The whole H.D. new product release got me wondering about vvt ( variable valve timing). The Pan America uses it while the new Sportster S does not. My question is this... with vvt is there a need or even an application for a higher lift cam, or would higher performance simply be a computer tweak thing?

 

Most VVTs are there for emissions. Can the work performance into it? I'm sure but emissions is the reason why VVT is used. If you want increased performance reflashing the ECM along with tweaking the exhaust and intake would be the options on engines like these.
I wonder why the S doesn't use it.

 

Well, first, the Sportster S does indeed have variable valve timing. It's a different engine from the Pan America, engineered for more torque earlier and across a broader range than the Pan America supplies. The Pan Am, on the other hand, is engineered for more horsepower.

Second -- why do you think you'd need or even want a different cam? With 150 horsepower in the Pan Am, that's about as much as we see from $10,000 engine upgrades to high-spec 128 kits on M8's. But stock. These bikes just plain may not need any sort of higher performance upgrades at all.

 

Oops, my mistake

 

There''s an advantage to performance cams just like in any other engine. Stock cams are usually conservative and the manufacturer is bound by the EPA, joe blow isn't. No doubt someone is already working on and testing some, the question is how difficult with they be to change? Is it an engine out operation?

 

In Toyota world, VVT is not emissions related, but for performance. You get the advantages of a "mild" cam at low RPM and the shift and valve overlap at high RPM. I suppose one could argue that emissions are also better because you don't have that lumpy inefficient low band to deal with, but performance is the main advantage. Toyota's have had VVT for >30 years. Not all of them, but the performance ones at first and I think most of them now, and they have gone on to VVTL-i, or Variable Valve Timing with Lift and intelligence, or something, where the valve timing will change a variable amount, not just "on" or "off" (the 'i') and different lift from an actual different cam lobe. I have 6 Toyota motors with some form of VVT and 3 without. Mild cams are great for driveability and you get to keep that and still have a screamer on top.