Most cars don't have it, most 300's have a 2 setting setup and some cars (Ferrari's, new Hondas etc.) have continuously variable valve timing AFAIK.

 

My question is, does neone know how much all this affects performance. Does it only matter at really high revs, and is there any way to compensate for not having it ?

Yea fit a nice set of Tomei cams and solid lifters,your variable valve timing then goes in the bin;)

Incidentally I think from '96 onwards in the states, the TT had adjustable cam sprockets on the intake. Or was that exhaust - one or the other!

 

There's no real way of compensating for it, whatever you do will be a compromise.. VVT is just a way of altering that compromise so that it suits a broader band of driving.

 

If I recall, the VVT will increase the valve overlap as the revs go over 4000rpm - actually I could have that the wrong way round, my brain has gone to sleep today..

 

But anyway, it's there to keep good top end power without losing bottom end torque.. So with adjustable (fixed) cams & sprockets on there (like the Tomei ones), you'll be able to alter the cam timing to increase bottom end torque or top end, basically to move the power band around to suit your driving style, engine and mods..

 

Er did that all make sense?

So with Tomei cams and solid lifters you don't need VVT, or does that mean you have it......I don't understand !:( :confused:

With Tomei cams & lifters you don't have VVT..

 

However your car will be more of a compromise..

 

Ok that's not a problem for most of us, we are after balls-out performance.. But consider this;

 

The VVT is really there to make a cammed car more driveable at low revs, rather than increase the power.

 

So with Tomei cams you will probably lose a little bit of that 'I can pootle around in 2nd with my foot off the throttle' driveability, BUT you'll gain a ton in the top end, because you can tune the cam timing to exactly match your other mods (intake, filter, ECU, injectors) rather than it being a factory compromise..

Thanx - got it !

 

I remember reading about the 300 being developed with 2-setting VVT, so that the car didn't have a rough idle OR low power top end.

 

All makes sense now - Cheers. Guesss some of you like a little rough idle - sounds sportier no ?

I dunno about liking a rough idle - but if it gives better power where you want it, who cares :D

 

My Ren 19 used to idle like cack, and go like stink.. That was nothing compared to the Clio Group N car I saw, idle.. what idle? chugga.. chugga chugga.. chug.. chugga chugga chugga.. Lol.

 

Anyhow, yep the 300 is only two setting VVT - on or off..

 

It's hydraulically actuated - there is a solenoid on the end of the cam (bulkhead end) that either lets oil in, or doesn't, which forces a helical gear around in the cam end, altering the timing.

 

Not bad for 1980's technology..