#617, "RE: HRC turbo fuel system (Check valve and fuel mapper)" In response to In response to 2
The check valve doesn't look particularly special. All it does is allow air to flow one way but not the other. So basically, it's about a one inch wide round plastic piece with smaller nipples on both sides. On one side a vacuum line would be connected. On the other side, just open to the atmosphere. This would allow excess boost to escape after the FPR is done with the signal and then close during vacuum to not allow air to come in the other way.
As far as the fuel mapper, it serves the same function as the VC1. Also, sounds somewhat similar to a check valve except it's electronic in nature and not mechanical like a check valve. (It's also known as a "pentantiometer" in the engineering community) Instead of bleeding off excess air, it bleeds off excess electricity that acts as a message sender from the map sensor to ecu. The excess message would come when the map sensor reads anything over 0 hg/in. of vacuum or just under 1 psi of boost. TO equate that in an electical format, thats anthing over 4.7-5.0 volts. That's a range where the ecu does NOT want to venture since at that air reading/voltage, the ecu will be delivering maximum fuel potential. It of course doesn't realize that when a vc1/fuel mapper is applied. Our cars with an upgraded fuel pump however are capable of delivering enough fuel to serve a stoichiometric ratio to around 10 psi's of boost. Just goes to show you how much extra they build into cars nowadays.
Jason 98' Eagle Talon ESi-T Mitsu Super 16g Turbo(HRC)
