Has anybody install a short ram air intake to replace the factory air intake. If so was there any noticeable performance increase in acceleration.

The R2C myself and others have on their G's are relatively "short ram" although I would personally see them as mid-length than short. The only long intakes for the G37 is the Stillen ultra-long and the Injen, everything else is short or mid.

HP for any of the intakes peak around 14hp but even that is debatable. You hear more that feel more with the aftermarket intakes.

I had R2Cs and yes there is a bump in power. The real benefit is the sound imo.

I installed the Stillen cold air intake with the Z-tube in my 04 sport 6MT three months after installing the Stillen catback exhaust and noticed a big difference after the intake was install. Seemed to "wake the car up." Not that it had been sleeping. I think the combo of the two (exhaust and CAI) has some kind of synergistic effect. And it sounds awesome, too. Have not dyno'd car, yet. My 0.02.

do you have any pictures of the install or sound clip?

Here are some pics and a vid with sound.

Stillen Air Box and Conical Filter



MAF Housing



Z-Tube



Exhaust and intake sounds

[youtube] http://youtu.be/W1NnjxnRtGQ[/youtube]

that sounded good man, good job