MegaSquirt

[mstemp]

For the MS guys on the forums.

Curtis's MS3-Pro looks fantastic but what are the advantages of it over the Microsquirt V3? Both offer nice waterproof enclosures but the Micro is so much less expensive and it forms the basis for all the PNP units. I understand that MS3 Pro gives easier data logging with the SD card, larger fuel and ignitions maps (16x16 vs 12x12). Full sequential injection vs batch. The Micro may not run the Rover IAC but will run a Ford PWM so easily overcome.

What else am I missing? Will the Batch injection be that much of a step backwards? Are the MS3 Pro features that crucial to a street driven Rover 4.6L?

[Moderator]

As I understand it, Microsquirt can provide direct ignition for a one or two cylinder motorcycle or snowmobile engine but isn't capable of supporting ignition control on additional cylinders. I'm running fuel-only for the time being - just to get going - but I expect a significant performance improvement when I upgrade to a multi-coil crank fired ignition system. MS3-Pro was designed to support that, and more.

[mstemp]

Thanks Curtis.

Micro will run the Ford EIDS though on up to 8 cyl.
I would need a different Ford style IAC valve as Micro wont run the Rover/GM style.
Hate to save a few $$ now and wish I had not in teh future. May follow your lead once again!

[BlownMGB-V8]

I have the MS  V2.2 and v3.0 boards (full size, not micro) and upgraded to MS-II several years back in order to have timing and IAC control. This year I'm stepping up to MS-III on the v3.0 board in the MG in order to get full sequential, COP and separate EGT inputs but it also requires additional I/O boards to do it.

There is no reason that the MS-II will not do all you need for almost any of these engines. The single biggest advantage that MS-III has to my mind is the ability to individually tune and optimize each cylinder, but batch fire and EDIS under MS-II is an excellent system and provided the engine has no serious built in imbalances (most do not, they once were run on carbs after all), will do a great job of running the engine.

Jim

[mstemp]

Thanks Jim.
Sure I will have lots of  questions once underway.

[Johnous]

If you are concerned with saving $$$ (who isnt) then a second-hand MS-II unit can be had for under $100. I bought mine on the cheap and with the help of a borrowed diagnostic tool replaced the one faulty resistor it had for a perfectly working unit - total cost: $55. Most of the mainboard repair parts can be found at radio shack. Batch fire seems to work fine, mind you I too am only using fuel at this point and have yet to fully tune on a rolling road...

[mstemp]

I guess one of the reasons the microsquirt is so appealing is the case and connector. Looks a lot like the MS3 pro without all the fancy features and cost that i likely dont need.The old case MS2 etc look rather poor in my mind. Yes I know a silly reason for something hidden behind the dash or wherever.

[Johnous]

One can always airbursh flames onto their MS-II... hmm you gave me an idea

[BlownMGB-V8]

The ampseal connectors are very appealing, and I considered going to Pro instead of upgrading the old MS v3.0 but in the end it was a lot more practical to do the upgrade. Take a close look at the comparable features, bearing in mind that the MS v3.0 is a lot more flexible in terms of upgrades. It just needs a cool dry home such as the passenger's footwell. I've not heard any reliability complaints with the D-sub connectors it uses.

As mentioned, the micro was designed for bikes. Be very sure it will run your engine before you go that route, as it does have some limitations, and it may restrict your future upgrades. As I recall it is more on par with the MS-I in functionality, which was pretty much limited to a fast idle solenoid rather than an IAC, couldn't deal with EDIS too well, and may have had real limitations on advance control. I upgraded to MS-II in order to get IAC and advance mapping for the EDIS I was using at the time. With the MS-III I am going to COP, full sequential and EGT inputs (which requires yet another board). You have to decide where on the continuum you want to be and allow for possible future upgrades.

MS-III Pro is somewhat expensive. But it is a well made unit and has the amseal connectors. It would be a good way to go if the cash is available, but again, look at the features.

Jim

[mstemp]

Thanks Jim, points taken.

A UK firm has a complete Mico kit with EDIS etc. Micro is also the basis for all the PNP units that DIY Autotune make.

http://trigger-wheels.com/store/contents/en-uk/d31.html

Bit expensive compared to here but shows that it can be done.
Unfortunatly I always want the best so MS3-pro is calling me. Too bad I still need a Diff etc etc.

[MG four six eight]

Here is a link to the mega-manual page, which shows the different features and functions of the various Mega-squirt products.
http://www.msextra.com/feature-xref.html

Bill

[waterbucket]

There is an English company producing plug and play Megasquirt  kits for Rover V8 engines if you can accept the cost they seem a very simple way to go over Megasquirt.

http://www.extraefi.co.uk/RV8_Kits.html#pnp

Philip

[Moderator]

Most MegaSquirt installations use a single MAP (manifold air pressure) sensor. The computer takes an initial MAP reading before you crank the starter. That initial reading is used for barometric (i.e. altitude) correction. After that, the MAP sensor is busy sensing engine load.

A single-moment barometric reading is okay if you don't change altitude much. However, if you're driving from 6000' above sea level to 14,000' feet (e.g. climbing from Colorado Springs to the summit of Pikes Peak) - it's not really enough. Most noticeably, you'll have a good idle where you start but a lousy idle where you end up. You can fix that at the top by turning off your engine and turning it back on - but then you'll be calibrated for high altitude as you descend lower and lower. So, if you live or drive in a mountainous region, you should consider an installation that uses a second MAP-type sensor for barometric correction.

I finally got around to installing one yesterday, and I test drove up to Estes Park with it last night.  I could continue living without a second sensor, but I feel this upgrade was a fairly significant improvement.

I used a GM 3-bar sensor just like the one that's actually connected to my manifold. The new sensor is mounted and measuring pressure underneath my dashboard. If the sensor at the manifold ever fails - for example due to getting contaminated with blowby oil - I'll have the immediate option of swapping the two parts and returning to a one-sensor configuration.

MicroSquirt in particular doesn't appear to provide an option for a two-sensor configuration...