Extra muscle: ECM reprogramming

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Updated Sep 17, 2013

Engine Tuning

Chris Backlund scoured the Internet for months looking for someone to reprogram his engine’s electronic control module. The Fort Collins, Colo., resident hauls asphalt and road base in varied terrain and says he wanted his 1995 Peterbilt 379 to have more uphill push from its 3406E Caterpillar.

He eventually found a local shop, Elite Diesel Services. The shop connected a laptop to the engine, flashed the electronic control module and inserted a file with new data.

“It’s been a night and day difference with fuel economy and power,” Backlund says.

He hasn’t tracked the exact fuel mileage benefits, but says he did gain nearly 150 horsepower – currently at 580, up from the stock 435.

Fuel costs can be cut and power squeezed from stock ECM programming, says Pittsburgh Power owner Bruce Mallinson, whose company specializes in diesel engine performance and does the type of work Backlund had done.

“If you can do just a mile or a mile and a half [a gallon] better, you’re going to put about $20,000 extra in your pocket each year,” he says. Pitt Power engineers are constantly researching modern engines and ECMs to determine what can be improved, he says.

Toying with tuning? Proceed with caution

Re-flashing your ECM or remotely advancing injection timing and the quantity of fuel that goes in for each power stroke could certainly give an underpowered, fuel-thirsty truck a boot in the rear.

It’s also bound to send Nox emissions through the roof and, along with them, peak cylinder pressures and the amount of heat your cooling system and engine oil will have to remove from cylinder liners, pistons and other parts.

A drastic increase in power is likely to significantly increase oil soot, caused by the greatly increased ratio of fuel and air going into the cylinders. It could also over-speed the turbo and cause erosion of the turbine blades on the exhaust side.

Increasing the torque sent through the drivetrain can cause serious trouble, too. Transmission, driveshaft and rear axle manufacturers design their products to precisely match the level of torque they are specified for.

Here are a few pointers to minimize impact of engine alterations if you decide to do so:


USE AN EXHAUST PYROMETER. If your dash doesn’t already include an exhaust pyrometer, install one. Then, consult an engine shop as to the maximum exhaust temperature that is considered satisfactory. When exhaust exceeds this temperature, back off on the throttle.

ANALYZE OIL AND LUBES. This way, you’ll know whether or not the soot levels in your oil are building to maximum tolerable levels and if your oil is breaking down from the extra heat. Keep a close eye on oil and coolant temperatures, too, and reduce power if they exceed normal operating recommendations. Watch transmission and axle oil temperatures, too. Pay close attention to the gearbox gauge because there is more friction and heat there. If the manufacturer’s recommended operating temperature is exceeded, reduce power until it drops to a satisfactory level. Also, use only synthetic lubes because they handle heat much better.

AVOID HEAVY THROTTLE. The most critical time for torque damage to drivetrain components is when running in lower gears. Mimic the operation of multi-torque systems by avoiding heavy throttle until you’re in high range and, preferably, until you are operating in the top two gears in the transmission.

–John Baxter

Companies like Pitt Power, Bully Dog and Delta Force have two major reprogramming methods:

• A flash of the ECM that tunes it to perform differently.

• Installation of a device on the engine that changes signals either to or from the ECM, based on parameters entered by the user.

Mack Trucks’ Dave McKenna cautions owner-operators to be careful with their equipment, as “bootlegged” data files haven’t been through the rigorous tests manufacturers subject their equipment and software to each year.

“We spend tens of millions of dollars a year – if you lump the industry together, hundreds of millions of dollars a year – to try to have a better product than the next guy,” says McKenna, director of powertrain sales and marketing.

“If you’ve got a guy with an iPad or whatever that says he’s got a file that can improve fuel economy, well, yeah, it may improve fuel economy but it’s going to cause problems somewhere else,” he says.

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McKenna points to engine life and disruption of meeting emission standards as probable compromises.

“It’s a balance,” he says. “When we put an engine data file together, the first thing we try to do is achieve a torque profile that’s going to work, a horsepower profile that’s going to work with that torque profile, and then we work our darnedest to get optimal power, fuel economy and emission regulation.”

Alex Nikolic, sales manager for Delta Force Tuning, based in Sanford, Fla., agrees that engine changes usually compromise the engine elsewhere. So his company carefully “tips the scales to make the engine achieve what the customer is after,” he says.

From a technical standpoint, electronic engine tuning slightly alters injection timing, pressure or a combination of the two, Nikolic says.

To determine how much to change timing and pressure and what parameters to alter in the ECM, Nikolic says the company quizzes owner-operators about driving habits, loads, terrains and desired effects. It then must obtain the engine’s base tune – the manufacturer’s settings – by hacking into the ECM with a worm, a virus-like program used to gather information.

Delta Force then alters the data, flashes the ECM and uploads the new file, unless it’s using an inline device, in which case hardware and a wire harness are installed.

Shawn Udy, project manager at BullyDog, says his company offers three basic electronic tunes – fuel economy, fuel economy with power, and a return to stock, which changes altered ECM parameters back to original settings. The basic fuel economy tune can increase fuel mileage by 6 percent to 12 percent, he says, and the loss of horsepower “is a wash.”

The fuel economy with power tune, however, increases fuel economy 6 percent to 12 percent and horsepower and torque each about 15 percent, Udy says. A tune at Bully Dog runs about $3,000. Udy says the changes don’t leave a footprint that manufacturers can see and it doesn’t interfere with diagnostic tools.

Small-fleet owner and driver Wes Malmgren of Malmgren Transport in Aurora, Utah, says in 2009 he installed Bully Dog’s Power Pup onto a 2006 Caterpillar and immediately saw an increase in horsepower and fuel mileage.

Manufacturers frown on retuning

NAVISTAR. Changing manufacturer ECM calibrations will decrease life of all drivetrain and engine parts, says Anil Bansal, global electronic and electrical systems director. “Anything that deals with fuel or turbo could be affected,” he says. Dealers will work with customers to change calibrations, which is the safest option, Bansal says. The company deals with third-party ECM tuning relative to warranty coverage on a case by case basis, he says.

CUMMINS. Lou Wenzler, Technical Sales Support Director, says the manufacturer has worked to prevent ECM recalibrating by requiring a tool that can only be obtained within the dealer network. He says Cummins’ dealers can uprate engines roughly 50 hp, but if done by a third-party, engine failures caused by ECM reprogramming will not be covered by a manufacturer warranty.

DETROIT. Mark Thomas says the company’s engines keep records of reprogramming and tools that have been used in doing so, and unauthorized tampering voids a warranty. “These are very finely-tuned machines,” he says. “It will take away from the life of the engine.” Thomas also says owner-operators could be fined up to $3,000 by the U.S. Environmental Protection Agency if their engine tampering defeats emissions technology.

MACK. With improving ECM technology, says Dave McKenna, Mack can track changes to an ECM with a log kept within the engine computer. He also says ECM flashing voids the manufacturer’s warranty. It can harm engine performance and engine life, and defeat emissions technology. “It can’t possibly be good for the engine,” McKenna says.

VOLVO. Ed Saxman, product marketing manager, says he’s skeptical of anyone “not schooled” in the manufacturer’s design. “If you change the parameters within the ECM, you could exceed design limits of some of the components within the engine,” he says. Spokesman Brandon Borgna says the company’s warranties do not cover any vehicle or system altered to affect “stability, durability or reliability.”

PACCAR. “There is nothing to be gained by unauthorized attempts to reconfigure the engine ECM’s calibrations beyond the available parameter settings,” says Paccar VP Craig Brewster. Tampering can reduce performance and engine life and, per EPA emissions standards, make the engine non-compliant, Brewster says.

“We jumped about 1.2 miles per gallon, and when running a hill, you’re basically a full gear higher going up it now,” he says. He’s since installed the devices onto four other trucks. “Anybody can do it as long as they have a computer,” he says. “You just plug it in, bolt it on the ECM and that was that.”

Malmgren also says he’s been able to have warranty work done to the engines after he installed the Power Pup. “I’ve been into shops and no one could tell the difference,” he says. “The warranty work was still done. I didn’t tell them, and I wasn’t going to unless they asked.”

Repair and maintenance hasn’t been an issue yet, either, for the five trucks they’ve tuned. “Compared to the other 28, we actually haven’t noticed a difference,” he says.

McKenna says that though dealerships or Mack-authorized mechanics may not be able to notice electronic tunes, they do void warranties when spotted, and steps have been taken on 2007 and newer Mack engines to decrease tampering. If parameters within the ECM change, a fault code will flash and issues are time- and date-stamped.

Mark Thomas, director of electrical and electronic engineering for Detroit, says the company voids warranties, too, when an ECM has been tampered with. “It could hurt the mechanics of the engine and it’s going to cut down on the life of the engine and the whole drivetrain – the engine, the transmission, driveline, axles,” he says.

“If you want 600 hp out of your engine, why buy a 450 hp engine in the first place?” Thomas says. “Spec a 600 hp engine to begin with, and it will end up saving you money overall.”

Carnduff, Saskatchewan resident Blake Small flashed the ECM of his current truck and his former truck. Performance Diesel in St. George, Utah, reprogrammed the 600-hp Cummins ISX he uses in his 2009 Peterbilt 389, and it now runs at about 800 hp, Small says.

He says the engine’s also running 2 mpg better than when he bought it. “The money saved in fuel costs more than pays for modifications, and it’s more fun to drive,” Small says. His former truck, a 2005 Peterbilt 379 with a 550-hp MXS C15 Caterpillar, has 22,000 hours on it and hasn’t had any major problems, he says. He had PDI tune it to about 750 hp. He sold the truck, but has kept up with its current owner.

Pitt Power’s Mallinson does say owner-operators should be careful about engine modifications when under warranty, but to consider the bottom line.

“Is it worth it to have a warranty and a truck that drives like a dog? Or do I want to drive a truck that’s a thoroughbred and going to save me $20,000 worth of fuel?” Mallinson asks. “It’s something to think about.”


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