oh damn i think you could have gone past 21psi if it were tuned but how in the heck did you end up with a spike in boost like that,thats like 13psi more. i have seen some write ups a of people using vitaras,eagle rods and arp stuff. running 25-35psi and running this on stock sleeves with a block guard and head work . google it there are write ups on it going back to 07 i think 1 guy in puerto rico claims he was the first to use vitaras in his sohc.Originally Posted by -S Double C-