For those interested, this piece was created by the techs at the Supersprint factory. Thought I'd share it with you guys due to some interesting insights from the technicians.

Warning: Pic heavy!!

Porsche 997.2 Turbo S R&D Notes

Supersprint has gathered a lot of experience with Porsche turbo engines, building exhaust systems for them since the very first air cooled versions. This Porsche 911 Turbo S (997.2) has been at the R&D department for a whole month. All the possible configurations have been tested and approved or discarded depending on the results on the dyno. The results are extraordinary, close to 50hp gains and sound worthy of the Turbo S performance.

Available configurations

Supersprint has released multiples configurations for the Turbo S. The production ready configurations are the results of hundreds of hours of testing different combinations. There are 2 main configurations available, the headers can be fitted with any of the proposed configurations or the OEM exhaust.

65mm modular rear exhausts

• Fits with OEM cats & tips (additional tips selection available)
• Available in SPORT & RACE sound level

70mm rear exhausts

• Fitted with HJS Motorsport Metallic Cats.
• Available in SPORT & RACE sound level
• Fits with OEM tips (additional tips selection available)

Headers development

The stock headers suffer from an unequal lenght primary pipe design and very restrictive merge collectors, this impacts mid-range and high RPM performance tremendously. Supersprint’s equal length manifold design is the result of extensive research and the necessity to keep the pipes short to maintain the highest exhaust gas energy while allowing the turbo to work on the highest pressure differential was the keystone of the research & development process.

Porsche’s Variable Geometry Turbos (VTG) reach very high level of operating temperatures, Supersprint chose 310S steel to build the 997.2 Turbo S headers due its improved heat management properties over 304 stainless steel. The headers are especially good on mapped cars as the 310S steel can keep up with a lot of heat. When on full boost for long periods at low speeds they get yellow, almost white hot! For track-oriented builds, we offer an inconel version of these headers.

Stock headers


Prototyping


Prototype Test Fitment


Primary tubes welded


Merge collector details


Welded and Installed


Production headers


Matched exhaust ports


Merge collector detail


Rear Exhausts Development

65mm modular

The first configuration is a 65mm modular rear exhaust, you are able to fit the rear exhaust with the OEM catalytic converters and OEM tips. You have the possibility to add HJS motorsports metallic racing cats and/or Supersprint tips, you also have the option to select a SPORT or RACE sound level.. The 65mm rear exhaust is ideal for those looking for additional sound and slightly better performance than OEM. Due to a flange-less/slip-fit construction and 65mm piping diameter, the 65mm rear exhaust is an affordable way to get the sound that you want from your Porsche Turbo S. Supersprint’s triple merged 70/80/100mm tips are also available.







70mm catted rear exhaust

Supersprint offers a second configuration for the 911 Turbo S. The system was built with optimal performance gains in mind and as such re-routes piping and integrates HJS 2×100 CPSI metallic racing catalytic converters. As explained during headers development, the compact nature of the 911 engine bay creates many heat issues, even more so with the Turbos reaching extremely high level of operating temperatures in high performance driving situations.

To counter-act such high heat levels, the system is fully built using flange connections for perfect fitment and leak-free usage for optimal performance. The spring loaded flanges with sealing rings allow for heat expansion and contraction while eliminating risks of cracking and leaking; critical on high performance turbocharged applications!

The system is available in SPORT & RACE sound configuration, performance is unaltered between the two. They are available with Supersprint’s quad 80/90mm or 90/100mm tips or can be fitted with OEM tips using Supersprint’s connecting pipes. The system is also available in catless configuration.











Dyno results

Around 30 runs have been done to ensure the reliability of the results and the progressive increase in performance for every component added to the system, starting from the rear exhaust only, then the cats and finally with the headers. Different rear exhaust, cats and manifold have been tested as well.

Here are all the charts of the approved components.

Dyno 1: Stock


Note that the stock car resulted in less hp than as advertised on the dyno. We used the dyno procedures that Porsche itself deem as correct but didn’t manage to come close to the claimed figures. The car feel faster on the road than the figures suggest, the high torque may be a factor.

Dyno 2: Stock vs 65mm RACE rear exhaust with OEM cats


We first tested the 65mm RACE rear exhaust with OEM cats versus stock, this chart shows the stock rear exhaust is highly restrictive. The rear exhaust does not seem to solve the 5,900 RPM important drop in horsepower and torque.

Dyno 3: Stock vs 65mm RACE rear exhaust with HJS cats


We then tested the 65mm RACE rear exhaust with HJS metallic catalytic converters versus stock. Top end gains above 5,900 RPM were significant however a dip in the curve emerged between 4,500 and 5,000 RPM.

Dyno 4: Stock vs 70mm RACE rear exhaust with HJS cats


Larger diameter piping from the 70mm rear exhaust got rid of the dip but lowered low rpm torque gains. In real life driving, the diference is very difficult to notice as the deeper, more aggressive sound of the 70 mm exhaust gives a greater sensation of speed.

Dyno 5: 65mm RACE rear exhaust vs 70mm RACE rear exhaust with HJS cats and Supersprint headers


The 70mm full catted system (headers + catted rear exhaust) makes a bit less of low end torque compared to the cats+ 65mm rear exhaust configuration, but the middle and high end punch is improved. You can clearly see the advantage of having headers installed above 4,000, allowing the turbocharged engine to breath to its optimal potential. The delivery is extremely linear and doesn’t need any ECU modifications, we do however recommend an ECU tune when going with the full system to extract max potential from our full exhaust system.

Dyno 6: Stock vs 70mm RACE rear exhaust with HJS cats and Supersprint headers


Stock
HP: 437.4 PS

We considered the non corrected values as the dyno was over-correcting. Also, the power figures are a lot lower than the claimed 530 hp, this is caused by the ECU not allowing the full turbo boost on the dyno. As such, on road gains are & feel a lot higher than our recorded 49hp gains!

Supersprint

• Headers 310S
• 70mm RACE rear exhaust w/ HJS cats
• 90/100mm Tips

HP: 486.9 PS

 

Do you dyno your cars the same way every time? What is the temperature of the compressed gas you are spraying into the intercooler ducts?

 

Yep! All dynoed the same each time. The MAHA as you may know is a great and accurate dyno and of course all of the ambient temps are recorded and shown. The operators are extremely experienced. Evolve also has vast experience with operating dynos and have written various pieces on them (how to get consistent and accurate results, what to look out for with unscrupulous dyno operators etc). One of the reasons we love Supersprint work, they have the same dedication to repeatable gains. Intercooler wise I've been told it is cold tap water used.

 

thank you for the post. I've been wondering for quite some time what the fitment difference is like for a 997.1 vs 997.2 ... what is it exactly that doesnt make exhaust systems for the .1 and .2 interchangeable ?

 

Let me answer your question and give more details about our exhausts:

Even though visually very similar, the two cars have completely different exhaust systems, so almost none of the components are interchangable.
The only exception are the two 90-80mm tailpipes of ours.

We obviously started from the 997.1 components when we developed the mk2, but ended up with a complete range of new products such were the mods necessary for fitment.

The stock system is 65mm on both cars, with ceramic ~400 CPSI cats and unequel length headers. The best solution for performance is obviously the full system. The Supersprint headers are equal length, with a more gentle curve and are made in AISI 310S stainless steel, which is highly resistent to thermal stress.
The cats we use are 100 CPSI. These shouldn't usually turn on the CEL as they reach the operative temperature very quickly. If required, for example if the car is used in very cold weather or often in heavy traffic we can build 200 CPSI cats, but it saps power and sound. Better to get a cheap diagnostic tool like an OBD bluetooth interface to turn off the CEL if it turns on at times, or an ECU tune.
The 70mm exhaust systems perform better and are a bit deeper in tone, especially in "race" specification. For daily use its better to stay on the "road" or "sport" mufflers, more adapt for track days and weekend cars.

997.1 Turbo 3.6
The headers are specific, they are optional and can be fitted by themselves or with the rest of the system.
Headers charateristics: Equal length primary pipes, 42mm external diameter. Main pipe after the collector is 50mm to match the turbo inlet.

The "road" rear exhaust is a single unit because the flex pipes are removed and there are two joints with the usual flanges + springs + sealing ring joints.
The pipes are 70mm e.d., the cats 100 CPSI 130mm e.d. The total weight is around 19 KG + tailpipes (if fitted with the stock tailpipes or with the adaptors it's 20.3 KG)

The holes in the bumper and the OEM tailpipes are smaller than on the mk2. There is room only for two round pipes, our inside ones 90mm, the outside ones 80. We have exit pipes for the OEM endpipes.

The "Racing" system is a bit lighter and doesn't have the flex joints, this means there will be some vibrations compared to the stock system or our "road" system. The cats are the same 100 CPSI 130mm unit.
It's possible to choose between the "Sport" and the "Race" muffler (245534)
The Sport is 15-20% louder than the road one. The Race is very loud, it's almost as loud as straight pipe at high revs, but retain a minimum level of comfort when cruising. It weighs 8kg (+7 with the cats for a total of 15 KG, it already has the connecting pipes for the OEM tailpipes, so it's 5kg less than the road one)
Both these two mufflers fit with the stock tailpipes OR can be fitted with our triple round tailpipes (here on a 997.2 but they look the same on the .1):



997.2 Turbo/S 3.8
The headers are different from the mk1 in many ways but the primaries and main pipes are the same diameter. The primaries are a bit longer because the turbos on the mk2 are moved a bit toward the back of the car and at a different angle.

The "sport" muffler (18,4kg + tailpipes) is the equivalent of the same name for the mk1, the only differencess are some reference points for the piping and other fitting details.

We also have a very loud alternative to that which is the "race" (15.5kg + tailpipes). As it's a 70mm unit with small silencers it's the loudest system available for the mk2 and it's the one fitted, with headers and cats, to che car in the VIDEO


(Same tailpipes as the quieter model and can be fitted with the stock tailpipes or with the 90-80mm ones.)

On the mk2 the holes in the bumper are bigger, allowing bigger tailpipes (100-90) that look great!

On the mk2 we have also prepared some "plug&play" 65mm components that can be fitted in place of the original cats and/or muffler. The cats are 100 CPSI 130 units as the previous ones but are compatible with the stock muffler. The muffler is available in two levels of loudness, a "sport" (a 20-30% louder than the stock system) and a "race" (much louder, see the race for the mk1). If fitted with the stock cats the "race" version is recommended!
Both these plug&play mufflers are directly compatible with the stock tailpipes or can be fitted with triple rounds.

I hope this is useful