4 degree Offset Cam key

[thewildblue]

Hello guys,

Have any of you tried the 4 degree offset cam timing key from here

https://928motorsports.com/parts/offset_camshaft_keyset.php

I've been doing a bit of reading and on the NA 8V it seems to make a nice difference in drive ability. I cant seem to find many results with the S2 though. I understand that you lose a bit of top end due to the advance, but you would gain elsewhere, which is where its more useful on the road.

Your thoughts ?

 

[zcacogp]

There is built-in adjustment on the cam sprocket so I'm not sure why you'd need a key like this.

I guess it will allow you more adjustment than you can get with the slots on the sprocket but I'd then be wondering how much adjustment you'd need and question whether it's necessary. Porsche knew a thing or two about engine building when they made the 944's and I tend to approach things like this with a degree (see what I did there!) of cynicism.


Oli.

 

[PSH]

Can't help directly with the question but if the NA is the same as the turbo and IIRC, it's been a while since I played around with this, but have you looked at adjusting the timing using the ECU 'FQ' switch?. This will increase your fuelling too...I just can not remember the options now....'0' setting is normal though. FQ is 'fuel quality' which increases fuel to compensate for low octane fuel but it also changes the timing.......

Pete

Edit: reading the link I may have missed the overall goal..ie more, low down torque...this may indeed need a mechanical solution rather than electronic....

 

[vitesse]

The key to it all is not having to explain your puns!

 

[zcacogp]

The key to it all is not having to explain your puns!

Not bad, Colin. Not bad at all.



Keep working on it and you stand a good chance of making someone smile (or even giggle) a little one of these days! []


Oli.

 

[vitesse]

Oli-thank you for your encouragement-I will keep on trying.

That apart an interesting subject -stepped keys have usually been used to correct a machine shop *ock up -I would have thought that the best way however is the adjustable camshaft pulley used with a DTI on camshaft lobes to optimise the cam timing rather than a fixed set of phase alterations.

Personally I have never accessed the ECU's on our cars but have noticed in the Porsche parts diagrams, the keyring like dongles associated with the ECU-do all the 2.5 L engined cars have this facility to tweak performance?

 

[TTM]

As said a cam key is not needed on the S/S2/968 as they all use the same cam pulley which is already adjustable. The cam timing is a pain to adjust as described in the workshop manual though there is no other way to do it properly.
Anyway after a top end rebuild on the S2 I adjusted the cam timing by trial and error - more advance will bring more low down torque and lose top end power, while more retard should give the opposite results though there is a retard point past which the engine will feel gutless at every speed. For a completely standard S2 this is something I would not play with.

I also played much with varying the cam timing on the turbo and would say that advancing it too much will cause detonation at higher rpm, though that was on a much modified engine that breathes a lot better up top (better turbine, exhaust and intake) than a standard-ish one.