Ok, I'm a MegaSquirt n00b, too...

[beren]

I can't find anywhere that lists (or that I can ask) what engines the different versions of MS (or MSnS, or MS2, or whatever) will run.

 

I know I can run the L6 pretty easily, but what about an LS1? Or a first gen SBC?

 

I'd love to do a LS1 with MS doing sequential injection (is that even possible?) I am under the impression that the LS1 does bank injection, is that correct? I am also under the impression that moving to a sequential injection would decrease my fuel consumption.

 

If I am wrong on any of those points, will someone *please* let me know?

 

Another question that may be rooted in mis-information: Is there a power or efficiency gain to be had *just* by moving to MS (in any variation)?

 

Thanks for the late nite replies. (I'm working nights this month, so I'm prowling around the forums at night mainly...)

 

Edit: For the record, I'm doing lots of reading right now on http://www.megasquirt.info/, let people think that I just don't know where to look. I was just hoping that someone had specific answers to my questions.

[z-ya]

An MS will run your Briggs and Stratton you want it to.

 

It will not do sequential injection, but for an custom performance application, it is not really important. I ran batch (all injector fire simultaneously) on a mild L28 powered race car and I was getting 25MPG on the track!

 

For an LS1, it you are going to run it close to stock tune, use the stock ECU and wiring. If you are planning a lot of mods, go with MS or another aftermarket ECU. Remeber that you need sone basic wiring and electronic skills to make an MS work. For a generic SB Chevy, definitely go MS. Someday I'd like to do an MS TPI small block (when I get tired of screwing with L28s).

[mobythevan]

The biggest problem I see with running late model engines is that MSnS can't do more the 4 coils, so COP systems will not work with 8 coils. You might have to downgrade the ignition system a little to wasted spark. Other than that any engine should be doable. Its always a question of trigger source. Some engines have some funky trigger sources that may not be supported, but almost everything is supported nowadays.

[tannji]

Moby, would you have any idea if MS is capable of managing the Toyota 3RZ with its DIS system? It comes in versions with Distributor, Dual-coil, and Quad-coil, and I dont think it is COP. Mainly, I havent been able to find out if the Toyota DIS as opposed to EDIS, is going to be a problem..... and no one on the main site has done a 3RZ yet, though one guy is attempting a 1UZ.

[beren]

Ok, what's wasted spark? It sounds like a setup where plugs (not necessarily all of them) are firing when the engine is not on its compression stroke, ie, exhaust gasses are venting or what have you.

 

What stroke is that, btw?

[tannji]

From what I have gathered, wasted spark is pretty much that, a coil that sends dual spark pulses, one to the cylinder that is on the intake cycle, and one to a cylinder on the exhaust cycle. It seems to be a cost control measure, less coils and a simpler ignition sytem are the results.

[mobythevan]

You guys have it right on wasted spark.

 

I really don't know on the 3RZ engine. Worst case look at a way to mount the EDIS wheel, but that can be a pain. I bet you can get it to work with the wheel decoder code.

[beren]

Quick rewind to sequential ingition. The MS site says that currently, one of the issues with sequential ignition is that at high rpms, your injector is firing on a closed valve more than 50% (I think) of the time in any case, so doing batch injection works just as well. I'm assuming that is because the injector can't spray the right amount of fuel into the chamber within the short window of the valve opening and closing.

 

Couldn't you overcome that by having higher Fuel PSI? More pressure = more fuel in the same timeframe, right? Or wrong? I'm talking theory that I have such a tenuous grasp on at this point, I might as well be thinking in Swahili.

[Mack]

more fuel pressure is a bandaid fix. the real cure is bigger injectors, but then your low RPM performance suffers because of crappy spray patterns and what not.

 

a lot of stock EFI systems have sequential injection at anything under 3000RPMS, or around town cruising, and once they hit 3000rpms they switch over to batch, because sequential has no real effect (or a VERY VERY minor one) on ultimate HP, which usually takes place high in the RPM band. where sequential has a real effect is on low RPM mileage, emissions and torque.

[beren]

more fuel pressure is a bandaid fix. the real cure is bigger injectors, but then your low RPM performance suffers because of crappy spray patterns and what not.

BAM! Just like that, he answers my next question, too. Thanks for the info! I'm still learning about general motor theory, sorry. Like, why does it seem to be easier to get lotsa HP outta a carb'd motor, but to get good numbers on a Fuel Injection system, you have to go Forced Induction?

 

For example, why can I put triple sidedrafts on my l28 and see mid/upper 200HP (with appropriate internal mods like port/polish, rods, crank, pistons, etc...), but I never hear of people getting those numbers with a N/A motor that is Fuel Injected? Is it just that a N/A Fuel Injected motor is boring, so people don't build up a Fuel Injection engine? I am genuinely curious, and lots of you guys have 10, 20, or 30+ years of experience working with motors, so topics get discussed at a pretty technical level. Not that I mind, please keep on doing so, it is great to hear about all of this stuff and think that someday I might know why on earth peanut shaped chambers combust better than stock L28 chambers...

 

Edit: Just saw this thread How much HP with stock FI and it seems that I (of course) just haven't been doing enough reading yet. Don't mention that to my wife, she thinks I'm reading too much on this board as it is...