On the CS, the throttle opening is restricted at higher RPM's. A tune will see both cars make the same power.

 

Any, legit mechanical, reason that this is done? Is this why the Boxster is a tad under the Cayman?

 

Anything done on the 3.4 HP between Boxster, Cayman, and 911 is marketing & branding.

 

This is just my opinion -- full disclosure, I own a 2015 Cayman GTS.
Porsche has a wide array of tuning options to either dial "in" more HP, or dial "out" HP (for example, the GT4 makes less power than the "same" 3.8 Carrera motor -- exhaust manifold differences was one reason/cause for this). As far as getting another 15 HP out of 3.4 motor, this is probably a very easy tune/fix by Porsche -- many other tuners offer the same or more HP gains.

Now, as to "why"... Porsche clearly uses HP differences to differentiate models -- look at the Turbo and Turbo S, with underlying mechanical differences to achieve the goal. Look at our 981 Cayman's -- base vs S.
Then there is the Cayman S vs Boxster S (and base models) where the Cayman is spec'ed higher. IMO, this was to help justify the higher price, despite the higher cost to install the soft top mechanicals.

To bring this thought to current models, Porsche is now using completely different engine platforms to differentiate the Cayman/Boxster line from the 911 line, as well as reported HP outputs. Frankly, this was brilliant. The GTS models were getting a bit too close to the 911 performance, by all accounts and surely the GT4 to 911 comparison. So, in one bold move, Porsche moved both lines to forced induction, kept the HP outputs "in line", but highlighted the 718 vs 911 lines by 4 vs 6 cylinders. Lets not get into the complaining about the 4 cyl motors and admire the marketing genius (the engineering capability only enabled this marketing strategy IMO) while all under the guise of environmental evolution.

Why does the Boxster now cost more than the Cayman --- simple, this is in line with historical premiums for the cabriolet models... no drama or controversy.

Oh well, back to refresh my Starbucks cup.
D

 

Why wouldn't they put say a 2.5 or 2.7 SIX turbo in the Boxster/Cayman instead of the four banger. I would still think they would meet their CAFE goal.

 

I think the Cayman was originally billed as the "more hardcore" version of the Boxster. It was lighter and had more HP (and more expensive) because it was viewed and marketed as the enthusiasts model. People in the market for a Cayman generally were not looking for a convertible, and vice versa. Now that they've equalized the hp and made the vert more expensive I don't know how things will shake out. Has Porsche release official sales numbers of the 718 vs the 981 so we can compare?

Regarding the hp, magic screws. Porsche uses magic screws to dial in the hp numbers.

 

So a tune on a Boxster S should safely unlock another 30hp, right? Any tunes available that can be reversed such that dealer can't detect?

 

Also don't forget the same 3.4L motor made 350HP on the base 911, so it makes from 315 to 350. The throttle-plate restriction makes sense, but I'd like to know if that's it, or if there's something more. What is strange is the 315HP Boxster has peak HP at 6,700 rpm, while my 340 GTS at 7,400. If only the throttle plate was restricted, it'd reach the peak at close to the same rpm IMO, but I guess we'll never know.

 

Also don't forget the same 3.4L motor made 350HP on the base 911, so it makes from 315 to 350. The throttle-plate restriction makes sense, but I'd like to know if that's it, or if there's something more. What is strange is the 315HP Boxster has peak HP at 6,700 rpm, while my 340 GTS at 7,400. If only the throttle plate was restricted, it'd reach the peak at close to the same rpm IMO

The throttle is only restricted at higher RPMs, it's fully open lower down. This has been datalogged by people many times. The same engine in the 911 isn't entirely comparable because it does have slightly different hardware there. Larger throttle body, different plenum, headers and exhaust system.

 

Yep, the new ones have worse fuel economy (even the official numbers) than the outgoing F-6s, so not the real reason behind the engine swap.

 

One thing I thought I "felt" when I moved from a CS to a CGTS was a peppier throttle response in S+ regardless of rpm. I am skeptical that this was due to such a small hp boost, but I have never seen anything about a different Sport mode setup in the GTS.


Sent from my iPad using Tapatalk

 

Okay, to answer the original question: According to Porsche drivetrain engineer Matthias Hoffstetter there are no mechanical changes (btwn S and GTS). The power and torque increases come from a combination of ECU remapping and the slightly reduced back pressure of the sports exhaust system. The ECU tweaks affected a number of factors including (but apparently not limited to) changes to ignition timing, direct injection fueling system and fuel pressure (no mention of throttle body restriction). This info gathered from excellence magazine 9/14.

 

So in a round-about way, someone from Porsche admitted that the PSE fitted to the Cayman does increase HP a bit?