C2 Motorspsorts
As we scoped out the C2 Motorsports Rabbit, it was far more obvious that it meant business. No peeking through rotors, no turning of keys or getting behind the wheel was necessary. Chris Collier and Jeff Atwood at C2 had been hard at work, continuing to use the unsuspecting white Rabbit as their development test-bed for all things turbo.
When we left off, the basic stage 1 non-intercooled turbo package was residing in the engine bay, the car had been lowered, and fitted with mild-mannered Audi A8 wheels.
After developing this base $3999 stage 1 kit to 220whp, they decided to add an intercooler and refine the programming slightly. The result was an additional 30whp at the same boost level, this time for just $4499.
While 250whp is good, more power is always better, and the guys knew it was lurking within reach. Making the additional power meant lowering the compression ratio, so C2 designed a laser-cut stainless steel head-gasket spacer with OE metal upper and lower sections for a perfect seal.
Built more for the street,...
Built more for the street, this Rabbit uses C2's stage 3 turbo kit which lowers the compression using a head gasket spacer and boasts 280whp
Unlike a VR6 engine, there's not enough slack in the timing chains on the 2.5 i-5 motor to raise the cylinder head even a few millimeters. The solution was a longer timing chain and a special tensioner. Both of these items, along with the aforementioned head spacer and programming, are included in the stage 3 package.
Ponying up the estimated $4999 for the stage 3 turbo kit will get you around 280whp at 15psi, depending on the exact modifications.
Installation times are estimated at around 10 hours for stages 1 and 2, with around 18 hours needed for the full stage 3 upgrade. Owners of cars with an automatic transmission need not shed a tear, as all three kits will bolt onto your car without additional hassles. In fact, a C2 customer has been running a stage 3 kit on his '07 Rabbit 2.5 auto for about four months without a hint of trouble.
It's worth noting that C2 now ships all its staged kits with the same 0.5bar (7.25psi) wastegate spring installed, and it's the owner's prerogative to raise boost levels once the remaining parts are in place to handle the power gains of the particular kit chosen.
"So even on a stage 3, it's going to start at 7psi, but obviously it has the capability, fueling and timing to run 15psi," Chris explained. "What we wanted to do with our kits was show a realistic upgrade path. We did that by sharing many of the same parts with stages 1, 2 and 3 so people don't have to re-purchase stuff as they upgrade."
So far, the drivetrain remains standard, including the clutch, and it has apparently held up to the use and abuse of 20,000 turbocharged miles in the development car.
It was at this point in the car's development that Chris began working with Brad Beardow of 1552v2 fame. They decided the plain-Jane Rabbit could use some visual muscle to accompany the increased power. So Brad concocted the genius idea for a fender flare kit for the Mk5 that harks back to the original Mk1 and Mk2 GTI models (see sidebar) This would not only provide a more menacing look for the base-model hatchback, but would allow much wider wheels and tires to be fitted.
A wide set of 18x10" BBS RE...
A wide set of 18x10" BBS RE wheels were used all round with 265/35-18 Sumitomo tires; Alcon brakes provide the stopping power
How much wider? How about 18x10" all around! Lightweight BBS RE wheels were installed on all four corners, shod in super-wide 265/35-18 Sumitomo HTR Z II rubber.
A set of B&G coilovers have lowered the car and sharpened the handling to a razor's edge. Recaro seats were swapped for the stock items, and keep the occupants firmly in place.
In order to safely slow a car that's making double the stock power, you need better brakes. Alcon is a name that needs no introduction, so when Brad heard UUC Motorwerks was working on an Alcon kit for the Mk5 platform, he wasted no time having a set fitted. The four-piston calipers clamp 330mm discs and provide more than enough stopping power for the 300 horses residing under the hood.
"It looks like an '80s rollerskate," Chris joked. "And without sounding cheesy, speed is nothing without braking, and as exciting as the acceleration is, the brakes offer such a secure and safe feeling. It's just perfectly balanced."
Bunnies
So now NGP Racing and C2 Motorsports have developed their respective Rabbits well beyond what anybody could have dreamed possible, but is this the end of the line? Far from it! Dave tells us NGP will soon fit a Peloquin differential to improve traction for the upcoming season. While Chris also mentioned C2 has a number of products still on the drawing board for the 2.5, including a short-runner intake manifold, performance cams and more.
By the time you read this, the little Bunny with the big flares should have a built bottom end ready for serious horsepower.
Although it would be rare, perhaps third time's the charm with these cars and we'll have to revisit the frontline of 2.5-turbo tuning. Watch this space.