Water on the POD does not = Bang!
Dave you go check the GRP-A Setups, Go put a AF & AT sensor in each throttle, an measure the restriction you'll be getting, it's simple science. I even remember this.
When aire is diverted off another pipe there will be concentration losses causing a diverse change in the air pressure, This causes a static like effect which will divert the air down a less restrictive passage, One throttle body will be getting more air because the V join that it hits will be causing the air to hit that center section of the split an it will cause the air to choose a passage, after enough flow the air will polarize an pick up a slight charge an it'll choose the most diverse passage for the air to flow.
Why'd the GRP-A Have a single... It was factory.
Why'd the WGR intake have a single... Wasn't run with any AT or AF sensors.
I know 3 people that have made this mistake personally, until there mech's suggested having sensors fitted, they found running 2 single intake pipes to the air box, an ducting the air box underneath was a more direct an even air flow into the manifold causing for a better response, Meaning when the air goes into the plenum its not comming in at two different pressures causing a tornado effect in the manifold.
Just think about it, have a bit of a read, Discard anything i actually know about this whatever.
All in all it was just a suggestion an a D-TB is still awesome.
Cheers
MaT