Those nice folks at Snow Goer Magazine actually wrote not one, but two articles on Jaws Performance in their Fall, 1998 issue. Click on the piece you’d like to check-out first; Chris Knowles’ introductory article “Power Hungry” or the main piece, called “Power Pipes – On the Dyno Inside JAWS Performance”.
(Reprinted, with permission from Snowgoer magazine, Fall, 1998)
The door is as thick as a bank vault’s but even when it’s closed tight, the sound barges through it in muffled waves. Greg Balchin taps a few buttons on the control computer, gives the throttle stick a few lazy pulls, and then buries the stick to its stop. On the other side of the door, a Thundercraft engine wails its approval, while we watch the tell-tell numbers flicker on the computer as the revs rise: 170…175…182…187…190.
Balchin suddenly releases the stick and the big Thundercraft triple plummets back to a purring idle. “Not bad,” he says quietly, pondering the computer printout that tops out at 190.1 horsepower. Not bad indeed.
We’re at Jaws Performance just South of Ottawa, where Balchin is
working his famous magic on pipes for the 1,000 cc Cat, which was among
Snow Goer’ s fleet last winter. We’ve been here most of the day,
skipping both lunch and then — oops! — dinner, engrossed in the pursuit
of power, energized by caffeine. Not that the Thundercraft needs more
strength — our mostly-stocker pushed the Jaws SuperFlow dyno to a high
of 172.7, surely enough for any sane snomobiler.
But, well, gee, you know…Call us crazy.
The first mod was the addition of a set of prototype Jaws pipes, which immediately recorded a 7 horsepower improvement at peak rpm and, notably, a corresponding increase right across the power band. Next, we removed the air box, bumped up to 490 mains, and welcomed another 6 horsepower to the party. What would V- force reeds and 520 mains bring? Another pony and a half, the dyno replied.
At that point, Balchin scratched his head, perused some numbers on the computer printouts, took a slip of coffee, leaned back on his stool in the dyno room for a moment, and then proclaimed; “490s again.”
Bingo: 190.1 hp at 8,600 rpm.
Best of all, the Thundercraft worked as well on the snow as it did in the dyno room, though we ended up going to a bigger main jet simply for peace of mind on the trail. And we had so much fun watching Balchin at work we decided to make a second visit with a notebook in hand, just to chat. For Greg Balchin’s thoughts on pipes and power, turn to page 14. — Chris Knowles.
Power Pipes – On the Dyno Inside JAWS Performance
(Reprinted, with permission from Snowgoer magazine, Fall, 1998)
Look at a snowmobile exhaust system, and most of us see a random bunch of bulbous tubes. Few of us can read the meaning behind them.
Greg Balchin reads a pipe as a composer reads music. He sees the symphony of every conical and cylindrical section acting in harmony to extract the maximum of an engine’s usable power. It’s more than the crackle that hits the ear; it’s the optimization of temperature gradients, exhaust trapping pressures, fuel/air ratios and the other complex interrelationships that govern the performance of a two-stroke engine. Peak horsepower is rarely the goal, either; good throttle response and a healthy torque curve are paramount.
Just as a successful composer leaves nothing to chance, Balchin’s musical score consists of computer graphs, dyno charts, e.t. slips and trophies that confirm or deny an engine builder’s success. And every so often, he sees the convergence of many hours of mental exercise and sheet-metal handiwork in what he calls a “happy pipe.”
In the past 11 years, Balchin and his company, Jaws Performance, have made many power-hungry snowmobilers happy, too. He’s seen his work win match races on the lakes, and put drivers on the podium in practically all racing disciplines. Plus, his pipes can be found under the hoods of more and more trail sleds. While he’s the brains and the heart of the operation, between August and January, his shop on the outskirts of Manotick, Ont., near Ottawa employs an average of nine people fitting, welding, painting and shipping Jaws’ production and one-off custom pipes to snowmobilers throughout Canada and the U.S.
Photo by Chris Knowles
photo by Chris Knowles
of Snow Goer Magazine
In the off-season, he keeps sharp on what’s happening with machinery of all descriptions. This can involve building pipes for racing chain saws (yes!), gyrocopters, motorcycles and even pulling tractors. An awareness of developments in other fields just adds to the database of knowledge and may eventually filter back into his snowmobile work. “It prevents you from getting too focused on one area,” Balchin says.
A graduate in instrumentation and controls from Algonquin College in Ottawa, Balchin, 38, worked for federal government agencies in functions as diverse as commissioning the Pickering nuclear hydro station and developing laboratory controls in disease research for the Department of Health and Welfare. He made his first set of pipes in 1979 and spent much of the early ’80s racing Formula III sleds and building pipes for himself and others. Head-butting a frozen haybale in 1988, the same year a friend was paralyzed in an earlier crash, prompted him to retire. Since then, he’s worked to enhance his understanding of how and why engines make power, and to build Jaws into practically a household name.
The Jaws tag stems from his background in watercross, when he painted shark’s teeth on an air intake for visual effect. Balchin is a keen enthusiast of the summer sport, seen by some as a bizarre and illegitimate son of snowmobiling. “It’s fun, it’s fast and it’s warm,” he says. “Plus it’s a good proving ground for sustained power.” Indeed, an engine that fades after a minute or two at full throttle is going to get wet. Drag racing, where Balchin learned much of his trade, is at the opposite end of the scale. It’s maximum intensity for a few seconds, and then you’re either a hero or a zero. It makes a whole different set of demands on the engine tuner, and hence the pipe builder.
The process of building a new pipe is centred not in the Jaws dyno room, but at Balchin’s desk, where his computer screen displays special pipe-design software that he says is not commercially available. The program can generate an accurate portrayal of an exhaust system’s performance as much as 85 percent of the time, which Balchin says is extraordinarily high compared with others of its type. He’s working steadily to raise that figure higher. Still, the operator is the key; as with other computer applications, it’s garbage in, garbage out.
Starting fresh on an unfamiliar engine is an exhaustive process — no pun intended. “We do very in-depth measuring of an engine — every angle and every radius. You can’t just measure it in an hour. There’s bore and stroke, every volume of every port, corner radiuses, roof angles, relationship to the next port, reed thickness, angles in the reed block… there’s nine pages to fill out. It could be 100 hours to develop the pipe properly, just working on the program.” All this hard data gets fed into the software, but there’s still room for Balchin to input his own subjective analysis of what he thinks the engine needs in the way of pipe dimensions.
“We have to figure out what we think will be the scavenging quality of the engine,” he explains. “Not all engines are built beautifully inside. There’s a whole lot of ciphering to figure out what is going on. Then we go back to look at other similar engines.”
Feeding this mountain of engine specification data into his program, along with all the what-ifs his experience tells him to factor in, eventually generates a multi-coloured trace on his computer screen. It shows a graph of pressure and temperature inside the engine during its operating cycle — intake, compression, combustion, exhaust — at any given rpm. It also shows how long the reeds are open and shut — as little as 40 degrees of rotation in some cases.
Photo by Chris Knowles
photo by Chris Knowles
of Snow Goer Magazine
All Balchin has to do, though, is change one factor by a small amount and everything becomes different. “It’s like a 12-number lottery; if you mess up any one thing, you mess up everything. Plus or minus one millimetre on diameter can make it or break it.” Once he’s confident of his calculations, Balchin builds a prototype that goes for testing by himself and trusted associates. This includes dyno testing as well as real-world flogging on the trail, on the race track and even on the water. If it performs as expected, the new design proceeds toward production; if not, it’s back to the computer and the process starts again.
Beyond just coming up with the configuration for a winning pipe, Balchin has to make sure it all fits under the hood. “Almost every day I run into a packaging problem,” he says. “Take a single-pipe machine and add three pipes, and it gets very cramped.”
Once it’s time to go into production, accuracy in manufacturing is vital. For that reason, he doesn’t trust hydroforming as a sufficiently precise means of shaping his production pipes. Instead, Jaws chamber halves are punch-pressed to shape by an outside supplier. The stamping dies are carved from steel, duplicating the exact shape of the final hand-built prototypes — at least, that’s the goal. Balchin describes the time and money involved as “horrendous… It’s spend, spend, spend.” If the dimensions aren’t spot-on, the dies have to be adjusted and tested until everything is right. This can take “six weeks if you’re very fortunate; more likely it’s three months and a lot of FedEx.”
The raw stampings then enter one end of the former heavy-equipment rental shop that houses Jaws Performance and proceed down the line. They get welded together on jigs or on actual snowmobile sections for an accurate fit. Slip-joints, flanges, heat shields and mufflers are also produced by outside suppliers. They are assembled, welded and finally finished with a water-based paint in batches of 20 to 30 at a time, drying on racks at the opposite end of the shop, ready for packing and shipment.
Supervising all this activity, Balchin has to wear many hats — perhaps more hats than he’d like. “They don’t fit,” he says in an uncharacteristically candid moment. “We started off as a two-man shop. Now we get up to 12 people working here at a time. Originally, I was building every pipe by hand by myself. Now I have a crew of people building pipes by hand and by stamping. There are quite a few thousand of my pipes out there now.”
With no lack of customers, his current challenges are to increase production, improve longevity against fatigue failures (such as by using ball-sockets instead of slip joints at the engine end), and improve silencing. “Noise is a constant challenge. We’re now using a synthetic packing material that won’t blow out.” He won’t say what it is.
In fact, Balchin is guarded about a lot of subjects regarding his business. He does acknowledge “quite a bit of help” from the Ski-Doo race shop over the years, but is reticent about pretty well everything else, including the number of units he produces a year, who he consults with for ideas, or the origins of the computer program he uses. “No one is going to hand you the answer to a problem,” he says. “At best, they’ll make some general suggestions, saying ‘You could try looking in this direction or that.’ There are no simple solutions.” Perhaps working for the feds in his early days taught him the value of keeping one’s mouth shut.
Ironically, though, Balchin does expect those ordering custom pipes to be fully forthcoming in revealing everything that’s been done to the engine that the pipes are for. Every change in port timing, squish-band configuration, ignition advance, rod length, crankcase volume, port-track length, carb size and so on must be revealed, as well as length of the race track itself. “When a person talks to a pipe manufacturer, they have to say exactly what they’ve got or what they intend to do. Don’t be shy. If I can’t help, I’ll say so or recommend another system to try.”
For his production pipes (as opposed to one-off custom pipes), Balchin stresses a balance of usable power with reliability. “You don’t focus on [peak] horsepower, but rather on all the characteristics of how it works. You have to build to your worst-case scenario — pump gas, deep snow, a cold night, big lake, sea level.” Fuel quality is a big variable, and generally you have to assume the worst. “Detonation is one of the biggest factors in pipe design. Nowadays, you tend to throttle pipes to keep the power in the range of unleaded fuel. As a rule, you can make a pipe too powerful for the octane you can get. You can ‘supercharge’ it so much you go beyond what 91 octane can handle.”
When all goes right with one of his designs, the results can be substantial. Balchin claims his reed and pipe combination yields at least 172 hp on a Ski-Doo 800 triple — “hot, maintained power” — compared with 157-158 hp for a stocker. Other examples? “With a Ski-Doo 670 MX Z we can maintain 8 – 10 horsepower over stock with wicked throttle response and regardless of heat.” At the time of writing he was developing a pipe for the new Ski-Doo 670 H.O. “We can make way too much power for pump gas. It’s a barnstormer.”
With word of his successes spreading, Balchin is having a hard time keeping up with demand. He picks up a customer’s faxed dyno sheet from next to his desk that shows regular runs of 176 to 180 hp. “Holy shit!” runs the customer’s written remarks, enough to warm any tuner’s heart.
It’s mid-summer and Jaws still has the occasional offbeat custom design project in the works. Inside the receiving door sits the rolling chassis of a Rotax-powered motorcycle inspired by Ted Wilkins’ machine profiled in the Fall ’97 issue of Snow Goer. Balchin estimates 50 hours for the job of building a suitable exhaust system from scratch. It’s going to be a long weekend.
On the side, Balchin is finishing the design of a Web site to be launched this fall: jawsperformance.com. In the meantime, there’s more testing, liaison with customers and suppliers, and routing of new ideas through the computer. “We’re very proud of the dependability and output of our pipes. Ultimately, the person who puts the product on his machine has to be faster. We strongly believe were the best at doing that.