Quote:
Originally Posted by Midship Runabout
D4s is for fuel
Vtec/vvti is for camshafts.
They have nothing to do with each other. And you can use both simuntainiously
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Wrong, dead wrong. VVT like vtec/vvti, all of it, is for MPG/Emissions/low end torque whatever you want to call it. You don't need 4 cams in a DOHC to make high end power either but you do need it if you want good high end HP and the benefits of a low end torque band.
Quote:
Originally Posted by Marrk
Using both is the opposite direction I want to go in. I want a solution that would simplify the design of the head, not complicate it.
Honda's VTEC may not be perfect, but they have had zero recorded failures of the VTEC system — a system that has been used in over a million cars. I would hope that reliability would be built into this car that we are already in love with. D-4S sounds like a recipe for all kinds of problems. Maybe is won't turn out that way, but that's how it look on paper.
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In most cases the high volume brands keep their systems pretty simple to keep costs down and maintain reliability. Direct injection is already used reliably on Diesel engines. It's all in the implementation.
Quote:
Originally Posted by Marrk
Again, you peeps are not reading what I am saying.
I am not interested in tuning.
I am not interested in HP (sacrilege, I know  ).
I am not interested in fancy, complicated b.s.
I am interested in relability. And, crazy as it may sound, I believe that simplicity, rather than complexity, is a step towards reliability.
I don't want to go back to carburetors, nor do I want to go back to the horse and buggy. My statement above was that, if you could get the same 200 hp from both, which system would make more sense and make you happiest.
@ Mata: The question imbedded inside my question is: Is this D-4S worth a damn, or will it be like Porsche (drive it every week and fix it every weekend)? |
I get you. But to make 100PS per Liter and still have a bottom end, it's going to need VVT and Direct Injection.
This car is going to be DD or street driven more than anything so I would bet against the Porsche example. We'll have to see really. This isn't the first D4S engine though.