Just looking around at plenum setups a bit more. YellaTerra have a dyno showing a 17rwkw increase on their website. The BPT front mount plenum doesn't mention power gains but I did notice it uses twin 60mm throttles compared to the YellaTerra twin 68mm setup (then again, size isn't everything, as all us blokes know). BPT did my tune so maybe I should speak to them about their plenum next time I'm up there.
At low engine speeds torque is actually aided by a larger port size and the corresponding lower air velocity (one of the reasons 2V LS1s feel better low down than the
4V Boss V8s - one of the advantages of a 2V head is each individual valve is physically larger than the smaller valves in a
4V setup). Same reasoning is behind the broadband manifold on the Falcon sixes.
Also found a guy on YouTube who did the YellaTerra plenum with 60mm throttle bodies and a tune and he picked up almost 30rwkw. Another reason I like the look of the YellaTerra ones is it uses the factory locations for all the wiring looms/sensors/
PCV etc. No need to dick around with them.
Damn it's tempting to get one now.... the 300rwkw is a nice mark to break.