Markus Strobl's $3 Fuel Pressure Regulator
I made my own adjustable fuel pressure regulator yesterday. Total cost was $3. What I did was make my stock regulator adjustable.
The fuel pressure regulator (FPR) has two parts. A wet part where the gas is and a dry part. The purpose of the dry part is to regulate the flow with a spring. The spring presses against a membrane, regulating the pressure. If the spring pressure is changed, the fuel pressure is changed also.
There's also a vacuum fitting. When the engine is in a high vacuum condition (idle, deceleration), fuel use is low, so the FP is lowered.
First step is to open up the dry part of the FPR. It is crimped on so it needs some violence to give in. Once the dry-part cover is off, I drilled a 1/4" hole in the cover, next to the vacuum fitting. Then I spot welded a nylon locking nut on it. I then screwed in a bolt, with the head on the outside of the regulator. A fine thread bolt & nut should be used.
To be able to lower the FP below factory spec, I cut 1 1/2 turns of the spring. I placed a hardened steel washer between the spring and the regulator bolt.
After reassembling I sealed it with sealer, waited an hour and checked for vacuum leaks.
Reinstalled the FPR and turned on the ignition. Hmm... 20 PSI. Turned the bolt in a couple of turns and pressure bumped up to 40. Started the engine and checked the adjusting range. Went up to 50 PSI easy. Didn't try more as the engine was starting to run alittle rough at this high setting. Set the FP back to stock, 43.5PSI.
The reason I built this FPR is not that I have a FP problem right now. It's for future use and I also wanted to see if it could be done.
Total time including removal/reinstall was 3 hours. An aftermarket FPR is over $100 with many in the $130-$150 range, so I feel good about saving some $$.
Markus Strobl 96 Z28 6M Black. Borla, !CAGS, 1LE shaft, B&M Shifter