Friday, June 1, 2001

Garretson's 935

911 and Porsche World

This is a special story about a very special Porsche 935 that was raced for more than 70,000 miles. The story actually starts a little earlier, but is mostly about this remarkable 935 that not only raced as a 935, but also masqueraded as a 934 and as a 930S, whatever was necessary to make this remarkable car eligible for the various racing classes in IMSA. Our story actually begins before this car was built and includes a little of the history of Porsches turbocharged 911s and some of the various different racing cars derived from those turbocharged 911s. 

A prototype 911 Turbo was first shown at the Frankfurt Auto Show in September 1973 to test the market potential of such a car. The production version of this car was introduced at the 1974 Paris Auto Show and then put into production as the type 930 Turbo Carrera in 1975. The original purpose of the Turbo Carrera was to gain homologation for the Group 4 and Group 5 cars that Porsche originally intended to race in the Manufactures Championship from 1975 on. To qualify as a Group 4 Grand Touring car a quantity of at least 400 units had to be produced over a period of 24 consecutive months. The original plan was to build the necessary 400 required for homologation and then cease production, but the car became such a success that it remained in production for fifteen years and in those fifteen model years between 1975 and 1989 over 20,640 the original 911 Turbos were built.

The change to Groups 4 and 5 classes was delayed by FIA (Fédération International de l'Automobile) from 1975 for one year until 1976. In 1976 when the rules for the World Championship of Makes were finally changed by the F.I.A. Porsche produced two new 911 based racing cars for the resulting Group 4 and Group 5 classes, the 934 and 935. The 934 was homologated as a Group 4 car and sold to Porsche's racing customers for GT (Grand Touring) racing, while the 935 was a Group 5 car and only the factory planned to race them. Although the Group 4 rules were really quite strict and restricted the 934s to very nearly to the same production configuration as the 930s the Group 5 rules were a much more liberal. The Group 5 class was based upon silhouette formula where the cars were offered a great deal of latitude as long as they resembled the basic silhouette of the car from which they were homologated. The rules stated that the aerodynamic devices not homologated for series production must fit with the cars frontal projection. What they mean by this is that when you view the car from the front the rear spoiler cannot stick out into view from the silhouette of the car, and this is in essence what they meant by the silhouette formula.

Thirty one of the group 4 934s were produced for Porsche's racing customers in 1976 and 1977. Most of these cars remained in Europe and competed in the Group 4 category. Toine Hezemans won the 1976 European GT with a 934. Only two of the 935s were built by Porsche for use by the Martini sponsored Porsche factory race team. The Martini team won the 1976 World Championship of Makes with these two 935s.

In the U.S. I.M.S.A. (International Motor Sports Association) had said no to the Porsche Turbos preferring to try to encourage Porsche to continue to build and support the normally aspirated RSRs in their series. Porsche, being a small company could not support more than one racing series at a time with customer racing cars and they had already chosen the Group 4 934 so there would be no more RSRs. SCCA (Sports Car Club of America) welcomed the Group 4 934s with open arms. Vasek Polakbought five and Al Holbert one to race in the popular SCCA Trans-Am series. Several different drivers drove the Polak cars over the year, but George Follmer drove for Vasek most of the season and was rewarded for his efforts with the 1976 SCCA Trans-Am championship. Al Holbert spent most of his time with his Chevrolet Monza winning the I.M.S.A. championship and had little time to race his 934 in the Trans-Am series.

For 1977 I.M.S.A. not only relented and let Porsche's customers race turbocharged Porsches, they also relaxed the rules letting an even more potent cross between 934 and 935 called the 934/5 or 934 1/2 compete in their series. Porsche produced a special series of ten special I.M.S.A. legal 934s which took full advantage of the more liberal I.M.S.A. rules and used many of the mechanicals from the 935. The I.M.S.A. cars were able to run with a lighter weight, wider fifteen inch wheels, tires and fenders, larger group 5 rear aerodynamic wing and the Bosch plunger- type mechanical injection instead of the CIS system. This change was to make the cars faster, more pleasant to drive, more reliable and able to produce nearer the 600 horsepower of the 935 instead of the 500 horsepower of the Group 4 version.

In Europe, over the 1976 season, a number of Porsche's racing customers had been converting their Group 4 934 racers to Group 5 specifications, so for 1977 Porsche also produced a small series of thirteen cars (Type 935/77) for their customers to race in Group 5 with. The new cars were a customer version which were in effect replicas of the two original 1976 factory single turbo 935s (Type 935/76).

For the 1977 season the factory team had a new 1977 version of the 935 for their own use. The factory 935/77 was quite different from the customers version and had new body work which had running boards, a new front end that had fared in mirrors at the edge of the fender which also served as fences to keep the air from spilling off the front end improving the downforce on the front end. They also had a raised false roof section to clean up the airflow over the back of the car making the rear wing more effective. The running boards were used to improve the air management and were the beginning of efforts to provide some ground effects for the 935. The rules said that the car had to retain its original rear window in its original location, but it did not say that there couldn't be a second rear window over the original so that's what they did. This new false roof faired into a new rear wing, and they used the edges of this false rear roof section as air inlets for the engine. This car again won the world championship of Makes for Porsche with the help of several of the customer teams racing the customer version of the Porsche 935.

I.M.S.A. decided to let people update their 934s to 935 specifications and also to let the 935s race in their series in 1978. Our story starts with the very last 935/77 built. Californian, Dick Barbour added the car to his team at the beginning of the 1978 season where it was a solo entry by the team at the first race of the season, the Daytona 24 hour race in Florida, in early February 1978. It was a good start for the team, Barbour, Manfred Schurti and Johnny Rutherford drove the teams 935/77 to second place to the German GELO team's 935/78 that was entered by Brumos Porsche and Driven by Rolf Stommelen, Tony Hezemans and for a one hour stint by Peter Greg. The next race for Barbour's 935/77 was Sebring where the car qualified second but did not finish. However, another Barbour team 935 driven by Brian Redman, Charles Mendez and Bob Garretson won Sebring so the Barbour team was improving on their good start. Barbour drove again with Johnny Rutherford at Talladega Alabama where they placed third. Barbour drove his 935/77 solo to a sixth place finish at the May Laguna Seca race in Northern California, which was the fourth time, and turned out to be the last time, he was to drive this 935/77. 

From 1978 on Porsche left the defense of the World Championship of Makes, which was based on these Group 5 cars to their customers. For the both the 1978 and 1979 seasons the Porsche customers did bring home the World Manufactures' Championship for the Porsche factory. To encourage the private teams to compete in the manufactures championship Porsche created what they called the "Porsche Team Cup" to be awarded to the private Porsche customer team accumulating the most points in races counting towards the World Manufactures Championship.

The Martini sponsored factory team only raced one 935 in 1978 "Moby Dick".The "Moby Dick"car was built with an aluminum roll cage/tube frame, the center section of the car was lowered and the floor section was raised up to regain the ground clearance. All new body work was developed to take advantage of the car's lower profile for improved aerodynamics. "Moby Dick" was created with the intention of doing well in just one race, Le Mans. At Le Mans the emphasis is more on straight away speeds rather than cornering speeds so the cars aerodynamics were compromised towards high speed rather than downforce. "Moby Dick" only raced four times and only won at Silverstone, but the concepts it established had a great influence on the future of Group 5 racing and Group 5 racing cars. Some of the features of this car were larger brakes, improved aerodynamics and its upside down transmission. The upside down transmission was utilized to reduce the severe angle of the rear drive axles created by lowering the car as much as they had with the larger diameter 19 inch wheels and tires.

For 1978 Porsche built a series of fifteen customer 935s (Type 935/78) and let their customers defend the World Championship of Makes. The cars looked very similar to the first series of customer cars, but they had some refinements and they did have a twin turbo version of the 935 engine similar to those that had been used by the factory's Martini sponsored cars in 1977. These twin turbo engines offered a big improvement in drivability and as a result reduceed lap times every where that they ran. The bodywork of these 1978 customer cars was a little different from the 1977 customer version in that the rear fenders were removable for the first time on the 935s. This made the cars much easier to work on and of course easier to repair. The rear wing was changed to a two stage wing to provide improved rear down force.

Barbour bought one of these new cars for his team in June 1978 for the Le Mans race. Barbour ran a two car team at Le Mans with Bob Garretson, Steve Earl and Bob Akin driving Barbour's old 935/77 while Barbour, Brian Redman and John Paul drove the new 935/78 in the race. Barbour's car did well and finished fifth overall and first in the I.M.S.A. class. The 935/77 did quite well for the first half of the race, running as high as 18th place. At 4:55 am, less than an hour past the half way mark, Garretson had a terrifying crash at the kink on the Mulsane straight where the cars are at their fastest, which for the 935s was 190 to over 200 mph. Garretson said that he thought he had caused the accident by getting a little off line while passing a much slower car. When the car crashed it rolled end to end and side to side until the wreckage was strewn over a quarter of a mile and left some of the body parts stuck in the nearby trees. The car was destroyed, but Garretson was only battered and bruised. 

Like the Phoenix the wrecked 935 rose again from its ashes. The team shipped the wrecked car back home to the United States for a salvage operation. The car was completely stripped of any parts that might be usable and the rest of the car was discarded. In May of 1979 a complete new chassis was purchased from the Porsche customer racing at Werke I. The made in "Mt. View, California by Garretson Enterprises" 935 was constructed from this new 935/79 chassis, the salvaged parts, and some new parts. Mountain View was the home of Garretson Enterprises so the team felt that this slogan was appropriate.

Again for the 1979 season Porsche produced an updated version of the 935 for their customers to defend the World Championship of Makes title, a series of 13 of these cars were built when you include those built from "tubs", or spare chassis. The 935/79 incorporated some of the innovations from their 935/78 "Moby Dick" and was the basis with which private teams were able to continue to develop their own more competitive versions of the 935.

The tub or chassis for the resurrected race car was one of these updated 935/79 replacement chassis, chassis number 0090030. The new car, which was built to the 935/79 specifications was completed in time for the June 1979 running of Le Mans, where Rolf Stommelen, Paul Newman and Dick Barbour drove it to second overall and first in the I.M.S.A. class. This car was but one of four cars entered by the Barbour team for the 1979 running the Le Mans race, one of the team cars failed to finish while the other two team cars placed eight and ninth. Stommelen, Newman and Barbour were teamed again In July for the Watkins Glen in upstate New York six hour race where they also placed second. The car was raced only once again by Barbour in 1979 at Elkhart Lake Wisconsin where it was a DNF with a broken rear trailing arm.

The car that had beaten Barbour's 935/79 at Le Mans was one of the Kremer Brothers 935 K3s. The Kremers had developed their K3 935 for their own use during the 1979 season. In 1979, the Kremers won 11 of the 12 races in the German National Championship in addition to their win at Le Mans. In 1980 the Kremers built replicas of their winning K3s and sold them as customer cars to anyone who wanted to win. In addition to the Kremer K3s they also sold several conversion kits so that 935 owners could convert their own 935s to K3 specifications. 

For the 1980 season Barbour bought one of the new K3s from the Kremer brothers for himself and co-driver John Fitzpatrick to drive. With Sachs sponsorship for the 1980 season Fitzpatrick was able to win both the 1980 Porsche Cup and the IMSA championship with this K3 935. The Made In Mt. View 935 remained in the Barbour Racing team, but the Bob Garretson team was the cars new owner. The old war horse's first race in the 1980 season was the 24 hour race at Daytona where Garretson finished ninth with Anny-Charlott Verney and Skeeter McKitterick as co-drivers. Before the cars next race at Sebring Florida the 935 was converted to Kremer K3 specifications using one of the Kremer's conversion kits. At Sebring, with Apple Computer sponsorship, Garretson, Bobby Rahal and Kees Nierop raced to a seventh place. The cars next race was at Riverside Raceway in Southern California where Rahal and Garretson placed second to Barbour and John Fitzpatrick in the other team car, the teams real Kremer K3 935.

That was the last time that the car did well for awhile as the car was a DNF at both Le Mans and Watkins Glen. In the July sprint race at Sears Point Raceway in Northern California Rahal again placed second to teammate Fitzpatrick. The car again DNF'd at Mosport when Garretson had an accident, and then a week later Rahal qualified on the pole at Elkhart Lake and he and Garretson drove to a third in the race.
For the 1981 season the Garretson team separated from Barbour and went off on their own. The Made in Mt. Veiw car was again modified to improve its performance, the suspension was revised front and rear and the body work was altered to provide better aerodynamics and improved intercooling for the engine. The Garretson teams engine builder, Jerry Woods, also redesigned the air-to-air intercooler system to further improve the intercooling for both more power and improved reliability. Garretson raced the car most of the 1981 season with various different co-drivers to win the 1981 World Endurance Drivers Championship and the Porsche Team Cup for the Garretson Team.

The 1981 season started at Daytona where Garretson, Rahal, and Brian Redman won the 24 hour race. With the same drivers at the Sebring twelve hour race great things were expected of this car, but unfortunately they ended up fifth in class and 17th overall. Garretson got off into the sand and flipped the car. Afterwards a great deal of time was lost because it proved difficult to make a windshield stay in the misshapen roof section.

At Riverside in Southern California Rahal and Redman finished third. The following weekend Rahal picked up a fourth at Laguna Seca in Northern California. The car's next race was Le Mans where Garretson, Anny-Charlott Verney and Ralph Cooke were sixth overall, second in the I.M.S.A. class. Rahal took the car to the July 4 race at Daytona, where an oil leak in a new engine relegated him to 18th place. Garretson co-drove with Johnny Rutherford and Rick Mears to a third place finish at Watkins Glen in upstate New York.

The car had problems at Sears Point California in 1981, breaking a crankshaft and costing Rahal another DNF. The following weekend at Portland Oregon Rahal placed third. The next race for the car was Road America at Elkhart Lake Wisconsin where Tom Gloy and Garretson drove the car to fourth. Then the car was taken to Brands Hatch for the final World Endurance Championship race where Garretson and Rahal placed second, which gave Garretson the 1981 World Endurance Drivers Championship and won the Porsche Team Cup for the Garretson Team.

Garretson and Rahal ran the car one more time in 1981 at the Daytona Finale. The car was delayed with a turbocharger failure and only placed 17th.

Because of limited finances the car was run in only a limited series of races in 1982 as a "renta-racer". When there was money and drivers to run the car it went to the races and when there was no money it stayed at home. At the Daytona 24 hour race Garretson, Jeff Wood and Mauricio de Naverez were third. At Sebring Ray Ratcliff, Grady Clay and Skeeter McKitterick placed seventh. Ratcliff and Clay were were fifth at Riverside and fourth at the Charlotte 500 Km. The car's finale race for 1982 was Le Mans where Garretson, Verney and Ratcliff placed eleventh. This was the last Le Mans where the Group five cars were still eligible and the first year of the Group C car, this was the race where the Rothmans Porsche 962 placed first, second and third.

At the end of the 1982 season, Southern Californian Wayne Baker bought the 935 from Garretson so that he could convert it to "934 specifications" and race it in the I.M.S.A. GTO class. I.M.S.A.'s GTO class was very loosely based on the F.I.A. Group 4 rules, the class where the original 934s were built to race in 1976. The I.M.S.A. GTO rules were less restrictive than the F.I.A. Group 4 rules and allowed many of the developments from the faster 935s. I.M.S.A.'s rules did, however, require that the cars physically resemble the 930 street turbos from which they were derived. This meant that all of the trick aerodynamic 935 body work had to go. The wheel size was also restricted to 12 X 16 instead of the 15 X 19 inch wheels that the car had been able to use as a 935. They also were required revert back to the single ignition and single turbocharger concept of the street 930 Turbo to comply with the rules. Baker felt that the rules had been made liberal enough by I.M.S.A. to give a well prepared 935 back dated to "934" specs a chance at the GTO championship.

Baker kept on most of the crew from the Garretson Team who had originally built the Made in Mt. View 935 in 1979 to convert the car to GTO specifications and crew the car at the races. They spent a month converting the chassis to make it more suitable as a GTO competitor. For 1983 the GTO rules required that the car weigh more than it had as a 935, so it was decided to take advantage of the additional weight to make the car stronger and to add some other features that would make the car more reliable. Baker designed and had new fiberglass bodywork made that would meet I.M.S.A. GTO requirements and still provide a reasonable amount of aerodynamic assistance.

The 3.2 liter 935 engine was modified to take advantage of as many performance opportunities possible while complying with the restrictions imposed by the GTO rules. Jerry Woods who was responsible for the engine took advantage of the fact that the body work was being completely redesigned to incorporate several improvements in the engine design. The bodywork change allowed him to design a new induction system with a very larger rear mounted air-to-air intercooler. Woods felt that the large twin inlet single turbo from the I.M.S.A. version of the 935/79 would offer performance similar to the twin turbocharged 935 engine if properly utilized. To facilitate the large twin inlet turbocharger Woods designed a pair of new equal length three-into-one headers, each with its own wastegate. The engine development program was very successful and the single turbo I.M.S.A. "934" did have performance similar to when it was a twin-turbo 935. Baker felt that it was critical to maintain engine performance at a level similar to what it had been as a 935 because the other restrictions: smaller wheels, higher weight and restricted aerodynamics were going to seriously restrict the cars overall performance.

The goals that Baker and Woods had set for the team and their converted 935/934 were to win GTO races, place well overall and win the I.M.S.A. GTO championship. At the first race of the season the Daytona 24 Hour race the car was not fully developed, but even so the car placed ninth overall and fourth in the GTO class.

The next race was the first race to be held at Miami Florida, which turned out to be more of a regatta than a road race, boy did it ever rain. Baker got tangled up with a spinning car in the rain and was a DNF. Sebring brought the success that the team was looking for and Baker, Kees Nierop and Jim Mullen won their class and first overall. This was the fourth Sebring 12 hour race that Woods had won as an engine builder and marked the first time that a GTO car had ever won that prestigious race. At Road Atlanta in Georgia, the car won its class and finished eighth overall with Baker and Mullen driving. Riverside California produced another class win for the team and a fifth overall. An accident at Laguna Seca in Northern California resulted in a ninth overall and a fifth in class finish. At Charlotte North Carolina, Baker and Mullen again won the GTO class and were fifth overall. At Lime Rock Connecticut they were second in GTO and fifth overall.

At Mid-Ohio the team had an unusual problem when the starter ring gear exploded in the last third of the race, destroying the transmission case, some of the wiring and some of the linkage for the fuel injection system. The mechanics made some quick repairs and drivers persevered to get the points and placed eighth in GTO and 24th overall. At the July 4th race at Daytona Baker and Mullen placed seventh in class.

In an effort to gain an unfair advantage over their competition the team went to Sears Point in Northern California a day early to tune-up both the car and the drivers for this tricky circuit. During their practice session Mullen had what should have been a simple off road excursion. The problem was that he came to stop in tall dry grass and the grass caught fire. By the time the fire was extinguished, most of the rear of the car had burned. The fire had been so hot that the rear view mirror melted.

The crew started working on the car Thursday night to assess the damage so that they could get the parts needed to get the car ready for the Portland Oregon race the following weekend. As they made a list of the parts needed, they discovered that most of the parts that they needed were on hand. When they discovered this they decided to attempt to get the car ready for the Sears Point race, 48 hours away.

It looked like a volunteer fire department with people showing up from everywhere at the Garretson Team shop to try to help get the car ready for the race in two days. Both drivers, the regular crew and all of their friends helped put Humpty Dumpty back together again. The minute the car was completed the crew loaded it in the truck and dashed off to Sears Point. They unloaded the car just in time to make three laps in the last few minutes of qualifying. Their efforts were not in vain; they qualified and the next day they placed third in class and eighth overall.

A week later in Portland Oregon Mullen and Baker were third in class and fifth overall. The teams last effort in the GTO class was at Elkhart Lake Wisconsin where Baker received enough points for their fifth place in class finish to win the GTO championship. Jim Mullen raced at Pocono Pennsylvania with another team and placed well enough to secure second place in the I.M.S.A. GTO standings. The team had achieved their season's goals, placing well overall in several races and winning the I.M.S.A. GTO championship.

Baker converted the old war horse back to 935 specs and returned it to its status of renta-racer for the finale at Daytona in November 1983. The conversion required putting back the 935 body work, wider 19 inch diameter rear wheels and adding the twin turbos and twin ignition to the engine. Baker, Mullen and Tom Blackaller placed 30th in the finale. The same team raced again at the Daytona 24 hour race in February 1984 when they placed fifth overall. Blackaller and Baker placed second at the second running of Miami. Baker, Mullen and Blackaller placed fifth at Sebring. Baker and Jack Newsum placed sixteenth at Riverside California. Blackaller ran solo at Laguna Seca in Northern California placing eleventh. Baker, Newsum and Chip Mead ran the old war horse once more as a 935 at the 1985 24 hour Daytona race where they placed ninth overall.

Chet Vincentz had been running a similar car in selected I.M.S.A. GTO events since 1982. Vincentz had actually showed the way for the 935 to 934 conversions when he and Baker had won the GTO class at the 1982 Mosport Canada event. In June 1985 Chet's 935/934 was badly damaged in a mid-week testing crash at Riverside California where it caught fire and burned to the ground. Vincentz bought the old war horse from Baker and again converted it back to 934 specifications so that it would be eligible to run in the I.M.S.A. GTO events. Vincentz Team used a 962 engine for their 935/934 conversion.

Their debut showed that Vincentz's teams efforts were well spent when they placed second in the GTO class at Road America at Elkhart Lake Wisconsin and twelfth overall. Their next race was Pocono Pennsylvania where they had a fuel injection problem and placed twenty sixth overall and ninth in the GTO class. Vincentz was fourth in the GTO class and fourteenth overall at the Watkins Glen Race in upstate New York. The final two races for the 1985 season were Mid-Ohio where he placed fourth in the GTO class and the finale at Daytona where Vincentz had an oil line fail and was a DNF.

For the 1986 season Vincentz was able to modify the body work back to a slope nose configuration similar to the cars original 935 body work. This had been allowed by the I.M.S.A. rules because Porsche offered a model that they called the 930S which had the front slope nose body work with pop-up head lights.

Vincentz's 1986 season got off to a slow start at Miami Florida where the car was a DNF with an electrical failure. Things got better at the next race at Road Atlanta in Georgia, however, where he placed second in GTO to Scott Pruett and beat Bill Elliott and Bruce Jenner on his way to second place. The next two races at Charlotte North Carolina and Mid Ohio were not too good for the team either with the car crashing out at the chicane at Charlotte and getting caught in a sand trap at Mid Ohio.

The next race was at West Palm Beach Florida where the car was geared wrong in qualifying and was seventeenth on the grid. Vincentz had a great race, passing cars right and left and working himself up into fourth before the checker. At Watkins Glen New York Vincentz placed fourteenth overall and fourth in GTO. The last race for the old war horse in the 1986 season was the street race in Columbus Ohio where Vincentz placed ninth in the GTO race.

Vincentz's 1987 season started off at Miami Florida where the old war horse was again the victim of another drivers accident resulting in another Miami DNF. The team placed a lowly sixteenth at Mid Ohio, but bounced back up to fifth at West Palm Beach. At Road Atlanta they placed twelfth in GTO. The team placed ninth in GTO at both Summit Point and Road America Wisconsin where they were also thirty fourth overall. Vincentz got tangled with a sloppy driver at Lime Rock Connecticut and crashed out of the race. At Watkins Glen the team started tenth and finished seventh in GTO. And at the old war horses final race at the Columbus Ohio street race Vincentz placed twelfth.

Most of the GTO races for the 1987 season had been held separately from the GT races. John Bauer a former SCCA Trans-Am champion co-drove with Vincentz for the whole year, but finally the car was just out classed by the tube frame U.S. domestic race cars running in the I.M.S.A. GTO class.

After the 1987 season Vincentz retired the old war horse to show car status,. The old war horse was run seventy two races, won two major international races, two championships and probably has well over 70,000 racing miles. Our old friend has given a great number of good people a great deal of pleasure and success and is now be given a well deserved rest after being put on display at the Vincentz business, Electrodyne Performance, Inc. in Alexandria Virginia.


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