My Gasoline Particulate Filter 718 Cayman GTS PDK down under.
I had the opportunity at the recent geometry check when my car was on the ramp, to have a closer inspection of the underside of this, the 2019 GPF evolution of the 718 Cayman GTS. Some interesting differences from my previous 2016 718 CS PDK were noted. I should mention that my previous car also had the Porsche Sports Exhaust fitted.
Previously posted photos of the revised exhaust mufflers had already indicated that things "down below" seemed a bit different in both layout and hardware compared to my previous car. The following photos clearly indicate the extensive development work which Porsche has put in to the GPF equipped cars, and the 718 CGTS in particular.
The exhaust mufflers are more compact than on my previous car. Some of the exhaust pipework has increased in diameter and the layout of the exhaust system upstream of the flange joints next to the rear wheel arches has altered significantly. It is already well known that the 718 GTS has a different turbocharger and revised induction and exhaust systems, so many of the changes from my previous 718 CS will be common to the pre-GPF 718 GTS models. On that note, I would be very interested to see if the exhaust muffler layout on pre-GPF 718 GTS cars is the same as on my 2019 model. The exhaust sound seems different on the GPF car, and with the compact mufflers, it would be a relatively easy modification for Porsche to design a different exit point for the twin tail pipes on a future evolution 718.
Moving forward to the undertray, is where the most significant changes apply. There are more cooling louvres and cut-outs in the undertray to facilitate expelling the extra heat generated by the GPF unit. I was surprised to see how small this unit is, which is in clear view being exposed to the airflow by a rectangular cut-out in the undertray. I looked hard for evidence of additional catalysers in the exhaust system but could not find any. I know from reading articles on the 718 GPF installation that a single large diameter 4-way catalyser/GPF unit is deployed on the flat-4 turbo. From what I could see there were no other catalyser units visible in the exhaust system other than this single GPF unit. To clarify this, my plan is to request another look underneath my car at my OPC when I next have my oil and filter change done. The undertray will be removed for this task, so I'll get a better view of the turbo, exhaust, and GPF/cat systems. I shall report back.
Whatever the outcome, Porsche have clearly put a huge amount of development resources into the 2019 GPF flat-4 turbo. Going by the vigorous and emphatic posts elsewhere on this forum, I seem to be one of the very few who see great potential in this excellent engine. I would not be sorry to see a GT4 Cayman or similar with a 450bhp version of the flat-4 turbo. As a motorsport driver now retired, I would not care two hoots how many pistons were involved in producing 450-500bhp with train-pulling torque to match.
Back to the road performance of my 718 CGTS, I would say that as far as road driving is concerned there is not a great deal of difference in acceleration through the gears compared to my previous similarly specced 718 CS PDK. If I were comparing a basic spec 718 CS PDK, that is one without the -20mm PASM, Sports Exhaust, Limited Slip diff, wider wheels etc, the comparison with the GTS would perhaps be more significant. So far, I would say that my GTS has optimised the 718 Cayman experience. This has not resulted in a huge leap in road performance, more like an incremental step forward in power, torque, and throttle response compared my previous car. The track day timings from the on-board Porsche Track Precision app following analysis at home may perhaps tell a different story.
The photos follow below.
Brian