Torq ZL1 Power Packages - Center Stage
Testing Torq's ZL1 power packages
From the November, 2012 issue of GM High-Tech Performance
By Justin Cesler
Photography by Justin Cesler
For everything that is amazing about the new ZL1, there is one major problem. It's called the GT500, and as far as stock for stock horsepower is concerned, it's not even close. While the ZL1 rolls from the factory with an amazing 580 hp, the GT500 slays it with a conservatively rated 662. On paper, that's 82 hp, but in the real world we've seen as much as a 100hp difference to the tires. It sucks, but there isn't anything we can do about it. Actually, that's not true, there is a lot we can do about it thanks to the awesome aftermarket support pouring out from speed shops across the country. And, when you really think about it, who cares what it belts out stock? We never leave anything stock around here and neither do you…
One such purveyor of aftermarket speed is Torq Speedlab located in Miramar, FL. Torq built a reputation for themselves based around the fifth-gen Camaro platform and have raced and built several highly successful fifth-gens in almost every aspect of competitive racing across the country for the last several years. Erik Cederberg, the company's Operations Manager, campaigned the infamous black Camaro, which gave closed, open, and parking lot road racers chills every time it entered into competition. To say that Torq likes proven, reliable, drive-it-anywhere and win-it-all power would be an understatement. For them, it's all about the data and the results.
So when we heard Torq's ZL1 had finally come in, we knew we had to check out what the speed gurus had to offer. After a couple of phone calls, we had a plan to cover the initial testing of Torq's Stage 1, 2, and 3 packages. Now, this wasn't just a "check out our parts" thing; we were on hand for the very first testing and even when things didn't go our way, we recorded it. It's how it works when you're trying to go fast. Sometimes you make power; sometimes you have 195-degree intake air temps… But that's testing, and that's how you end up with proven power combos. So, stick with us as we run through the packages and show you what does and doesn't work. Pick the right combo and you're gong to be slaying GT500s in no time.
1 Our test ZL1 belongs to...
1 Our test ZL1 belongs to Erik Cederberg and is the official Torq R&D mule for the ZL1 program. Besides the painted engine cover, everything in the engine bay and drivetrain of the ZL1 was bone stock and, with the factory tune, laid down 460.5 rwhp and 454.9 lb-ft of torque on Torq's Mustang dyno.
The first step in any ZL1...
The first step in any ZL1 upgrade is the Stage 1 package, which is a very simple upgrade that focuses on freeing up all of the easy horsepower and torque that the factory left on the table. Able to bolt on and tune in about an hour, Stage 1 is about as easy as it gets.
Torq worked closely with...
Torq worked closely with Airaid to develop the ZL1 intake system, which ships with a large 4-inch air tube, a massive conical air intake filter, and a Camaro-specific molded airbox. Along with the new intake, Stage 1 kits come with an SCT handheld tuner, preloaded with Torq's ZL1 specific calibration, which simply plugs in to the ZL1's OBDII port and flashes in an instant.
With the tune loaded and...
With the tune loaded and the intake installed, Paul Meister spun up the rollers and recorded the ZL1's new power numbers. Horsepower and torque were up big as the ZL1 laid down 499.1 horsepower and 483.7 lb-ft of torque, a gain of 38.6 horsepower and 28.8 lb-ft of torque. An increase in boost, from 8.3-psi peak to 9.9-psi peak, proves the intake's ability to flow more than the stocker, with boost up from 3,000 rpm on.
Chances are, if you like...
Chances are, if you like Stage 1, you're going to quickly be back on the phone to start on Stage 2. Building off of the new intake and tuning capabilities, Torq's Stage 2 package includes a 2.55-inch upper blower pulley for increased boost, a new belt, a 160-degree thermostat, new NGK plugs, Torq's double-pass heat exchanger unit for improved Incoming Air Temperatures (IATs), and an MSD programmable fuel voltage booster to provide enough fuel flow for the increase in power.
Reducing the upper pulley...
Reducing the upper pulley diameter increases the speed at which the supercharger spins, which results in more boost. Torq uses a 2.55-inch upper pulley, along with a solid LS9 isolator coupler, to increase the supercharger's speed by almost 20 percent, which resulted in a 3.6-psi gain on our test ZL1, taking boost from 9.9 to 13.5 psi.
And yes, you have to remove...
And yes, you have to remove the factory snout to install the pulley, which requires removing the upper portion of the supercharger to gain access... thanks GM. It's not necessarily difficult, but there is a bunch of stuff in the way, so make sure you take your time here. Plus, it's always cool to peak inside the supercharger and see the twin rotors, so don't forget to check that out.
In any engine, but especially...
In any engine, but especially in supercharged applications, heat is the enemy. Increased IATs require tuners to pull timing (to stave off detonation), which results in decreased performance. During the development of the ZL1, engineers worked tirelessly to build a heat exchanger that would properly cool the stock supercharger. And, in stock form, it works well. But, well, who stays stock?!
The factory heat exchanger...
The factory heat exchanger core measures in at 21.5 inches wide, 11 inches tall, and .650 inch thick. For a stock piece, it's substantial, although the thin core combined with the single-pass design doesn't allow for very much fluid capacity, which makes heat soak an issue. Additionally, the factory unit relies solely on free air flowing across it and it doesn't come equipped with any fans to pull air across the core at low speeds or in the staging lanes.
On the other hand, the...
On the other hand, the Torq heat exchanger comes equipped with two massive 10-inch SPAL units (optional, but we recommend it) attached to its thick 2-inch dual-pass core. At 26 inches wide and 11 inches high, the Torq heat exchanger core is much larger than the factory unit (49.5 square-inches to be exact) and over twice as thick for additional fluid capacity and cooling.
Best of all, the upgraded...
Best of all, the upgraded heat exchanger bolts directly in place of the factory unit and comes with everything needed to complete the installation at home. Two small holes need to be drilled for the additional support bolts and some wiring is necessary, but it is nothing a GMHTP reader couldn’t handle in an afternoon. The stock cooler lines even hook right up, which is a nice touch.
Back on the dyno, it was...
Back on the dyno, it was time to test the Stage 2 upgrades. The additional boost from the smaller diameter pulley combined with lower IATs increased power significantly. From stock, the ZL1 was up 86.3 horsepower and almost 100 lb-ft of torque. Peak power rang in at a much more respectable 546.8 and torque followed suit at 540.2 lb-ft.
Looking at Paul Meister's...
Looking at Paul Meister's datalogs, you can really see why power jumped so significantly. Boost was up from stock by 5.2-psi peak, while the curve was raised dramatically, starting at 9 and quickly working to 12.5 psi.
Comparing IATs, the new...
Comparing IATs, the new heat exchanger did a terrific job, dropping temperatures by upwards of 30 degrees compared to stock and 16 degrees from Stage 1. This control over air temp is key to maximum performance.
With good data and climbing...
With good data and climbing power numbers, it was time to test out combinations for the Stage 2R and Stage 3 packages. At this point, it was purely about testing, as the crew from Torq was looking to create packages that worked perfectly on the street, strip, or road course without any issues or unnecessary parts.
With boost levels looking...
With boost levels looking pretty good and the air temperatures under control, Torq's next step was to free up flow in to and out of the motor. To accomplish this, the Stage 2R package was created, which includes a ported 102mm billet throttle body, race ported supercharger snout, a set of Kooks ZL1 specific long-tube headers, and upgraded fuel injectors to keep the air/fuel ratio perfect.
Comparing the Torq race...
Comparing the Torq race ported snout (right) to the stock unit (left), the differences should be quite obvious. For starters, the opening has been moved from 90 mm to 106, which requires the removal of the factory O-ring. Further back, the entire snout has been modified, with special care taken to optimize airflow wherever possible.
Underneath the car, you...
Underneath the car, you can see the beautiful Kooks Custom Headers ZL1 specific long-tubes, which connect to a set of Kooks' Green Revolution catalytic converters. Torq prides itself on being an environmentally and socially responsible company, and the Kooks green converters reduce emissions, clean up the exhaust smell, and don't hurt horsepower, which make them a great option if you're trying to stay legal.