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+--- Thread: the fly-by-wire "throttle" project thread (/showthread.php?tid=1029)
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RE: the fly-by-wire "throttle" project thread - Kozuka - 01-30-2010
and for us humans who hate every interation of C for various (mine is a long list haha) reasons can use Ruby + RAD http://rad.rubyforge.org/ which will prevent you from going bald, having a distaste in women, and accumulating the leaning tower of mountain dew cans.
Keep up the good work cell, you make me want to go out and try out this stuff for myself.
RE: the fly-by-wire "throttle" project thread - Rudolf_Diesel - 01-31-2010
Haven't read entire thread, but hopefully this hasn't been repeated and is relevent...My Ford Powerstorke is fly by wire, albiet the throttle signal is contoling the injectors and not an injection pump, but throttle response is instant - that takes a little fine tuning on the IVS switch and TPS relationship. It seems to work for ford.
I may not consider using such a system for my vehicle, but I have to give someone a lot of credit for tryingto make an improvement on these vehicles that may evolve into something more useful down the road.
Keep up the good work and don't let anyone discourage you!
RE: the fly-by-wire "throttle" project thread - GREASY_BEAST - 01-31-2010
Thanks a lot Cell for all the great info!! The cruise actuator I am talking about is not the awful vacuum contraption you are thinking of. It is some sort of analog electronic device I found on my 1984 300TD and a parts car of the same vintage. I believe it has a position sensor built in. A picture of it can be found here.
Kozuka, I really like the simplicity of C++, and the control it gives. Unfortunately I don't know it that well, but I'm working on it. I am not balding, love women, hate mountain dew (unless its the kind warm from the still and lit by the moon
).Rudolf_Diesel's mention of instant throttle response gave me an idea for another feature to implement. When the throttle is depressed, have the rack "jump forward" for some duration then return to the position called for by the pedal sensor, that is, make the actuator surge to give a little extra hit of fuel before retracting to the position indicated by the pedal sensor. This will spool the turbo quicker, resulting in faster throttle response at any rpm. The amount and/or duration of the "surge" would be a function of rpm, boost, and throttle position. The inclusion of boost as an input would allow for smoke limitation. As always, two modes could be implemented: smoke free, as well as a performance mode with no attention paid to smoke output.
RE: the fly-by-wire "throttle" project thread - Kozuka - 01-31-2010
Well I lied. RAD generates Arduino C++ code but ruby man is awsome but I guess that means you can always edit it.
def func(int,string,float,whatever)
if int == 1
puts string + ' ' + float.to_s
return whatever
else
puts 'Error'
end
end
output = func(1,'The Float Is ', 0.75, 'awsome')
puts output
Try that in C++, ruby is where simplicity is at.
RE: the fly-by-wire "throttle" project thread - GREASY_BEAST - 01-31-2010
I think we may have conflicting definitions of "simple".
RE: the fly-by-wire "throttle" project thread - 300SD81 - 01-31-2010
I'm using Microchip's PIC microcontrollers instead of Amtel chips so I'm stuck with C, no C++ avaliable. I can get used to it though, haven't felt like I needed any C++ features since I've started working with micros... Theres always assembly too
which I've started porting some of my interrupt and timing code to.
RE: the fly-by-wire "throttle" project thread - cell - 02-05-2010
parts are starting to pile up...
![[Image: parts-piling-up.jpg]](http://jason.pepas.com/images/parts-piling-up.jpg)
RE: the fly-by-wire "throttle" project thread - GREASY_BEAST - 02-06-2010
Very cool. What are all the sensors on each side of the IC?
RE: the fly-by-wire "throttle" project thread - Rudolf_Diesel - 02-06-2010
They look like thermocouples - temp gauges I would guess.
RE: the fly-by-wire "throttle" project thread - cell - 02-06-2010
(02-06-2010, 05:10 PM)Rudolf_Diesel They look like thermocouples - temp gauges I would guess.
yup. I'll have pressure sensors as well (eventually).
RE: the fly-by-wire "throttle" project thread - GREASY_BEAST - 02-06-2010
So I've been looking at actuators.. I found some throttle body actuators listed on ebay for ~$25. Using a part like this certainly fits the criteria of being able to get one at any auto parts store or junkyard. My question is, will this be fast enough and precise enough to maintain idle speed? Idle speed control seems like the application where rack control is most sensitive, as well as where the fastest corrections need to be made. Another option would be to cannibalize the correct part from an electronically controlled diesel IP. Possibly expensive.
The cruise servo is another option, but I don't know anything about it and its listed as NLA from mercedesshop.
RE: the fly-by-wire "throttle" project thread - cell - 02-08-2010
(02-06-2010, 09:19 PM)GREASY_BEAST So I've been looking at actuators.. I found some throttle body actuators listed on ebay for ~$25. Using a part like this certainly fits the criteria of being able to get one at any auto parts store or junkyard. My question is, will this be fast enough and precise enough to maintain idle speed? Idle speed control seems like the application where rack control is most sensitive, as well as where the fastest corrections need to be made. Another option would be to cannibalize the correct part from an electronically controlled diesel IP. Possibly expensive.
The cruise servo is another option, but I don't know anything about it and its listed as NLA from mercedesshop.
Hey that's an idea I hadn't thought of. It looks like the BMW ones are the most common on eBay and several are listed for $50.
RE: the fly-by-wire "throttle" project thread - Tymbrymi - 02-08-2010
The good thing about stuff like the cruise control and throttle actuators is that they have safeties. ie, the default, no power state is 'off'.
The problem is that you'll have to build an h-bridge motor drive circuit since most of the actuators contain only the motor with no control logic.
RE: the fly-by-wire "throttle" project thread - GREASY_BEAST - 02-08-2010
The big question is how fast do these things need to respond to control the rack quickly and precisely enough for idle governing? This could severely limit the choice of actuator. I imagine this is something that will have to be found out by trial and error, but if that's the case, they better be cheap errors!
EDIT: The expensive trial/error cycle could be completely bypassed by using the right part. Check out the thing on the back of this P-Pump. Also look at this picture. I bet one of these governors could be adapted to the MW with a really simple adapter plate.
RE: the fly-by-wire "throttle" project thread - cell - 02-09-2010
my w115 intake arrived today. thanks forced!
![[Image: w115-intake-60mm.jpg]](http://jason.pepas.com/images/w115-intake-60mm.jpg)
great pics of that governor greasy, thanks!
RE: the fly-by-wire "throttle" project thread - winmutt - 02-12-2010
I spy harbor freight tools!
RE: the fly-by-wire "throttle" project thread - Nick - 02-18-2010
(02-12-2010, 07:32 PM)winmutt I spy harbor freight tools!
LMFAO! great thread so far!
RE: the fly-by-wire "throttle" project thread - cell - 02-19-2010
(02-12-2010, 07:32 PM)winmutt I spy harbor freight tools!
guilty as charged
no updates in a while -- I'm taking the second analog circuits course this semester (I'm a UT employee -- we get a free course per semester), and its requiring a lot more time than I had anticipated.
also, in order to mount the intercooler, I'm going to need to modify the "radiator bulkhead" portion of my front bodywork (core support?). actually, I'm planning to eventually do a tilting "front clip" to make it easier to work on the engine, and this would be the perfect time to do that. here's an idea of what I'm talking about:
![[Image: tilting-front-clip-46-ford.jpg]](http://jason.pepas.com/images/tilting-front-clip-46-ford.jpg)
edit: ooh, video of a tilting front clip. and its electric! http://www.youtube.com/watch?v=JEwNG1P65Og
all of that means I'm probably looking at 6 months+ before I'm actually using this new-fangled turbo and have fly-by-wire.
RE: the fly-by-wire "throttle" project thread - Alastair E - 03-11-2010
Looked over the idea, and to be honest, I cant see why you're doing it....
Electronics are all very well, as I should know, It used to be my profession!
Better way forward would be to Common-Rail the 617 and do it properly!
RE: the fly-by-wire "throttle" project thread - winmutt - 03-11-2010
If he was able to control the rack I could see a point. Otherwise its just a fun project.
RE: the fly-by-wire "throttle" project thread - Alastair E - 03-11-2010
(03-11-2010, 02:38 PM)winmutt If he was able to control the rack I could see a point. Otherwise its just a fun project.
Well, Thats the whole thing innit....
The rack/plunger fuel output is Not constant anyway. It Varies with plunger-speed for a set rack position, so That will have to be accounted for or it'll be a nightmare!
Nah, If I was gonna attempt summit like this, I would go Common-rail, as you have Much more control options, even Pilot Injection etc....
RE: the fly-by-wire "throttle" project thread - Kiwibacon - 03-11-2010
(03-11-2010, 02:57 PM)Alastair E Nah, If I was gonna attempt summit like this, I would go Common-rail, as you have Much more control options, even Pilot Injection etc....
You'd have to start with a direct injection engine, then you'd have to engineer a lot of parts to handle some rather high pressures. It's not something that many people would have the resources to pull off. If you had a quarter of a million bucks to burn maybe.
RE: the fly-by-wire "throttle" project thread - ForcedInduction - 03-11-2010
Common rail does not need to be direct injection.
RE: the fly-by-wire "throttle" project thread - cell - 03-11-2010
(03-11-2010, 02:34 PM)Alastair E I cant see why you're doing it....
I spend most of my free time doing things to learn how to do them, rather than to achieve an end result.
RE: the fly-by-wire "throttle" project thread - Alastair E - 03-12-2010
Ah, Fair enough!
Nothing like Doing to learn about summit!
With regards Common rail, FI is quite right, Doesnt HAVE to be Direct Injection,--Why do you think it Has to be? (Maybe to get the full benefit, then yes, DI would be the compliment to CR system.....)
--CR fuel-system, is after all, Just another type of fuel-system, allbeit more complicated with its own unique issues such as the extreme pressures etc.
Issues as I see them for a C.R. 617 would be the actual Injectors, But with a good machine-shop and using existing CR injectors as donor devices a Hybrid injector could be made up I'm sure.........
ECU could be severely modded 'Mega-Squirt' (Yes, I know its a gasser system, but you'll need summit that you can alter parameters reasonably easily, and Bosch aint forthcoming with such software!)
-- pump, rail, pipework can be kulled from summit I'm sure, Sensors are no prob, loads around to choose from! (At least here in U.K. we got Loads of CR systems in bone-yards, so parts are not too much of an issue....)
RE: the fly-by-wire "throttle" project thread - Kiwibacon - 03-13-2010
(03-12-2010, 06:33 AM)GREASY_BEAST 3) Kiwibacon, I doubt it's a quarter mil. I'd guess about 10k would do it if you were careful. $4000 worth of injectors + pump + controls. Then there would be the problem of getting it to run...
Quarter of a million if you wanted to develop your own head, valve train etc to convert an old idi motor to direct injection common rail.
Common rail does need to be direct injection to work properly, you can't run multiple injections with a precombustion chamber, you'd just be making smoke by dumping fuel at the wrong times into a precombustion chamber without air being forced in at the right time.
If you're not running multiple injections, there is no point to common rail. Stick with an electronic plunger pump.
If you want to take a direct injection motor and convert to commonrail, the bosch motorsport commonrail ecu is about $EU7000,
http://www.bosch-motorsport.com/pdf/ecus/diesel/MS_15.1.pdf
without all the necessary parts, like a commonrail to fit your engine layout and withstand the necessary pressures, injector lines to fit your engine layout and withstand the necessary pressures, injectors themselves (you may get lucky and find some that fit). These parts need to be custom engineered unless you can find some that fit exactly off a production engine. The costs for that will scare you. This is not home machine-shop stuff, a fuel leak can blow through your skin, enter your bloodstream and kill you.
I'd say $US25k minimum. Compared to maybe $US5k plus time to buy a wrecked vehicle and take the engine/ecu/harness and make it fit.
So aside from looking at the commonrail nightmare through rose tinted glasses, the electronically controlled mechanical pump is a worthy goal.
RE: the fly-by-wire "throttle" project thread - Alastair E - 03-13-2010
Bosch VP37 type I.P. for just making it electronic, be the most straightforward way, Fuelling by electric actuator and timing control by solenoid PWM There's a actuator position sensor and even a fuel temp sensor all bundled in there to add to the merryment!...
IF --and I dont actually plan to--I was common-railing, a proper crank-angle-sensor mounted in bell-housing with the appropriate magnets on flywheel would sense accurately enough--Its how the CR systems Ive seen get crank position...
--You would Have to add a Cam position sensor too, so the ECU 'Knows' what cyl. is on firing-stroke too
As to injectors, I seem to remember a 'KCA' type C.R. holder on some older Peugeot engine, Screwed in similar to M.B. engine, and as I recall, had a DNOxx.xxxx 'type' nozzle....
--This is getting me interested now.....
As to cost, the motorsport ECU may be available,--But like everything thats a little out of the ordinary, I doubt if its easy to get here in UK, and you can Guarantee it would cost not 7000 Dollars, but 9000 Pounds!!!
I disagree on the idea of the CR being no benefit and just make smoke when using Pilot-Injection etc, All parameters are adjustable, and you're able to inject fuel at ANY time during the full four cycles --Thats how these newer things clean their DPF's--They Inject Fuel On the Exhaust Stroke, Therefore, It could be fully taylored to the old and venerable 617 I'm certain!!
RE: the fly-by-wire "throttle" project thread - Kiwibacon - 03-13-2010
Where do you find common rail parts (indeed even the rail itself) rated to 26,000psi? Remember that's everything from the high pressure pump to the injectors.
Can your home-built controller work with the millisecond calculations and switching required?
Sure you can build a 1930's era commonrail system at home running very low injection pressure into an idi engine. But it will be a big backwards step over a normal idi diesel.
Remember the commonrail is one of the oldest injection systems tried, but it only became a realistic alternative to fully mechanical pumps about 15 years ago.
The "commonrail" systems which use engine oil aren't commonrail. They're unit injection.
RE: the fly-by-wire "throttle" project thread - Alastair E - 03-13-2010
Getting parts rated for the CR system pressures is easy. Just use proper C.R. system components from junkers....!
As to calculation speeds etc, The Mega-Squirt seems to manage reasonably well, as its doing basically the exact same thing on a Gasser engine....
RE: the fly-by-wire "throttle" project thread - Kiwibacon - 03-13-2010
(03-13-2010, 08:36 AM)GREASY_BEAST(03-13-2010, 07:48 AM)Kiwibacon Where do you find common rail parts (indeed even the rail itself) rated to 26,000psi? Remember that's everything from the high pressure pump to the injectors.
Can your home-built controller work with the millisecond calculations and switching required?
Computer's are computers the world 'round. I doubt the ECU of a common rail engine is any more powerful than your average PC, in fact, I'd be willing to bet its a lot slower. The code running on these things is dead simple. All the "long" calculations (thermodynamics, hell even the trig functions if it matters) can be done beforehand and stored in a binary search tree or some other method for quick access.
As for a rail which holds 26000psi, get a piece of pipe that's rated for it, thread a plug in one end, weld 5 fittings on it (do a good job, obviously), and call it done. What's the problem? If the welding is too scary, then just get a really thick tube, thread everything, and weld it to boot.
Hideously expensive industrial PLC's can't respond fast enough for diesel injection so I can't see anything easy or cheap doing the job well enough.
As for pipe rated to 26,000psi. There is none. Take a look through a standard pipe pressure rating table like this one. The best you'll find is about 10-20% of the needed pressure.
http://www.engineeringtoolbox.com/a106-carbon-steel-pipes-d_370.html
Welding commonrails together or welding on extra ports. Nope, you can't do that either. You cannot get welds strong enough or able to handle the continual pulsation.
26,000psi fittings. Again there are none commonly available.
Scrounge existing parts. Sure if they fit. But you can't even rebend injector lines for that pressure without risking them cracking.
RE: the fly-by-wire "throttle" project thread - Alastair E - 03-14-2010
Forced, Any chance of splitting off the CR discussion from the O/P thread, as its distracting the O/P subject somewhat...
As to speed in the ECU/Controller, IF you're saying it cant be done, Then--How is it done in the millions of CR systems running all round the world!??
Rail aint no issues or the HP pipes, We've been making up replacement pipes over here for years!
As to rail, Get a 6 Pot rail, and block off one of its ports, Simples!
Always ways and means if you think about it and Look as to whats available either S/H or new components...
RE: the fly-by-wire "throttle" project thread - Kiwibacon - 03-14-2010
(03-14-2010, 04:12 AM)Alastair E Forced, Any chance of splitting off the CR discussion from the O/P thread, as its distracting the O/P subject somewhat...
Good idea, looks like a popular topic.
(03-14-2010, 04:12 AM)Alastair E As to speed in the ECU/Controller, IF you're saying it cant be done, Then--How is it done in the millions of CR systems running all round the world!??
Rail aint no issues or the HP pipes, We've been making up replacement pipes over here for years!
As to rail, Get a 6 Pot rail, and block off one of its ports, Simples!
Always ways and means if you think about it and Look as to whats available either S/H or new components...
The controllers are dedicated to commonrail engines and designed for the purpose. I'm not saying it can't be done, I'm saying it can't be done at home unless you're an electronics engineer.
You personally make injector pipes or other people in the UK? Once again it's not that they can't be done, it's simply beyond the resources most people have at their disposal.
Regarding a scavenged common rail, I mentioned that earlier. 5 cylinder commonrail diesels are quite common in european commercials and even cars. VW, Volvo, Fiat/Alfa, MB etc have all done them.
But by the time you're taking a whole heap of parts of one of those engines, why not just use the whole engine and get a far better result? I know you guys love your old MB engines, but the reality is they have been surpassed in every area, particularly fuel economy and performance.
RE: the fly-by-wire "throttle" project thread - Alastair E - 03-14-2010
(03-14-2010, 07:12 AM)Kiwibacon(03-14-2010, 04:12 AM)Alastair E Forced, Any chance of splitting off the CR discussion from the O/P thread, as its distracting the O/P subject somewhat...
Good idea, looks like a popular topic.
(03-14-2010, 04:12 AM)Alastair E As to speed in the ECU/Controller, IF you're saying it cant be done, Then--How is it done in the millions of CR systems running all round the world!??
Rail aint no issues or the HP pipes, We've been making up replacement pipes over here for years!
As to rail, Get a 6 Pot rail, and block off one of its ports, Simples!
Always ways and means if you think about it and Look as to whats available either S/H or new components...
The controllers are dedicated to commonrail engines and designed for the purpose. I'm not saying it can't be done, I'm saying it can't be done at home unless you're an electronics engineer.
You personally make injector pipes or other people in the UK? Once again it's not that they can't be done, it's simply beyond the resources most people have at their disposal.
Regarding a scavenged common rail, I mentioned that earlier. 5 cylinder commonrail diesels are quite common in european commercials and even cars. VW, Volvo, Fiat/Alfa, MB etc have all done them.
But by the time you're taking a whole heap of parts of one of those engines, why not just use the whole engine and get a far better result? I know you guys love your old MB engines, but the reality is they have been surpassed in every area, particularly fuel economy and performance.
For my sins, I do happen to be an electronics engineer, but havent been in the game for a few years, Things have moved on somewhat from the devices I used 10 years ago, Speed, efficiency and power-ratings of devices has improved 100 fold since then!
As to Why to 'update' a 617, well, -we do love the old beast, but in comparison to a newer engine, it is low in power, high in emissions and rather inefficient in economy--But it'll still be running when all those shiny new mega-efficient engines have boiled into destruction!--Bit like an old Flat-Head!
Pretty sure that economy and power gains can be had from the use of a more precise fuel system on the older engine, without sacrificing its longevity...
No, I dont personally make up new CR pipes, but they can be made by various Co's here in the UK. I have made up 'standard' H.P. pipes though...
You can send in a broken or pattern pipe to these specialists and get a new one pre-bent to match, with all the correct fittings on the ends....
C.R. pipes should ever only be used Once--Allegedly! --If you remove it, you chuck it,--But I guess that doesn't happen all the time!
RE: the fly-by-wire "throttle" project thread - ForcedInduction - 03-16-2010
At 5,500rpm the engine is rotating 91rps, 229 injection events per second for 5 cylinders. I don't see it taking much (modern) CPU power to do a pilot and primary injection accurately. Now trying to control a 5 injection piezo system, that might be a different story.
Bosch sells stand alone common rail ECMs, From $4100 for basic solenoid injectors to $8200+ for piezo injectors.
http://www.bosch-motorsport.com/content/language2/html/3690.htm
RE: the fly-by-wire "throttle" project thread - 300SD81 - 03-17-2010
I'd have no problems timing those injections on the 80MHz PIC32.. If you have 5 crank sensors driving an interrupt on the controller for each cylinder, you can potentially time things down to one clock cycle in assembly code fairly easily. Actually driving the piezos shouldn't require much more than a high speed MOSFET (switching times in the nanoseconds).
I'd love to see someone attempt a system on the 617... The hard part from my perspective is actually getting the parts made, not the control of them. I'm having the same issue with the turbo..control system is functional, but the closest thing I have to connecting it to the car is a blank piece of 1in steel...
RE: the fly-by-wire "throttle" project thread - ForcedInduction - 03-17-2010
Right, I don't see recycling the stock injectors with just an inline solenoid as any advantage over the inline pump. That means R&D and building several different test sets of IDI common rail injectors, that would make the control system look as cheap as picking up a "day laborer" from Home Depot.
Just imagine how empty the engine bay would look with just a CP3 in place of the injection pump.
RE: the fly-by-wire "throttle" project thread - ForcedInduction - 03-17-2010
(03-17-2010, 02:50 PM)GREASY_BEAST Why make several sets of injectors?Since its never been done by anyone in the world, it would be a safe bet that the first set won't work quite right and at least one more set would be produced to "polish" the design. Even multi-million dollar R&D teams rarely get a design perfect from the first attempt.
RE: the fly-by-wire "throttle" project thread - Kiwibacon - 03-18-2010
(03-17-2010, 02:50 PM)GREASY_BEAST Why make several sets of injectors? I agree, trying to use the stock injectors would be folly, but a swirl chamber that goes in place of the pre-chamber should work great, and you could design everything around some existing, cheap, and easy to source injectors. Build everything in a CAD environment with fluid mechanics software and you can make sure everything works before any metal is cut. The only investment is time spent in front of a computer, and a bit of a learning curve.
You've just described about 3 years of full-time design work.
Remember, ontop of getting great flow geometry are considerations like manufacturability (can it be built), strength of the final design, optimal amounts of swirl etc.
Addressing each of those will take you a long time. That's once you've got the necessary software and enough computer grunt to run it.
Just to put it into perspective, if you want to model up a simple pipe (say an exhaust with some bends) and model flow through that, it'll take half a day.
Regarding processor speeds.
Can your processor run completely through the program and modify all necessary parameters (i.e. monitor every sensor and recalcuate everything needed) in a microsecond?
I think the electronically controlled mechanical pump on an IDI engine makes sense. Trying to convert an old IDI engine to commonrail doesn't make sense on any level.
RE: the fly-by-wire "throttle" project thread - 300SD81 - 03-18-2010
For calculation speeds, I believe someone has a port of openfoam that uses your GPU to do calculations, about a 10-50x improvement over using the CPU...and additional GPUs are relatively cheap compared to multiprocessor systems...
RE: the fly-by-wire "throttle" project thread - Kiwibacon - 03-19-2010
(03-18-2010, 08:55 AM)300SD81 For calculation speeds, I believe someone has a port of openfoam that uses your GPU to do calculations, about a 10-50x improvement over using the CPU...and additional GPUs are relatively cheap compared to multiprocessor systems...
I've never used openfoam, but I believe you can run it across multiple computers.
Your GPU is nothing compared to half a dozen or more computers all grinding away.
You could only do this without spending thousands if you want to pay yourself less than 50c/hr. Even decent CAD software will cost you thousands, thousands more for a computer to run it at a useful speed. Gaming systems are no use for CAD. My almost three year old CAD laptop is faster than a mates "no holds barred" desktop built to gaming spec when running the same solidworks models.
BTW the years it will take is not the years of computers grinding away on analysis. It's the years of actual engineering design and brainpower. People who don't do this tend to underestimate the time and brainpower required. But this is what I do for a living. I'm a mechanical design engineer.
RE: the fly-by-wire "throttle" project thread - Kiwibacon - 03-19-2010
(03-19-2010, 05:23 PM)GREASY_BEAST The CAD models involved in something like this aren't a big deal (computationally). In the SolidWorks it would just be a piston, cylinder, and head/valve geometry. 5 parts total, I think the average laptop could swing it! While these models might take quite some time to get right (lots of complex organic curves), there are only 3 moving and 2 stationary parts to model.
At one point I thought I wanted to be an engineer (mechanical) but realized that physics was way more fun for me, so I am now a physics/math undergrad, but I still think engineering is cool and may pursue it as a career later. I have played with SolidWorks and Pro/E a bit, but as I understand it they aren't great for the fluid dynamics calculations that a swirl chamber design would require. I appreciate your experience KiwiBacon, and I am not trying to step on your toes. In "estimating" the costs of this project a I wasn't factoring in getting "paid" at all for my time, its more of something fun that I would do in my "free" time. If you had to assign a monetary value to the time spent on something like this it would be unconscionably expensive. I hope my naivety isn't too frustrating
I appreciate that you weren't going to factor in being paid. Otherwise this project would be headed straight towards 6 figures. I put in the reference to being paid under a dollar an hour just to underscore how much work is in it.
I've been using solidworks for 11 years this year, which is one of the reasons why I think you're underestimating the work. Solidworks is also terrible at modelling the surfaces you'd need for port shapes. Sure it can do it, but it'll tax the computer and you far more than you'd ever believe. You can also run solidworks on pretty much any computer, but you get sick of waiting in between mouse-clicks.
Here's an example of some engine parts I've done on solidworks:
![[Image: rrchassis.gif]](http://users.actrix.co.nz/dougal.ellen//images/rrchassis.gif)
BTW I'm also a big physics fan. But I became an engineer so I could build more stuff and ultimately be paid for it. There was a lot of competition at my university between physics and engineering. All the engineering students start with a year of maths, physics and chemistry. Those three departments try their hardest to siphon off all the best students to their own departments. In the physics dept they take the top students for special tours to show them the lasers and other cool stuff.
RE: the fly-by-wire "throttle" project thread - Kiwibacon - 03-22-2010
(03-20-2010, 12:25 PM)GREASY_BEAST That's a pretty cool model. What's the parts count?
Are you aware of any free/open source CAD packages that are worth a damn? BRL-CAD is one I hear about occasionally, but I've never tried it out. My student copy of Solidworks has expired, and I'm not about to pay $90 or whatever it is for another one. Its FOSS from here on (ha).
I was just browsing some of the OpenFOAM documentation and they have a few standard solvers for diesel engine spray and combustion. The more I read about this package the better it seems.. it solves everything from the Black-Scholes Equations and electrostatics equations to compressible flows and engines..
The parts count looks pretty horrendous. But when you consider it includes right down to the internal parts of the turbos it's not that bad. There's more in it now than that picture above shows. The only parts not modelled by me from scratch are the ball bearings and fasteners.
483 parts total.
153 unique parts.
The feedback on openfoam is quite impressive, but I've never had the chance to use it. As far as free CAD. Alibre has free versions and quite cheap versions but I've never used it. I think the free version can only do parts and not assemblies.
RE: the fly-by-wire "throttle" project thread - Tymbrymi - 03-25-2010
(03-12-2010, 03:27 PM)Alastair E ECU could be severely modded 'Mega-Squirt' (Yes, I know its a gasser system, but you'll need summit that you can alter parameters reasonably easily, and Bosch aint forthcoming with such software!)
I really really doubt it... the precision of the injection events is much higher with a diesel.
(03-13-2010, 04:27 AM)Kiwibacon Common rail does need to be direct injection to work properly, you can't run multiple injections with a precombustion chamber
Common rail is simply a means of controlling the fuel injected. An IDI engine does not need pilot injections since the pre-chamber design performs the function of a pilot injection (minimize noise and change in cylinder pressure). An IDI common rail would only need a single injection event.
(03-13-2010, 04:27 AM)Kiwibacon If you're not running multiple injections, there is no point to common rail.
Nope! You get dynamic control of timing, individual cylinder fuel balancing, overall higher injection rates, slightly adjustable injection rates (you can vary the rail pressure), and the injection rate profile is MUCH better. You don't have a slow ramp-up and ramp-down as you do with a plunger based system... it is much closer to a square wave.
(03-13-2010, 05:19 AM)GREASY_BEAST You could make an "adapter" out of a stock pre-chamber using just a lathe which would allow you to install an injector.
The problem with this is all the CR injectors are for DI engines... so the spray pattern is completely wrong.
(03-13-2010, 05:19 AM)GREASY_BEAST But I still claim the real problem is knowing the angular position of the crank. Could the solution be as simple as just adding more metal "bumps" to the crank balancer for the stock rpm sensor to pick up? If not, this might not be a home-shop project.
On the OM60x engines (well, maybe not my 606... need to do some testing), there is a variable reluctance sensor on the flywheel. I have personally verified with a scope on a '92 300D 2.5t that there are 150 pulses per a single rotation of the engine. I imagine that is as good as you're going to get!!
(03-14-2010, 04:12 AM)Alastair E Forced, Any chance of splitting off the CR discussion from the O/P thread, as its distracting the O/P subject somewhat...
x2
(03-17-2010, 12:11 AM)GREASY_BEAST Now I don't know what exactly is required to drive a piezo injector, but I can't believe its very complicated..
ROTFL!!!! The drive requirements of a standard solenoid based injector are crazy. There is a two stage driver circuit where you have an initially very high voltage and current applied to the injector, and then there is a constant "hold current" to keep it open. The voltage spikes caused by quickly switching the inductances involved are also pretty intense. I don't know exactly the drive needed for a piezo injector, but the timing and power requirements aren't going to make it a simple affair!
RE: the fly-by-wire "throttle" project thread - Tymbrymi - 03-26-2010
(03-25-2010, 09:57 PM)GREASY_BEAST As for the "multiple injection pulses won't do anything" argument... There's a reason for that little hole in the center of the DN0SD240 nozzles. Same concept is at play with the flat cut on the DN0SD265's.
Keep in mind, you'll still see the "throttling" effects of those designs even on the second injection.
(03-25-2010, 09:57 PM)GREASY_BEAST It doesn't seem to me that there should really be a big problem with multiple injections in the pre-chamber..
I don't forsee any problems from having multiple injection events, I just don't see any benefit. Also, I don't think we can realistically (all being relative here!) design our own injector that can do multiple events. A co-worker and I have come up with a plan for making a common rail injector by modifying our existing injectors, but are years away from pursuing any more than the initial pilot valve testing we've done.
Check out the pilot valve action of some of the common rail injectors...
RE: the fly-by-wire "throttle" project thread - Tymbrymi - 03-29-2010
(03-27-2010, 12:26 PM)GREASY_BEAST Would love to hear about it.
We're being bastards about it and waiting until we have something that works until we talk about it. Sorry...
RE: the fly-by-wire "throttle" project thread - RonB - 04-04-2011
I watched the video and you basically just going to control the injection pump throttle lever with a servo?
i have thought about this concept before ,but for my MFI equipped 300SEL 6.3 mercedes. it has a bosch PES pump with a governor which looks like a Diesel governor but with a 3 dimensional cam which controls the rack. This is OK until the wear in the minute linkages within starts causing running problems like too much fuel etc etc.
My thoughts lead to getting rid of the governor completely and using a flyby wire device connected directly to the end of the rack to control it.
This where i believe you should be heading to as you aren't actually doing anything to control the engine that is different apart from just revving it up.
If a fuel/air ratio reader was incorporated which can also correlate the engine temp and speed of the car compared to the throttle position the rack would be adjusted automatically to provide the correct amount of fuel as required, while allowing for cold running ,starting etc.
This what the mechanical device in the PES pump does already.
With your device you are really still at the mercy of the governor control.
RE: the fly-by-wire "throttle" project thread - tomnik - 04-05-2011
Hi Ron,
check this out for your 6.3:
www.lambdacontrol.com
Tom
(04-04-2011, 05:29 PM)RonB I watched the video and you basically just going to control the injection pump throttle lever with a servo?
i have thought about this concept before ,but for my MFI equipped 300SEL 6.3 mercedes. it has a bosch PES pump with a governor which looks like a Diesel governor but with a 3 dimensional cam which controls the rack. This is OK until the wear in the minute linkages within starts causing running problems like too much fuel etc etc.
My thoughts lead to getting rid of the governor completely and using a flyby wire device connected directly to the end of the rack to control it.
This where i believe you should be heading to as you aren't actually doing anything to control the engine that is different apart from just revving it up.
If a fuel/air ratio reader was incorporated which can also correlate the engine temp and speed of the car compared to the throttle position the rack would be adjusted automatically to provide the correct amount of fuel as required, while allowing for cold running ,starting etc.
This what the mechanical device in the PES pump does already.
With your device you are really still at the mercy of the governor control.
RE: the fly-by-wire "throttle" project thread - RonB - 04-05-2011
(04-05-2011, 04:29 AM)tomnik Hi Ron,Perfect ,Danke Shoen!!!!!! i will email them for costs etc immediately. Saves me rebuilding the governor. A job I have been putting off for months.LOL!
check this out for your 6.3:
www.lambdacontrol.com
Tom
(04-04-2011, 05:29 PM)RonB I watched the video and you basically just going to control the injection pump throttle lever with a servo?
i have thought about this concept before ,but for my MFI equipped 300SEL 6.3 mercedes. it has a bosch PES pump with a governor which looks like a Diesel governor but with a 3 dimensional cam which controls the rack. This is OK until the wear in the minute linkages within starts causing running problems like too much fuel etc etc.
My thoughts lead to getting rid of the governor completely and using a flyby wire device connected directly to the end of the rack to control it.
This where i believe you should be heading to as you aren't actually doing anything to control the engine that is different apart from just revving it up.
If a fuel/air ratio reader was incorporated which can also correlate the engine temp and speed of the car compared to the throttle position the rack would be adjusted automatically to provide the correct amount of fuel as required, while allowing for cold running ,starting etc.
This what the mechanical device in the PES pump does already.
With your device you are really still at the mercy of the governor control.