Porsche Motorsport Division X51 PowerKit (320 PS/235KW)

The 996 X51 has an historical importance and pure engineering at its heart. For two years this was the most powerful 4 seat or 4WD model (the Turbo had yet to be released). Significantly, it is not just power output upgrades, having both additional cooling (centre radiator) and lubrication upgrades (high-G sump baffles, additional pump and oil lines). Those two options are almost worth the entry ticket alone: as the 996 cylinder failures almost always involve the overheating and under lubrication of cylinder number 6, these modifications go someway to mitigating the seizures. The 996 X51 was the sister model to the GT3 during development. Porsche Motorsport Division parallel developed the narrow body C2 with C4 strengthened front chassis/body structure, track suspension and roll cage and even the aerodynamic Cup AeroKit (note: its note even officially called the GT3 kit), but with different engines. The GT3 3.6 (M96/76) and X51 PowerKit 3.4 M96/01S engines were both developed together, in case what became the actual GT3 3.6 (GT1 derived block) failed racing regulations and/or reliability requirements for a successful homologation. In other markets, such as Germany and Japan, these options (along with M030 sports chassis, bigger wheels and sports seats etc) were sold as one. In the guise of a 2WD (but C4 chassis) 3.4 X51 with Cup Aerokit it was an additional model in its own right called the "Carrera Cup" in Germany and the oddly named "PowerUp" edition for Japan. When they were released in the UK, the Cup AeroKit and PowerKit were separated as options (XAA and X51 respectively). The X51 was almost certainly only given an additional 20 BHP for "political" reasons - the much more expensive GT3 996.1 3.6 M96/76 only developed 360 BHP. In 2000 the X51PowerKit cost £8,725 from the factory. Expensive as it was (and with on-paper low absolute power enhancement), at least the 996 PowerKit had extra lubrication efficacy (via a larger alloy racing sump baffle with valved apertures, dual chamber oil pump and additional lubrication plumbing on cylinders 4-6), additional third cooling radiator, high lift valves, revised camshaft and optimised (machined and polished) exhaust ducts. The X51 was not available in the US in 996.1 guise. Attached images: Sand-cast aluminium cross-section modified intake system Optimized exhaust ducts (machined and polished)

For what it's worth, your source did not get his information absolutely right. Whilst the development of the GT3 engine and the X51 Powerkit may have overlapped chronologically, they were not developed "together", since the X51 kit was developed by the same series-production motor team which developed the M96/01 base engine, not in the Motorsport division.

opcorn:

I will pass your regards on to Adrian Streather. By early 1998, the Porsche Motorsports division, under contract to develop the Pirelli Supercup and in house to develop the Carrera Cup cars for the 996 program, completed 30 prototype 3.4 M96/01 based development mules for testing. Although the M96/76 and M96/01 are effectively completely different (one being a GT1 block, the other a Boxster block!), the original M96/01S PowerKit was overseen by the PMD. Although in the end the "new" GT3 was a success and delivered both on time and within regulations, the PowerKit vehicles were its back-up plan and would have stepped in for at least that season. Not something you leave to the series-production motor team. Subsequently, although not identical, the specifications and lessons learnt from the Pirrelli Supercup/Carerra Cup PowerKit vehicles formed the blueprint for the productionised retail X51 option.

I don't ever remember Adrian Streather being involved in the project, so he will have got his information second-hand.

Unfortunately when he acknowledged Porsche AG for their assistance in writing the book, he did not specifically name any individuals. So on that basis I cannot confirm or deny any further details.

Woah Paul, you'd better get reading. It would appear you've been trumped mate! :lol:

Hold on! It wasn't in any way my intention to "trump" someone. :hand: I just suffer from an allergic reaction when I read stuff in the net which I know not to be factual, because it can so quickly become urban myth. You've surely heard the words: "It's got to be right, I read it in the internet". Where Streather's text is concerned, he'll probably have got his information through the PR department, if usual procedure was followed. An awful lot generally gets lost and "found" in both transmission and translation when an author or journalist has to put a piece together in that manner.

As I say, on that basis I cannot confirm or deny any further details. Until I hear or read any different, the account I have read still makes more sense to me than you simply disagreeing with a few words or, at worst, a sentence of a 40-line post. However, X51 being of particular interest to me, I would be very grateful if you could direct me to any source(s) electronic or hard copy that would enhance my knowledge and understanding. I, or you, could then update this thread to broaden all of our insight of Porsche history and engineering. Don't keep it to yourself, otherwise only rumour and hearsay with continue to pervade the internet. You can start with "the project" ...

Vroom Vroom..! Argey Bargey! I'm just kidding with you both.. You know more about cars than me that's for sure, I just wash and go! :lol:

Wash and go? More like wash and gone.

:floor: Bloody excellent..! :thumb: :bandit:

I'm allowed to say that as I, too, am in the unenviable position of choosing suitable pate attire for the summer season. Quite pissed off last year, it was the first time I had to actually close the sunroof to prevent sunburn. I had to bit the bullet and admit defeat by taking a cap with me for the subsequent drives. :sad:

I know what you mean, but your pate isn't as polished as mine yet..! Don't forget The Beast comes from Transylvania and has been alive for hundred of years..! I tried going faster to escape the sun's rays. That didn't work, so I went one better and bought a coupe. Now although I don't miss the sunburn I miss having the top down...! :frustrated: The only solution is to drive along with my head sticking out of the window.. and according to your thread X51 has better cooling, so maybe the eventual solution will be to procure myself an X51 Cabriolet.. :grin:

Look you are all going off topic here I'm not sure about others but I for one will not rest easy until this is all shook up and sorted out......now what we know for a fact is it was definately a German fella..........sooooooooo GT good informative thread & pics (as usual)