posted on November 25, 2013 13:31
Project MKVI Golf TDI: Rawtek Exhaust and Malone Tuning
Modern diesels are light years ahead of their predecessors when it comes to power. No longer is the diesel owner subjected to white-knuckle freeway merges at school zone speeds, scary amounts of noise, smoke-screen plumes and honking horns as fellow motorists pass them with windows down. That doesn’t mean they can’t be faster. This goes doubly true when you consider Project Golf TDI’s sporty looks. Getting passed by Mom in the minivan with nary a glance was getting a little depressing.
TDI: torque for days, but just not a runner at the stoplights. Yet.
Yes, yes, we know common rail TDIs have 236lb-ft of torque, and yes, this is a fairly healthy sum. However, while that makes the motor feel strong, especially with how effortlessly you can pass people or squirt through traffic, it doesn’t mean you won’t get passed by late soccer moms at a merge. Go ahead, Google it. If you’re in a Golf TDI and a Honda Odyssey, Chevy Equinox, Toyota Sienna, or even the lowly Chrysler Town and Country pulls up next to you, you’d better hone those reaction times and hope mom’s settling a who-touched-who tussle, or you’re going to see some tail lights.
That, and we just like making things go faster. This goes doubly true for cars that can’t beat minivans. If you think this silly, please check in at Basketweavers Weekly.
To start our mods out, we decided on the eviction of the device that offends not only our demanding backsides (acceleration, you twits), but also our pocketbooks. Project Golf, like most diesels built after Ultra Low Sulfur Diesel (ULSD) was released in 2007, comes with the questionably effective and much resented Diesel Particulate Filter (DPF) – one can spend hours scouring the Internet for information on these nasty devices. No doubt that the DPF, like the catalytic converter before it, will morph into a nearly unnoticeable byproduct of the modern era, but for now it’s a device that keeps us up at night with its power-blocking potential and fuel-wasting regen cycles. During a regen cycle, fuel is literally introduced out of cycle and into the exhaust stream to burn out trapped particles in the DPF instead of being used for useful and fun explosions. Economy suffers. Huge EGTs are made (some vehicles see constant 1400-1500 degree EGTs during regen) and reliability suffers. And having a giant exhaust filter can’t be good for power production.
The stock exhaust system, while mandrel bent and reasonably-sized, features a lot of pollution control devices of dubious effectiveness.
To slow the exhaust during regen cycles, VW installed this exhaust flapper thing. At least VW had the decency to use V-band clamps everywhere.
Luckily, the folks at Rawtek make a beautifully crafted turbo back exhaust (downpipe, midpipe and cat back) that eliminates all of this nastiness and more. Before we continue, we must warn you that this modification is not road legal, and we cannot recommend you install this on any vehicle intended for use on public highways. Of course, if you listened to everything we said, you’d try something stupid like tossing a Hayabusa motor into a Miata simply because it makes racy vroom vroom noises, so proceed at your own risk.