The problem was that I couldn't provide enough transient enrichment at all speeds or base injector duration beyond 7k. I did suspect the lines and the condition of the pump, or it's basic delivery, which was unknown to me. All the previous cars I've had running engines like Josh's have been competition cars with custom tanks and lines, but still single pump in tank and I always use Bosch or Weber fixed regs in our own or Weber housings, by the rail. The ECU wiring was all my brand new competition spec, a substantially proven set up! Time was running out on that mapping session and I knew there was a fuel delivery issue at high demand; Josh had to leave, so I advised him of the problem and the likely solutions.
Obviously changing the pump to the uprated one was the easiest/cheapest fix to try and my suspicions were clearly correct, because it worked. The whole map needed to be revised. Ultimately he'll still need to run it over half a tank to resist surge and a custom tank would be the best solution to me, I'm not keen on engine bay swirl pots.
Whether or not this particular pump was weak, it's a common problem from what I've seen and leads me to heartily recommend replacing the standard pump when fitting a new higher spec engine, because the old pump is likely to be tired by now regardless.
Footnote; this year I've been working with a friend developing class one Lamborghini powerboat engines, they're reputed to be in the region of 960bhp already and the factory engine has a single -6 JIC fuel line. Surprised me.
Last edited by Sandy309; 19th September 2012 at 06:28.
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