Hmmm, that's an interesting point. Presumably all they've done is remove the 'late' inlet valve closing that they use to make a Miller cycle like 'Atkinson' simulation. Got me thinking, seeing as the VVT on all of todays Toyotas is electronically controlled from an ECU, surely you should be able to 'rechip' these models with an aftermarket piggy-back/replacement chip to alter the inlet valve timing under certain conditions to give a low power / high efficiency Atkinson-cycle like effect? Could this not then mean that the Prius style Atkinson-cycle effect could be added aftermarket to all new Toyotas, ie doing the reverse of what they've done with the track Prius, with just a rechip?can an engine having its peak power at 6500 rpm still use the Atkinson cycle ?
From the description, it sounds more likely that they replaced the long dwell intake cams of the Prius with normal dwell length. Quite possibly just substituting an Echo engine (same block, different valves/cams). It probably wasn't just a "rechipping", so an aftermarket Atkinson-cycle kit for other Toyotas probably requires a new intake cam with the longer dwell as well as "rechipping".clett said:Hmmm, that's an interesting point. Presumably all they've done is remove the 'late' inlet valve closing that they use to make a Miller cycle like 'Atkinson' simulation. Got me thinking, seeing as the VVT on all of todays Toyotas is electronically controlled from an ECU, surely you should be able to 'rechip' these models with an aftermarket piggy-back/replacement chip to alter the inlet valve timing under certain conditions to give a low power / high efficiency Atkinson-cycle like effect? Could this not then mean that the Prius style Atkinson-cycle effect could be added aftermarket to all new Toyotas, ie doing the reverse of what they've done with the track Prius, with just a rechip?can an engine having its peak power at 6500 rpm still use the Atkinson cycle ?
