VVT on Exhaust Valve

On reading the Haynes manual, I was surprised to find that some (all?) of the petrol models are fitted with variable valve timing (VVT) on the exhaust valve and wondered if anyone has explored the system further, or tweaked it? My surprise was that the exhaust valve is varied, and not the inlet. Normally getting the gas out isn't the problem, its getting enough in, but I assume its to vary the overlap to improve low end torque and probably more for reducing emissions than increasing performance? Would be interested in comments here. Are there any models that have both inlet and outet variance? Cheers

I think it arrived with the B41xxT2 engines........

Turbo engines have the VVT pully on the exhaust side to help spool up and N/A's have it on the intake side, unless you have a S60/V70R and they have it on both sides as do new T5's

The exhaust Variable valve timing on the turbo is simply to warm the catalytic converter up quicker from cold by opening the exhaust valves earlier .... so for emission purposes only... The variable valve timing on inlet valves is to give more mid range torque and works all the time in the 3000 + rpm range

Does anyone know which year they added VVT to the inlet (as well as to the exhaust) on the 40-series turbos? My T3 engine has it on exhaust only, I think...

I thought that the 2.5T and T/R series engines have had VVT on both the inlet and outlet cams since 99/00 (well, 2003 for 2.5T). Think it extends to V40/50s in 07/08 with the ME9 (rather than ME7) setup.