Well, intercooling of course can be an option if it is needed. And it wouldn't be hard to get one to fit in the system. essentially it would entail the removal of one length of intake piping and the addition of a different piece and an intercooler.
Boost control is going to be very straight forward and controlled by pulley size. No clutch, although there will be a blow off/bypass valve for when the throttle plates close to keep the oncoming air from slamming up against it. I will tell you why we are going with this system. Reliablility and ease of use are the main reasons, but also, it is my belief that with the very limited rpm range on the 2.5 liter that no other types of boost control should be needed to have an effective and extremely fun to drive supercharged Subaru. If you are below 3000 rpms, chances are you don't want to be running gobs of boost, more than likely you are cruising along at highway speeds or something similiar. You will still have more power on tap than you would stock, it just isn't going to be throwing gobs of air into your manifold, and then the ECU having to throw gobs of fuel in to compensate. It isn't until 3000 rpm that most medium hard driving begins in the RS, and even in stock form revs rise pretty quickly from there until about 5800 then it goes pretty flat. Well, with our kit in place, we believe that the power is going to be in the powerband where you want it, and it will be available very quickly. Since it will be running off of the crankshaft pulley, you will always be running a little boost, unlike in a turbo application where you fall into vacuum when cruising along. So when you get on the gas, that extra power from even the small amount of boost, coupled with the nice, fat amount of torque already in place in the 2.5 liter engine, will propel you up in the rpm rangevery, very quickly. The pulley size we have selected was recommended to us by the supercharger manufacturer based on all the information we gave them about the size of our crank pulleys, rpm range, stock hp, torque and displacement, and of course our boost goal.
We have made no plans for water injection at the moment, but when we start making plans for upgrades and subsequent stages we are planning on looking into the matter a bit more thoroughly. At the moment, it looks like we are going to be able to market the kit as the head unit, mounting brackets, belts, upgraded fuel pump, a Bell Rising rate fuel regulator,blow off valve, and of course all of the intake piping, hardware etc.
Of course this is subject to change based on the actual results and EGT's that we see once the unit is inside the car. As you know, sometimes theory and reality are two completely different planes regardless of what the available facts say.
Some of our biggest concerns had been on upgraded engine management for the higher boost stages, but I think we have made some headway in that direction with some new products which have recently come out that will keep the price in a more reasonable realm.
At the moment we are certain to be offering the stage 1 kit for MY00 and 01, plus 02 RS models, and probably on 98 and earlier phase I 2.5 liter applications, as these were the easiest to add boost to. If we do offer an app. for the 99 it will be because we are approached to do a custom settup. The hot film MAS on the 99 was just too fragile, and would require a replacement which is something we aren't even wanting to get into developing unless it looks like there is going to be demand, and if a project car presents itself to us.
If you have any question feel free to email me. I am also emailing several folks with regular updates on the project so if you would like, let me know and I will add you to the list.