Just chasing some advice. All ideas welcomed. I have a 427ci RHS block with ETP LS7 heads. Also running an ASE turbo kit with GT4508 turbo. Shaun's manifold, ice coil packs, and the usual other bits and pieces. The car is also running on E85. We're continuing to have a tuning issue. The car runs fine when driving normally, but as soon as we try and get the tune right on boost on the dyno it has been breaking down. Has fuel, has spark. AFR is spot on. Have tried brand new Ice coils, along with the previous Ls1 truck style coil packs which had worked ok on previous tune. Engine is making boost according to gauge and ECU read out (12psi). We've tried 3 different ECUs thinking it was an electrical 'glitch'. Added 3 new sets of plugs (6s and 8s) gapped down to 25thou. Motor is good in leak down test, valve springs are good with seat pressure fine. Thought we had found an issue with the earth from the ECU so fixed that... but no improvement. In fact, the issue seems to be getting worse. It is gradually losing more power, currently down at least 200rwhp on where the car had run previously (>700rwhp). The tuner has been scratching his head, along with everyone else we've run it past. Tech2 shows no issues either, so not tripping an error in that way.

As I said, the car runs fine in 'normal driving', but when it comes on boost it's not happy. No power and misfiring.

At this point we're about to pull the engine and start changing crank angle sensor and cam sensor. Just looking for any other ideas before we set off on that path. Any ideas welcomed... other than a hell of a lot of work we've pretty much run out of them...

Cheers

Tony