Sequential injection

[figgie]

Well

what ECU are you considering?

I though that even the M4 could do 4 cylinder sequential injection though making the which is better point almost irrelevant since you could configure it anyway?

[MarkMc]

Hi, a 4ag, a personal favorite.

Realistically with injectors that are sized just right for the power your engine is making the thing is basically group fired at the high RPM and load when the injectors are at 85% duty and above (i.e. open nearly the whole cycle anyway).

Sequential injection give one quite major advantage and that is the ability to tune each cylinders fuel and ignition individually, no matter what the size of hte injector. We have seen some very good gains by making sure every cylinder it tuned to its peak.

If you wanted the ulitmate setup you would have the high injectors (at least) a bit larger than necessary to give you low duty cycles even at high RPM and load. This will allow you to move the injection timing around relative to the TDC of the cylinder, there are gains here as well......sequential only of course.

As you quite rightly say the M4 and M400 will not do hi/lo injection sequentially but an M48 will. Depending on how much of a "tinkerer" you are and how much you value your data logging an M800 would be the best overall solution and the software is light years ahead of the M48 in terms of flexibility.

[MarkMc]

The other thing we just though was if it was going to be of any benefit to have the low injectors....? You engine goes to 9500rpm so I ass-u-me you never drop very low in the RPM range on the track, maybe it will never need the low injecotrs for anything other than driving around the pits.

Unfortunately it is a case of trying it and see.