You remember the commercials Volkswagen aired when the Rabbit first launched, showing them breeding like rabbits? They weren’t kidding — within a few months of bringing our Candy White ’07 Rabbit home from the dealership, the cars were everywhere. Which is why we had to differentiate Project Turbunnium from the thousands of other white Rabbits prowling the streets. Thanks to Volkswagen’s Thunder Bunny™ body kit, we’re satisfied that we don’t see ourselves coming and going. But it’s a familiar story for any of us who mod our cars: Now that the body kit is on, other parts of our Rabbit are starting to look shabby.
Smoked VW Accessory Taillights
Nothing looked shabbier, in our case, than the stock red taillights. We’re sure that their bright red housings were what the people wanted, but we couldn’t get past the fact that they made the rear of the Rabbit look like any other economous anonybox on the road. There were several choices that could be had for upgrades — everything from complete LED replacements to Euro-spec amber units are on the market — but we chose to go with a factory upgrade in the form of the smoked lights from Volkswagen Accessories.
Why did we go with those? First, they’re OE replacements, so we were sure that they’d bolt in and seal up without problems. Second, we’ve had nitpicky cops look for the “DOT” certification stamp on the lamp lenses when they were trying to find a reason to write a ticket — and since these lamps were designed for North America, they’re stamped with the government’s seal of approval.
Installation can be completed in ten minutes with a flatblade screwdriver and a 10mm wrench:
• Open the tailgate and remove the trim panels on each side that cover the nuts holding the backup lights into the hatch.
• Depress the locktab holding the wiring plug into the taillights and disconnect it. You can let the plug hang.
• Remove the two 10mm nuts that hold the light to the tailgate and gently press it outward to remove it.
• Installing the new lights is a simple matter of reversing the process. Be sure not to overtighten the nuts holding the lights on, as they’re simply threaded into plastic.
• Pull back the carpet in the corner of the cargo hold to reveal the two nuts holding the taillight to the body. If you’ve never poked around back there before, there will be some small perforations on the carpeting that you’ll need to tear to gain access.
• Using a small flatblade screwdriver, release the tabs that hold the wiring harness to the taillights by turning the blade until the catch releases.
• Remove the two 10mm nuts that are holding the taillights against the body and gently remove them. It’s very easy to accidentally scratch the paint when pushing the threaded studs out, so be careful.
• Installing the new lights follows exactly the same process as the removal. When reinstalling the electrical connector, you’ll need to push on the plug with a good amount of force until it’s fully seated, at which point the plastic catch will snap shut. We thought that we’d break the plug off before it finally snapped closed, so a good bit of muscle is required.
VW Accessories Smoked Taillights
1K0 052 200 N – Rückleuchten / rear lamp set, Golf V SAE
JCaps Billet Aluminum Caps
A frequent comment we heard from people looking under the hood of Project Turbunnium at Waterfest was, “What the hell?” After all, in its current state, our engine bay still houses a bone-stock 2.5-liter I-5, down to the factory engine cover. Then peoples’ eyes would drift down to the black anodized caps on the coolant reservoir, oil filler, and washer bottle, and they’d understand why we were showcasing the engine bay.
Jay Ayers made a set of custom strut tower caps to replace the cracked plastic pieces on his MKIV R32, and the forum response was so positive that he turned his hobby into a business. A mechanical engineer by trade, Jay’s “JCaps” are available for a variety of VW and Audi models, and can be had in multiple finishes. After seeing the black anodized caps that he has available, we decided they were the perfect way to eliminate the ugly plastic coolant, washer, and oil caps on our Rabbit.
Installing the caps was a simple matter of popping the hood and unscrewing the old pieces — it was, literally, less than a minute to install all three. The only special tool needed is an allen wrench to turn in the set screw on the coolant bottle cap cover, and even that’s supplied with it.
Aside from the JCaps’ good looks, we’re most impressed by the quality paid to details. Jay talks about the thought that went into our Rabbit’s caps with all the gratification of a proud papa. The cover for the coolant bottle, which presses on top of the factory blue cap, is machined within a few thousandths of an inch of the factory part. If the original cap is too hot, Jay tells us, it would expand to the point that his aluminum trim cap wouldn’t fit over it. The washer bottle cap takes more than eight different tools for the CNC mill to create a shape that “snaps” over the original plastic bottle’s neck, and its nylon lanyard has factory-style indexing tabs to keep it from turning in place. Volkswagen kept switching vendors for OEM oil filler caps, so Jay sources a replacement piece from German vendor Febi that replaces them all, and then fits that with one of his custom-machined aluminum caps.
JCaps Billet Aluminum Caps
C2 Motorsports 2.5L Software
Since our Rabbit is a 2007, we’re saddled with the 150-horsepower engine and its diesel–like 5800 rpm redline. While we have bigger upgrades in the future for the car, for the time being we got in touch with Chris Collier and Jeffrey Atwood, co-owners of C2 Motorsports, to see what kind of life their 2.5-liter software could be breathe into the otherwise-stock drivetrain.
There are three different flavors of the C2 software available, so you can choose the minimum fuel you’d like to feed your tank: 87-, 91-, or 93-octane. The 87-octane software produces the lion’s share of gains with a claimed bump of 8 peak horsepower and 10 lb-ft of torque, while the higher-octane calibrations are there for those who want to wring every percent of potential without cracking into the engine. We opted for C2’s 91-octane program, so both the timing and fuel maps have been rearranged slightly to take advantage of the high-octane fuel’s ability to run more aggressive curves without detonating.
C2’s Jeffrey Atwood talked us through the changes that we’d notice with their software, all of which fix annoyances we’ve had with the Rabbit since day one. The redline has been raised to 6800 rpm, which the 2.5 will rev to without hesitation — or danger, since the 2.5 uses valvetrain parts from the higher-revving 1.8 Turbo. “I looked the valve springs up in ETKA,” says Atwood, “and they’re from the 20-valve.” The drive-by-wire lag has been removed, and the decel “hang”, which kept the throttle open for several seconds while coasting, has also been eliminated. The top speed limiter has been removed, but unless our Rabbit gets hooked to the tow loop of a Veyron, we’re never going to have a chance to explore that. We’re also promised that the software doesn’t trigger any stray check-engine lights, and that it can be recalibrated for cold air intakes so that those notorious code-throwers don’t make the CEL wink on, either.
Installing the software at C2’s Waterfest booth was a fifteen-minute job, after which the Rabbit, with its temperature display showing a sizzling 103 degrees, settled into a quiet idle. It was past five o’clock on Sunday, so we were ready to head out onto the turnpike and find our way back to the hotel, giving us lots of opportunities to try honking on our freshly flashloaded VW.
The first thing noticeable about the C2 software is that the throttle tip-in remains natural and progressive, instead of yanking the throttle wide open to simulate big horsepower gains. Puttering through the parking lot on our way back to the highway, the engine behaves exactly the same as it did when it was stock. Bringing the clutch up to its friction point didn’t make any unexpected stumbles or chuggles, and rolling the car out didn’t require ditching the past 15,000 miles of learning.
The first surprise came when shifting from first to second — engine RPMs drop like a brick when the throttle is released, without any of the hang between shifts that the original programming exhibited. We’ve never been jazzed about the Rabbit’s artificially padded throttle behavior, and C2’s software makes the Rabbit respond as if there were a cable between the pedal and the throttle body. Quick jabs of the gas pedal, which the original software would grind down into small hiccups at the throttle body, actually translate into small revs — we have a feeling that the limiting factor in the Rabbit’s throttle response is now the heavy stock flywheel.
On the nearest freeway on-ramp, the Rabbit pulls smoothly (if not eagerly) to 6800 rpm — yes, it is strange to see the tach needle buried deep past redline without hitting the limiter — and the newfound RPMs mean that 60 mph can now be reached without having to grab third gear. Fuel economy seems mostly unchanged, with the Rabbit returning the same 26 mpg during the drive home from Waterfest that it averaged on the drive out.
The big question, then, is if we’re making the advertised 8 horsepower and 10 lb-ft of torque, and that’s one we can’t answer just yet — in the week since our car was flashed, we haven’t had the chance to get the car back on the same Dynapack that was used to make our baseline passes of 146 whp. But we do plan on hooking the Rabbit up soon, and when we do, the results will be posted here.
C2 Motorsports 2.5L Software
91-octane program, without cold air intake — $249.00
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