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Inlet plenum design - sources of info
bi22le - 14/4/16 at 03:41 PM

Hi,

I am planing on designing and making a custom inlet manifold. I have a fair idea of what I want and what I expect to have to design but want to ask the LCB collective if any one has some good reading. For NA set up a large plenum chamber, plenty of fluid flow, dont lean chamber 1 and make chamber 4 rich. The balancing of flow can be achieved by offsetting air supply tube to trumpet ends., which on that note trumpet design I know is also important.

The other thing I want to consider is that I want to future proof it for boost (SC approx 1 bar at a later date). My gut feeling is that this is impossible as there are some conflicting design attributes that conflict between a NA and boosted plenum. Sizes of chamber is one that immediately springs to mind.

So, Any sources of info. Google brings up many pics and articles but I want to read more.

PS, anyone else want one?!?!?


coyoteboy - 14/4/16 at 04:49 PM

I think boosted manifold design really just reduces the importance of certain areas of normal manifold design, it doesn't negate their value entirely.

Just a few uneducated thoughts...

The key points to note in my mind are that as far as I'm aware, in boosted apps, you need to pay more attention to flow distribution. You need to look at the increased runner/port density to adjust runner length to suit if you want to maximise effect but largely the boosting will make much bigger difference and matching off-boost sizes will give you better torque off-boost. In boosted apps, plenum size seems to make very little difference to power gains, maybe larger will give a little throttle response delay but how noticeable given the bounds of possible sizes?

Get some approximate formulae from literature and perform a sensitivity analysis for all the variables you might change.

[Edited on 14/4/16 by coyoteboy]