Megasquirt Advice and discussion.

[Max777]

I have been considering building a megasquirt setup for my car. Considering the alternatives, such as used Haltech units, or RTEK, which ends up at around $750 after all is said and done, and any other alternatives such as a blow-through carb setup for my car, I have arrived at the conclusion that an MS standalone would fit me very well.

After reading over Aaron Cake's guide: http://www.aaroncake.net/rx-7/megasquirt/index.asp

I have priced out all the major components that I will need at roughly $500, plus all the misc stuff like solder, connectors, etc, so figure $700 for the budget...

This price includes the MS 1 V3 kit, An LC-1 wideband kit, and some mod chips and misc items such as fan controllers, boost controller kits, wiring harness, etc.

I have seen used standalones such as Haltec and Microtec sell on the forums for a similar price, most with a complete harness and sensors included. While I would like to build my own setup, I thought that I might need to weigh in the advantages of other options.

As far a tuning, I believe that I can get a rough map going, but in order to REALLY tune the car, I will need to seek help of a pro. How much of this stuff can I get done myself if I really study it, and spend time adjusting the maps? I don't seem to have many tuning options in my area other than Banzai Racing and Chris Ludwig in Indiana, both of which will require me to drive the car over there in order to get it tuned, how scared should I be at this point?

Opinions, experiences, suggestions, and all are welcome, the stock setup on my TII has aged well, and is in need of replacement sometime soon.


Max.

[dregg100]

go with anything but a ms. by far the worst standalone i have ever used.

[RotaryProphet]

If you know what you're doing, the Megasquirt is fantastic. Cost to feature ratio is unparalleled, and I've put a hundred thousand miles on my DD while it's been Megasquirt powered. To top it off, it has OEM drivability, never surging or bogging, and you can reach in through the window on the coldest day of the year, turn the key for a half second, and it's running. The hardware does what the hardware does, it's up to you to tune it, though.

As for tuning, there are a few ways to go about it. The easiest is to take it to someone who specializes in it. I'm near Cincinnati, and I have an engine dyno cell setup pretty much just for doing Megasquirt installs that I build and wire, but I'd be more than happy to help you out for pretty cheap; I try to cut forum members price breaks where I can.

Secondly, with a wideband you can run a datalog while driving (assuming you've roughed out the tune to where you can drive it), then import that into excel or openoffice, and go back through and look at the recorded AF ratios at given RPM and MAP points, then do the math to figure out what the cell -should- be at to get your desired AF ratio. It's far from perfect, but I've tuned cars that way that ended up working very well, and without an engine dyno, it's one of the only ways to really tune the regular city driving areas of the map.

The last method would be to recruit a friend to drive around while you sit in the passenger seat with a laptop, and adjust as you see fit. Before I had my dyno, I used a combination of logging and shotgun tuning to get a reasonably good tune, but it is time consuming.

[Whizbang]

i am going to be converting from distributor to CAS w/ ms controlled spark (already running fuel) over the winter. The ITBs and anything with vacuum control dont get along...

[Max777]

So, what if I were to fully set up my car with the MS, and then trailer it over there to get it tuned?

[85rx-7gsl-se]

I love my Microtech...There is a reason some of Australia's fastest rotaries run Microtech

[TitaniumTT]

Motec all the way baby. Functionality, configurabiltiy, adjustability is unparelleled.... not to mention the best support I have ever had the pleasure of dealing with.

You have problems with the MS, where do you turn?

[85rx-7gsl-se]

Microtech's Tech Support is good but kinda slow...But half the price of Motec too

[Max777]

Well, if I had $8,000 for your setup, T, I would duplicate it minus the sequentials.

[RETed]

Originally Posted by RotaryProphet

If you know what you're doing, the Megasquirt is fantastic. Cost to feature ratio is unparalleled, and I've put a hundred thousand miles on my DD while it's been Megasquirt powered. To top it off, it has OEM drivability, never surging or bogging, and you can reach in through the window on the coldest day of the year, turn the key for a half second, and it's running. The hardware does what the hardware does, it's up to you to tune it, though.

You seem to imply that only MS can do this...

The fact of the matter is that almost any competent aftermarket EMS can do this, and it's not limited to MS.
My Haltech E8 has no problem doing any of the above that you have mentioned unless one of it's sensors dies - I recently had a TPS (*#%& GM sensors) fail on me.
Anyone that has driven my car also comments how "OEM" it feels and drives.

Bottom line...the EMS if only as effective as the tune or how competent the tuner is.
Given the best EMS like a MoTeC in the hands of someone who doesn't know what they are doing, and it's...useless.


-Ted

[RotaryProphet]

Originally Posted by RETed

You seem to imply that only MS can do this...

The fact of the matter is that almost any competent aftermarket EMS can do this, and it's not limited to MS.
My Haltech E8 has no problem doing any of the above that you have mentioned unless one of it's sensors dies - I recently had a TPS (*#%& GM sensors) fail on me.
Anyone that has driven my car also comments how "OEM" it feels and drives.

Bottom line...the EMS if only as effective as the tune or how competent the tuner is.
Given the best EMS like a MoTeC in the hands of someone who doesn't know what they are doing, and it's...useless.


-Ted

Actually, that's more or less exactly what I was trying to say. That the MS is directly on par with any other EMS system I've seen as far as in-use functionality.

It's just, every once in a while, you have to build a circuit to do some goofy thing you want to do; and even that isn't a big deal if you're handy with a soldering iron, and know what you're doing.

The Megasquirt is the option for people who really really know what they're doing, or want to learn. The upside is, it's damned cheap, and works just as well. The downside is, it's more work, at least the first time.

I'm actually curious about how poor a reception the MS gets in a lot of car circles; even those who are thoroughly DIY with their engines are terrified at the thought of doing the same to their ECU.

[RotaryProphet]

Originally Posted by Max777

So, what if I were to fully set up my car with the MS, and then trailer it over there to get it tuned?

Better option would be, since I have an engine dyno, not a chassis dyno, just bring the engine, with complete intake and whatnot. The dyno cell has it's own water supply into the water pump, and it's own fuel system that hooks up to the rails. It also has a water-air intercooler to be used to control IAT.

If you're interested in tuning it on the dyno, give me a PM, and we'll talk about it.

[Max777]

Well, I see the only problem with the MS install is that I want to have my car ready for DGRR-10 this spring, so if I can save up the cash, install the hardware, and get it tuned in time, then I will be going with this setup. Otherwise, i will need to put it off and get an RTEK 1.5 chip instead.

[jgrewe]

There are enough maps out there on the forums that you can have your car drivable with a MS within an hour of initial startup. Help is the MS forum away for anything, Ihad an issue once that took as much time as it took to hit the refresh button for an answer. When I first built one about 4 years ago I think I read for a month before I was comfortable enough to do it. This was before you could buy everything from one place and you had to order stuff from 3 different places.

Aaron Cake's write up is probably the best I've seen for a car specific set up. The only difference I went with is the Zeal daughter card for the extra VR circuit instead of building a circuit in the proto area.

With the MS there are probably 9 ways to do anything. Once you get a hardware setup you like you can stick with it(until MS3 comes out and you want to do a new install...lol)

[NoDOHC]

I have experience with all ECUs mentioned except for Microtech. They are all basically the same when it comes to the basics. Each has a fuel injection duration and ignition timing map that it references based on engine RPM and load (as measured by a MAP sensor, MAF sensor, AFM, or TPS). The available features or adjustments vary widely, but for your first system, simple is better.

Basically, aftermarket EFI is only as good as the time you spend learning about it and the time you spend tuning it.

Dyno tuning is necessary for peak power because the car is either speeding really bad or revving so fast that you can't even get an idea what the AFR is. Dyno tuning for driveabiliy is unnecessary and actually more difficult than tuning while driving.

If I were you, I would learn the Megasquirt with your turbo sitting safely on your bench in the garage. That way you will not hurt the engine when you make a mistake (which you will).

The driveability will be mostly the same with or without the turbo, and the vacuum map will be identical. Really all you will need to tune is the boosted part of the map when you install your turbo (after you are comfortable with the software and your wiring).