calculating procharger boost

I'm running a 3.05" blower pulley and the 7.65" crank pulley. Mods in signature. How much boost do you guys figure? I'm shooting for 9lbs to the motor.

For a stock LT1 Z28 w/ a P600b, Procharger lists the 3.15" blower pulley at 8 psi, the 2.75" at 12 psi, and the 2.55" at 15 psi.

I read here that you can figure 1 lb. increase for every .1" smaller in pulley size. So now it looks like I've got a 9lb pulley (what I thought). How much boost do you think I'm losing to the ported heads and cam? I know I just need a guage but I dont have much use after the first time I check bc I want the car to look stock.

When I installed my CNC Heads with LTs, stock cam, boost dropped by two pounds but HP went up significantly.

Your best bet would be replacing those stock exhaust manifolds for better flow.

I know, I know. Aside from a 12 bolt or 9" that would be the last part I need.

also guys, I pulled the blower pulley off because the bolt was backing out all the time (red loctite anyone). How snug should the keyway hold the pulley on? I could rock the pulley back and forth on the shaft. Is this normal for the P600 because it isnt dual keyed? Should it be totaly snug with no play? If so I need to find a new one in town. If I cant do you think an impact and loctite will keep the pulley bolt from ever coming loose and will there be a risk of shearing the keyway?
TIA

The pulley rocking back and forth is not normal. Check the pulley keyway groove for wear and also inpect the fit between the shaft and key. If just your key is worn then give us a call and we'll send one out to you.

I ran a small 12 rib/ 12 psi setup on the p600b. I rolled the key. The pulley contacted the drive head. Good thing I found it in time. I dont think the p600b can handle 12 psi with that small key. 9 psi worked great. I now have a D1. Larger shaft and 2 keys is much better, and the added 4.44:1 step-up ratio. A taper-lock shaft/ pulley set-up would be a better for the p600b smaller shaft. But. that requires machine work.

Last time the blower was serviced I had the input shaft replaced so thankfully its still in perfect shape. The pulley looks good too. I want to find a key in town somewhere so I dont have to wait but I might have to order one from ATI if I cant:cry: I really wish there was a duel key option but when I had the shaft replaced they said there wasn't. I'm sure the key got rolled from the bolt backing out. I plan on loctiting the bolt and impacting it. Is there anything else to do to make shure this quits happening?
TIA

Make sure you use a good bolt that can streach properly. The stainless bolts that come with my stuff had the same marking that the bolts at the local mom and pops hardware store has. (High Lead IMPORT .....SOFTNESS). Get a bolt from a reputable fastner supplier. ATI Enginneering must have been out-witted by the newbie WALMART MANAGEMENT SUCKASS that is spreading cheapness at others expense at another great AMERICAN company.

Dude, that's really uncalled for. I haven't heard of a fastener failure from brackets or any other area.

I am planning on replacing the bolt with a grade 8 bolt just to be safe. What options do I have with the washer? Locking washer on top of the regulat one?

No, use no split washer, just use the one provided with Loctite 272.

Thanks Mark. I'm going to find a keyway today. If I dont you guys will hear from me.