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2009 Chevy Cobalt SS ECU Tuning - Recession-Proof High Performance

Upgrading A Front-Wheel-Drive Cobalt To Be Cool--And Fast--Like Its GM Siblings

Michael Galimi Jul 1, 2009

Before the custom Tune Time Performance tune, our test Cobalt SS barely fried the tires in first gear. After the test, the car was a different animal. It smoked the hides in first and second gears with ease.

Amidst the myriad of GM performance vehicles of the modern era sits one of GM's best-kept secrets. It is not a limited edition model or a one-off product built to destroy the supercars of Europe, but rather a high-performance vehicle based on an economy car.

In today's economic environment, it is amazing that more people haven't discovered the Cobalt SS. It is fun, fast, and definitely won't break most people's ever-shrinking wallet thanks to the recession. The 2008-2009 Cobalt SS is a gem that is hiding on dealer lots and can be had for a lot less than most people realize. It enters the market in the low $20k range but packs a punch that could rival the mighty Mustang GT with the proper mods.

"I am an enthusiast and I didn't even hear about this car until one pulled up beside me," commented John Franco, the owner of the Cobalt SS on these pages. He is a die-hard car guy that has had everything from low 10-second Grand Nationals to a blistering twin-turbo '68 Camaro capable of six-second times. He is well versed in high-performance cars in his 20-plus years in this great hobby. Franco's racing credentials would hardly reveal that a front-wheel-drive car could satisfy his needs, let alone a Cobalt SS qualify as a daily driver. "I wanted a daily driver that would be fun and quick," he stated and he proudly proclaimed the Cobalt SS as fitting those requirements and being perfectly priced for the average working man.


The baseline numbers are a respectable (for a four-cylinder) 248 whp (5,400 rpm) and 251 wtq (2,800 rpm).

The Cobalt SS is a hidden treasure that comes with a potent turbocharged Ecotec engine, stylish interior, and great looks. A quick look at some of the specs shows us the car comes stock with Brembo brakes, aggressive suspension, and racing-inspired seats. There are those who will criticize the front-wheel-drive system, but if you are in the market for a daily driver while your rear-wheel-drive GM performance car sits in the garage, then you should consider the Cobalt SS because it is fun, cheap, and fast.

Like everything on the road, however, the SS model can be modified to be even better--enter Tune Time Performance (Toms River, NJ). Some readers might recognize the shop from its efforts in G8 and Trail Blazer SS performance. It specializes in all high-performance vehicles and focuses on GM models. At the prodding of Matt Hauffe, head guy at Tune Time Performance, we made a trip to the shop for some dyno testing and subsequent tuning of Franco's '09 Cobalt SS. Our focus was to get the most of what the GM Performance Division engineered from the factory. That meant upping the power and torque output at the wheels by adjusting the tune. Hauffe manipulated the factory ECU to up the boost and add more timing.

The Cobalt SS, like most of today's EFI warriors, relies on tuning the computer rather than a mechanical adjustment for the increase in boost and timing. To do so, Hauffe utilizes special software from HP Tuners. A laptop is attached to the factory ECU via the OBD-II port. The port is used by diagnostic computers to evaluate the computer systems onboard of a vehicle. Aftermarket tuning companies utilize this port to gain access to the ECU to essentially hack into it and adjust its parameters. The level of tuning capabilities using software from companies like HP Tuners is amazing. We can attribute the success of mild-mannered 1,000 horsepower street cars (using a stock ECU) to the tuning adjustments made possible by HP. Our test Cobalt SS was soon to be a Mustang-slayer in less than 45 minutes of dyno testing and tuning. The longest part of the task was downloading the stock tune to the laptop. It took about 20 minutes to accomplish it.


Matt Hauffe of Tune Time Performance used HP Tuners equipment to modify our Cobalt SS ECU.

Our first dyno pull, in completely stock trim and only 2,400 miles on the odometer rewarded us with 248 horsepower and 251 lb-ft of torque at the front wheels. Not a bad start and Hauffe decided that the first move was to add some more boost. At this point, we asked Hauffe about changing the MAP sensor from the stock 2.5 bar setup to a 3 bar one like some people have suggested on various message boards. The MAP sensor is used to detect vacuum and boost for the computer to reference. The 2.5 bar sensor is capable of readings up to 21.5 psi, which isn't a problem with our new tune because Hauffe cranked the boost to a maximum of 20 psi. In stock trim, the boost gauge only swept to 15 psi. A few dyno pulls later, the car registered 268 hp and 290 lb-ft peak numbers. There was a spike up to 313 lb-ft, but we dismissed it as irrelevant, 290 lb-ft is the accurate measurement.

Our third set of chassis dyno pulls were performed with some more mods to the tune up, once again using the HP Tuners software to make the changes. The boost was left alone at 20 psi and this time Hauffe played with the timing curves. Adjusting timing in the Cobalt SS computer is vastly different than other cars. The ECU just doesn't command a set timing number, "this Bosch computer bases the timing on several factors like cam timing," commented Hauffe. He made a few more pulls on the Mustang Dyno and the final figures were an impressive 278 hp and 300 lb-ft. That works out to a gain of 30 in the horsepower department and 49 in torque--at the wheels. Hauffe concluded our dyno testing by saying, "we could make more power but then you run the risk of smoking the stock clutch." Thankfully, GM Performance Parts sells a replacement clutch for the turbocharged Cobalt SS cars, something we will be looking into before performing any more modifications.


The laptop plugs into this converter, which is then run to the OBD-II port under the dashboard. It is how the HP Tuners software accesses the factory ECU. Other companies use separate handheld tuners to re-flash the computer, whereas a laptop is connected directly with the HP way of doing things.

"With these things, the horsepower is cool, but it's the torque that makes the car fun to drive on the street," commented Franco after getting in the car and making a blast up the street on the way back home. He continued, "you can feel the turbo kick in so much faster now, there is no more lag. On the highway, you tap the gas and the car goes from 65 mph up to 90 almost instantly. The tune definitely helps the turbo spool faster. Before, I wouldn't be able to smoke the tires in Second gear. Now, I just get on it quickly (with the traction control off) and the tires beg for mercy!"

Hauffe was quick to comment that in looking at the dyno graphs, the car's engine accelerates much quicker to his self-imposed peak rpm of 6,200. In stock trim, the complete dyno run took 22 seconds. All runs were made in Fourth gear and recording started at 2,800 rpm and shut off at 6,200. By adding more boost, the car accelerated the Mustang Dyno rollers from 2,800 to 6,200 rpm in only 18 seconds. The final pull, with both more boost and increased timing, the Cobalt SS impressed us even more by slashing the dyno pull down to a mere 16.5 seconds for the same 2,800-to-6,200 rpm zone--in Fourth gear. That means quicker overall acceleration. It is no wonder we felt the gains immediately as we took turns beating on the car on the way back home.

Franco has yet to line up against a Mustang, but that time is drawing near as the warm weather in the Northeast is finally here and the tracks are open. We expect the Cobalt SS to run with the new Mustangs thanks to the tune from Tune Time Performance. We are left wondering--what other mods can we add to GM's best-kept secret?


HP Tuners
Buffalo Grove, IL 60089
Tune Time Performance
Lakewood, NJ 08701



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