anyone have or used this setup? power gains? also do you have to use the s2 hardware/egr kit?

 

This is a pointless modification without some serious cams/compression setup or a turbo setup. The loss of the secondary butterflys will murder your lowend for daily driving as well as probably cause a lean condition.

My advice would be to spend the money on a fantastic header that is designed for your application as well as some 2.5 inch exhaust piping and a decent muffler of your choosing. Then, move to cams as well as valvetrain and possibly Type S pistons or something of that nature.

The stock IM has been used in setups making in excess of 500 WHP. It is not the bottle neck. The exhaust system is.

 

I have this fitted, but like 98typesh has commented, it is really only useful and "fully" beneficial once you have cammed, ECU'd and increased the CR or FI your engine.
Otherwise, like mine at the moment (above work yet ot be undertaken - NA), it will only sound a little louder on VTEC engagement, and might lead to a whole host of idling problems etc.
Your best bet is to remove the fast idle valve under the OEM TB, and blank off the holes. I used a very rough grit paper to score the bypass passages and then used Glass Fibre Filler (or Bondo in the US) to seal the holes up. Then just sand the surface smooth.
Idle is perfect, and no air leaks. Just bypass the hot water pipes with a single pipe and take it from there. May not add any HP but allows you to smooth the TB internal bore a little, but will probably make zero difference.

Beware tho with Skunk2 TB, as they dont provide you with the MAP sensor take off adaptor. I made mine from aluminium and a little bit of copper pipe brazed together and then sealed to the TB MAP sensor hole. You'll see what I am talking about if you already have the TB.
Skunk2 have said to me that they are releasing an adaptor kit for the MAP sensor take off vac port.

Hope this helps.

Mike