So I picked up a used D1SC stage 2 kit for my 09 GT and require a few odd parts to complete it. I've been reading post after post and as well have talked to Procharger and am still at a loss about a couple of things. First, the cooling fan, Procharger says the stock fan has to go, their slim fan is required. I have seen where some have kept their stock fan, wondering if someone with this kit can chime in on their experience. Also wondered if there is an alternative from the Procharger fan as theirs is stupid expensive. Maybe a GT500 fan? I understand they are slimmer? Second is the pulley size, this one has me completely baffled. I have a stock motor except for Brenspeed NA cams, no long tubes but catless. I'm looking to stay in the 450-470 range. I told Procharger this and they are telling me a 4.13 pulley. I haven't found a single post with someone using a setup like this and staying around that HP range. Most seem to be 4.25 to 4.5. I'd really appreciate someone's input that is running a similar setup. Thanks in advance.
You can run the stock or GT500 fan if you're willing to do a bunch of fab work. The pipe routing of the Stage 2 kits vs HO kits is different, personally I don't see the advantage of the Stage 2 kit, most of the time I wish I had just bought my own pipe and fab it up myself. If you want to spare yourself the headache of dicking with fab work on the fan shrouds, just get the prochargers fan and be done with it.
I humbly suggest getting the ATI Super Damper and matching procharger crank drive pulley. I didn't like the way the procharger crank pulley was fit to the stock crank pulley. The ATI setup is stupid clean for fit/finish with an ARP crank bolt to top it off, and I feel much better about spinning my motor on a performance damper than the OE, it's definitely a better long term investment, but to each his own.
How many psi you see will strictly be determined by what is after the throttle body for restriction and how high you are going to spin the motor/blower. I run the 4.00" Pulley and I see 7psi by ~4500rpm, after that I couldn't tell ya since I'm wastegated for 7psi. I have hit 9psi around 5k/rpm once while I was dicking around with my MBC. The guy that ran my blower before me had a 4.25" pulley on it and claimed to make 10psi and 500whp, but failed to specify at what rpm. You can call Procharger and they will help you size your pulley too (if they say 4.13, just get a 4.00 and shift early, lol). As far as my boost readings, they are based on stock cams/intake/T-body and LT headers. I also have a 4.25 I could sell ya if someone else doesn't hook ya up. Not free though, lol.
To touch again on the fan, it has nothing to do with the depth of the fan/motor itself. It's the shroud. On the PS/DS leading edges of the radiator, the shroud is too beefy. The stage 2 pipe routing runs the pipe right up to the radiator pretty much and sends it down between the radiator and support brace. I suppose this helps keep the pipe tighter to the undercarriage so a lower car doesn't bottom the piping out (haven't heard much complaint from HO owners about it) but makes it a precision PITA fit up.
If you get the Procharger fan, you'll have to do something about your coolant reservoir and Power Steering reservoir. I bought JPC's coolant reservoir that relocates it to the PS strut tower, and bought line/fittings to extend it accordingly. It's roughed in right now, I plan to adjust some of the lines later. But it's an easy move and looks clean. The PS I kept on the procharger fan and zip tied the shit out of the PS lines. The AC lines are the fun ones to fuck with, the procharger drive belt path and crank pulley play all kinds of hell there. Have fun with that lol. I plan on having stainless braided AC lines made to clean it up, AC hardlines suck balls.