Hate to drag up a rather bitter topic that seems to have died, but have done some reading this weekend (scary) and now have some limited knowledge about this stuff.

In particular, I have read a fair amount from Motec and Megasquirt about the advantages (perceived or real) of batch v. sequential firing of the injectors, which seems to be one of the big issues the anti-rule crew had with this change.

As I read the Motec and Megasquirt literature, sequential injection of course gives you the ability to control the firing of individual injectors with the goal being to ensure that they fire only when the intake valve is open. Further reading suggests (and I'm not saying this is 100% accurate, just looking for viewpoints on this) stock injectors will for the most part be unable to deliver the full injection charge in the short period of time the intake valve is open (usually less than 300 degrees of the camshaft rotation). Thus, even with sequential FI, on MOST cars, you are going to end up with the injector firing against a closed valve.

Motec still claims that despite the above sequential firing will smooth idle (ok, but don't care), reduce emissions (don't care), increase fuel economy (don't care) and may improve mid range torque (ok, like that, but it is qualified -- MAY).

Megasquirt is pretty adamant that batch firing is fine for stock injectors. They contend that firing against a closed valve doesn't really cost you anything -- the intake sits there for a split second until the valve opens and draws the charge in. Really the only negative effects could come from the port wall temperature increasing the intake charge temperature, but even that Megasquirt claims is minor.

Last, you have to have a cam position sensor to make sequential work. I'm new to FI world -- do most cars have this? The FI setup for my car, a dinosaur, does not. I know SMs do. In any event, it seems that sequential would only be availble to cars that had this stock, since you can't add sensors that aren't there in the first place.

In any event, this new rule has made up my mind for me. FI motor, probably with Megasquirt, being built over the winter. We'll see how this goes.