Optimal Fuel Pressue for Best Performance

Q: What fuel pressure setting will give me the best performance?

A: The stock setting is 42 PSI. Much track testing has showed that any type of increase will greatly benefit both horse power and torque. Here’s some dyno testing on a stock 350 motor which substantiates those claims:

          42 PSI (stock)           46 PSI                    50 PSI     RPM     Torq     HP      Torq/diff    HP/diff      Torq/diff    HP/diff     ————————————————————————     2250    237.7  101.8    254.9/17.2  109.2/ 7.4    275.0/37.3  117.8/16.0     2500    241.7  115.1    262.1/20.4  124.8/ 9.7    283.3/41.6  134.9/19.8     2750    241.5  126.5    275.2/33.7  144.1/17.6    297.0/55.5  155.5/29.0     3000    237.1  135.4    278.2/41.1  158.9/23.5    305.5/68.4  174.5/39.1     3250    233.8  144.7    278.9/45.1  172.6/27.9    311.3/77.5  192.6/47.9     3500    241.0  160.6    278.2/37.2  185.4/24.8    309.5/68.5  206.3/45.7     3750    246.6  176.1    283.4/36.8  202.4/26.8    303.3/56.7  216.6/40.5     4000    250.4  190.7    278.3/27.9  212.0/21.3    298.0/47.6  227.0/36.3     4250    251.6  203.6    272.5/20.9  220.5/16.9    289.1/37.5  233.9/30.3     4500    253.5  217.2    257.3/ 4.2  220.5/ 3.3    277.0/23.5  237.3/20.1     4750    245.0  221.6    242.1/-2.9  219.0/-2.6    266.4/21.4  240.9/19.3     5000    227.6  216.7    225.0/-1.4  214.2/-2.5    237.8/10.2  226.4/ 9.7  

It shows that by increasing the fuel pressure to 50 PSI, results in maximum torque increase of 58 ft-lbs (along with a much flatter torque curve) and a maximum horse power increase of 19 HP over stock. 46 PSI also provides a noticable increase which should work well for day-to-day street driving. An adjustable fuel pressure regulator (see Chap 5.2) is required to increase the fuel pressure.