anyone want to make thier non adjustable FMU fully adjustable? look within-->
ok, i wanted to share what i had done to make my paxton nonadjustable 12:1 FMU fully adjustable fom 1:1 to 12:1. most people pay big bux for the fully adjustable FMU's. well theres no need. i was originally going to create my own adjusters & sell them for cheap to help my fellow blower friends but i dont have alot of free time for this & im not sure if interest would arise....
ok, i applied some of my turbocharging knowledge to supercharging. i took a cheap(self assembled) manual boost controller for a turbocharged vehicle & used it in a similiar mannor. this controller is just a brass distribution bock with 2 barbed hose fittings, a 1.5" long allen head bolt, lock nut, a spring & ball bearing. i assembled these parts to create a boost diverter/bleeder that would not bleed under vacuum, only boost. the unit is working seccussfully..........
this controller is put inline on turbocharged cars to fool the wastegate into thinking theres less boost then there actually is so the wastegate stays closed longer building up the boost pressure higher. the screw, spring, & ballbearing control how much boost is allowed to pass. there is a small .050 hole drilled into the body of the brass block. boost bleeds out through this hole & only a small amount of boost can get to the wastegate. as the boost drops or stops, the ball bearing seats back up & doesnt allow vacuum to leak, very clever!
well, i used this in junction with my FMU. this controller allows you to set how much boost goes to the FMU, thus lowering the fuel pressure under boost & adding horsepower as you lean the mixture. YES, precautions have to be taken, too lean of a condition will cause problems. you must guage your fuel pressure, & air/fuel to be certain you are safe. the true tune should be done on a dyno for maxumim benefit & safety. before i go on i must say that everyone is responsible for thier own actions & they should install one of these at thier own risk. im not trying to scare anyone here, these type of FMU's are sold by Paxton, Vortech, ATI etc. to adjust the fuel pressure under boost to get the required ratio. just like changing discs in the vortech FMU's. only difference in the ADJ. FMU's i have encountered for sale by these well known manufacturers, they bleed boost by means of a bleeder screw & cause a vacuum leak under idle!my method will not due to the ball & spring to seal the air!
there will be pics posted after this initial thread wich will help aid all my descriptions & how the unit works as well as how it gets installed. you can do a search online for manual boost controllers, these can be bought for less than $25. for what we are using it for nothing extensive is needed. i may start making some of these if people seem interested. ill assemble them, test them & package them included with instructions. id probably sell them for about $10+ shipping...let me know if this sounds interesting to you. ill be more than happy to help those that want to make thier own. i have 13 years cnc, lathe, robot & fabrication experience. see the pics below of my unit. there are exact designs of this sold on the internet today. harware store bought items fabbed perfectly for its intension............(sorry for the length, i tried keeping it as short as possible w/o leaving major details out)
-justin