Hi,
I recently began doing a few pulls to measure my 100-200 times with draggy.
I'm DCT on a European E92 335i. IJE0S if that matters. Spraying port meth injection. Running a JB4 and a trebila back end flash.
I normally use 1 step colder plugs. These seem to work best for me. I gap them at 0.45mm (0.0177") and have the BL kit with R8 coils. I know that gap may seem small but it has worked well for a number of years up to around 25 psi. Fuelling appears good during pulls.
On recent logs cylinder 5 has often shown to be lagging behind in the timing. Where cylinders 1,2,3,4 and 6 may be at 9.7*, cylinder 5 might be at 7*.
The interesting thing though is that cylinder 5 doesn't get to x degrees of advance and then drop back a few degrees indicating knock. It always has lower timing than the other cylinders during the whole rpm range. A compression test has shown all 6 cylinders to be almost identical.
I don't know the logic of the DME. Will the DME not allow cylinder 5 to go to the same timing as the other cylinder because it sounds noisy (to the knock sensor) from the start or possibly the oil vapors from the PCV has lowered the octane in that cylinder? I recall many threads in the past on other forums saying cylinder 5 is often problematic.
I've tried changing spark plugs and changing coils. I haven't tried swapping an injector. I don't have an injector tool to swap the injector seals. (Maybe if I swap 2 injectors quickly, that won't matter?)
Anyway. On 2 step colder plugs the timing was alot worse and on multiple cylinders.
So really my question is why cylinder 5s timing is always lower than the other cylinders. Is it knock related or something else?
If it was a lazy coil then I'd expect a misfire to eventually happen but 5 doesn't misfire. The spark plug has been swapped with others but the issue remains.
I recently began doing a few pulls to measure my 100-200 times with draggy.
I'm DCT on a European E92 335i. IJE0S if that matters. Spraying port meth injection. Running a JB4 and a trebila back end flash.
I normally use 1 step colder plugs. These seem to work best for me. I gap them at 0.45mm (0.0177") and have the BL kit with R8 coils. I know that gap may seem small but it has worked well for a number of years up to around 25 psi. Fuelling appears good during pulls.
On recent logs cylinder 5 has often shown to be lagging behind in the timing. Where cylinders 1,2,3,4 and 6 may be at 9.7*, cylinder 5 might be at 7*.
The interesting thing though is that cylinder 5 doesn't get to x degrees of advance and then drop back a few degrees indicating knock. It always has lower timing than the other cylinders during the whole rpm range. A compression test has shown all 6 cylinders to be almost identical.
I don't know the logic of the DME. Will the DME not allow cylinder 5 to go to the same timing as the other cylinder because it sounds noisy (to the knock sensor) from the start or possibly the oil vapors from the PCV has lowered the octane in that cylinder? I recall many threads in the past on other forums saying cylinder 5 is often problematic.
I've tried changing spark plugs and changing coils. I haven't tried swapping an injector. I don't have an injector tool to swap the injector seals. (Maybe if I swap 2 injectors quickly, that won't matter?)
Anyway. On 2 step colder plugs the timing was alot worse and on multiple cylinders.
So really my question is why cylinder 5s timing is always lower than the other cylinders. Is it knock related or something else?
If it was a lazy coil then I'd expect a misfire to eventually happen but 5 doesn't misfire. The spark plug has been swapped with others but the issue remains.
