unit, so i would guess 8-10 hp is about right.

there was a perfect B&S vertical shaft motor that i really liked that was 15.5 hp and a V-Twin, but again, it was a horizontal shaft motor, and i dont really want to have to fab an oiling system so that it will run on its side...

the electric motor is a 32v 15A DC motor. not sure of the power, but it is pretty hefty.

we snagged some wiring and hoses and such, and i grabbed a nice .065" or so steel sheet to start fabbing an intake!!!

tuesday we are going to go steal some fuel injectors to start tinkering around with them and look at ECM's

i am still a bit worried about the throttle body though.
a progressive linkage will help, but it can only do so much when you are working with an engine that small.

hopefully we can find a GEO METRO or something. maybe a motorcycle...

im still looking to find out how hard it is to use a carburetor as a throttle body.
that might be the best option.


its starting to come together!

 

32V X 15A = 480Watts = .64HP...

 

What type of vehicle are you trying to power with this?
That dc motor is pretty low on power, 1 hp = 748 watts
Watts = Volts * I (current) so 32*15=480 watts. Now thats consumed power by the motor thats not final shaft power. Brushed motors are only in the 40-50% efficiency range. So you get half that at the shaft. I just want to make sure you were aware of this. Keep in mind dc motors are everywhere so if you need to up the power it will be an easy swap.

Now on to the throttle body issue. My own plan for the efi computer for my dirt bike that I am building/programming was to use the existing carb with a small aluminum coupler with a bung welded to it so that I could have a 100% mechanical back up system. If the efi gets damaged I can switch over to the carb and still get to my destination. You can get aluminum tube in all wall thicknesses. Get a single efi bung and have it welded on. Put in inline in front of the slider/butterfly. Just an idea.

Also whats the intake manifold for?

 

acutally, it might be 28 amps now that i think about it.
DOH, i forgot about the 748:1 conversion. haha.
the efficiency should be 85%... i seem to remember that being written on the motor.
its in the shop, which isnt close by, but whatever. its not a big deal. either way, all the stuff was FREE, so i cant complain.
1 hp aint bad.

what i would REALLY like to find is one of those electric lawnmower motors... too bad they are all AC not DC

 

what do you mean "whats the manifold for"...
i am converting the carb setup to fuel injection.
i still have a lot of math to do to figure out the plenum and runner sizes.
question:
do i even need a plenum?
i mean, as far as i know, a plenum is only a 'resivoir' for air to be used from.
with a single cylinder, is it even needed?
if not, my job just got insanely easy lol

 

It would be easy enough to test, using a prepexisting box to put over the inlet trumpet to the throttle body.

I hadn't really thought about the effects of a plenum on a single cylinder. lol

 

I would say a plenum is not necessary. My 700 efi single atvs with efi don't use them for example. Singles with carbs don't use them so I would tend to say no just from history alone. I don't mess with singles really at all but I think you would have seen it by now if it were a benefit. Now here is some food for thought. Every time you have a volume change it takes energy to accelerate the fluid. Air is a fluid with mass. Most likely a plenum will cause issues with fuel distribution/atomization since the velocity will be dropping. Q = mass flow, flow is conserved through the intake, so mass in = mass out. Q= Vel*Area, so if Area increases Vel decreases, then Area decreases Vel increases, you have just spent extra energy moving air across the system. This is why when you really start to get into airflow and port design cross sectional area (csa) is a very important aspect to control as you come up with an initial design for the port along with shape geometry to keep the air where you want it to flow. With certain types of port shapes, very straight through design like motorcycles and F1, you can use computational fluid dynamics (cfd) to model the ports because they become so predictable without all the bends like a gen1 chevy head would have. Enough of my rant on airflow.

Anyway don't change anything, efi doesn't require anything different for the tuning of the intake tract than what the carb needed. Just try to get the injector to spay on the back of the valve to help maintain good atomization and distribution in the airstream.

Just look at generators and performance dirt bikes etc. No plenum in use.

You have got me curious exactly what the build parameters are and the budget. I would like to know a little more about this, it may help also for people to give you better advice. I assume you are in an engineering program, so which one, Mechatronics, mechanical engineering, Electrical, Computer science?

 

sorry, i thought i said already lol
its Mechanical Engineering

ok. my only objection to that is that a carb intake on any small block chevy has no plenum either... with the exception of the tunnel ram with 3 deuces, you have basically all runner.
look at any TBI injection system... no plenum.

the reason for this is that a plenum is a storage reservoir... it stores air.
if you store air AND fuel, you get fuel puddling
as you said, and is also a well known fact, Q=AV. Q remains constant throughout the system, but A and V are more than welcome to change.
in the plenum, A is HUGE, and V is small by comparison.
in the runner, V is large and A is small.

as a result, you have a high 'velocity head' due to the moving column of fluid (air) in the plenum. the high velocity helps push more air into the cylinder. a longer runner helps get more momentum going to help push more air in.

as i said, this is not going to have to be perfect, but i would like it to be close.

my thinking is that i will use a plenum that is equal or slightly larger (1-1.25x) engine displacement.
the reasoning for this is that we already know that there will be a lot of pusations going on in the intake. the computer will have trouble interpreting this, and with a plenum, you have essentially given the air a larger 'mass' to have to accelerate and decelerate.

i disagree.

TBI aside, there is nothing similar between an air gap manifold, which was once the peak of technology, and an LS intake manifold.
nobody uses TBI any more, so it is not a concern of mine
EFI, is the future. LS engines are a great example of this. Ford has a great modular engine (did i really say that)
both have a lot of new thinking. i would like to borrow from this

i havent studied motorcycle engines, but perhaps i should.
i would guess that an engine similar to the big bad 'busa, would use very short runners and a small plenum to make throttle response better.
it doesnt need the low end torque boost of a long runner engine because even at 3000 rpms, it still has enough power to wheelie in just about any gear.

if you look at a EFI metric cruiser, i would imagine you would find an intake similar to a TPI intake.
i mean that it would most likely be a LTR design, and have a relatively large (for the displacement) plenum.
the plenum can get away with being a bit large because the bike is heavy anyway, and the extra torque will be more useful than the extra 1000 rpms that you trade away.

in short, a small plenum gives you razor sharp throttle response, and a large plenum dulls out the throttle response
long runners allow for more air 'momentum' in the runner, but limit the overall top end. short fat runners allow for a high revving engine, but dont give much of a boost in torque, and can severely limit low end torque.


carbs...
there is only 1 EFI dirtbike that i know of.

budget?
HAHAHAHA

well, the max budget, is whatever we can scrounge up.
we are taking freebies and handouts, and hopefully we can start getting some money together to purchase parts that we wont be able to find in a junk yard

one of the group members has access to either of 2 junkyards. one does exclusively cars and trucks, the other is more of a scrap metal yard, and takes in a lot of random crap that will be of use only for the metal it contains.

we got our motor and engine from the scrap yard, and are headed over to the junk yard for some car parts on tuesday.

i am apparently the unofficial leader of the group (it was my project idea)
i have appointed someone to be in charge of getting us money and publicity... hopefully he does his best!

if anyone on here has some stuff laying around that you dont want, and might be of use, let me know... i will gladly pay for shipping and whatever i can afford out of pocket if i think it can help in any way

 

as long as you aren't planning on the injector spraying into the plenum, you can honestly go with whatever size necessary to tune the powerband into a better range(solves the puddling issue). i think grape ape racing had a decent document explaining practical sizing and it's effects on engine performance.

and it seems to me that a larger plenum would help smooth out the vacuum flucuations inherent with a single cylinder engine... IMO anyways.

 

Actually what you are referring to is an airbox plenum resonance tuning and runner wave tuning. Theres alot more involved than just making a long runner and nolting it to an engine to make them work right. And actually all chevy v8 engines have a plenum after the throttle body, all multi cylinder engines that aren't independant runner do!!! TBI's have a plenum, Tunnel rams have a plenum, LS series engines have one, TPI intakes, LT1 intakes, Single Plane intakes have one, the carb sits on top of it. So there are 2 different types of plenums related to where they are in the intake system. Do I need to say more.

You need to be more clear about what you are driving at because there are many different ways to describe something and we all don't think alike.

Actually you can compare the two in many ways. I think you are to quick to judge. They have their purpose and they work all on the same principles. They are radically different in looks, but functioning very similarly.

There are many more than just one dirt bike and atv with efi by the way.

 

i really hope i am not coming off as disrespectful, but i know there is more to it than that.
i have found a lot of good information on how to get close to ideal, but the consensus among DIY'ers is that you use the formulas to get close, and from there, its an iterative process.
i wont be 'iterating'.
in reality, this whole thing doesnt even need to work. its the planning, budgeting, and presenting that really count. if it works as planned, +1, but friends of mine have finished their project class with a B+ and the thing didnt even work AT ALL.

I PERSONALLY want at least my fuel injection setup to work, if for nothing else than my own knowledge.

oh and the motor is actually 75A. i was way off.
that yeilds about 3.2 NET hp, which works out to about 2.5 shaft hp

 

just a small update:
got a center section from a mazda IRS to act as a coupling device between the motor, engine, and output shaft.

on another note, the computer may become an issue.
i dont know anything about honda ECU's but there was literally a pile of Honda ECU's that stood 3 feet tall.
they ranged from 91-2008

just for info's sake, there were a total of 6 4th gen camaros all were LT1's, 1 thirdgen IROC, and 2 thirdgen V6 cars.
one of the 4th gen's is missing a coolant overflow tank.
i just had to snag one while i was there... ;-)

more updates will be coming later.

 

picked up the IRS and i have good news.
the thing uses bolt on axles and a bolt on drive shaft...
ie. no slip joints or splines to worry about
that makes our job so much easier.

we started tearing down the IRS and will have more info on that later.
i got to go home for mothers day... so no more progress for a while.

i promise pics are coming soon