Hi, I'm from DIYAutoTune.com tech support - we found the thread through the link posted here and wanted to answer a couple of the questions asked in this thread. MegaSquirt had had a good bit of development in the past couple years, so I'll go over its current features.
There was a bit of a question mark about how to control ignition on SHOs as their setup is something of a rarity, but it can be done now. Turns out they're very much like TFI, as far as the Megasquirt setup is concerned, just with slightly different settings. If you have an automatic transmission or EATC, you'll need to do a parallel installation and have the stock ECU control those - at least with current hardware. The MegaSquirt would have full control over fuel and ignition.
I'm trying to pull this info just from memory from tuning classes I had 2 years ago, so corrections are welcome ...
1) TwEECer R/T datalogs .. Megasquirt doesn't.
The current MegaSquirt has two means of external data logging; you can use a laptop connected to it or a Palm handheld. The one sort of data logging it does not currently do is internal data logging, without an external device attached.
and is Megasquirt capable of using a MAF or do you have to convert to a MAP system?
It has a built in 2.5 bar MAP sensor as standard equipment. You can set them up for MAF input as well. Most MegaSquirt owners don't bother, but the capability is there.
I don't think anyone on this board is familiar enough with MegaSquirt to actually talk intelligently about it, much less compare it to another system.
I've read up on it quite a bit and do know that for the longest time, Megasquirt could not do sequential injection control. Now they can. It can also read air volume through a MAF sensor or a MAP system, or both at the same time.
The sequential fire system is in beta testing right now and is running on a couple engines. The Sequencer should theoretically work on a SHO but will probably require removing the DIS module.
I think that no matter which you choose, you should have access to a dyno to verify your work.
Tom
Very good advice there.
ms has had different versions too, the newer v2 setup is lightyears beyond the original board. The big difficulties are that you have very few people that has ran the ms on a sho to really break the coding down. Pretty much the difference is that a ms is a clean slate, you program it to do and be what you want, where as the other is more about tweaking or changing an original coding. The big advantage of the ms is controlled actuator circuts you can add...ms can control your nitrous, boost solenoids, DIS ignition, etc, ms also uses a higher speed processor where your others IIRC are using the oem processor. the ms2 has datalogging and IIRC the ms1.5 did too. Once you have the basic coding, if you hookup a wide band o2 sensor and set the desired a/f ratio, it will self tune.
Megasquirt numbers can be a bit confusing, as there's processor numbers (which don't have a V number) and main boards (which do). Currently, there are V2.2, V3.0, and V3.57 boards, while processor versions are called the Megasquirt 1 and Megasquirt 2. Both can control fuel and ignition on the SHO, and support data logging. The self tuning works reasonably well for fuel after you have it started, but there is no self tuning equivalent for spark.
IIRC, I think there's even a ms v2.2 board out now that's even a little more compact, and allows for more input/output channels.
The Megasquirt 1 and Megasquirt 2 are the same size externally, but there are a couple other versions out there. The Microsquirt is a smaller version with fewer outputs, while the Sequencer (which is not quite out yet) is in between a Microsquirt and Megasquirt in size and has the most inputs and outputs of any of the current Megasquirts.
If you guys have any other questions, feel free to ask. I'll keep an eye on this thread.
