Fuel System Design for a Supercharger
Posted: Mon Sep 05, 2011 8:17 pm
I've been planning and accumulating parts for the new powertrain for my tow rig. I had planned on a Ford 5.0L stroked to 347 CI with a truck spec EFI setup and an MSII. My plans changed a little this weekend. I bought a supercharger kit designed for the intake system I planned to use at a swap meet. It's a Kenne Bell twin screw blower. I got a great deal on it and I'm thrilled. I think it will fit really well into my plans and needs for the truck.
All the important stuff and the original installation manual is there and in great shape, but a few of the misc. pieces are either missing or in rough condition. In reading through the manual, all the stuff that is missing or junk is designed to fool the stock speed density ECU into running the engine correctly and raising fuel pressure under boost to meet fuel demand. My thinking is that with the MSII, I can simply eliminate the FMU and all that other stuff, run a fuel pump and injectors that are large enough to meet fuel demand under all conditions, and tune it from there.
My concern is what the larger injectors will do to driveability. I'm NOT building a race motor here. It's a driver and a trailer puller. I need it to have excellent manners at idle and part throttle as well as lots of torque and power at wide open throttle. It will be limited to about 4500-5000 RPM max and I'm figuring on about 425-450 HP. I've calculated the needed injector size to be about 36 lb. The stockers are 19 lb. Will I have issues with the injectors being to large for a smooth idle and low speed operation or am I worried about nothing?
All the important stuff and the original installation manual is there and in great shape, but a few of the misc. pieces are either missing or in rough condition. In reading through the manual, all the stuff that is missing or junk is designed to fool the stock speed density ECU into running the engine correctly and raising fuel pressure under boost to meet fuel demand. My thinking is that with the MSII, I can simply eliminate the FMU and all that other stuff, run a fuel pump and injectors that are large enough to meet fuel demand under all conditions, and tune it from there.
My concern is what the larger injectors will do to driveability. I'm NOT building a race motor here. It's a driver and a trailer puller. I need it to have excellent manners at idle and part throttle as well as lots of torque and power at wide open throttle. It will be limited to about 4500-5000 RPM max and I'm figuring on about 425-450 HP. I've calculated the needed injector size to be about 36 lb. The stockers are 19 lb. Will I have issues with the injectors being to large for a smooth idle and low speed operation or am I worried about nothing?