I have a 2004 GTX Supercharged but not intercooled, I have a solas 13/20 impeller that I am only getting 6900 RPM's and everyone tells me I should be getting 7600 with the stock inpeller I get 7600 but when I put the solas in I loose. I had a blow off valve on and was told that I was loosing boost thru that so I took it off and put it back stock and am still only getting 6900 rpm's. I live in Wichita, Ks is there a possibility that the 13/20 pitch is not right for where I live since there are alot of factors that go into what pitch etc. you should be at? I have purchased the intercooler thru Greenhulk however have not installed yet as was trying to get the rpm's right first.

Thanks for the help.