RED ALERT
When a former Porsche factory motorsport engineer builds a car for his own pleasure, you can bet your bottom dollar it will be something pretty special. Armin Knüpfingʼs St-inspired 911 is a case in point…
Armin Knüpfing is an ex-porsche motorsport engineer. This is his 911
There are countless garages and workshops that rebuild and modify Porsches. Many are able to create eye-catching cars with unique modifications, but only a very few distinguished people can make a Porsche that is far more than the sum of its parts. Arguably Singer is currently the master of this, but although the name doesnʼt really slip off the tongue as well, Knüpfing Motorsport has just finished something rather special.
The deep red ST replica is stunning, but looks are perhaps the least of its attributes because, like Singer, its builder Armin Knüpfing is an ex-porsche motorsport engineer, having been involved with such legendary cars as the 962, the 959 Paris-dakar entries, as well as the 959 Le Mans effort. All of this special life experience has gone into Armin building himself the perfect Porsche.
As far as Porsche tuners go Armin is somewhat ʻoff the radar ʼ, but the fact that Porsche luminaries such as Jürgen Barth and Roland Kussmaul bring their personal cars for him to work on speaks volumes about the quality of his work. In addition to the car you see here, there are a couple of projects in progress in the workshop and itʼs only a matter of time before Porsche enthusiasts will be hearing Arminʼs name a lot more often in the near future.
As well as the new car, Arminʼs background is also part of the story. Some lucky people land a dream job once in their lifetime, but Armin managed to walk straight out of engineering college into the team that was turning aluminium sheeting into the chassis for the first 962. The Indycar project, 2708, was another with which he was involved, but the biggest was the Dakar as he worked on all of the cars, from the 1984 911-based 953 to the full development of the 959.
The list could have grown longer but at the end of the 1980s he took a couple of weeks off to help out with his familyʼs business...which somehow turned into thirteen years. But one day in the mid 1990s a friend asked if he would put his old skills back to work by tuning his road-going 911, which Armin was happy to do in the evenings and weekends. The work was of such good quality that the local Porsche dealer asked if he would like to step up and help get their Cup cars ready for the track. Again he agreed, and not too long after was providing race support. ʻNormally if you leave Porsche then you donʼt get to come back,ʼ he says. ʻBut they knew I left for family reasons so they said yes and I got back into it from there.ʼ
This was all part-time work, but after a few years he began getting enquiries from his old place of work and important Porsche people began bringing their personal cars for him to service and tune. And now with this absolutely stunning ST replica, heʼs reached another point in his career: based on his experience in Porsche motorsport, together with his experience of building modern race cars and fine-tuning classics, heʼs created his own car from scratch.
Armin once owned a real ST, bought at a time when prices were humorously lower than they are today, and over the years did many regularity events in it, until a road traffic accident with an uninsured Italian on the Targa Florio in 2013 brought it home that it was much too valuable to throw around rally stages. He came up with a great compromise, though: he sold the original, rummaged around the workshop for all the ST parts heʼd collected, bought a relatively worthless 1973 911E bodyshell and began to make a replica which would be as good as, if not better than, the original – and equally importantly be worth a mere fraction.
With the experience heʼd gained at Porsche, this was always going to be a stand-out build, but with the contacts heʼd made there it became extra special. His friend Roland Kussmaul had been part of the development team for the original ST back in 1970 and, not only did he still have the original FIA homologation papers, he personally helped Armin by sketching out the design for the oil cooling system. In 1970 components were pilfered from parts bins rather than made from scratch which is why, for example, the ST had a pair of coolers from a 356 Carrera 2 mounted in the front bumper. Arminʼs has the same.
The homologation book was also invaluable as it had all the exact drawings and measurements for small but important things such as the additional plates that reinforced the suspension mountings and torsion bar tubes. As STS
were competition-oriented cars, many details were unique, such as the bolts on the shock mounts used in place of those on the road cars, so that the mechanics wouldnʼt have to waste time looking for a special tool.
Another essential focus on the ST was extreme weight saving. With a kerb weight of just 960kg it was a seriously lightweight car, and if a couple of kilograms could be saved somewhere they were. Stripping out the soundproofing and carpets obviously saved a bit.
Arminʼs wife Marion is an interior expert and works on many projects that come out of the Knüpfing Motorsport workshop. As spartan as it is, itʼs her excellent craftwork on display inside. Map pockets arenʼt normally a major topic of conversation when discussing a car such as this but the insides of the doors have a special set of map pockets, out of no lesser a car than Gérard Larousseʼs 1970 Monte Carlo 914-6 GT: ʻI restored this car and for some reason the new owner said he didnʼt want them,ʼ Armin explains. ʻI kept the pockets and had the idea to use them, so I asked him again and he still didnʼt want them, so now they are here.ʼ
The interior does have a nice concession to comfort, though. Armin intends to use the car year round in all conditions so he fabricated the heating pipes out of much larger 38mm tubing. Another precaution to protect against the ravages of winter motoring is that the bare shell was treated in a 280°C cathode dip paint bath.
The build is not an exact replica by any means and one major difference is the engine. The original ST had a magnesium engine block which was very light but Armin thinks that they were also a little too soft, and so he chose an aluminium one. But not a 2.5, though. Half a century ago the 2.5 was perfectly adequate for powering Porsches but Armin used a 3.3 930 block which he bored out to 3.4, ported the cylinder heads and added a dual plug ignition set up. Schrick cams were installed, although not motorsport based ones.
ʻI want to enjoy driving to the events I do in Italy or other places,ʼ says Armin, ʻso I needed a car thatʼs easy to drive for normal road use. Although this engine doesnʼt have all the
“AN ESSENTIAL FOCUS ON THE ST WAS WEIGHT SAVING…”
power it might be possible to extract from it, it has a much smoother power band.ʼ It hasnʼt been properly tested on a dyno yet but Arminʼs educated guess is that it puts out around 320bhp, which is a significant increase on the originalʼs 230bhp.
The bespoke Eisenmann exhaust with 38mm headers help the car sound as good as it looks. This prototype turned out so well that Eismann will soon be offering this as a catalogue part. Other special details include a 100-litre Lupoline fuel tank so that it has enough range to compete in long distance events where fuel stations might be a little hard to find.
The three-piece wheels are BBS E50s with Continental Conti Sport Contact 2N2s, 205/55-16 on the front and 245/45-16 on the rear. The brakes are from a 930, not an unusual choice, but the suspension is from the SCRS parts shelf. A history in Porscheʼs motorsport department does have its advantages…
The build was all done in Arminʼs spare time so, from finding the shell and collecting parts, it was two years before the finished car was ready. The first test was a tail happy jaunt around local lanes seeing what 320bhp in a 930kg car on old tyres felt like. But unlike many builds that have random Facebook comments to deal with, Arminʼs STʼS first audience was a much more discerning crowd.
As a founding member of a group of former and current Porsche employees who meet every month to discuss or propose projects that some might like to get involved with, it had a very critical appraisal. Such Porsche luminaries as Peter Falke, one of the companyʼs most famous engineers, and Jürgen Barth, the ex-motorsport director, regularly attend. He wasnʼ expecting any fanfare, though as Swabians (people from Stuttgart) are famously reserved. But the smiles and pats on his shoulder were enough to let him know that his fellow club members were impressed. As they should be.
But donʼt think for one moment the story ends here: Armin has a few more amazing builds in the pipeline that will be gracing these pages soon. As they say in all the best stories, watch this space… CP Contact: Knüpfing Motorsport Otto-hahn-str. 1b D - 97230 Estenfeld Germany Tel: +49 (0) 9305 - 10 97 www.knuepfingmotorsport.de