I'm looking at a vortech with 2 crank pulleys and 1 blower pulley. The crank pulleys are 6" and 6.66" and the blower is 3.33. Is the lowest I can run with these combo's 6psi? It has custom hard tubes also so I'm sure the boost will even be a little higher. I don't want to run more then 5 really. I have a zz9 cam with stock iron heads with a vavle job. That's all for main engine mods besides bolt on's. What size pulley's should I run?

 

The stock 6 psi system from Vortech uses the 6"/3.3" pulley combo. The 6.6" crank pulley will probably get you up to 8 psi. I run the 7"/3.3" combo through an aftercooler and have the Brad Brand hard intake tubing and get 10 psi through mildly ported heads.

 

Ok, so if I want to run less then 6psi with the hard tubes is there a combo for that? Do they make a bigger blower pulley? Smaller crank pulley? I'm trying not to blow my engine up too soon lol. thanks.

 

Even if Vortech makes a bigger blower pulley, it may be a challenge getting things to fit. My 3.3" pulley is in close proximity to the upper radiator hose and bypass tube. One option may be to shift sooner as boost is a function of rpm.

 

Well I don't think the rad hose will be too much of a problem since my setup is totally custom in my car and I can just make a new one My trans shifts at only 4500rpm unless I shift it by hand lol. I could also just loosen the belt up so it slips I guess I could just run the 6psi if I had to...It's just that I don't have any knock system on my car and possibly have cast pistons cause the previous owner of the engine keeps getting confused about what is in there. So I was a little worried about those 2 things.