i wanted to do this as cheap as possible with no problems. i got a dsm bov that has been slightly crushed for 10 bucks. the guy said it would hold 21 psi. i got an extra uppipe for 15 and the flange is 10. do you think this will hold up to 21psi, i never run over 17 psi. if it doesnt work, ican sell it on ebay. ive seen them going for up to 50 dollars just for the bov.