Does anyone know anything about it? I saw an ad and looked for it at Summit, but the only listing there was for the TPI version. It looks interesting as a stand alone engine only system. Supposedly there's a version for the LS type engine too.

 

would like to hear more about it

 

There is info here:

http://www.painlessperformance.com/perfect.asp

It basically uses the GM MEFI ECU. Its fine for a stock LS1, but the ECU can't easily be tuned if you make changes to the engine.

Andrew

 

That looks good for the show car crowd but a gearhead won't buy that. I'll bet it's a lot more $$$$$$ than a Speartech harness and HPtuners , too.

 

I think the price is around $1200 bucks. Its definitely more for the show crowd and not the gearheads.

Andrew

 

Thanks for the comments. I'm looking for a system to control only my engine (ignition and fuel) no transmission or anything else. The fuel pump will be on a switch, and I'll be using aftermarket gages. I need to run open loop, since I won't have O2 sensors. I'll need tunability since I will be modifying the engine. I've been waiting for the MotoTron unit, but haven't seen anything new for a while. If the Painless setup isn't tunable, it won't work for me. I've also considered the marine pmc setup for the 6.0 Vortec marine engine, but haven't been able to find much about it. Is that what you meant by "MEFI"? I emailed Speartech, but they didn't seem very interested, since my second email wasn't answered.

The problem is, it's for an airplane (dirty word in today legal atmosphere, even though I'm willing to sign any release necessary) so it appears I'm on my own. The engine ( I have a new 6.0 long block) will basically be a 6.0 with the block replaced with a LS2 block, a fairly mild cam to get the best torque/hp curve at a fairly low rpm, truck EFI, and short stacks for exhaust....the reason for both the lack of O2 sensors and need for tuning. The engine will be operated at no more than 4800rpm and will cruise at around 3400 at fairly high power, around 200 to 240 if I can get it; depends on altitude.

The engine will be operated like a marine engine except for the obvious changes in altitude.

 

I forget what MEFI stands for, but it is the GM/Delphi marine computer. I believe the current Mercury marine computer is made by MotoTron. MotoTron is developing a system for Edelbrock.

Why are you looking to run openloop? Wouldn't it be better to have the computer compensate for the altitude changes?


Andrew

 

My understanding is that the O2 sensors aren't required for altitude compensation. Isn't there a sensor for manifold pressure? Don't speed density systems compensate for altitude/baro pressure?

The reason I can't use O2 sensors is that my exhausts will be short (10 inch or so) individual stacks...no place to put them.

Possibly I am confusing the terms, but in short: No O2 sensors = open loop, but since the computer has tables for fuel required for various combinations of manifold pressure, throttle position, and rpm, it will still compensate for altitude. Am I wrong?

Thanks.

 

Correct. The MAP sensor (Manifold Absolute Pressure) compensates for altitude at key on, and at some various throttle transitions.

I think retaining the O2 sensors would still be nice in order to make sure the tune in the ECU is correct (or at least close) by monitoring how much fuel is being added/subtracted; at least until you know it's all mapped out correctly.

BTW, MEFI is simply Marine Electronic Fuel Injection. As it has been revised over the years it has been called MEFI 2, MEFI 3, MEFI 4. It's kind of a simplified engine only controller that's good for things like boats that don't have much complexity or requirements. Basically idling, full throttle, a little cruising.

 

Thanks, John. I sent you a second email a couple of months ago, but maybe you didn't see it. I wish I could use the O2 sensors, but I understand they must be mounted further downstream from the heads than my stacks will allow. How far away from the port do they need to be and do they need to be in a collector (not in an individual tube)? Another problem with them is the use of 100LL avgas with it's high lead content.

What I'm trying to do is figure out how to put together a system that will do what I need. Right now it appears all I really need is ignition control and fuel control with altitude compensation. I'll be running two pumps individually selectable with a switch, so the computer won't need to control that, and I want to completely delete the VATS, since it isn't necessary and I certainly don't need something that can shut off the engine. I understand this can be completely deleted through programming. I'll be using aftermarket gages with no computer interface. Simple is good.

I'll be using a LS2 block, so I don't know if the knock sensors will be workable or not, but by the time I first run my engine I suspect they will. Knock sensors would be desirable, but not necessary.

I'll be using a truck intake setup (I already have it) with a cable controlled throttle body and a mongrel 6.0 with LS2 block. I assume starting with a truck harness would be simplest. The engine will be mildly cammed with a stock compression ratio. The thing that will be farthest from stock and require tuning will be the short exhausts.

If you'd feel comfortable modifying a harness and programming the PMC, I'd be willing to sign whatever release your lawyer might come up with. I know "airplane" sets off all kinds of alarms, but I'll try to work out whatever concerns you might have.

By the way, I'd like to run 2 (selectable) PMC's for redundancy. Any thoughts about how this could be done?

Thanks,
org

 

A picture of a similar installation (LS1 instead of 6.0).

 

megasquirt?


If it were I, I would run duplicate sensors etc and run duplicate megasquirt systems, isolated where need be (spark plugs if single plug heads and injectors unless you could install redundant injectors) with as cheap as that system looks to be I think you could get a lot of redundancy and safety margin out of it.

I would think that you could leave boath system powered up and just run 1 set of injectors at a time that way they would be hot all the time and ready to switch over. by disabling 1 set of injector ballast resisters (1 relay for simplicty) and the same for the spark's with dual coils (that would take some thinking due to possable feedback). the 2 systems would run and only 1 would be running the injectors the other would be along for the ride unless needed.

More Than Zero

ps oh yea run in SD mode and that would comp for alt realtime.

 

so not that perfect then? should be called the flawed engine management system. thank you thank you, i will be here all night.

 

Don't quit your day job!



Andrew

 

M.T.0. the megasquirt is interesting, but from what I read (I admit I haven't had a lot of time to really get into it) it appears to need an O2 sensor. Is this correct? If so, how far downline from the port does it need to be? (You certainly wouldn't need a heated sensor in a 10 inch tube:-)

I'll investigate further. Looks like a fairly simple system compared to some.

org

 

Megasquirt doesn't necessarily need an O2 sensor, and it's MAP sensor helps it compensate for air density.

What you'd set on the ground would work all the way up until you run out of air, but it would keep the mixture perfect.


I would still try to get an O2 sensor in there, for both logging purposes and corrections on the fly (pun intended).

Funny you bring this all up - I'm a private pilot, and also an EAA member.


You DO realize the extreme chances you take when installing ANY kind of aftermarket EFI on the motor and go for a flight? I'm sure you've heard this a thousand times. What kind of plane is this going into?

I'd be glad to help, and there's a thread on MS-EFI.com about guys who use Megasquirt in their airplanes. Crazy bunch, but I *DO* have to point out that I have yet to see a single megasquirt failure while driving, and Ive built a number of them already...

I'd consider a dual-megasquirt setup that you could switch manually between. It wouldn't be that hard to do. Ask any questions you like, this is interesting!

-scott

 

I agree 100% with the above, The Megasquirt would be what I would use But I don't want the liability for this one. and no you can run it in SD mode which just looks at map and rpm (and a few others) but the O2 gives you feadback to fine tune itself on the fly lol pun intended lol.

but anyway good luck with this one.

More Than Zero

PS: the problem with the O2 will be that with only 10" of exhaust tube you will be getting a lot of o2 back up the exhaust from the outside and it will read lean all the time. you might try to incorperate an antireversion cone into the exhaust stacks and install the O2 upstream of that to get a good reading.

I belive that MS is now incorperating knock sensors into the system you can use the stock LS2 or ls1 sensors threaded into the exterior of the block.

 

Maybe. Does MS use a full time baro input?? If not, I don't think it could know the pressure change that occurs with altitude, unless it has an algorithm to check for it.

 

would you freakin beleive im still at the same day job andrew? honestly i dont know how with their fire happy way of business round here. but that may change within a week, i might have a new job downtown since im a college grad and all

 

Ban!!!! Hi Pickles!