Project Sipster Part 6 – Faster Sipster


We poke and prod, we e-mail, we stump both the Marks, and finally, we make the right phone call. Scott Russell runs BioChoppers Mobile TDI repair. BioChoppers because he makes motorcycles that run on biodiesel, Mobile TDI repair because he’s been working on nothing but TDIs for the last 5 years and will come to your house and fix yours right there in your driveway. Since we’re homeless and have no driveway, we clatter and smoke over to his driveway, a few suburbs away in Whittier.

Over the following 16 hours, Scott and Jared check every common failure mode and replace countless questionable parts, including the fuel filter we replaced just a week ago that is now clogged with rust… again. Finally, at 2:30 in the morning, Scott replaces the diesel injection pump. It’s an act of desperation; TDI injection pumps never fail, but it’s the only thing left. Turns out it’s the right thing. TDI injection pumps never fail because they never have to try and suck 239 lb-ft of Diesel through a rust-filled filter. To celebrate, Jared goes to sleep in Scott’s driveway.
Back on the dyno the next day, the torque is back, but those 15 hp we were expecting haven’t materialized. We’re up 4 hp, to 124, and one lb-ft of torque, to 240. Turns out Malone didn’t send us the big injectors we were expecting (part number PP520), he sent us more efficient ones (PP357) that he recommends for people trying to do crazy things like squeeze 70 mpg out of TDI-powered Rabbits. 

Project Sipster MD Automotive
But wait, we might need that extra 15 hp to hit our 7-second goal! To find out, we head back to the weapons depot. To tell the slightly embarrassing truth, we didn’t have any way of accurately measuring our 0-60 time last week when we supposedly recorded a 9.8-second 0-60 run. We actually recorded that time with a stopwatch, the inaccurate speedometer, and our trusty 160-lb intern riding shotgun and adding ballast. 
On the drive down from Canada, Jared noticed that when the speed readout on his Navigon navigation system said 60 mph, his Canadian speedometer read 109 kilometers per hour (if the gears and tires were the right size, it should have read 97 kph), so during the acceleration test, he’d yell “stop” as soon as he saw 109 swing past, and sometime later Chris would stop the stopwatch. Between Jared’s reaction time at the launch, his reaction time seeing 109, and Chris’s reaction time pushing the button, there’s no telling what the 0-60 really was.
This time we send the ballast back to New York, take the luggage, spare tire, and week-old banana out of the car, and stick a G-Tech to the windshield. The G-Tech measures 0-60 automatically using a precise, 3-axis accelerometer. No speedo error, no reaction time, just real data.
Launching is easy. Bring the revs to about 1500 rpm, step on the right pedal, lift off the left pedal, and turn the tires to smoke. Second gear lays a satisfying set of stripes, too, but when the G-Tech finally beeps, it says 7.8 seconds. Two shifts and a lot of wheelspin are dramatic, but not that fast. Refining his launch technique for less wheelspin and speeding up his shifts, Jared knocks the time down to 7.5, but no less. 
Then the epiphany: We have 240 lb-ft of torque, why don’t we launch in second gear? Doing so will save the time we normally waste shifting from first to second, and might even waste less time smoking the tires. It works! First try and the time drops to 7.09 seconds. A little more practice and we’ll have it. 

Second try. Jared brings the revs to a cacophonous 4000 rpm, releases the clutch, lays 25 feet of black stripes, grabs third gear and… the plastic zip tie holding the metal zip tie holding the shifter cable in place finally decides we’re done testing. We broke the cheap Volkswagen shifter cable bracket last time we tried 0-60 testing and the chain of zip ties was the only fix we could come up with short of replacing the entire (expensive) shifter cable assembly. 
No more than 30 seconds elapse between a stop along the fence separating public road from the Navy weapons cache before the MPs arrive and politely inform us that we will very much be rounding down our 0-60 results to 7.0 and proceeding on our way stuck in third gear. 
Yes Sir!


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