Anyone knows how the flow distribution is with the HSR under boost?

Miniram have some problems under boost with the air is being pressed to the rear end and making the rear cyl go lean.

I emailed Doug at holley and got this answer:

"Honestly I haven't tuned one myself with a supercharger so I can't give you that data. On a naturally aspirated engine, the front cylinders are actually a bit leaner. If/when I get the chance to tune one, if it isn't on a dyno with 8 widebands like we have at Holley, I will put a wideband sensor in a front and rear cylinder to monitor each cylinder. I know that doesn't answer your question but I don't know from my own hands on exerience."

/N.

 

I use a HSR on my boosted car. I believe when the manifold is pressureised there is no cylinder taking more air than another. If there is it is minimal.
If you have 10 lbs of boost Everything should be filled as boost is a measurement of restriction. The mini ram has a small plenum which probably leads to the problem. The hsr is just short of 340c" so it is almost where it needs to be for a 355.
I have a DFI on my car and have not trimmed any injectors. All the plugs read the same. I would worry more of the 5/7 holes stealing from eachother than worrying about the manifold under boost. I do know they have some distribution issues on the N/A applications but not enough to worry about.
We have a twin turbo race small block with egt's on every cylinder, no injector trimming there either, a manifold that is not much different than the HSR and the cyl. temps are scary close.
If i were you I would look more into camshaft design/profile than the manifold.

 

Thx/ N.