I own a beautiful orange 2007.1 RS and reading where the the Cup Cars of the same era were producing 440 hp versus 415 hp for the street cars. It specified that the differences were due to different engine management and a special exhaust. Am I to assume that the engine management is altered to run on race gas, and that the exhaust mods dispense with the cats (in comparison to the 3.8 Cup Cars which retain their cats)? In other words, there is no way our street cars will show similar gains? I guess the Sharkwerks 3.9 package is the best method to substantial hp and torque gains. Planned for in the future.

 

Factory Cups run cats. Not sure where the extra power comes from, but probably intake and ecu tuning. Maybe compression?

 

Main differences are a Motec ecu, different inlet/airfilter system and deck lid plus exhaust system.

 

Cams should also factor in there.

\m/

 

ECU's are Bosch.

 

Modified to run on race gas, and special exhaust?

 

Cams Crank Intake Injectors Valves Management Port/Polish Exhaust

 

Motec on their web site state an afiliation to OEM Porsche, I know the Cup cars run Motec dash units and thelemetry plus the engine harnesses use Motec Mil' type metal connectors not the Bosch plastic connectors, as for the ECU, I cannot confirm its origin so you may well be right in stating Bosch.

The only online statement (from Metec's website) is "t is also a factory fitment to the current Porsche 997 GT3 Carrera Cup race cars." but it may be refering to the Dash/thelemetry side of things?!

Cheers
Jay

 

I am sure they are limited only to 440 hp because they use air restrictors which makes the racing even\fare. Otherwise they would make a whole lot more. They can run so much more timing thanks to race gas, plus the bigger cams, better breathing heads, intake, exhaust, etc. etc.

 

You are correct.

\m/

 

The factory Cups do not use restrictors. The RSR does use a restrictor plate (or rather did in the ALMS series)

 

I think they are pretty much maxed out at 440BHP?

 

The 997.1 Cups (3.6) usually put out about 360-70 whp. The 997.2 Cups (3.8) put out close to 425 whp.

 

There are many differences between the road going engine and the cup race version. We work on them day in and day out.

Although the engine architecture is relatively the same some of the primary differences are as follow

ECU- and Emissions control
The cup car uses a very simple ECU where as the road car is much more complex additionally the race ECU has no provisions for the emissions or drive by wire.

The street engine uses a vario cam where the race engine uses fixed cams and no vario cam. Street cars only have vario cam on the intake cam for the 3.6 engine- the 3.8 engine have vario cam for both intake and exhaust cams.

The cams have slightly different profiles between the two engines. ( race and road going)

The 3.6 crank shaft in the road car is identical to the CUP version.

Most importantly the race engines have considerably less torque than the road cars due to not having the vario cam function.
( If we could run a road going based engine in racing we would because the road going make a considerable amount of torque over the race engine)

I see no advantage in a CUP engine for road car use. What you gain in HP you loose more in TQ and drive ability not to mention the need to have the engines rebuilt every 80-100 hours for amateur club use and as often as 40 hours for pro racing use.


A larger displacement big bore kit without changing the stroke will only move the power band up in the rev range.

You can obtain a good amount of power from some basic bolt ons.

We have found a considerable increase in performance can be achieved with a high flow cat and header system, however I recommend leaving the stock mufflers ( although heavy) not to sacrifice torque.

We have developed such a system which is available here.
http://www.gmgracing.com/store/index...er-system.html


Many customers have been very pleased with a simple software upgrade which we have developed with GIAC and the use of our header and cat system. To save some additional weight and improve the sound of the vehicle many replace the secondary muffler ( or rear muffler) and install center section like our World Challenge or RSR unit.

RSR Center section
http://www.gmgracing.com/store/index...r-section.html

World Challenge center section:
http://www.gmgracing.com/store/index...n-exhaust.html


If you need more info please feel free to email me directly I am happy to help and share the data we have found over the years building street cars and race cars.


Enjoy some of the videos below

 

Thanks to all of you for your learned replies. It sure is hard to beat what the engineers originally came up with.