Do It Yourself AFPR
Thread Starter
Advanced
Joined: Dec 2004
Posts: 82
Likes: 0
From: Kalamazoo MI
Do It Yourself AFPR
On the 3rd gen site there is a tech tip for a do it yourself adjustable fuel pressure regulator. Basically you remove the cap, weld a 1/4" nut on it and put a 1/4" bolt in the nut, install a ball bearing on the diaphram, and put it back together. Has anyone tried it?
Burning Brakes
Joined: Jan 2006
Posts: 847
Likes: 0
From: Colorado Springs CO
On the 3rd gen site there is a tech tip for a do it yourself adjustable fuel pressure regulator. Basically you remove the cap, weld a 1/4" nut on it and put a 1/4" bolt in the nut, install a ball bearing on the diaphram, and put it back together. Has anyone tried it?
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Le Mans Master
Joined: Feb 1999
Posts: 9,916
Likes: 38
From: South Carolina
St. Jude Donor '03 & '05
injectos at whatever pressure you need all the time, instead of relying on the regulator to get it where you need it.
Thread Starter
Advanced
Joined: Dec 2004
Posts: 82
Likes: 0
From: Kalamazoo MI
From what I can see in the advertisments in the magazines, it looks like all that comes with the kit is the cap, new bolts, and plenum gaskets. Seems like a lot of money for so little product.
Melting Slicks
Joined: Mar 2001
Posts: 2,149
Likes: 302
From: Timra, Sweden
injectos at whatever pressure you need all the time, instead of relying on the regulator to get it where you need it.
With this mod you raise fuel pressure at idle and low throttle. During WOT it is the same as before. The ECM will detect a rich condition and try to lean down the engine when you cruise. During WOT it will run lean - BAD.
The fuel pressure regulator is a REGULATOR to keep the differential pressure over the injector constant. With a constant differential pressure over the injector each mS of fuel spray will deliver the same amount of fuel. If the differential pressure varies then the ECM has no control over fuel metering.
The vaccum hose is there for a reson
To raise fuel pressure you should increase the preload of the spring in the regualtor. By welding a nut to the cap and have a bolt that move the spring retainer you can adjust the spring preload. Aftermarket AFPR are just that, a new cap with a nut and a bolt to move the spring retainer.
Last edited by JoBy; Jan 16, 2007 at 06:51 AM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
So basically by removing the vacuum this guy just set the pressure at WOT pressure, which is high. Interesting. Why do we need the regulation of the regulator on our engines. Why not just have the
injectos at whatever pressure you need all the time, instead of relying on the regulator to get it where you need it.
injectos at whatever pressure you need all the time, instead of relying on the regulator to get it where you need it.