Hi, I have a stock 6.2 with a D1 on 10 psi, headers and catback. High and low pressures were falling off so we put in a high flow lift pump. Seems low pressure is still not where it should be and rail pressure is still nose diving after 4000 rpms and the engine will only take about 10 degrees of timing on a long pull, even when at .81-.85 lambda. When I command 12 degrees it knocks which seems a bit low to me. I'm thinking the low rail pressure might be causing the engine to not take much timing. What do you guys think? Also getting a P2635 (fuel pump 1 flow insufficient)
10 degrees.hpl12 degrees.hpl16 silverado THS supercharged modded 13.hpt