I built a engine forged conrods and pistons (slightly higher compression) stock head. Hardware mods: Large front mount intercooler with upgraded boost pipes, Downpipe 76mm, Full stainless 76mm exhaust upgrade, Upgraded coils, Duel Hybrid turbo (IS38), Water-methanol injection system 50/50 mix ratio.
I started the engine and did all basic adaptations and settings. All ok. Drove the car for about 3000km on the stock tune with decat off only. No issues. Thereafter i loaded a mild tune 1.4 bar boost for 91 octane for daily use. after that ive tried a bunch of revisions and also used purchased tunes but with all of them i got the same error.. I get cylinder pressure too high. then EPC light and limp. After switching off and again on the car runs fine again. This happens only under higher load and boost. Not normal driving. Also especially higher rpms.
Initially the car was a full stg3 setup but customer was under the impression it has a forged engine..which was not the case and it threw a rod. Customer brought a donor block and we reworked everything and rebuilt. All OEM parts used except for the upgrades.
I logged the car in stock form and get quite a bit of knock retard on the stock tune already. up to -10 deg retard on random cylinders.
No missfire detection or any other codes. I think this is caused due to more engine noise from the forged internals and also in combination with the slightly higher compression. (9.5:1) Mahle (82.5 Bore). The engineering bored to specs given on pistons by mahle for street use. Clearances is bigger than OEM clearances obviously and i figure this makes the knock sensors read more noise and ecu sees this as cylinder overpressure.
Have anyone had this problem before?