LT6" Heimholtz Tuning 2 Plenums Dynamically??

[NewbVetteGuy]

Can anyone provide an explanation on why / how controlling the opening up of throttle bodies between the two LT6 split plenums helps the LT6 make more power?


I feel like I understand intake runner length-related wave tuning and the benefits, but when it comes to what's happening before the intake runner inlet, not so much...

I roughly understood heimholtz tuning of cold air intakes and plenum systems to be a similar concept to intake runner wave tuning, but I don't understand how connecting and disconnecting the two halves of a split plenum intake like this can help...

This isn't just about providing what amounts to a "dynamically larger plenum volume" available to each cylinder above a certain RPM, right?
Is it about some how taking advantage of the chaotic pressure pulses that make their way into the plenum from the valve closing and then traveling back up the runner?


https://www.holley.com/blog/post/everyt ... _crank_v8/

I read SOMEWHERE a description of the strategy that's was used to open / close the valves in the LT6, but can't find it anymore. (Valves closed up to x,xxx RPM then open the front two together, then open the rear valve or somethings similar.)




Adam

[BOOT]

What are the cam specs?

[dannobee]

Since it has a flat crank and doesn't have two cylinders firing right next to each other, the dual plenums can be used to resonance tune the pulses. This is only possible on flat crank engines and boxer style flat engines as you need each side to alternate cylinder filling. Porsche has used similar intake systems with vacuum (and later electric) controlled flapper valves between each side since the late 80's. Obviously they've refined it a bit since they're still using it today. In a nutshell it flattens out the torque curve when compared to an intake without the flapper valves.

Google Porsche intake resonance tuning for more info.

https://www.autozine.org/technical_scho ... haust.html