Car Magazine just announced a scoop on the 981.2 models - Porsche's Boxster and Cayman are reported to be powered by 4 cylinder turbo motors. This comes on the heels of the news that the 991.2 will feature turbo engines across the board, similar to the Macan S and Macan Turbo today. (both are turbocharged motors, differing by displacement.) Turbo charging has come a lot way since the 80s, the last time turbos went mainstream.
In the face of ever increasing government CAFE standards here in the US and others in Europe, turbocharging results in the power of a larger displacement engine with the efficiency of a much smaller one. This is, of course, if you can keep your foot out of the throttle - often times, due to increases in heat ingested by the motor (PV=nRT - when you compress a gas, it heats up) turbocharged motors do WORSE when you drive them hard. That said, Direct Injection has made a huge difference in turbocharging, both in terms of lag and charge cooling due to evaporation in the cylinder, which keeps knock down without having to dump too much fuel. Direct Injection (as opposed to Port Injection - DI injects the fuel directly into the combustion chamber, rather than before, increasing atomization with higher pressures, and enabling much leaner mixtures both under cruise and heavy throttle.) and advances in turbo technology (lighter wheels, more efficient turbine/compressor wheel shapes, etc) has made turbo cars much less of an on off switch (I'm looking at you older 911 Turbo!) and more of a natural feeling power curve with a broad torque band.
Car Magazine reports that the 981.2 Cayman and Boxster will look like the following:
370 hp and potentially lighter weight sounds pretty fantastic to me. The Cayman and Boxster are already some of the lightest sports cars you can buy with a decent motor and going to a flat four maintains their low center of gravity but potentially lowers the weight. This could be, of course, be offset by the turbocharging itself - Typically, the ancillary components of turbocharging weigh quite a bit more. For example, a cast iron manifold that has to support the weight of not only the exhaust system but the turbocharger turbine and compressor wheel has to be stronger, no only by the turbo system components but to hold them up. And, you typically need longer intake piping and intercooling, and associated ducting, all of which are heavy. And, turbo motors, naturally need to be stronger, so the motors themselves often times weigh more.
That said, losing 2 cylinders and the associated hardware for those could make it net neutral, and the smaller overall block casing/etc and advances since the 9A1 family of motors were introduced could end up with a net weight loss. Interestingly enough, historically, the Cayman has been more expensive and has been differentiated by an extra 10 or so hp over the Boxster twins. This never made sense to me, emotionally, as lover of top down motoring in a convertible, or logically, given that developing a power top that doesn't leak when up and hides itself so masterfully when down is much more expensive than a hatchback roof. It will be interesting to see if Porsche tries to take the slow selling Cayman down market for the 981.2 release - if the HP figures really are the same or if they reverse their stance and the Boxster gets the same power, they may be trying to open up appeal of the Cayman by lowering either the entry point or the overall cost structure.
The 370 hp figure for the GTS butts it right up next to the sold out GT4. The interesting thing is that the GT4 is expected to continue, so all of you paying markups for 2016 GT4s may want to reconsider as it looks like the model has staying power which means people won't be so silly about them in a few months. Sure, you get basically the GT3 suspension for the GT4, but that likely only matters to track junkies, the GTS suspension, especially when you properly check the X73 option, is fantastic in and of itself. (My 981 Boxster that I retrofitted X73 was one of the best factory suspended cars I've owned.
I think there are two ways this 981.2 could go:
Porsche's turbo motors have always been fairly conservatively rated. This seems to be the trend with European manufacturers - VW&Audi/BMW/Mercedes turbo motors make more than a similarly rated NA motor from the same manufacturer at sea level - they seem to be rated at worse case scenarios and in most cases do quite a bit better than indicated. Look at the E92 M3 vs the F82 M4. My e92 M3s have made 315-330 wheel horsepower out of an engine rated at 414hp. My F82 M4 made 403 wheel horsepower out of a motor rated at 425hp. You expect a 15-20% loss from the crank once power makes it way through the transmission, driveshafts and differential, to the wheels. This has born out with acceleration numbers. The M4 is trapping in the 1/4 mile nearly 5-7 MPH faster which indicates a huge increase in power. (one of the best indicators of real power is trap speed for a drag strip 1/4 mile run). If the 981.2 motors are conservatively rated (and let's face it, the GT4's NA motor is likely conservatively rated as well, to differentiate itself from the 991S) and the 981.2 ends up weighing less (due to the smaller 4 cylinder motor, it could be a VERY compelling package. Imagine a 370 hp 2700 lbs Cayman GTS, that takes to modifications well.
The other way it could go would be terrible - Let's say the turbo motors turn out NOT to be conservatively rated and the cars gain weight from the plumbing. Plus, there are so many things Porsche could do to hose them up, but the main thing I worry about is Porsche being sensitive to the European Sports Car buyer not wanting a 4 cylinder engine and try to cover up the sound with stereo generated fake engine sounds, like BMW did with the M4 (one of the first things I disabled on both my F80 M3 and my F82 M4). What if we end up with a Cayman GTS that sounds like a rusty Subaru gluglugluguguggulgubbbugugugugugbb, with fake engine noise played over it, so you are protected in this heavy bubble of video game sound but the rest of the world is pummeled with a nasty engine note - the sounds of a thousand forum haters being waterboarded to like the new cars.
Ok, Porsche - don't screw it up! I'm optimistic that things will be closer to the good scenario, but we will see - the 981.1 brought electric steering and a bizarre numbness to the helm of the Boxster and Cayman - despite their stunning good looks, the cars are much more sterile for it. I really enjoyed driving my Boxster once I figured out it was like an S2000 - you had to drive more with your butt than the sensations through the steering, since there were none. But, it didn't feel as alive to your finger tips and a lot of what makes a sports car a sports car is that je ne sais quoi that comes from a proper steering rack.
I'll be anxiously awaiting the arrival, but I'm sure not pre-ordering one.
Silicon Valley Dad, who loves cars, cooking, clothes and cameras