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The C30 Polestar concept was everything Volvo’s little fun-hatch should have been, with all-wheel-drive and 405 horsepower. But the car buying public only ever got the front-wheel-drive C30, even when Polestar tuned it up. That is, unless you took matters into your own hands and Frankenstein’d an all-wheel-drive C30 from the Volvo parts bin.

Polestar Performance’s concept C30 was the starting-off point for Travis Morgan’s epic C30 build. The concept car made a big splash when it first came out, with a K26 turbo, Haldex all-wheel-drive system and a more aggressive bodykit that took it from “that one car from the butt-awful Twilight movie” to ultra-hot-hatch territory.

The C30 Polestar concept next to a sign instructing you what to do with it in the snow.
Photo: Volvo

In 2013, Morgan asked the C30 Crew forums—a forum he started—if an all-wheel-drive swap was even possible. The biggest problem everyone brought up is that what Polestar did to fool the ECU into working with the all-wheel-drive system would never be road-legal, as Morgan explained in a build breakdown on C30 Crew:

The AWD conversion done by Polestar was not a viable legal solution because their vehicle used the modules from a V50 which basically forces the C30 to take the identity of the V50. If you were to look it up with VIDA [Vehicle Information and Diagnostics for Aftersales] it would show a V50 VIN. Plus, the power output was not what I would want; it was only a 70/30 split with the Haldex in the V50 and S40. Elevate has done it as well, but it was a pre-production car and was crushed after SEMA. I wanted my car to read as the original VIN and have it know it was a C30, just as if Volvo created it from the factory…time to research!

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Morgan’s car, named Max, had already gotten a larger K16 turbo and he was starting to get bored of it. An all-wheel-drive system would definitely make it a keeper, and as the resale value of C30s isn’t that fantastic so he figured, why not try? Though many believed it couldn’t be done, he eventually found help from Volvo techs Rich Forsythe and Kevin Reed, who also wanted to prove everybody wrong.

The donor car. Photo via Johnny Youssef/C30 Crew; used with permission.

A Volvo S40 donor car was acquired from an auction with the requisite AWD system for around $900 (including auction fees). Unfortunately, there was only one lift in the shop Morgan runs with a friend in Kansas City, and they couldn’t afford to keep a long-term project on that lift. Forsythe then made a connection with Momentum Volvo in the Houston area, which was down to help this crew bring this crazy franken-car to life.

I can’t believe this makeshift dolly held a car. Photo via C30 Crew; used with permission.

It cost about $1,000 to ship the donor car to Houston, which was comically rolled around on a makeshift dolly made of 2x4s and two-inch plastic casters.

Keeping It All Volvo

Morgan didn’t just want an all-wheel-drive car—he wanted it to drive like an all-wheel-drive C30. This meant that a few modifications had to be made under the skin to get the S40’s all-wheel-drive system to work.

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The S40 was a northeastern car, so there was a lot of surface rust to remedy before anything else could happen. A needle scaler was used to get rid of the surface rust before a rustproof coating was installed.

Rustproofing in progress. Photo via Johnny Youssef/C30 Crew; used with permission.

They kept the C30's front subframe to keep the suspension geometry roughly the same in the front. On top of that subframe, however, the engine had to be raised with roughly 3/8-inch spacers for everything new to line up properly.

Both cars use variations of the M66 transmission, but the S40’s had to be used to work with S40 all-wheel-drive system. There’s a few key differences that forced them to use the S40’s transmission–namely, a larger axle output size and different LSD bearing sizes. The biggest bonus is the S40 transmission’s 4.00:1 final drive ratio that turns sixth gear into a usable, pulling gear instead of the mere overdrive gear found in the C30.

Photo via Johnny Youssef/C30 Crew; used with permission.
Fresh, shiny parts. Photo via Johnny Youssef/C30 Crew; used with permission.

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Everything around the transmission also got a solid freshening up. New clutch lines, bleeder valve assembly, throwout bearing, lube and fluid went in. A Quaife all-wheel-drive limited-slip differential, Spec six-puck racing clutch and aluminum single-mass flywheel has also been shipped directly to Momentum in Texas to install—just to make things more fun.

Then there’s all the nitty-gritty packaging details, which were surprisingly not as painful as you’d expect. Piping for the turbo had to be rerouted to and a 3/8-inch spacer was added to clear the angle gear. The C30 driveshaft still worked with the driver’s side, but an S40 AWD driveshaft had to go into the passenger side.

Cleaned-up parts to go back on the rear of the car. Photo via Johnny Youssef/C30 Crew; used with permission.

Believe it or not, the rear half of the car’s drivetrain was much simpler. Both the S40 and C30 happen to have a 103.9-inch wheelbase. Holes needed for the center bearing support and S40 saddle fuel tank were even already on the C30, as if Volvo really planned for an all-wheel-drive version but never released it. The S40 fuel pump even plugged into the C30 harness just fine.

Yet there were a couple issues with the S40 fuel tank, Morgan notes on C30 Crew—accuracy and heat:

The only issue is with the fuel tank, as the new saddle tank pumps from one side to the other so your fuel gauge will be VERY inaccurate until you run multiple tanks of fuel for it to calibrate. The rear exhaust was wrapped in titanium heat wrap to keep the fuel tank safe beside it.

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A wrapped exhaust keeps the rear fuel tank cool. Photo via Johnny Youssef/C30 Crew; used with permission.

The rear subframe and spindles from the S40 were used as well—which also bolted right in. This changed the shock height a tiny bit but the group was able to adjust and reuse the car’s existing CEIKA adjustable coilovers to make it work.

The car’s EVAP cylinder was also mounted on top instead of near the camber arms to make working on camber arms easier. The car also received new bearings and an exhaust system that was routed around the car’s new AWD system.

Likewise, Morgan claims that wiring wasn’t as hard as it appeared. It’s largely wired up like an S40 now, only they used the European diesel fuel additive dosing module (ADM) to tie into the C30’s CAN network.

The car spun its rear wheels once all the S40 bits were swapped on, but flashed a traction control light, much to Morgan’s dismay. After some research, they determined that swapping in the Gen 3 Haldex unit from a Volvo XC90 would solve the issue, as the older Gen 2 Haldex unit that controlled the S40's AWD system relies on sensing the front wheels spinning before it sends power to the rear wheels—which can throw a code if it’s not entirely happy.

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Under the finished car. Photo via Johnny Youssef/C30 Crew; used with permission.

At the end of the day, or many days as this project too, Morgan ended up with what he wanted: a C30 that registers itself as a C30, but didn’t have to be fabricated, programmed or hacked into accepting an AWD system. The swap used all Volvo parts and was absurdly easy to pull off, considering the scope of the project.

Finally, he has the Volvo C30 we should have gotten in the first place. Maybe the fun little C30 would still be around if people associated it more with AWD snow slides than sparkly vampires?

To test it out, Morgan took it on the Tail of the Dragon, where the lighter flywheel and racing clutch took some getting used to, but definitely seemed to work well enough.

“It will spin all the tires and still squeal in third!” Morgan wrote of his new conversion on C30 Crew. As it should!

Best of all, as Morgan’s friend Johnny Youssef explained to Jalopnik via email, it’s a swap the forum crew hopes will spread far and wide, and breathe new life into the humble C30 as an enthusiast’s car. Do try this at home, folks!

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“BEWSTD” is a really fitting plate for this.
Photo: Johnny Youssef

You can the full story of Morgan’s swap in his own words on C30 Crew here, which goes into all the insane details if you’re like to try it out.


We’re featuring the coolest project cars from across the internet on Build of the Week. What insane build have you been wrenching on lately? Drop me a line at stef dot schrader at jalopnik dot com with “Build of the Week” somewhere in the subject line if you’d like to be featured here.