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it makes a lot of sense in a mx5, and i know someone with a 2jz with vvt and it makes a lot of sense too. it depends on your application. my ute weighs 1600kg unladen, and needs to pull from 1200rpm : supercharger! a lighter ute, without f-in heavy hydraulic tipper would be fine turboed. i also like to have consistent throttle control, so big turbos will always be out for me.
with regard to the bigger valves thing, lets do the math :-)
its all about curtain area. 33mm intake 9mm lift stock for arguments sake.
33/2 times PI = 51.8362788 from my favourite calculator.
times 9 = 466.526509 sq mm
change lift by 1mm and you get 518.362788
change valve head by 1mm and you get 480.663676
i know that this isnt the whole story, but to pick up more flow by going bigger in a valve you also have to increase the port diameter in the bowl, and get a valve job(that you would be getting anyway) or you will LOSE flow,whereas to get more lift with the custom cams that you are already getting made with more duration takes a few quick words to the manufacturer, and stiffer springs/stronger valves.
this isnt about cost/return, its about what people want, and how they should get it. dutch is doing it. good on him. if i had a light vehicle, i'd jump in headfirst too.
have a good day.
Fred.
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