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EJ257 Cam tuning

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I've decided to put a set of GSC S2 272 cams in my engine so I'm starting to do some research on the AVCS tuning end of things. Does anyone have any experience tuning these particular or similar cams? I'm mostly looking for what I can expect in the low and crusings load areas. I'm just looking to draw off some experience to get ahead of the game a bit.

Dual AVCS.

The general trends of the stock AVCS maps will still be correct however the magnitude of the advance and retard will almost certainly not be optimal. It's a little tricky if you're reflashing as you can't easily make cam timing changes live (unless your platform supports RTT). When full power tuning I'd suggest making a 5 degree change to the entire WOT area of the cam table (either inlet or exhaust on its own first) and assess the effect. You'll quickly pick up what the engine wants to see and what it will respond to. Once you've dialled in one cam table you can repeat it on the other. Doing one cam in isolation like this affects the overlap too so it becomes an iterative process and my process will be to optimise the inlet, then optimise the exhaust, then come back and see if the inlet needs further optimisation. Take a look at this webinar for some more insight - https://www.hpacademy.com/previous-webinars/how-to-dyno-tune-cam-control/

Part throttle is a bit tricky if you can't live tune. The best you can hope to achieve is picking a couple of specific cells in the table, run the engine in steady state accurately in the centre of the cell and monitor torque and injector pulse width. Make a change to the timing and then compare your results. This is a tedious way to optimise the tables but you may have little choice. I normally focus on a couple of cells in the area the car will cruise in and then once you see the magnitude of change required you can extrapolate the trend to the rest of the table. It won't be perfect but it's going to get you pretty close.


Thanks for the detailed reply, this was exactly what I'm looking for. In looked for some webinar content on the subject, but I must have missed that one.

I'm running Cobb's AccessTuner which unfortunately does not give me the option for RTT with the AVCS tables.



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