Aftermarket Fuel Injection 1

[thruthefence]

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.

 

[mattsooty]

E-Bay it...

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

 

[stephenw22]

I would have a difficult time justifying the use of a megasquirt system, when an OEM system can had from a junkyard or used parts store.

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.

 

[thruthefence]

The main problem I'm having, is locating components; The 20 valve engines apparently were never sold in the USA, but are desirable in the rice-rocket 'drift' boy racer market. altho the "blacktop" engine is the more desirable, I'm told. I have, however, located an ECU as of this writing. I also have an AFM, swinging gate type, (like the older Bosch ones)supposedly 'in the mail' . All I lack now, is the ecu harness. The engine is going in a '70 type 65 Lotus Europa. I will be placing the megasquirt components on Ebay; as suggested.
thanks for your responses.
regards, steve

 

[Cronik]

If components for the silvertop are a problem we have them in abundance down here in New Zealand. Very reliable engine, not bad on fuel but do tend to use a bit of oil.

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

 

[70AARCUDA]

...just remember, ANYTHING that's "...easily changed/modified..." is also by default likewise also "...easily screwed-up/misadjusted..."

 

[MargayKart79]

I've built and tunned several Megasquirt systems. As long as you have a good air/fuel meter and datalog as you drive (which MS does), it can be tunned. (Having access to a dyno doesn't hurt either if your by yourself) The main issue with the system usually is determining a way to get a decent tach signal. Otherwise theres tons of information on getting started and base calculations for fuel tables. You can buy a base wiring harness from DIYtune and hook it up yourself its very straight forward. Also chances are someone already put MS on silvertop considering its a popular swap, so you should check out their forums and read up on their manuel.

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://videos.streetfire.net/video/76f7cc7d-b3be-4e7c-bbe3-998200c91606.htm

http://i138.photobucket.com/albums/q249/MargayKart79/PA210011.jpg

We are also putting a MiniMS on our 240sx, so clearly I recommend it but thats just me.

 

[mattsooty]

MargayKart79,

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

 

[MargayKart79]

I suppose I did glance over the issue of "driveability"...but I dont see it as an issue if MS was tunned properly. I've used three of their ecu's and once everything is adjusted properly there were no issues. Its not a very complicated process at all other than following instructions and changing the fuel table by reading an air/fuel ratio gauage. As far as saying the system is less capable than stock, that really depends on your perspective. Both accomplish the same goal of operating the same systems. If it really effected the driveability then no one would use them. Some of us just prefer the ability to adjust their engines as required without spending 1000 dollars on a standalone system with tech support.

 

[dgallup]

The biggest difference between OEM & aftermarket systems are not going to be seen until you start measuring & trying to control emissions. If you don't care or don't need to meet any formal emission standard then you don't need the vast additional control complexity the is included in OEM systems. Your butt won't be able to tell the difference. Your lungs might.

 

[mattsooty]

Well, whether or not your butt will be able to perceive a difference is wholly dependant on how sensitive your butt is.....

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

 

[bobqzzi04]

While I agree OEM systems are more finely developed, aftermarket systems can be made to run extremely well and offer much better adaptabilty for the end user. This is particularly true in the case of an engine swap or when the engine is altered.

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.

 

[mattsooty]

bobqzzi04

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

 

[NormPeterson]

matt - how would you rate the megasquirt in comparison with the DFI system marketed under the Accel banner?


Norm

 

[franzh]

It seems that much of the discussion has focused on how much difference there is between an OEM system and an aftermarket system. I would like to pose this:

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 for tips on how to make the best use of Eng-Tips Fora.

 

[thruthefence]

I want to thank everyone for their input on this subject; I found some kid who wants to build up his Toyota drift racer, and we swapped straight up for his uncut harness & manual trans ECU, and my megasquirt box & EDIS components. I, for one am happy as a clam. And as to the AFM being unreliable, I now own 3 (three) afm's, total cost < $50.00. I have no doubt, that you can tune the megasquirt down to a gnat's ass, that is, if you have the time & inclination.I have neither. If you want to see some of the problems megasquirt users can have, go here:

http://forums.club4ag.com/zeromain?id=2

& do a search.

 

[bosscat]

thruthefence - glad it worked out for you.

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

 

[Warmington]

Mattsooty,

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.

 

[mattsooty]

Warmington,

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

 

[Warmington]

I am not sure I have EVER see an 'aftermarket' ecu come with a strategy guide!

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?