megasquirt with tbi? Options

[tdsmoonchild]

Has anyone here built a megaquirt system using aftermarket dual throttle bodies?

[lapuwali]

Well, you'll also have to deal with MAP issues. ITB systems generally have a highly unstable MAP signal at idle and low loads, which will require either a MAP plenum, a very small restrictor in the MAP hose, or a combination of both. Some people will tap all of the manifolds and plumb them with tees into a fuel filter, which can often stabilize the MAP reading enough for speed/density to function.

The other alternative is to use Alpha-N instead, using only the TPS as the load signal. This is often tricky to tune.

This topic (ITB with MS) is discussed pretty regularly on the MSEFI forum, so searching there should give you a lot more data to chew on. The problems are pretty much the same from engine to engine, so no need to look only at Type IV based systems.

Since Jake sells SDS with ITB throttles, he's obviously gotten it to work well. SDS has pretty much the same limitations as MS in this regard, so what works for one should work for the other.