Mining Journal Article
June, 2010
(Slightly edited for accuracy)

Nancy and Jon Wennerberg with their ZX12R racing motorcycle
at the Twin Jugs Racing “pit” at Maxton, North Carolina

Seldom Seen Slim – Seen Once Again

Nancy and Jon Wennerberg, land speed racers from Skandia, traveled to the Maxton Monster Mile in southeastern North Carolina this past weekend (May 22-23) for another outing on their Kawasaki racing motorcycle.  The Wennerbergs compete in top speed trials both at Maxton and the better-known Bonneville Salt Flats (which are west of Salt Lake City, Utah) at least a half-dozen times each year.  This past weekend they were once again concentrating on getting Jon’s ZX12R nitrous oxide motorcycle tuned and readied for an assault on a 36-year-old record, of 232.597 mph, at Bonneville later this summer.

Jon was the rider this past weekend, as he was a month ago – when he took the bike to a best standing-mile speed of 185.8 mph.  The bike was “naked” at that meet – that is, there was no streamlining, not even a windscreen, on the bike.  This past weekend the Seldom Seen Slim crew chief, Todd Dross, of Twin Jugs Racing in Fredericksburg, Virginia, chose to outfit the bike with the custom bodywork that Jon and Nancy had built for the bike a few years ago.  The bodywork makes quite a difference, allowing Jon to race to a best speed of 196.714 miles per hour.  “I probably could have found at least four or five miles per hour more”, Jon said, “if the crosswind from the left Sunday noon wasn’t so strong.  I was cautious and therefore not as aggressive as I could have been toward the end of that run.”  He said that because of the wind he was tilted hard to the left as he was approaching the timing lights – and still was only about 6 or 7 feet from them as he blasted through the 132 foot timed stretched in less than a half-second – while leaned over about 10 degrees to the left.  Even at that speed Wennerberg was well below the existing record in his class, but since the goal for the event was testing and tuning the motor – not setting a record wasn’t a big disappointment.

The next event at Maxton is in late June, and then Todd will have the bike set to run with the nitrous system operating – giving the bike a big extra horsepower boost at the touch of a button (well, really, when the on-board sensors tell the computer that all programmed parameters are met and the tuner wants the extra power to begin).  The bike has gone 217 mph using nitrous oxide at Bonneville – but with a much smaller motor than it runs now, so the tuning at Maxton is giving Seldom Seen Slim not only plenty of “seat time” to help Jon become more familiar with the high-powered bike, but also to get the bike setup and engine tune up right – to avoid damaging the engine when running flat out for five miles at Bonneville this August.

Nancy, by the way, is patiently awaiting the completion of major engine improvements on her Kawasaki ZX14 – the bike she rode to a best mile speed of 204 mph last September at Bonneville.  She’s hoping for a record well over 205 mph this summer.  Last year the engine was tested and found to have about 207 horsepower, and the new work should bump that amount to around 225 hp.  For more information about Seldom Seen Slim Land Speed Racing you may visit their websites – www.nancyandjon.org and www.landracing.com.  The Wennerbergs are supported in their top speed endeavors by Signs Unlimited, Zambon’s Kawasaki, Public Service Garage, CarQuest of Marquette, and their own business – Kudos Laser Engraving.

Maxton, NC
April, 2010

Riding the Kawasaki ZX12R faired, with nitrous

(Short video)

SKANDIA - Nancy and Jon Wennerberg, otherwise known as the Seldom Seen Slim Land Speed Racing team, visited the "Maxton Monster Mile" racetrack in Maxton, N.C. recently for their first land speed motorcycle race event of the year.

Jon rode the Skandia couple's Kawasaki bike this time, getting onto the 2000 ZX12R for its first outing since late in 2005. The bike has undergone extensive modifications since then.

The bike is being built for an assault on a 232 mph Bonneville record speed later this year, with the North Carolina event mostly for "test and tuneup" riding.

The motor's size has been increased from the stock 1198 to 1349 cubic centimeters, right at the limit of the class that allows motors of up to 1350 cc displacement.

Jon said it's vital to keep the engine size under the maximum since world record-setting engines are measured before a record speed is certified.

The bike's engine is built for operating with nitrous oxide as a power enhancer. But since nitrous oxide can destroy an engine if not used properly, a correct tuneup and build is vital.

Jon entered the bike in a base class for the outing - a class that doesn't allow any streamlining. This holds down top speeds and also makes the engine work hard in order to gather data.

The established record in the class when the weekend started was 175.439 mph.

The Maxton Mile is a WW II glider pilot training strip. It's concrete, with one mile from the start line to the timing lights where the racer's speed is measured. There's then about one more mile to slow down.

Jon's first run -his first time on the bike in 4 years - yielded a speed of 176.75 mph. It was record speed, and per the Seldom Seen Slim crew chief Todd Dross' instructions, Jon never shifted past fourth gear (the bike has a 6-speed transmission) and went more than 176 mph without using the top two gears.

A few hours later, he ran the bike again, pulling harder on the throttle and this time shifting into fifth about 100 feet before the timing lights and recorded a 182.4 mph speed - another record-setting run.

The next morning Dross gave Jon the go-ahead to run at wide open throttle and use fifth gear if the bike would accelerate enough to warrant it. Jon then set his third record speed of the weekend, this time at 185.85263 mph.

Jon is a member of the Maxton and the Bonneville Salt Flats 200 MPH clubs, both of which require setting records over that number.

Jon's wife, Nancy, has been over 200 mph on the couple's Kawasaki ZX14 production class bike. She hopes to ride it into the Bonneville 2 Club later this year, too.