This is NOT your father's .

by: By Keith V of CA & Bob W of IL

The RCT at Parade 50 in Hershey
Despite the car being located in the shade with the bright background making it difficult to capture a good image,
you can clearly see it is a very striking vehicle.

The second sighting

In July 2005 PCA was celebrating its 50th year with the annual Parade in Hershey, PA and while there, I noticed a black 964 with the following license plate
The plates are the give away.
To those who know what it means, the license plate is a warning not to mess with this car.

I remembered the car from the year before when I'd seen it at the 2004 Parade in Fort Worth TX, but throughout the whole week of parade, despite seeing the car regularly, I had never managed to meet the owner. When I saw it this time it was parked in the shade with the owner unloading it. I introduced myself and asked him a few questions about the car and I found him to be a very interesting man with a very interesting story about how he came to have such a rare car.

His name is Bob W and he is a Professor Emeritus of Engineering at the University of Illinois. Bob has done research work in the area of rocket and jet engine integration issues such as the base drag question and his sharp mind and quick wit make him a very engaging man to talk to. His passion for well executed engineering is clear when he talks about many things, but especially when he speaks of his RUF RCT.

I must have asked Bob around a hundred questions while he showed me his car and he patiently answered them all. One of my questions was would he be interested in writing an article on his car for the registry website and, being a true gentleman, he agreed. The result is below along with a few of my questions and Bob's responses.

The man and his machine

The man and his machine.
Bob W of IL and his RCT. An interesting man with a confidence that comes from experience and understanding.

Bob W of IL

Besides being Professor Emeritus of Mechanical and Industrial Engineering at the University of Illinois, and in charge of the department's Automotive Systems Lab from 1978-1997, I spent time in Sweden at the Aeronautical Research Institute of Sweden and at Porsche's Weissach Research Center.

During our time in Germany, my wife and I were active with PCAs Germany Region. In fact my wife was the Zone Rep for PCAs overseas region at that time, which included Germany.

Within Germany Region one of the more active members was Alois Ruf who sponsored PCA events including hosting several at his business in Pfaffenhausen which is about 40 miles south west of Munich. During this time we became good friends and during my last sabbatical before I retired, I spent some months with him in Pfaffenhausen.

Indeed - a wolf in sheep's clothing.
When you look in the dictionary for the phrase
“a wolf in sheep's clothing”
there should be a picture of this car.

One of the journalists at Road and Track is quoted as saying “Alois Ruf is the nicest person in Germany - or at least a very close 2nd” - but they didn't say who the other candidate was. I soon found that he treats everyone as if they had just bought his most expensive car, even if they haven't bought anything.

A picture of innocence!
At first glance - just another 964.

While in Germany, I drove almost everything Luis has built in the way of cars (including the legendary Yellow Bird, the CTR2, 3.8L BTR) and I discovered I really enjoyed the RCT. I had owned a 1978 3.3 Turbo which I never really liked very much and which had put me off turbo's. Besides, my wife said the car had a “fat ass”!

The RCT, on the other hand, doesn't have the classic turbo feel. It's power delivery is much more like a very strong small block V8 with well-tuned cams.

Luis had mentioned that he wanted to certify the RCT engine for US emissions and, after some discussion, we came to an agreement that I would buy a US car and it would be converted to RCT specs for the US emissions certification process. I decided that I wanted the lighter weight and the narrow body (for its aerodynamic benefits) of an .

Selecting the right car.

After I returned from Germany at Christmas in '93, I bought the RSA here in Chicago where I had a choice of three or four. I selected one with air conditioning, an Alpine single CD player, limited slip differential but no sunroof. I started on the “conversion” process in early spring 1994 (on one of only 84 1994 made) with the things I was able to do myself - such as fitment of the “big red” turbo brakes and the 18” RUF wheels and the modifications to the suspension.

Within the next few months, Luis shipped three crates full of parts over from Germany and in the fall of '94 he sent one of his mechanics over to do the rest of the transformation including converting the transmission to a six speed.

I was able to use a friend's automotive shop in a suburb of Chicago, which helped significantly as it meant we had full use of lifts and so forth. The actual shop conversion took a total of about two weeks, but part of that time was a delay due to the fact that the wrong differential ring and pinion had been sent and we had to wait for the correct one to arrive.

Reasons to convert.

The RCT is easy to drive, quick, responsive, flexible, driveable anywhere at any rpm. Owning a car converted to RUF specifications puts you in a pretty exclusive group. Most people do not know what a RUF RCT is and are amazed by the cars performance. Even among Porsche owners and fans, many people don't know what an RCT is, and some mistakenly consider RUF to be a tuning company that specializes in tuning Porsches. Quite the contrary, the RUF company is recognized internationally as an independent manufacturer of sports cars. They will gladly convert your Porsche into one of their models, but new cars built by them not only have significantly higher performance, they have their own Vin# and are without question definitely not Porsches.

So the RCT is different, but just how different is it from the stock ?

What all the fuss was about.
Analysis of the above proves conclusively that RCT >

The RCT has exceptional driving characteristics particularly in the mid-range from 1500 to 5500 rpm. You can see in the torque curve below that at 2500 rpm it actually has more torque than the 3.8L BTR! The RCT's compressor/turbine combination is such that you have some boost on the throttle plate even at low rpm - which gives essentially instant response. Once again, compare the torque curve with other models such as a stock 964 C2 3.6L, a stock 993 C2 3.6L and the 993 based RUF BTR.

You do lose out somewhat to the BTR at higher rpm but, in the words of Luis Ruf,

“..... it is not the top speed that is fun, it is the acceleration between 30 mph and 150 mph that is wonderful.”

Torque Curves 964/993/RCT/BTR
Torque curves for Porsche 964-C2 / Porsche 993-C2 / RUF RCT and RUF BTR.

The following table shows the (significant) differences between the two cars.

Engine displacement 100 x 76.4 = 3.6 Liters Engine displacement SAME - 3.6 Liters
Two sparkplugs per cylinder Two sparkplugs per cylinder
Compression ratio - 11.3 Compression ratio - 8.5
Bosch Motronic Fuel Injection Special Motronic Fuel Injection
Standard Bosch Fuel Injectors Bosch Increased flow Fuel Injectors
Normally aspirated Turbocharged with 9” x 20” x 4” Intercooler
and 0.77 bar boost
Emissions controlled by catalytic converter Emissions controlled by catalytic converter
Single oil cooler in right front fender Additional Aux oil cooler left front fender
bhp - 247 @ 6,100 rpm bhp - 385 @ 5,800 rpm
Torque - 247 ft-lb @ 4,800 rpm Torque - 395 ft-lb @ 4,500 rpm
5 speed 6 speed
Differential - 3.333 with limited slip Differential - 3.444 with limited slip
1st = 3.500 : 1 1st = 3.154 : 1
2nd = 2.058 : 1 2nd = 2.058 : 1
3rd = 1.409 : 1 3rd = 1.409 : 1
4th = 1.090 : 1 4th = 1.074 : 1
5th = 0.87 : 1 5th = 0.86 : 1
N/A 6th = 0.718 : 1
Wheels & Tires
Front wheels 17” dia. x 7” wide
Tires 205/50ZR-17
Front wheels 18” dia. x 8.5” wide
Tires 235/40ZR-18
Rear wheels 17” dia. x 8” wide
Tires 255/40ZR-17
Rear wheels 18” dia. x 9.5” wide
Tires 265/35ZR-18
Stock 964 C2 3.6 Turbo “big reds”
Front Anti-swaybar - 22mm Front Anti-swaybar - 22mm stiffer design
Rear Anti-swaybar - 20mm Rear Anti-swaybar - 22mm stiffer design
Front springs - stock 964 Front springs - RUF custom design
Rear springs - Turbo 965 Progressively wound Rear springs - RUF custom design
Shock absorbers - stock 964 F&R Shock absorbers - RUF Custom F&R
Front - none Front - RUF lip spoiler
Rear - whale tail Rear - Turbo whale tail
Curb weight
2,954 lb 3,071 lb
0 - 60mph 5.4 sec 0 - 60mph 4.1 sec
Top speed 164mph Top speed 193mph

Performance Testing.

In April 1996, I was asked if I would loan the RCT to a reputable motoring magazine in order for them to perform a road test and write an associated article.

If you are ever asked this question and you decide to go ahead, I would like to offer you some advice.

DO NOT watch while they do performance tests on your car!!!

People side-stepping the clutch at 4500 rpm with the throttle wide open time after time - in your car - is not really something you want to witness - unless you like to hear and see the clutch and tires experiencing about a years worth of wear in ten or fifteen minutes. If the tester feels during a particular maximum performance run that the rpm may have dropped too low, then he simply does it all over again starting at 5000 rpm until he's convinced that he has the best result.

After my car had been tested, the inner edges of my rear tires were down to the cords - which I didn't notice because I couldn't see the inner edges of the tires from behind the car. The first sign that all was not well was when the left rear tire went down on my drive home.

When I checked the right rear tire, I found that it wouldn't have made more than another few hundred miles either. If you're ever bored or just like to accept a challenge, try to find two 18-inch tires in northern Florida on a Sunday.

Fortunately, a friend from near Palm Beach found some rims complete with tires and drove up to where I was in northern Florida. On Monday we took the car to Brumos in Jacksonville to change the tires, but even they said they couldn't get 18-inch tires in less than 24 to 36 hours.

Below is one page of the test notes detailing various aspects of the RCT's performance. Note the acceleration times and the comment on brake fade.

Test notes.
Test notes detailing the RCT's performance. Including acceleration times.

Below is the 1997 Car and Driver article on the RCT.

RCT article.

Q and A.

Keith V: Have you owned Porsches before your /RCT? If so, how many?
Bob W: Too many! Actually, I have never really counted and I am not about to now. I can say I have had five 356's including an Abarth Carrera GTL, one of the “plastic” Porsche race cars - the 906 .... well, you get the idea.

Keith V: Is this the first RUF you have owned?
Bob W: Yes, and it may well be the last because I like it so much. The only thing I should have done was to have power steering installed since it is hard for my wife to drive at low speeds with the 18” wheels and tires. I may still do that.

The reason the stock whaletail was not used becomes glaringly obvious as soon as you open the rear deck lid.

Keith V: Roughly how many miles are on the car?
Bob W: We have 60,000 miles on the car since the RCT conversion.

Keith V: What do you use the car for primarily?
Bob W: We use the car as a highway car. It has been to every PCA Parade since 1994 (which was when my wife said she would not attend another Parade without a/c).

Front end.
The lightweight 18” dia. by 8.5” wide RUF front wheels display the “big red” brake calipers and cross-drilled rotors.

Keith V: What do you feel are the best traits/characteristics about the RCT?
Bob W: It is easy to drive, very responsive and fast enough (190+)...... what more could you want! As I said earlier, the RCT engine is like having a strong small block V8 with great cams. Additionally, on the highway, I get as good or better gas mileage as I did before the conversion - which is typically 27 mpg when cruising at around 80 mph!

Keith V: Do you have to get it serviced/maintained at a special shop? Are there peculiarities of ownership?
Bob W: I do all the maintenance myself. Other than the required valve adjustment at 10,000 to 15,000 miles there is nothing that is unusual. Except, of course, that it takes several hours to get to the valves to do the adjustment, that is, several hours to take everything off (intercooler, turbo, etc.) and an additional several hours to put everything back on.

Rear end.
Engine access is significantly limited by the Turbo's intercooler. Also note the twin exhausts.

Keith V: Have you ever driven another car that is similar?
Bob W: Yes, including most everything RUF (as mentioned above). A story comes to mind which addresses this question. I remember I was driving a RUF 3.8 BTR (about 425 HP., narrow body, etc.) in Germany and stopped to visit Helmuth Bott (a long time friend and V.P. of Porsche Research & Development at the time) and he said “Why don't we go for a test drive with the BTR and I'll bring my 959?”
So, sure enough, we headed out and during the test drive we switched back and forth between cars. The reason for mentioning this is that at one point I recall Helmuth was in front of me in the 3.8 BTR on the autobahn heading South toward Constanz. I was doing an indicated 185 mph in the 959 and he started accelerating, so I put my foot flat “in it” and Helmuth in the 3.8 BTR was rapidly pulling away from me!
Now THAT is what I call performance!

Keith V: Have you ever driven your RCT on a race track?
Bob W: Yes, at places like Brainerd International Raceway MN, where I remember being on the 3/4 mile straight and seeing the speedo indicating 170mph and still climbing. However, in my opinion, the RCT is not really a track car because at 3071 lbs. it is simply too heavy. On the other hand, my 2.7L Carrera RS, which weighs in at 2250 lbs. and has around 230 bhp, is a really GREAT track car. You can use the RCT on a racetrack but it is just too heavy to get the type of handling response I would like.

Front lip.
The RUF front Lip spoiler reduces front end lift and ensures front end stability at speed.

Keith V: Were there many problems getting the car federalized to be registered in the US?
Bob W: No there were no problems because federalization is not required for conversions. As Luis Ruf is legally considered a manufacturer by both the US and German governments, in the end we didn't have to take the car to the EPA for Luis to certify the engine. The engine was certified in the US under the so called “family” rule. That is the 3.8 liter BTR had previously been certified, and the EPA therefore considered the 3.6 the same engine family.

Keith V: What would you trade your RCT for - if anything?
Bob W: I would not trade it! I have had it for 12 years and not too many cars can come close to its performance, even today. What's the difference between 0-60 in 4.1 sec. and 3.9 sec. (and how many people have ever done either)? As I quoted Luis above, it is the 30 mph to 150 mph acceleration that's fun and that is where the narrow body car really makes it look easy. Even after 60K miles, I still would not exchange it for anything else.

Rear quarter.
The rear quarter is dominated by the RUF 18” dia. by 9.5” wide rear wheels with 265/35 Michelin Pilot Sport tires.

Keith V: How would you sum up your feelings toward your RCT?
Bob W: It is just a truly great car!!!!

RUF facilities in the USA

RUF now have a facility here in the US in the Dallas TX area, and I'm sure that they'd be more than happy to convert your into their latest version of the RCT - which is called the RCT Evo and has a further 40 bhp for a total of 425 bhp and around 420 ft-lbs of torque.

To view the RUF USA website select

If you're interested in seeing the list of conversion accessories in the RUF parts program for the 964, and would like to get a general idea of their respective prices, click here.

In conclusion

I want to thank Bob W of IL for agreeing to put this article together (although I'm not sure he realized quite what he was getting into) and for his patience in answering my barrage of questions.

I can think of very few people who can understand and appreciate an RCT from initial concept to final execution as completely as Bob W of IL.

When I consider Bob and his RCT, I can't help thinking that they are a well matched pair ..... I'd even go so far as to say ... they deserve each other!

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