i had one way back, looked at it, trial fitted it, it did'nt fit
ibiza due to bonnet clearance, and woulod never port to fully big port like they said it would. It got returned. The aspect i liked the idea of was dual plenum and its equal filling ability, but its equal filling is also a restriction by definition.. For total flow, high flow, then more is required. The lehmann design which dahlback use was motorsport derived, and as such FIA regs clamps down on intake restrictors, 34mm currently on WRC, so its design premis as such does'nt neccessarily match our unlimited cars. It does flow the most equal of the small port versions tho, but I was surprised how little more it flowed over even a stock mani.
I have replaced my pro-alloy/JS dual plenum (largeport, dahlback inspired) mani, and seen significant gains from this alone. We want flow from our motors, boost is just a means of pumping it through, although some people fixate on more boost more boost, and forget total flow is what makes more power.
Its a case of having all the parts sized to the appropriate airflow you are running.
As it happens, as mine was one of the first to be made for me, I run the largeport 007 mani, with R32 throttle body, and am very happy with it. The flow bench results are indicitive of its potential to flow well, but not the be all and end all in it being the highest bhp intake on a given spec motor (which is muchos variable) - for me 32bhp and 22lbft were gained from this manifold alone, over the largeport dual plenum i ran before it.
Was'nt a back to the dwg board, i could have stuck with it, but my gut feel was it was holding the motor back. Consequently proved to be the case and allowed the motor to break into the 500+ level