Discussion
Because even a car with merely variable cam phasing is more optimised than a old style fixed cam timed engine- you would probably loose torque throughout your normal operating rev range. If you were revving it higher- you would have to rev it ALOT higher to see gains of the newer longer period- I'm talking over 1000 rpms (if your bottom end can even withstand it) and you'd lose lots and lots of low speeds.
The is even MORE the case with something like a Honda VTEC which effectively has two cam profiles, so it varies both duration and timing. It's not worth doing unless you REALLY know what you're doing i.e have an engine dyno and engine simulation package. That means I wouldn't trust a profile from some of the after market profile grinders. With something like an S2000 if you went for a wilder profile at top end and kept the same mild profile you'd end up with a massive hole in the middle of your rev range.
Did you know that the Honda S2000 has 336 inlet periods for the wild cam and 264 periods for the mild inlet cam?
The is even MORE the case with something like a Honda VTEC which effectively has two cam profiles, so it varies both duration and timing. It's not worth doing unless you REALLY know what you're doing i.e have an engine dyno and engine simulation package. That means I wouldn't trust a profile from some of the after market profile grinders. With something like an S2000 if you went for a wilder profile at top end and kept the same mild profile you'd end up with a massive hole in the middle of your rev range.
Did you know that the Honda S2000 has 336 inlet periods for the wild cam and 264 periods for the mild inlet cam?
You could go for a bit of a regrind, if you knew what you were likely to expect, you would know what to specify. I would have a big look at where the zeroed point is and the characteristics. Are we looking at a "wide" cam retarded low or a "thin" cam advanced high? Once you have got the static figures, you can then have a look at the valve sizes/lifts and see what is likely to benefit from being altered. Only then.
If you start playing with the cam profile, it may sod the whole thing up bigtime. However, if you are interested in making your engine scream, a regrind resulting in 10 degrees duration (for starters) should see a considerable shift, all depending on what the start spec was. Post as much information on the valves/ports/bore/stroke/cam as well as final drive/gear ratios. A dyno print out would be good for the engine with VVT and non VVT. I would hazard a guess with that info.
Stu (Likes silly cams)
If you start playing with the cam profile, it may sod the whole thing up bigtime. However, if you are interested in making your engine scream, a regrind resulting in 10 degrees duration (for starters) should see a considerable shift, all depending on what the start spec was. Post as much information on the valves/ports/bore/stroke/cam as well as final drive/gear ratios. A dyno print out would be good for the engine with VVT and non VVT. I would hazard a guess with that info.
Stu (Likes silly cams)
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