Automotive News and Motor Trend say the engine will be 3.5 liters or no larger than 3.5 liters.
Edmunds is the one who is assuming 3.7 liters.
Honda remains silent on the actual displacement.
I think until Honda announces we can't assume anything about the displacement.
I'm also thinking the power output will be one of the last things specified.
I'm sure somewhere in Japan this engine has been running on dynos for some time with a variety of turbo boosts, cam timing etc.
Honda is very good at this and I'd think at some point they'll choose a tuning set-up that will yield the torque delivery and reliability they want for the road car
No doubt they've taken the engine to very high levels of boost and cam timing to see what can be wrung out of it for racing applications, type R versions and so on.
I think it was in 1988 that the Honda 1.5 liter 80 degree V6 turbo F1 engine was putting out 675 hp at 12,500 rpm or 450 hp per liter.
That's 25 years ago so with today's electronics, alloys, injection and turbo systems I'm sure it would be higher.
Our NSX by comparison seems to be a pretty mild tune with perhaps 500-525 hp at 9000 rpm.
I wouldn't be surprised to see a racing version of the NSX engine come close to 900 hp depending on the boost allowed in the rules.
In short I don't think displacement will be as important as the bore/stroke relationship and weight of the spinning components.
Larger displacement means larger heavier pistons, rods, crank etc. and I would think Honda has considered all that in deciding on the final engine size.
The choice of going turbo may have come down to the Honda policy of using V6 engines and the total weight of the new NSX.
Perhaps they felt they couldn't reach the performance goals with an NA engine and needed to up the power without making a larger heavier engine.
In any event, as Dave says, how the new NSX drives, handles, sounds and makes you feel as an owner is the most important aspect.
I think Honda will blend all the variables into another great car.
