Originally Posted by blur (Post 165539)

I hope mazda comes out with a high mpg 240hp 2+2 coupe that looks like the rx7...

and nissan debuts the s16 naturally aspirated inline 4 producing 240hp as well...

both coming in at 2900 lbs ish wet :)

Originally Posted by OrbitalEllipses (Post 165550)

Keep dreaming.

Originally Posted by OrbitalEllipses (Post 165550)

Keep dreaming.

Originally Posted by serialk11r (Post 165486)

mmm 1.6L is quite a bit of displacement (3.2L equivalent), if they can hit 20/27 EPA that would be pretty phenomenal IMO. If they can get BSFC to within 10% of traditional piston engines they could squeeze those numbers out.

With a 1.6L engine with significant combustion efficiency improvements you'd be (hopefully) looking at well over 300hp though, since those rotaries rev so high. 100hp/L happens at about 7500rpm redline or so (power peak somewhere in the low 7000s such as on the FA20), 9000rpm gives you over 120hp/L on a well designed street legal engine (such as the S2000, which hits max power in the mid 8000s). 9000rpm with a 1.6L rotary with comparable efficiency to a piston engine would be like 3.2*120=380hp at a bit over 8k rpm :O. The Renesis managed like 230 out of 2.6L effective displacement with a really high redline, so its BSFC at peak power was probably about 25% higher (assuming comparable volumetric efficiency to the F20C). A lot of the fuel consumption is attributed to poor combustion, and so if they can fix the fuel consumption they should be able to increase the power output.

Originally Posted by Zaku (Post 165818)

What is the world avg. Mpg standards for about 2014 to 2016 cause i highly doubt 27 avg would pass @@ i might be wrong though

Originally Posted by Dimman (Post 165785)

One of their big hurdles is they can't mess with their intake and exhaust events, since they are fixed ports rather than phaseable cams. They have their work cut out for them...

Originally Posted by serialk11r (Post 166319)

That's true, although I think that matters more for improving torque at different points in the rpm range than emissions and whatever. Set up the ports for very little overlap, set up intake for high rpm power, low rpm VE goes down and fuel economy goes up. Of course, this is given that they can figure out the rest of the problems first.

Now the little overlap is bad for power, but one of those electric turbo systems could nicely take care of the problem and give efficiency improvements, albeit at higher cost. But we're talking >400hp anyways :P

Originally Posted by Dimman (Post 166342)

They've mentioned the rotary in the context of the generator engine in a Volt-type hybrid in the past as well. This may be more realistic.

They are un-nervingly smooth, and can probably be tuned to be very efficient at a narrow rpm, and just spin there until the battery's charged.

Originally Posted by serialk11r (Post 166357)

As an electric power generation unit peak efficiency would be most important as you know. The challenge I see here is that the surface area to volume ratio on these things suck, so they reach peak efficiency at 5000rpm or something whereas piston engines of comparable displacement reach peak efficiency usually no higher than 3000rpm. I imagine 5000rpm is a bit noisy. If they can redesign the seals as described in the article, friction could be much less of a problem compared to piston engines though, and it would be promising.

Oh right, does anyone have any idea how the friction of a rotary compares to a piston engine? Rotaries have inherently less friction in the design, but I remember reading that because of sealing considerations they have more? friction.