Flat 6 Magazine
In the last issue we had the ANDIAL Carrera 4 with the water cooled 962 engine and now we have another contender for the ultimate street hot-rod, a 1989 Porsche Speedster with an IMSA version of the 962 engine installed. We actually have a number of good Porsche tuners in the United States and one of these tuners is an old friend of mine Bruce Canepa, of Canepa Design in Santa Cruz, California. Canepa has just finished a 1989 Porsche Speedster that may just be the ultimate street hot rod Porsche.
Bruce Canepa has been involved with Porsches as a business, in racing and as an enthusiast for years, but recently Canepa and his company, Canepa Design, have been known for their aerodynamic truck conversions and specially outfitted racing trailers. Canepa says that they have built about seventy percent of the large semi trailers that are used in racing here in the United States. They have built them for most of the Indy car teams, IMSA teams, vintage racing, stock car racing and drag racing teams in the country. Canepa' s trailer company, Concept Trailers, custom outfits the trailers that haul racing cars. The equipment that they install in these trailers ranges from the elevators used to load the cars, the tents that mount on the side where the teams' mechanics work on the cars at the races to completely outfitting the interior like a motor home.
In addition to building trailers for racing teams they custom outfit trucks and trailers for a variety of other applications A few years ago the built the truck and trailer rigs used by Porsche Cars North America, Inc. for their Driving Experience program. The Driving Experience was a program where they would take prospective customers for the new cars out to a site where they could drive the whole model range. The trailers were outfitted like a dealers sales room where they showed videos showing all of the features of the various models to the prospective buyers and tried to close sales.
One of the things that Canepa Design is doing now is making portable motion based theaters comparable to the motion based theaters at Disney Land and Disney World where they are able to give rides that simulate space ships, a F 16, a race car or blood traveling through arteries, etc. The portable version has been made possible by the development of movable self contained two passenger seats. These seats can do a lot more, faster than the big moving floors in the regular motion based theaters can do. It can tilt forward steeper, tilt backwards steeper and move left or right faster and steeper than the movable floor in the Disney theaters can do. All of the responses are controlled by a computer signal which is related to the visual action displayed on the screen and the pair of seats can do more faster and more accurately. Concepts Trailers designed and built the theater enclosures to put these seats into. Two semi trailers lock together and become one theater with a sixteen foot movie screen. They slide the seats in and lock them down to the floor and then hook them up the computer feed and they are ready for action. If you have not been in one of these motion based theaters yet you should try one. They are so realistic that you feel like you are in the cockpit of an F16, or a space ship or a race car or whatever the simulation is, "because your really are".
Canepa Design did a lot of Porsche slope nose conversions when they were all the rage here in the United States in the nineteen eighties. Canepa said that they developed their own slope nose conversion in 1983. He said that he felt that they could do as well and maybe even better than the factory conversions. All of the brackets and mounting hardware for the Canepa Design slope nose conversions were made of stainless steel to prevent corrosion. They used the factory fenders that they did the slope nose conversion on and then re-zink coated the fenders for rust prevention. They ended up doing a lot of the slope nose conversions while they were still the fad. They even did one car for a customer in Australia.
In the mid-eighties Canepa Design decided that if their conversions were good enough for Porsches they would surely be good enough for trucks too and there are a lot more trucks than there are Porsches so they started designing custom aerodynamic body kits for Kenworth and Peterbuilt trucks. And while they couldn't do slope nose conversions to the trucks they could clean up their aerodynamics using side skirts, wheel covers, flush mounted head lamps and smooth bumpers with their conversions which greatly improve the trucks appearance and fuel economy. These kits have been so successful that the truck manufactures themselves have used Canepa to redesign their trucks. Canepa says that he and his employees are all really car guys and that they just treat the trucks like big cars, they just take up a little more room. He says that they have added a level of quality and finish to them that the truckers are not used of seeing.
Canepa Design has always done restorations on Porsches and in the late eighties they were fortunate enough to have a customer that wanted a 935 and a 936 restored, which Canepa said, really allowed them to hone their restoration skills. One of the latest restorations that Canepa Design did was an extensive restoration of a 906 that was little more than a valid set of serial numbers when they started and took nearly 4,000 hours to complete. This car turned out really well and won the Santa Barbara concours and has been featured in several magazines articles since it was completed.
Canepa has always been a Porsche guy and has had his own Porsches since he was a teenager starting with a 1968 911L that his dad, a car dealer, took in on trade. Canepa bought his first new Porsche in 1970 and wrecked it in the rain finding out ho fast he could go around corners. He drove a 911R to college that he bought from Dick Smothers of the Smothers Brothers. Canepa now has an RSR, a 934, a 935 and a 959S. He raced the 934 and 935 back when they were contemporary race cars placing third with Rick Mears in 1979 at the Daytona 24 hour race. Bruce Canepa also had one of the Holbert built 962s which he restored, raced and then sold. The 962 was really one of the things that led to the building of this hot rod Speedster. The 962 had a spare engine that was worn out and a good candidate for detuning for use in a street hot rod.
The hot rod Speedster that Canepa Design just finished belongs to Gary Primm a casino owner in Las Vegas, Nevada. Primm is a car guy with a large collection of cars, but he was not a Porsche enthusiast and when he bought the Speedster he was disappointed with the performance and quickly became bored with it(the car had less than 100 miles on it when he turned it over to Canepa for its transformation). Primm was introduced to Bruce Canepa by AMG and they talked about what could be done to the Speedster to both improve its looks and make it a really exciting fun car to drive.
Primm and Canepa sat down about a year and a half ago and talked about what the car could and should be like when Canepa was done converting the car. Cane pa said that he felt that since all of our US 911 Speedsters had the turbo look bodywork and suspension that they should have been turbocharged. He said that he thought that the performance should be like a modern update of the old Carrera four cam Speedster, a car that was great fun to drive in its day. Canepa's idea was to scale that sort of performance and fun up to contemporary levels of performance.
Canepa had the spare 962 engine that he knew could be made over into a wonderful street car motor. He told Primm that they could change the whole car over into something that was exciting and would be an incredibly fun street car. It would have a lot of power, it would handle, it would stop, it would ride well and have a stiff chassis, but not be too stiff in terms of the ride. Primm said go.
Originally Canepa said that he wanted the car to look stock except for a large DP (Design Plastic) rear spoiler, but then he decided that he would need larger wheels and tires for the cars potential performance envelope than would fit under the stock turbo look bodywork so his concept for the car changed. He said that he felt that the appearance of the car would probably be unbalanced with the oversized DP rear spoiler. Canepa likes the looks of the 934, and adapted some of the design characteristics of the 934 to the Speedster. Canepa says that he likes the design because it maintains the Porsche tradition, but I suspect that it was as much because he has a 934 himself and he just likes the car's looks. Canepa says that he feels that the 934 looks very competitive yet subtle, and pretty classy, but at the same time is very serious looking.
In any case they decided to use the 934 fender flares and the 934 front spoiler. A DP rear wing was used because something larger than the original Porsche 934 wing was needed because they would have to fit the huge intercooler of the 962 engine under the wing and they also wanted to keep the air conditioner which required space for the AC condenser in the wing.
Goals for the car were that it be very, very fast and still had to retain all of the comfort features of a street Porsche. One goal was to have at least 500 horsepower and another was to have a top speed in excess of 200 mph. Because of the speed potential they installed a low profile roll bar for safety. The roll bar is tied into to a side bar structure that is tied in from the back of the car all the way to the front tower assembly for chassis rigidity.
They felt it was necessary to stiffen up the chassis because the stock Speedster is a fairly flexible car and as result the car doesn't ride as well as it should or could with a stiffer chassis. The chassis should be rigid like Porsche coupes so that the suspension can work properly. In addition to the roll bar and side stiffening bars they also reinforced the chassis by boxing in the rocker box area and developing an extra monocoque substructure, raising the floor level from the seats back to get some additional strength in that area. The result is that they created a very stiff "tub". For a open car it is very impressive, and they couldn't have asked for more without putting a roof on the car.
They used 935 center lock hubs and nuts so that they can use center lock wheels. They used the new BBS GTP wheels 9 1/2" in the front and 12 3/4" in the rear. BBS designed a new wheel because they needed more strength for the slide loads of the GTP cars. The new wheel is a cleaner design with bigger spokes than the older style BBS wheels. The tires are the new Goodyear GSC tires 275/40 ZR17" in the front and 315/35 ZR17" in the rear. Canepa said that they are going to trim and fit a set of BBS racing wheel fans before they deliver the car to Primm.
Originally they had planned to use coil over suspension. Canepa says that although the coil over suspension works fine for race cars that it is not the right compromise for a street car. In the middle of the Speedster project Canepa Design had the opportunity to do a Porsche Club race track car for someone who was going to both use it for street and track use. He said that when they chose a coil over spring rate that would work well for the handling it was too stiff for a good quality ride. They did a lot of testing of spring rates and found that they could make a car handle well and ride well on very smooth roads, but the fact is there aren't many smooth roads left anymore and the car just plain rode horrible. When they softened up the spring rates enough so that the ride qualities were acceptable the handling went away. Canepa feels that this is because of changing where the load is transmitted into the car's chassis from where the loads were absorbed from the torsion bars.
As a result of their testing they decided that for the Speedster, they would not to use the coil over springs, but instead they chose to use torsion bars because they work well on all pavement conditions providing a good ride and handling that will allow you to take a corner as fast as your fear level will take you. The whole chassis and suspension plans for the Speedster were based on their experience with other cars that they had built. They used riffle drilled torsion bars made by Stevens Machining, 33 mm diameter in the rear and 23 mm diameter in the front. The front and rear sway bars are 22 mm "Charlie Bars" made by Wrightwood Racing. The shock absorbers are custom valved Bilsteins. Canepa says that the Speedster handles better than any street Porsche that he has ever driven. He says it actually handles as well as his RSR, but for the fact that it does not have racing slicks on it. He said that it is the only street Porsche that he has driven that handles as well as the 959. He says that he feels that the car really rides well, as smooth as the brand new Carrera or Carrera Turbo on all of the different type of roads that they have tested it on.
The oil system is designed like a racing Porsche with the oil tank in the front trunk. The system holds 28 quarts of oil. The engine breather "breaths" into an accumulator tank back in the rear fender well. The accumulator separates the oil from the oil fumes and pumps the oil back to the tank and lets the fumes breath into the oil tank under the front hood like the Porsche racing cars.
The brakes are the big Brembo calipers like the ones used on the 959 or 928 GTS with 935 rotors mounted to the 935 hubs. They didn't want to give up the power brakes so they designed and fabricated a vacuum storage tank using the 962 engine for the vacuum source. They were able to retain the comfort of power brakes with the stopping power of a race car.
Almost everything in the car had to be moved around or changed somehow to make all of this work. For example they chose to use rear ducts similar to those use on the 959 because they were attractive and functional. These rear fender ducts are used for the inlet air to the turbos. A hose goes from the intake duct back over the wheel wells to the rear of the fender up by the taillight where there is a K&N filter in a canister on each side. From the air filter canister the air is ducted directly into the turbo charger by a tube that rolls right down into the turbocharger inlet.
They used the G-50 five speed from the 1989 911 Turbo, but they shortened it by and inch so that it would fit into the Speedster chassis. The axles and CV joints are made by Super Boots, the company that makes the Indy Car racing axles.
The spare motor from Canepa's 962 was used because he felt it would make a good starting point for their Speedster hot rod. Unlike the World Endurance Championship 956 and 962 engines which had water cooled heads and then towards the end were completely water cooled the IMSA version of the engine was an air cooled evolution of the 935 engine. Canepa wanted to use the IMSA 962 engine with the flat fan to bring the better cooling of the racing flat fan to an air cooled engine in a street car that would be producing well over 500 horsepower. Canepa said that he also wanted to use the flat fan for esthetics and because, he says he thinks that they sound so neat at idle.
They got together with Jerry Woods who Canepa feels is the best Porsche motor guy around. They talked about building a motor that was a street motor with a lot of torque, a lot of bottom end power and as little lag as possible so that it would be driveable all the time. It would have to be something that you could drive all around town and then go out on the freeway and go as fast as a race car. That is exactly what they ended up with, a 600 hp (actually 581.5 hp. at 1.1 bar boost) motor that you only have to turn up to 6,500 rpm. It can light the tires in first, second and third gears. Canepa says that it can literally fry the tires in the first three gears if you aren't careful and that is with 13" wide sticky Goodyear tires. On the freeway at 2,000 rpm he says that it accelerates like a 450 cubic inch V8 powered car does. Well it should with the torque curve that this engine produces. At 2,000 rpm the engine produces over 300 lb. ft. torque, and from 2,500 rpm to 7,500 rpm the engine produces in excess of 400 lb. ft. torque with a peak torque of 550 lb. ft. at 4,000 rpm (see: Speedster 962 engine for torque and horsepower curves for the 962 engine with 1.1 bar boost.). The engine performance was measured with all accessories in place including the muffler. The engine was also tested at higher boost levels where it produced in excess of 600 hp, but the 1.1 bar boost level was chosen as a practical boost level for a street driven engine.
The turbo lag is well below 1,500 rpm. Canepa said that he cruised all around town for a couple of hours one day just to see what it was like and to see how it would perform. It is smooth, it is everything that you could ask for. Jerry Woods converted the 962 engine to 3.3 liters by using 100 mm pistons and cylinders the 70.4 mm stroke crankshaft. He chose to use the HKS electronic waste gate control with two preset positions and a variable position instead of the manual valve traditionally used on modified turbocharged Porsches. Woods used a programmable twin ignition system that he has developed himself and a prototype of a new Haltech fuel injection management system. The Haltech injection management system takes advantage of the existing 962 intake manifolds which used twin staged injectors. The engine runs on one set of injectors while the engine is running normally aspirated and the second set of injectors is phased in when the engine comes up onto the boost. This system with staged injectors provides better control over the fuel mixture under all operation conditions so that the car runs better as a street car.
Canepa Design had to design and build their own exhaust system to do what they wanted it to do and fit everything into the car where they wanted it with the twin turbos and all. They were originally going to try to use one of the stainless steel systems that are on the market, but it just wouldn't work for their application. The made their own stainless steel exhaust system and that gave them the opportunity to put the turbos behind the rear tires alongside the motor, which let them keep the primary header pipes short for better performance. Their turbo placement also gave them a straight shot up through the car to connect to the large intercooler that they used. By keeping all of the plumbing short they were able to cut the turbo lag considerably. The turbos that they used were the original K26 turbos that came on Canepa's 959S. The turbochargers are sized for low end or overall performance and driveability rather than peak power as you would with an engine used for racing.
Most of the engine accessories had to be relocated because the 962 was a mid-engined car and the engine faced the opposite direction in the 962 from what it does in the 1989 Speedster. Fred Garretson supplied the large intercooler core for the engine conversion. Canepa Design built their own intake plenums and intercooler plumbing so that they would all fit under the DP rear wing and engine lid. Everything was designed to be functional and look good when you opened the engine lid. They wanted to be able to use all of the standard engine lid mounting and latching hardware. They built the rear motor mount plate so that they could mount the air conditioner compressor on the back side of the motor plate where there was still some room. They specified a reverse direction compressor so that it would work facing backwards in the car. They built their own stainless steel muffler with two large rear outlets to look like the tailpipes on the twin turbo 935 engines. The muffler kills most of the noise, but the car still sounds great.
They had to develop their own heater system because there wasn't room for heater boxes on the headers. They used the gas heater that Porsche uses in their rally cars. The heater works well and will allow the owner to warm the Speedster up on a cold day in the desert area of Las Vegas.
They also had to design their own emergency brake system because with the 935 brakes they didn't have an emergency brake. They designed a system that uses an Accumulock to apply pressure to all four calipers when it is in use. To apply the emergency brake you pump the brake pedal and hold up the lever on the Accumulock and it sets all four brakes. When the brake is set it will safely hold the car on a hill, park the car on a hill and it isn't going to go anywhere.
Canepa Design put in a good set of TRW four point competition belts. They put a slot in the headrest so that the shoulder belts can come through the seat from the right height for safety very much like the new sports seats for the Carrera Cup cars from Porsche do.
I asked Canepa how fast the car was and he said he wasn't really sure because he hadn't had it flat out, but that he had it up to 6,800 rpm in fifth gear and that Jerry Woods calculated that to be 202 mph with the gear ratios and tire sizes that they were using. The car uses a 959 speedometer, but the with the different wheel and tire sizes the 959 has different final drive ratio so the speedometer is not accurate and it read only 190 mph at 6,800 rpm. He said that at 200 mph the car feels pretty comfortable. It is noisier than anything that he has driven before because it is an open car, but otherwise it feels fine. The car is geared to go over 210 mph and should have plenty of power to pull the gearing.