STD Cam Timing?

[Tricky-Ricky]

Anyone ever experimented with the std timing using adjustable pulleys, wondering if the torque curve can be brought down the RPM range a bit?

[JohnA]

For starters, I'd try advancing the intake by 4-5 degrees and the exhaust by a couple.
Not a dramatic step, but if it moves in the right direction you can play a bit more.

[Tricky-Ricky]

Thanks John, have made adjustments on N/A cars with good results, but not turbo.

[bondango]

TBH Ricky you really need away of measuring Hp/Trq to do it right, even if its something like an AP22 or the new Gtech Performance meters. Out of the factory things are normally optimised for all round driveability but more importantly (but not to us) emmisions, so without doubt there may be some gains in there. Increasing cam timing on BOTH cams the same amount does increase low end Trq with high end HP being effected.

This is an excellent read, and also gets down the the nitty gritty of Cam timing..
http://www.lotuselan.net/publish/valve_cam_timing.shtml

[Tricky-Ricky]

My I- colour claims to be able to measure HP but, it all just a guess, like most of them;)
i guess I'm just hoping that someone has already done the hard work;)
I am trying to get the best of off boost and spool up and low boost performance as i run hybrids in TTC mode, hence the other question about the maps, and in particular ign advance, if i knew just how much retarded the std map was due to the first turbo spooling up, it would save me a lot of runs with det cans trying to find how far i could safely advance it.

[smarty]

Just re read your first post. Trying to adjust via the CAMs not ecu.

[bondango]

My I- colour claims to be able to measure HP but, it all just a guess, like most of them;)
i guess I'm just hoping that someone has already done the hard work;)
I am trying to get the best of off boost and spool up and low boost performance as i run hybrids in TTC mode, hence the other question about the maps, and in particular ign advance, if i knew just how much retarded the std map was due to the first turbo spooling up, it would save me a lot of runs with det cans trying to find how far i could safely advance it.

Drive your fav stretch of raod and do a few runs on the same stretch and get a baseline Trq figure, then try advancing both cams a few degrees and repeat the process and see if it shows up any noticeably difference on the I-colour?

[JohnA]

Thanks John, have made adjustments on N/A cars with good results, but not turbo.
On turbos the cam effects can be quite dramatic.
You can make the power come on noticeably earlier and with a stronger 'hit' - but it will feel asthmatic at the high rev end.

At some point you can enhance low-revs and lose most of the midrange, while losing less of the top end. This will make it feel very fast but it really won't be if you time it (weak midrange and good top end give you the feeling of an explosive top end, but it could just be an illusion). It's really the midrange that makes the car fast to drive in everyday situations.;)

You can also change the overlap by not shifting both cams at the same angle. This has an amplified effect on turbo engines because it controls reversion, especially on 'undersized' turbos. The stock setup has very little overlap, so if you have a badass turbo you might want to experiment with a bit larger overlap and see how it feels.