Ask Away! with Jeff Smith: Fuel Pressure Regulators, Brake Pedals,and Accessory Drives

It's a trio of tech Q&A this month in our Ask Away! with Jeff Smith column. We've got questions on proper fuel pressure regulator location, master cylinder sizing, and power losses from engine-driven accessories. 

Why Fuel Pressure Regulators Should Be Close to the Engine
Reader B.F. is planning to swap an LS engine into a Chevelle, and wants to know if he can place the a Corvette fuel pressure regulator/filter toward the back of the car and save the hassle of plumbing a return line back the fuel tank. Jeff turned to Brett Clow at Aeromotive to answer this one.

Basically, the regulator would work at the rear of the car, but not very well as it should, That's because the regulator controls pressure fluctuations better when it is close to the fuel rails and injectors. The further the regulator is from the engine, the less able it is to control pressure fluctuations, which leads to inconsistent fuel pressure at the injectors. Brett has more advice on the subject worth heeding.

Master Cylinder vs. Brake Pedal
J.R. converted his ’64 El Camino to front discs using 1970 Chevelle parts. He used a dual reservoir power brake master even though the car does not have the power brake booster. Now he has a brake pedal that is way too hard.

The problem comes down to master cylinder piston diameter. The larger the piston, the less brake fluid pressure, and the harder the pedal effort becomes. Most GM power brake master cylinders have a one of 1 1/8 inch diameter piston, which is too large with the assistance of a brake booster. Jeff goes into some math to show you how to determine the properly sized master cylinder for any application.

Parasitic Power Losses
G.L. autocrosses a 1971 Camaro, and wanted to know how much power the following parts use at 6,000 RPM:
Flex fan 
Alternator
Water pump
Power steering pump
2 1/2 inch exhaust system with Flowmasters
TKO 600 transmission

Jeff provided not only answers, but also why and how these items consume engine power. Some of the answers might surprise you.