The older Porches will always be favorites of mine, beginning in the early 70’s with the Carreras, which were the platform for the later ’74 IROC racecars. Not soon after their arrival, the wide-bodied IROC’s under went yet another metamorphosis. They led the way for what would become the Porsche Group 4 and 5 racecars of the late 70’s and early 80’s. These cars became the infamous 934’s and 935’s. Of course, anyone who knows me knows that my two all-time favorites are the 934’s and 935’s. These cars were some of the fastest, but yet hardest to drive cars that Porsche ever built. So, when I was asked by Russ Wahlers to help him with his replica 934, How could I say no? I had seen this car before, where Russ used to keep it stored. He had been working on it for a few years and the project was now nearing fruition. Russ had done all the work on this car himself. This 934 copy started life as a 1976 Carrera 3.0. The body type is of the earlier 934 vintage, which consisted of bolt-on fender flares in the rear, allowing a rear tire width of 14” and bolt on front flares for an 11” wide tire. The lower front valance section on this car is actually made for a 934-!/2 car. All the pieces on this car are copies of originals. The only original piece lives just under the 930 type extended rear tail. It is the rear reflector cover, painted white, as is the car, and it spells “PORSCHE.”
He installed “Koni” shocks all around, with 23mm torsion bars in the front and 33mm bars bringing up the rear. The brakes were also upgraded a few years back to “Big Reds” with true 13” front race rotors. On the back he used C-2 front calipers re-machined to fit the earlier rear trailing arms. A 23mm Turbo master cylinder rounded out the brake package.
A body color matched roll bar was installed, with “Sparco-Evo” race seats and 5-point harnesses. An RS type carpet kit dressed the interior well. There were some items that still needed to be addressed. One of them was the engine, and this is where Russ decided to call me in.
Russ shipped the engine down to me and we disassembled this injured warrior. The engine turned out to have a problem that I have rarely seen. It had been run with a poorly reground crankshaft. The crankshaft in a Porsche engine is a precisely manufactured part. Every journal, radius, chamfer and dimension must be, and is, perfect. Next it undergoes a process called “Nitriding,” it is given a “Tenifer” treatment, and lastly followed up by “Ferrofluxing.” The crankshaft we took out of Russ’s engine had been reground by who knows. It had eaten itself up, worn out the end of the thrust bearing and started to eat up the case! There is only one company that I would send a crank to for it to be race-prepped or repaired. They, in my opinion, do the proper job. Russ’s, obviously, hadn’t come from there.
We were able to save the case for Russ and the rebuild process began. After thorough cleaning of all the parts, they were inspected, tolerances checked and any bad parts were discarded. Russ was smart by letting us install a race-prepped, center-drilled crankshaft. We installed the crankshaft with a special center bearing, increasing oil flow to the numbers 2 and 5 rod bearings. He chose to use ARP rod bolts. We thought that was definitely a good choice. After the crank and rods were assembled, we installed them into the case half. A 930-type oil pump will feed the new crank with the proper amount of oil and also scavenge the used oil out. Using number 730 silicone to seal up the center case section, the engine was coming together. (We find the 730 Silicone better for sealing than the factory “Loctite,” especially on an older case.)
As Russ walked around the garage in thought, he looked into my 3.8-liter engine, which was on a stand and partially assembled. He noticed the size of the intake ports. They were much bigger than the 31mm sized (anemic) ports that are found on his basically stock 3.3-liter turbo engine. We had a discussion about horsepower and airflow. Soon after that, Russ was on his way home with his cylinder heads in hand, to take a grinder to them. The next day he returned with his heads, now with the intake ports opened up to 38mm. The heads had already been machined for a twin-plug application. Russ had decided install the “Electromotive HPX” system to control engine spark.
The assembly process continued with stock 3.3 Turbo pistons, “Total seal” piston rings and stock cylinders. Russ had also ported his intake manifold to match the intake ports in the heads. (You’ve got to be able to flow a lot of air to make some real horsepower.) Since the phenolic (plastic) intake risers could not stand being bored to 38mm, we chose to get a custom set of aluminum intake risers made by “Powerhaus.”
The camshafts Russ chose to use were SC sport-grind cams, which would give him a useable power band between 4500 and 6800 rpm. We degreed Russ’s cams to the retarded side of the cam timing spec. This would raise the rpm where the max power would come in. On Mike Stenko’s engine, in which he runs the same SC sport cams, we set his cams to the advanced side of the spec. Mike’s power (580hp @1bar) is reached at 5800 rpm. With Russ’s B&B header (heat exchangers cut off) and a K29 Turbocharger, along with some other tricks, his horsepower figure should be in the middle 400’s. (I’m guessing 450hp at 1 bar of boost.) I am sure that, sooner or later, Russ will opt for a better intake system and a complete engine management system. A different type of intake system with engine management would get him over that 475 horsepower C.I.S hump. For now, my part of the project was done.
This car is gorgeous and a real no-nonsense racecar. The pictures really do not do the car proper justice. It was born and bred from Russ’s heart and has certainly won me over. With a gross vehicle weight of 2,282lbs, this car should really move. As we know “Lighter is faster.” I asked Russ if he’d trade me for my #29 car. (Russ wanted my car plus $3,000 cash! LOL.) We both thought about it for a while and decided we’d keep what we have. I was happy to have helped Russ and proud to be part of his 934 project . Now, it will be up to our PCA DE instructors to teach him how to drive it.