LS-Swapping a Porsche 944

A family practice doctor in a town of 15,000 has a full plate. Sterling, Ill., has been Eric Kuhns’ home for the last 23 years, and he appreciates the peace a smaller town offers. He needs it because his schedule has only gotten busier in years. Recently elected the President of Medical Staff, Kuhns has been tasked with improving morale and minimizing staff burnout – something he understands well from the pandemic.

Twenty years ago, he began racing in 944 Spec. “As racing cars was the only sport I really showed much proficiency in, I dove in with both feet,” he said. Quickly, he was appointed series leader of 944 Spec in the NASA Great Lakes Region before being promoted to National Director, where he served for four years. A full plate, indeed – and one made possible by a supportive family.

“Racing has given me a way to check out from the pressures of medicine, and has taken me and my wife all over the country. Even more importantly, racing has made me interesting and successful friends whom I wouldn’t have been able to meet otherwise,” he concluded.

944 Spec took up all of his free time then, and it showed. He won the National Championship in 2007 and 2008, and just missed the podium in 2009. After those three successful years, he wanted something else.

Some of his friends from 944 Spec had moved into stock cars because recently retired NASCAR parts could be — and still can be — found cheaply. “I wanted to leverage the low prices of the NASCAR stuff, but I didn’t want to lug a 3,500-pound car around.

“I knew 944s pretty well, and I decided to Frankenstein some parts into that chassis to see if I could have the best of both worlds,” he said. So, he hatched an idea.

With a track-oriented 944 Turbo chassis he bought for just $3,000, he started his project. Dubbed “Franken44,” he had use a basic Chevrolet LS motor and a few items plucked from retired stock cars with the hopes of building a hodgepodge 944 with three times the power he had been accustomed to.

“If anyone was planning on doing a big-power 944 build, I’d advise against using the early (<1985) car, as it has thinner sheetmetal throughout, specifically in the floor. Start with a later model. Look for a Turbo as its spindles and gearbox are stronger, and ideally get a Turbo S if you can find one. The S chassis has a few more gussets and the strongest transmission,” he explained.

Then came a set of Wilwood brakes off a Winston Cup car for the low price of $300. The price was hard to argue against, but getting them to work required Kuhns to crunch numbers. “I had to do some math to get the piston sizes right. It was a bit of work to find the appropriate master cylinders to ensure the right leverage.”

Thankfully, parts for these brakes were plentiful and easily acquired. The fronts needed only a three-eighths-inch steel adapter, and would accept OEM Volkswagen Touareg/Porsche Cayenne rotors, too. The rears were stock 944 turbo units, which held up fine with aggressive pads.

Placing a V8 inside a 944’s engine bay works fairly well, but the left bank doesn’t leave room for a booster. He decided to run manual brakes and steering, and while this setup required him to apply 80 pounds of pressure to get the car to stop, he was fine with that. “I needed to get a pretty aggressive pad to produce enough friction to keep pedal pressure workable, but as long as I used sprint-spec pads and didn’t miss leg day, I was OK.”

The lightweight brakes not only were cheap, but also part of the greater plan of keeping weight down and in the right places. “I tried not to mess with the weight distribution much, so I mounted the pedal box farther back in the footwell, extended the steering column, and basically mounted the seat beside the B-pillar,” he explained. With the transaxle setup helping, he was able to achieve a near 50:50 weight distribution.

He sourced a gearbox from a Turbo S, which is plenty beefy and has a short fifth gear, too. Thankfully, Spec makes a clutch for an LS-to-944 swap, and Quicktime makes a steel bellhousing for the 944 torque tube. He tried using a C5 Corvette’s aluminum bellhousing, but it blew up pretty quickly. The steel Quicktime comes with a scatter shield, which is nice to have when the clutch is mounted right next to your ankles.”

The coilovers of choice were two-way JRZs plucked from a cost-no-object car that had been sitting for 12 years after the owner died. Though they needed a rebuild, the price was low, and Kuhns knew just the guy for it. “I have to thank Olsen Motorsports. He went above and beyond helping a grassroots racer and even helped me improve the setup at the track.”

The first engine, an aluminum LS1 plucked from a junkyard GTO, ran well for the first season in Super Touring 3 and produced a healthy 350 horsepower – an amount his 275-section driven tires could easily handle. Essentially, the car felt as docile and predictable as his old Spec car, with better body control from the Olsen Motorsports tuned JRZs.

The main differences in driving revolved around power application and line choice. With so much power, he had to start straightening his lines out and sacrificing a little midcorner speed, later apexing more of the time. Also, down time reduced as the straights got shorter, and bends became real corners with more speed on tap.

It was a thrilling first year in ST3, but it had taken a toll on the engine. During an off-season inspection, he noticed shavings in the oil. One of the rocker arms had cracked.

With gritted teeth, he decided to buy once and cry once. The crate engine replacement he had in mind was by far the most expensive part of the build, but it was worth every penny.

“I got a crate LS3 from GM with their hot cam, their performance ECU, and a new harness. This plug and play solution allowed for factory tuning, improved reliability, cold starts, and adjustment to different fuels. Having OEM functionality made life easy, so I couldn’t recommend buying a turnkey crate motor enough. It drove like a factory Corvette with a lumpier idle,” he said.

With the help of friend and mechanic Jim Hartman, Kuhns was able to install the replacement engine that winter. The first event out, he ran without overheating, but the ambient was working in his favor. “The problem with V8-swapping these cars is keeping the engine temps down,” he said.

Kuhns knew he needed to make a few adjustments to get the thing to run in all conditions, so he flipped the modular intake toward the firewall to open up a necessary space in front of the engine to install a critical cooling component. Without his carefully crafted extractor running from the radiator to the sealed hood opening, the car simply wouldn’t have run right in mid-summer temps. At the rear of the bay, he designed a cowl induction system to help evacuate more air over the windshield.

Once he had grown accustomed to the 450 horsepower on tap, he moved up to ST1. His best finish in that category was at the rain-shortened 2015 National Championships in second place.

Even with the extra shove, the car was exploitable. “I think it’s one of the easier platforms to add a lot of horsepower to,” he began, “The way the weight is distributed, it’s sort of like a dumbbell with most of the mass at either end. The polar moment is quite high, and that makes it a little lazy in quick transitions, but that adds to stability. Its breakaway is progressive and gives you time to correct.”

However, the rudimentary suspension forced him to work the right ride heights before it was truly in race-ready condition. “You can’t lower the front too much because it causes the control arms to pull in, which causes dynamic camber loss,” he explained. This was remedied with extended lower ball joints. At the rear, he tried to minimize the suspension’s tendency to squat under power by using a smaller diameter tire, which did not require as much lowering. In an ideal situation, he’d reposition the pickup points, but that was more work than he could manage then.

The added speed didn’t add much to his running costs. “It was surprisingly nice on tires,” he recalled, “I was able to get three weekends out of a set of Hoosier R7s. The brakes lasted forever, too — they were designed to stop a 3,500-pound car with 900 horsepower. In this car weighing just 2,750 pounds, the pads were good for a full season.”

However, it consumed about 12 gallons of fuel an hour. Thankfully, the late model 944 has an enormous 21-gallon tank.

When he decided to move into ST1, he had to fit some aero. The aero kit consisted of a homemade plywood splitter protruding 5 inches in front of the Supermiata-style front fascia made of plastic roll. “It helped clean up the superfluous openings and allowed me to dial in the ducting,” he added.

Then came a set of fender vents for added extraction and a single-element Predator wing at the rear. Underneath that, he installed a homemade aluminum rear diffuser, which had to be durable enough to deal with some light dragging. The car simply squatted too much to avoid all contact.

After that, he installed a full flat bottom, but “having 500 horsepower and a contained exhaust made so much heat it burned the underbody seam seal. “Even if that hadn’t happened, I was cooking in the car,” he said.

After removing a section of the flat bottom and adding a NASCAR-style fan-tipped side-exit exhaust, he could run in comfort. “I didn’t bother running a muffler, but it still met all the noise limits – even at National Corvette Museum. There, the sound meters are on the driver’s side, and I made sure the tip pointed out of the passenger’s side,” he said with a chuckle.

For all the work that went into it, Franken44 left Kuhns’ life somewhat unceremoniously. After enduring some light damage after an off at NCM, he had to fix his recently-broken coilover – not a cheap item. That, and the fact that he had two kids on the verge of entering college, he decided to step back from racing for a while. Sadly, the Franken44 was parted out over the following year.

Once the kids were out of school and his work schedule had freed up some, he decided to return to racing, but this time with an emphasis on seat time. With his schedule as hectic as it is, he wanted to keep wrenching time to a minimum, so no more Franken-projects.

His ST4/5 Porsche Boxster makes about half the power of his old 944, but its chassis is far better, and it requires far less wrenching than the previous project car. Lighter, and with most of the mass in the middle of the car, the Boxster is more eager to rotate and change direction. It’s less forgiving, and things happen much faster than they did in the old Franken44.

Few $35,000 builds could touch Kuhns’ wild creation. The key was finding high-quality parts at a discount, and using his considerable intellect to make this build something more dependable and durable than what some might mistake it to be: a wide-eyed attempt at hot rodding. It taught him a lot about the tradeoffs of building a car, gave him space to relax, and helped further the education of several young fans.

Part science experiment, part vacation vehicle, the Franken44 served Kuhns well. If nothing else, it taught him what’s most important to him – and how to make the most of one’s limited time.