Aftermarket Fuel Injection
Aftermarket Fuel Injection
(OP)
Does anyone have experience with after market Fuel injection systems, " Megasquirt " in particular. There is a huge presence on the web about the system, but is seems very disorganized. Having 'inherited' a system, ( basically a box of components ) when I purchased a rebuild project, I'm wondering if I should not acquire the oem harness & ecu, rather then reinvent the wheel. The engine is a 4AG 20 valve Toyota "silvertop". I am not as interested in wringing the last bit of power out of the engine, as I am in driveability.
Thanks in advance for any insight.
Thanks in advance for any insight.





RE: Aftermarket Fuel Injection
The functionality of aftermarket EFI is abysmal when compared to OEM in terms of driveability.
Yes an aftermarket system will allow you to re-map just about everything but it will not be nearly as 'well mapped' as the OEM system. Furthermore the transient behaviour (driveability) of most aftermarket system is well behind that of the OEM systems.
MS
RE: Aftermarket Fuel Injection
In some common applications (SB chevy) there is a large enough installed base that the fuel maps and such have been largely figured out. Also, where no OEM injection system is available, the megasquirt is a nice alternative to other (and much more expensive) EFI kits.
RE: Aftermarket Fuel Injection
thanks for your responses.
regards, steve
RE: Aftermarket Fuel Injection
They were sold new in only japan and south africa I believe, but due to the sale of used japanese imports are very common in NZ.
If you need some info on the silvertop or a source of parts google toyspeed. Its a NZ toyota club and has a couple of toyota parts guys that are quite helpful. Only problem with getting parts from here is going to be the cost of the freight.
The blacktop is a nicer engine, they just tend to throw rods out the side of the block if abused. Easiest fix is silvertop rods.
HTH
RE: Aftermarket Fuel Injection
RE: Aftermarket Fuel Injection
This was our EFI Turbo briggs, it used MSI and you can see in the video we just adjusted the fuel table with the laptop while the engine was underload.
http:
http:
We are also putting a MiniMS on our 240sx, so clearly I recommend it but thats just me.
RE: Aftermarket Fuel Injection
That a megasquirt system can be 'tuned' is not in debate. The system is more than capable of running an engine, the point is that the driveability will undoubtedly suffer.
The MS system is far and away less developed than an OEM system and also lacks the same level of functionality.
MS
RE: Aftermarket Fuel Injection
RE: Aftermarket Fuel Injection
RE: Aftermarket Fuel Injection
No, in all seriousness I dispute what you are saying. There is a huge difference in what some people refer to as acceptable and there are an awful lot of people who will notice the difference.
Whilst emissions are very important they are not the be all and end all of an OEM controller.
Any aftermarket FIE system will 'operate' the engine but it is the hours spent in function development and calibration time that you just cannot replicate with these systems (as well as the actual capability of the system itself).
Not only that but there are a huge amount of noise factors that the backstreet tuner just cannot eradicate/control that the OEM calibrator will during the calibration development.
MS
RE: Aftermarket Fuel Injection
In this case I would certainly use the MS rather than import and ecu adn flapper door air flow meter. The latter are dreadful and prone to failure.
RE: Aftermarket Fuel Injection
I agree.
If you stray away from the original OEM hardware set up then your calibration is wrong and an aftermarket system is required. That is why I guffaw at all of these aftermarket tuning products that promise the earth a deliver 9 tenths of sod all.....Without a remap most are a complete waste of time.
Whilst I have no direct experience with the MS system I hear that it is quite competent and user friendly. If I were, god forbid, calibrating aftermarket systems then it would be one I might look at.
MS
RE: Aftermarket Fuel Injection
Norm
RE: Aftermarket Fuel Injection
ALL of the current OEM's now use fuel injection rather than carburetion for two reasons: 1) They just simply perform better, and in a competitive world, a substandard performance automobile will not sell, and 2) A carbureted engine cannot meet any emission requirements, period. One can toss any add on components you wish and a carbureted engine will not compare with the emissions controls of an EFI engine.
Now, will the driver feel the difference between a carb engine and an EFI engine? Usually not, no matter how well calibrated ones butts is, the proof of the pudding is in the lab. There have been numerous hot rod tests comparing a carb engine against an EFI engine and the end results have been a very close call, barely measurable, but in the long term, the EFI engine will ALWAYS perform better since it is constantly calibrating itself (at the OEM level).
Back to the discussion. A tuner with a laptop sitting in the front seat tweaking the engine while driving is a poor comparison to the lab and tuning resources of a major OEM. When the end result is taken in, the driver may never FEEL the difference, but the actual "out the tailpipe" can be evaluated.
Franz
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: Aftermarket Fuel Injection
http://forums.club4ag.com/zeromain?id=2 & do a search.
RE: Aftermarket Fuel Injection
As someone who has an entirely homebuilt EFI/Mapped ignition engine management system, based on Megasquirt and junkyard hardware, built into a 60's Triumph, I think those who rubbish aftermarket ECUs in general and Megasquirt in particular are missing the point.
Sure, modern (say mid nineties on) engine management is much more sophisticated and better mapped. But, if you have a situation where your car either never had fuel injection, had rudimentary fuel injection from a bygone age, or has modifications outside the ability of the stock ECU to allow for, then you have a problem. These wonderful modern ECUs are not easy to modify or to apply outside their intended application. Aftermarket therefore fills this niche.
I can only speak for Megasquirt (MS), but I found it to be very cost effective and reasonably easy to use, even with no prior EFI/management experience. Power, torque, fuel efficiency and driveability, yes driveabilty, are all significantly improved over the standard carb/points setup. With a wideband oxygen sensor I can set target tables to control AFR over the working range. The open format means I can use software created by a number of clever people (for free!) to help me tune and tweak the maps and get the best out of the car.
Can it achieve todays emissions legislation for new cars? - I doubt it, but that is not the point of it. However, I would be very surprised if a properly set up MS installation does not drive every bit as well as a modern factory build.
Sure, plenty of people have problems with their MS installs. Plenty of people have problems with the other other aftermarket systems too (not to mention OEM!), but with MS you see alot about it on the web because that is where you go for help. The low cost of MS also means it falls into the hands of backyard tinkerers who are punching way above their weight....
Just a case of horses for courses really.
Nick
RE: Aftermarket Fuel Injection
I disagree with your feeling that non-OEM ecu's are always going to be worse. Remember that OEM ecu's have to be mapped taking into account the differences in thousands of engines, operating conditions and driver styles. A specifically tuned ECU (forgetting a non standard car) that had the same amount of time spent on the mapping has the possibility to be better than OEM.
I think what you are confusing is poor mapping for poor hardware! Of course no-one is going to spend as much time mapping as the OEM, but you can sure make the car 'feel' alot better. In fact some OEM mapping is downright embarrasing! Its worst case scenario stuff. Its getting better these days but you should still be able to wring a little but more from an engine using mappable software, and keep emissions in check.
Basically, the more time spent, the better the map and therefore the drive. Its a shame that alot of the people who fit non standard ecu's dont get them mapped competently.
RE: Aftermarket Fuel Injection
I think you are missing my point.
To put it bluntly aftermarket systems are very, very basic - so much so that an OEM idle speed controller probably has more lines of code in it than the entire Mega Squirt software.
There are software functins in an OEM system that simply do not exist in the world of MS etc, not only because of the complexity involved but also because the lack of knowledge/ability for a backstreet tuner to calibrate them.
Not only that but the OEM cal will start life on the engine dyno before it even sees a vehicle, the vehicles will all have proper diagnostic software and also measurement capability. Everything is done to the nth degree.
Anyway, this is straying from the OP and starting to become an 'oh yes it is' 'oh no its not' type of argument.
Just out of interest have you ever seen an OEM software strategy guide in comparison to one of these aftermarket systems?
MS
RE: Aftermarket Fuel Injection
The OP I feel has been answered, and thruthefence seems to have chosen the best solution to his particular problem, and I agree, with a standard install like he has, it is MUCH easier to plug the standard ecu back in than rely on someone elses mapping/ unknown bodges. He will have instant solution rather than messing about. That doesnt mean he couldnt have got the same driveability with the a bit more power and torque from the MS.
Can I just ask, which particular part of the MS lacks complexity compared to the OEM ecu for say an XE? What measurement capability do you mean?
RE: Aftermarket Fuel Injection
RE: Aftermarket Fuel Injection
Could you perhaps list a few of these functions? Aside from likely differences in map resolution and naturally the trouble codes, I'd like to bounce it off DFI's capabilities (supposedly that system was developed by an ex-GM engineer). I do know of one function in the DFI that has not direct OE counterpart, but which could probably be used to drive a specific OEM intake system feature (and may have been developed from that).
Norm
RE: Aftermarket Fuel Injection
RE: Aftermarket Fuel Injection
There ARE things in OEM EFI programming which are neither present (nor, in many cases, necessary) in aftermarket EFI programming: OBD-II compatibility, very fine closed-loop programming for emission control purposes, redundant fail-safe programming to allow limp-home capability in case of certain failures, etc.
For a bone stock engine that is fairly recent production, no argument that there is really no substitute for the OEM programming.
BUT ... Take that same engine, change the camshaft, change the pistons, put different cylinder heads on it, maybe throw a turbo on there, and generally make big, big changes to the intake and exhaust systems so that the end result shares pretty much nothing other than its bore-centre dimensions with the original design, and now tell me how far that OEM ECU is going to get you. (Answer: Nowhere.) For a situation like this, the OEM ECU on its own is simply not going to get the job done.
Personally, in a racing application that "really mattered", I think I'd lean more towards something like Motec rather than Megasquirt for its additional functionality, but the simpler systems still have their place. Racing applications don't have to meet OBD-II ...
RE: Aftermarket Fuel Injection
Perhaps the OEMs have stepped up to the plate since the late 90's, however at that time I could find none that would allow a reasonable idle quality with 96 Lb injectors.
Granted the OP's question was with a less than sophisticated unit such as the sequential FAST unit I run or a Motec, but I still fail to see how anyone who can tune a carb and set an ignition curve would have issues with tuning an ECM appropriately matched to an Injector. ( I.E. matching a 300 dollar Megasquirt to a set of 96 Lb injectors )
In case anyone might be interested in one of the newer aftermarket systems out there, one that should open peoples eyes, here is a link.
http://www.mastmotorsports.com/proto90ecm_main.php
RE: Aftermarket Fuel Injection
With that said, I'd have agree most with franzh acessment though. To paraphrase: OEM are unmatched in drivabilty,emissions, durability, ect. Most aftermarket systems can get you 95% of the way there with good programming, enough so that the end user barly notices any difference.
Although the aftermarket is at best only 95% of the oem, it will also be 95% better than the carburator it usually replaces.
To thruthefence; I've never cared for the Megasquirt and usually advise against it in favor of the ADDED VALUE of other aftermartket systems. It will "work" no doubt, but, imo far too much depends on the assembler and end user. I believe many first time efi users are enticed by the low purchase price, but imo its a bait and switch. You get no wiring, no enclosure, poor non-automotive spec headers, poorly placed board mounted MAP sensor, no other sensors included at all, little no vibe proctection, ect. Even most aftermarket ecu's go through some sort of validation testing for vibration, esd, thermal, ect,,, your MS unit is just a mystery. If you Add the value of all the NEW sensors, wire harnessing, ecu enclosure, and quality testing of any off the shelf aftermarket EFI systme INTO the price of a MS, it could be an EASY $1000-$1500 EXTRA!
Since a decent Accel DFI or Holley C-950 sytem is only $1000-$1500 brand new(usually including a new fuel pump too), the added value does NOT favor a MegaSquirt.
RE: Aftermarket Fuel Injection
HOWEVER
Let me link you guys to something that might change your opinions! Well, two things really. First and foremost:
http://www.megamanual.com/seq/
You must click that. It is promised to stand the aftermarket ECU world on end.
Secondly, click this one:
http://www.megamanual.com/357/
The first is a VERY compact fully sequential surface mount version known as MS2 Sequencer - sequential fuel and sequential ignition control.
The second is a current (and what powers my car) version called MS 3.57 - its a surface mount version of the normal 3.0 boards. You can run MS1 or MS2 CPUs on it. The improvement though is that its SMD, so no issues with thru-hole construction!