adjustable cam pulley group buy?

[rgvlee]

Search for "cam pulley" on the group.
Basically was much of muchness. I'd probably go cat anyway.

[simon k]

if its possible it makes sense. I was thinking more along the lines of just doing 3 power runs and logging it with nefmoto to see which gave the best MAF curve. I have no idea how the inlet cam is keyed into its sprocket. The inlet cam has the cam position sensor on it. I don't know how many degrees of freedom its allowed (how far out of the expected window vs the crank signal) it can go before the ECU has a wobbly. Gav did mention that the ECU is always watching with cam timing changes. It could be that beyond a certain threshold you need to set the cams back to zero and just be going for a different grind - nor sure at the moment.

it's irrelevant to the discussion, but the ECU shouldn't care - it's still only 2° of advance on the inlet cam... the adjustable pulley has lots more than that on it...

[sambb]

The ECU does watch though, I think to monitor the VVT. On my other engine I was getting " inlet cam not retarded in time" or something like that errors which was probably the VVT system needing an overhaul. The only way it could know that is by comparing the inlet cams pulse/position (exhaust not monitored) versus the cranks? So if its new zero position is say 2 degrees advanced then it stands to reason that it might not reach retard setpoints in time and maybe generate that same code? Possible but I really don't know

[Sydneykid]

The ECU does watch though, I think to monitor the VVT. On my other engine I was getting " inlet cam not retarded in time" or something like that errors which was probably the VVT system needing an overhaul. The only way it could know that is by comparing the inlet cams pulse/position (exhaust not monitored) versus the cranks? So if its new zero position is say 2 degrees advanced then it stands to reason that it might not reach retard setpoints in time and maybe generate that same code? Possible but I really don't know

It depends on how the ECU interrelates the triggers for the camshaft angles (inlet + exhaust) compared to the crankshaft angle. i'm no VW ECU expert but most tolerate a couple of degrees variation to allow for chain/belt, guide and tensioner wear. Keeping in mind that 1 camshaft degree = 2 crankshaft degrees.

Cheers
Gary

[sambb]

If it was an issue you could theoretically offset key the cam pulse wheel back to the standard position? I assume that the independent cam conversion shown earlier has some way to deal with that.

[simon k]

if it's worth doing, I'm sure it's a case of solving the problem if it arises - looks like the cam sensor is just 4 slots in a pressed steel bucket. It's probably on its own keyway

[sambb]

yeah it us from memory.

[rgvlee]

Anyway price up the cat cams gear and let us know. Ive probably got a timing belt to do at some point and i like wasting my money on things i dont need, this fits the bill perfectly