no time for detail now, but for completeness's sake, here's my data:

 

So the experiment says there is no substantial difference. But did it run long enough?

 

yea.

 

I've got a window of opportunity, since my head's off, and my injectors are out, I've got 550's I can run. Still no dual feed rail, though. So I could do another, more careful test, but for now, yeah... I'd say you are either superstitious or you're not.

$200 will buy you some dyno time.

 

Incidently, the shop that is rebuilding my car also said they cannot see how a second feed is going to improve anything. Or better yet, how there could be a problem feeding #4 in the first place.

I also talked to Corky today and he said that they have discovered that the standard intake manifold gives slightly more air to #4. Nothing to worry about at stock power levels or even 230rwhp - or so I understood. But if you are on the verge of running lean or hot you may very well be lean in #4 and have knock there.

So for now, the #4 failures are most likely from lean due to more air. Not from less fuel. And running hotter than #1, #2 and #3 due to the OEM coolant path. Maybe.

 

Yeah - if you wanted to actually fix something, instead of just making it look better, you'd want to have individual fuel TRIM per cyl. Just adding feeds is like taking a die grinder to the head and just carving some more power without having any idea what you are doing, or else it's nothing but another point of failure.

And if someone thinks otherwise, test it, or send me a rail that's better to test.