Originally Posted by gpshumway
1 - The FR-S starts at $25k and it has unique chassis and drivetrain.
2 - The CR-Z starts at $20k, despite its expensive hybrid drivetrain.
3 - The Civic Si starts at $22.5k.
4 - The drivetrain I mention would be identical to the next gen Si drivetrain, possibly minus the header, which is about optimizing powerband for a sports car and doesn't cost much.
The CR-Z is still produced in far greater numbers than the FR-S/BRZ, and despite the "expensive hybrid system," they also sell hybrid powertrains in a number of other cars (Civic, Insight, etc.) that help them recoup the costs of such technology. Pricing a more mass-produced hybrid against a hypothetical mid-engine sports car isn't really a way to gauge its theoretical cost.
Part of the Civic Si's starting price is minimized by the fact that much of its interior and exterior is shared with the rest of the Civic platform and is produced in numbers well into the six-figure range. The development costs and price per unit aren't a big concern at that point since they're shared and don't require much extra. The bodystyle is already there, and the K24 as it is in today's Si is nearly identical to the K24A2 in the earlier TSX and the K24Z3 in the most recent TSX. If there were no other Civic models aside from the Civic Si, rest assured it would cost significantly more than what it does by at least a few thousand. (And if it were its own platform, it would also probably have more aggressive bodywork, which would probably be a tad more costly to produce than its relatively smooth body panels.)
Sharing the powertrain with a future Civic Si would help, but it's not going to just bolt up to a mid-engine layout with ease just because the engine and driving axle are on the same side of the passenger compartment in both applications. Additionally, pushing a 2.0-liter NA four-cylinder to around 250 hp (which is what you suggested) is likely going to require parts and labor that aren't always cheap. For example, the K20s in the JDM CTRs are still a bit off of 250 hp and have upgrades:
Civic Type R: 225 hp from higher compression, larger diameter throttle body, larger and straighter intake manifolds (with resin coating on inner surface, a technique used previously in the NSX) and exhaust
Civic Mugen RR: 240 hp from upgrades above and Mugen cams and exhaust (only 300 cars produced)
Is it doable? Yes. But to hit those numbers with a 2.0-liter is going to need some intensive work, kind of like how different the Integra GS-R and Type-R were in terms of their materials and the assembly process, as the ITR managed another 25 hp over the GS-R from being handbuilt and having cams, valves, forged/polished pistons, etc. Getting a K20 to go from ~200 hp to 250 while still complying with emissions regulations is going to take some work. The S2000's motor is close, but again it has hollow cams, forged pistons and rods that certainly accounted for some of what brought the price to around $30,000... in 1999. So a mid-engined car with more power is likely going to cost more than a front-engined S2000, even before considering inflation. Mid-engine cars aren't the cheapest to produce.
Originally Posted by gpshumway
Given the above facts, please explain to me why my suggestion is so unrealistic. It's $4.5k more expensive than an Si, and $2k more expensive than an FR-S, which shares fewer parts with other cars than my conceptual mid-engine S2000 would. Might it be more like $29-32k? Maybe, but a coupe which shares a transverse drivetrain with the Civic Si could certainly be brought out for less than the $35k S2000 with it's unique chassis and drivetrain plus power top.
Honda used to make the CRX and Prelude, both affordable, simple sports cars with a modest premium over other cars in the Honda lineup with which they shared much componentry. Why is it so unrealistic to think they could do it again?
The CRX and Prelude were both produced in far larger numbers, and their engines were good but nothing too intensive. The H22A was a solid motor (I even was trying to hunt one down to put into my Honda Accord back in 1999 or 2000) but it didn't have much exotic material in it. Also, the CRX and Prelude had FF layouts -- not too difficult to develop and make compared to an MR, let alone an FR.
Again, don't get me wrong... I would love to see the car you are describing at that price point. But I guarantee we will never see a new Honda MR car with a 250 hp NA 2.0-liter I-4 with an MSRP below $30,000.