Featured: Frankenstein's Restomod: This Porsche 912 Is Powered By A Subaru STI

Frankenstein’s Restomod: This Porsche 912 Is Powered By A Subaru STI

By Alex Sobran
December 14, 2021

When I think of 912s it’s all easter egg colors, chrome roof racks, and drivers who tend to be a bit more down-to-earth than your typical flat-six diehard. The letters S, T, and I conjure up World Rally Blue exclusively, NEOchrome lug nuts, and fourth owners abusing their poor Subarus after slapping a few askew energy drink stickers on the rear window and invoking the spirit of K. Block to guide them sideways through a parking lot at the local mall. But by fusing the two together, Mike and Mat Davidson have created something different. They built it together in a condo carport, and after five years of teaching themselves how to do it on their own, the two engineers (Mike mechanical, Mat software) have managed to merge two seemingly disparate ends of the automotive universe into one of the most intriguing hot rods in the Porsche scene or otherwise.

My first and so far only encounter with the car they call the 912R-STi came near the end of this year’s LA-held Luftgekühlt, and after walking through rows of 911s all hot-rodded within a pretty narrow band of variance (that’s not a bad thing, because there’s nothing wrong with tried-and-true when it leaves you with a 911 sitting pretty on big rubber with a set of Cibies on its nose), the Davidsons’ Porsche was a welcome deviation.

It hides its secrets at first glance though, and if you don’t notice the radiator piping running along the rockers you might assume it’s all status-quo here: ATS Cookie Cutters with some sticky stuff around them, RS-style bodywork, a bolt-in cage, a Prototipo wheel in front of some plaid buckets—it’s a handsome car that doesn’t present itself as overly aggressive, yet there’s nearly 300hp to push its sub-2,000-pound short-wheelbase self around. Though clearly modified, I’d still consider it a sleeper up to the moment the deck lid is lifted to the sight of a beefy intercooler. If you’re curious to know how it came to be, here’s the story of how two brothers, a beat Bel-Air, repurposed 914 plans, and a hearty dollop of willpower led to this point.

Mat and Mike grew up in the midwest, and after graduating college, Mat moved to the Bay Area for work, tinkering in the evenings on a ’75 911S project at the time. Mike, the younger of the two, was still in school closer to home, and was hoping to build a very different Porsche in the near future: a 914. His father had given him a thoroughly rusty 1957 Chevy a few years earlier, and after trying to save something that was keen on resisting such efforts, he decided it might behoove him to trade it for something that wouldn’t. Mike found someone in Monterey selling a 1967 912, proposed a trade, the cars criss-crossed the country on trucks heading in opposite directions, and Mike had replaced his rough Bel-Air with a rough 912 that barely held an idle.

He finishes up at school, packs up and moves west to the Bay Area like his brother, and all the while Mike’s trying to get the 912 into reasonable working order, but hand tools with just one set of hands to use them in cramped starter-apartment garages can only go so far. Mat and Mike took the project Porsche for a New Year’s Day drive in the Santa Cruz mountains one year, and found their tipping point—it wasn’t just a car in need, it was unsafe. Rust had done more than swiss-cheesed parts of the bodywork, there were maws of open space where metal had once been, and so the 912 was parked in Mat’s garage in San Jose where they would start the long process of stripping and restoring it.

Mat knew how to do some basic welds and had done some paint and body stuff on his own Porsche, but it was a self-taught bag of tricks and with full-time jobs the work went slowly at the beginning, with the first two years spent almost exclusively on welding the car back together. They had a nebulous idea of where they wanted to go with the project—it was never going to be restored to stock spec—and in the process of putting fresh metal in the floor and front suspension pans, the rocker panels, the striker panels, and one of the taillight buckets, Mat also welded in metal 1974-’77 flares and filled the joints with lead as they would have done at the factory. Perhaps they weren’t certified Porsche techs, but they weren’t about to half-ass it.

Seeking higher performance from the get-go, the plan always involved a good deal of fiberglass bodywork, and they sourced the bumpers, fenders, and duck tail deck lid from a local racer. These weren’t his pristine garage-kept spares either, so like every other panel on this Porsche, these too needed some significant work to get sorted. Eventually though, Mat had everything prepped and primed (all done in his condo’s designated parking spot), and the shell and its ancillaries were sent out for paintwork at a local shop. Mike moved to Orange County for work, but Mat had recently bought a house in San Jose so the car stayed with him while the brothers worked out a plan to get the 356-based boxer four running. They wanted to rebuild it into a flat-four hot rod job, but once they started tearing it down those plans changed when they discovered the motor was indeed made by Porsche, but not for a 912. Specified as type “marine,” they were literally working with a boat motor. Three trials and three errors of carb setups later, they decided to ditch it.

Not long afterwards, Mat gets home after a day at the office to find his path blocked by a large wooden pallet in his driveway—with a motor and transmission sourced from an ’06 Subaru WRX STi sitting on it. A few weeks later and a brand new TIG welder shows up in the same fashion. Mike had always wanted to swap a WRX boxer into the 914 he never got to build in college, so why not just do it with the 912 instead? Mike—he’s the mechanical engineer—had some experience with welding aluminum, so after shipping the TIG machine and the powertrain to his brother he taught him the basics and the two got to it.

Using an adapter made by Kennedy Engineering (if you’re surprised this existed, you’re not alone), the brothers mounted the STi motor to a Porsche 915 transmission, and sold the Subaru transmission and headers to buy stainless steel exhaust pieces in order to fabricate their own system with equal-length headers. The TIG welder came into play when they began tackling the issue of cooling a modern turbocharged motor that’s not used to being stuffed in the back of an old rear-engined coupe. There are three radiators in the 912R-STi: one in the front bumper, one in each fender, and without cutting into the tub as is commonly done for such jobs, they eventually built a system of aluminum pipes and silicone elbows that would hold pressure and keep the Subaru stuff happy.

A company called iWire supplied a wiring harness, and after getting it all plugged in and routed, the project car finally shed that title after five years of patience and hard work. Today they are simply enjoying what they’ve built: an outrageous, out-there, but totally right car. The goal was to build a 912 hot rod with a flat-four after all, and this is the kind of creativity that’s helped the early 911 and 912 maintain such a populous and diverse following.

The car lives in Orange County with Mike now, where he auto-crosses it on occasion and takes it to shows so people like me can excitedly ask what in the hell we’re looking at. To describe the driving experience, I’ll let the ones who actually have some tell you what that’s like:

“The car itself is a total sweetheart to drive. It starts, idles, and accelerates like a modern Subaru, but steers, shifts, and brakes like an old Porsche. Under 3K RPM it’s as comfortable as any car I’ve driven: soft, compliant, no lurching of a big high-strung carb’d motor to snap your neck around. Once the engine is uncorked though, 3K and up, the power is savage, and feels almost endless. The motor last dyno’d at around 300hp at the wheels, and it made 265ft-lbs torque. More than enough for a sub-2000-pound car.”

I’d say so, and not to take a dig at Porsche purists, but if you don’t think this is cool then I doubt many people think you are. Summarize the story and tell me it’s not perfect: two brothers, both building cars in college, they move to the same area, then a bit further away, but all the while they’re collaborating on this bitchin’ Porsche. It was likely beyond what most would deem savable, and rather than presenting the world with another Bondo’d-up lump of a “restoration” they’ve built a totally unique machine that’s wildly different than its starting point in 1967 but that’s still respectful to the marque. Hats off.

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KellyP
KellyP
1 year ago

The pump itself is archaic, complex, and finicky to adjust, but it rewards exacting setup with crisp, torquey, and instant power delivery.

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Ethan Walker
Ethan Walker
1 year ago

The Porsche 912 is typically associated with vintage, colorful, and more relaxed driving, while the Subaru WRX STI is known for its rally-inspired, high-performance capabilities and a younger demographic of drivers. However, the Davidson brothers have merged these two worlds together, creating a unique hot rod that blends the classic style of the 912 with the modern performance of the WRX STI. https://cincinnatiseo.io/

Brett Michael
Brett Michael
2 years ago

Awesome post you shared here, interesting one. https://www.getshinedetail.com/

SAPP
SAPP
2 years ago

Been saving my pennies for one of these some day. Love these machines.
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Rosa Mannelli
Rosa Mannelli
2 years ago

Block to guide them sideways through a parking lot at the local mall. But by fusing the two together, Mike and Mat Davidson have created something different. 
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arkm Tony
arkm Tony
2 years ago

Lovely car. One of the best.
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leather Genuine
leather Genuine
2 years ago

Thank you kindly for giving this data out. This is magnificent! Cruella Coat

Wally Flatfour
Wally Flatfour
2 years ago

Amazing build, having an Impreza in the garage makes me consider buying a 912 shell….

Bryan Dickerson
Bryan Dickerson
2 years ago

Long time Porsche 912 lover here and I think this is wonderful. Even before I discovered this fabulous build a few years ago, my ultimate dream car had long been a Subie swapped 912. I wouldn’t need a 300hp STi motor, though. A 150hp 2.2 N/A engine would suit me fine. 60hp more than the original 90, better mpg and Japanese reliability in Porsche’s best – perfect!

Mcark thony
Mcark thony
2 years ago

One of the greatest car ever made.
Bill

drake
drake
2 years ago

Some people should just get a life.They area so blinded by their bigotry they can’t see what is right in front of them. Their arrogant assumptions of what is “right”causes blindness . I think this is one of the greatest cars ever.

Jorge Cristóvão
Jorge Cristóvão
4 years ago

Best of both worlds! Great work!

Peter J Smith
Peter J Smith
5 years ago

Anyone who would replace a Porsche engine with a lump of Jap crap, doesn’t deserve a Porsche.

Carlos Ferreira
Carlos Ferreira
5 years ago
Reply to  Peter J Smith

You’re of of those uncool snobs the article speaks of. Jap crap? The STi motor is exactly 100 times more sophisticated and better in every way than the old Beetle engine in the 912, and it’s bred from rallying. Tough as nails, as you’d expect from a benchmark.

The two brothers replaced a flat four with a much better, modern, infinitely superior flat four in a tasteful project. Well done, I’d say.

Mel Chanic
Mel Chanic
6 years ago

I have seen these engines stuffed in beetles and always wondered when I would see them in Porsche’s.
On the other hand does anybody else miss Guitars Silnger?

shralp
shralp
6 years ago

Ah, another butt-hurt narrow minded purist in Franz Kafka. I particularly relish walking all over drivers like you at the track. In a Subaru. Legacy. Wagon, (Gasp!!). Its quite enjoyable to pass you turn 3 and then watch you slowly decrease the circle that you walk around the car back in the paddock as the day progresses. You never get closer than 30 feet though, as to not give away your utter befuddlement. Its ok Franz, I can toss this tube of Preparation H to you from here…

Carlos Ferreira
Carlos Ferreira
5 years ago
Reply to  shralp

‘Enthusiasts’ like Peter are why I rarely go to single marque car shows, especially anything German that’s not VW.

Joe
Joe
6 years ago

nice job, not everybody can afford a $20,000 2.7 to put into a car

Russell Buonasera
Russell Buonasera
6 years ago

Great stuff. KEP (Kennedy Engineered Products) produces a crazy variety of adapter plates for Porsche & VW transaxles. There were a fair # of 914s that got Mazda rotary and Chevy small-block transplants decades ago, the Porsche snobs (yo, Franz) didn’t get as ticked off ‘cause the 914 wasn’t REALLY a Porsche.

The brothers did a great job. A bit of Shelby spirit, a taste of Chapman, maybe a little Tim “The Toolman” Allen….cross breeding, lightness, more power.

Todd Triebler
Todd Triebler
6 years ago

It would have been even better if they had used the matched Subaru transmission that the STi engine came with and reversed it with a Subarugears kit. That horrible dog leg first gear of the 901 would be gone, replaced with a smooth shifting Subaru 5 speed.

PDXBryan
PDXBryan
6 years ago
Reply to  Todd Triebler

Todd-
Don’t the Subarugears reversed set-ups have some reliability issues?

Mina Ingraham
Mina Ingraham
6 years ago
Reply to  Todd Triebler

Except the subie 5 speed is quite weak even with treated gears. That said idk if a 901 is stronger, so maybe you’re right.

joshgtv
joshgtv
6 years ago
Reply to  Todd Triebler

The article says that it’s a 915 gearbox. No dogleg.

James Jensen
James Jensen
6 years ago

I love it. Awesome job. Given the choice of a “proper” restoration north of six figures or a true California hot rod, I’d take the latter every day. No apologies forthcoming. We are just different out here.

Bill Meyer
Bill Meyer
6 years ago
Reply to  James Jensen

On the subject of California hot rods I seem to remember some guy named Shelby and a car called……..lemme see here, oh yeah, the Cobra.

I’m old enough to remember the purists sneered at that for some time until it disappeared down the back straight.

Craig S
Craig S
6 years ago

Wow, Franz, you sound like quite the arrogant douche! Perhaps you need to get laid. Don’t eff with red neck garage engineering.

Carlos Ferreira
Carlos Ferreira
5 years ago
Reply to  Craig S

Nothing redneck about the engineering in this project

Jack M
Jack M
6 years ago

This very cool. Although I wish the article was a bit more techincal, it looks like they did a great job. Also, who gets mad when a car is made more fun to drive?

Mina Ingraham
Mina Ingraham
6 years ago

Apparently, Franz really has turned into a cockroach. Love the build and the ingenuity of it. The world is a big place Deal.

Bill Meyer
Bill Meyer
6 years ago

This 912/Subie is just a splendid poke it the eye of purist snobs everywhere.

joshgtv
joshgtv
6 years ago
Reply to  Bill Meyer

This long-term Carrera 3.2 owner fully agrees. The 912 was never worth preserving, go to town on it!

PDXBryan
PDXBryan
6 years ago

Thank you Alex, Matt, and Mike!
This is real grassroots enthusiast stuff. Maybe it comes from being a bootstraps farmer, but I love it when folks take the best of what’s laying around, combining the best of then and now, and make something great! The analog driving experience of the 901 and the affordable, reliable power, of the Subaru into one beautiful Frankenstein. It’s astounding but inevitable that some berate this. I love pristine original cars too but why can’t they take their blinders off and see that this kind of project has it’s place too, especially since it means that at least one old rear engined Porsche will be driven and enjoyed by folks NOT in the 1% bracket. Hooray for the riff-raff!

David Moore
David Moore
6 years ago

It’s scary to be in, that’s all I know.

Also, for the people that hate it, it’s ok to be wrong.

And no, it doesn’t overheat in 15 min, he’s chased my front engine Toyota with a Subaru motor through very hot mountain roads for a whole day, and it was fine. So, suck it. =P

Reid Conti
Reid Conti
6 years ago

Fantastic. Perfection. A half decade of hard work pays off in a major way.

Franz Kafka
Franz Kafka
6 years ago
Reply to  Reid Conti

Suffice it to say your definition of fantastic and perfection are in dire need of correction as is your overall taste : or lack thereof .

Peter J Smith
Peter J Smith
6 years ago

That’s a shame.

Franz Kafka
Franz Kafka
6 years ago
Reply to  Peter J Smith

Sadly I’m in complete agreement in light of the rest of the work the owner did . The very epitome of the axiom just because you can DOES NOT mean you should .

A hopped up Type 4 certainly . A POLO flat four most definitely ( assuming the budget was adequate ) But a godawful flatulating Scrubiru in the tail end of a Porsche ? Any Porsche ? Beyond heresy verging on criminal

Suffice it to say I can barely tolerate the flatulence of a Scrubiru in a Scrubiru , never mind in a 912 . Damn . What a waste of effort and a perfectly good 912 . May the car gods and the lords of Porsche look upon the owner with abject and utter disdain tossing down what ever punishment they deem appropriate

I’d add the more severe the better but in light of the fact that all bets are this thing’ll overheat in 15 minutes or less in the least amount of heat , traffic or urban driving I’m guessing the owner has punished himself more than all the gods combined .

😎

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