2012 ZL1 - Race To The Top

From stock 10.30s, we follow Redline Motorsports '12 ZL1

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Redline Motorsports has come a long way, literally, on the back of its owner Howard Tanner, since we first encountered them some 5 years ago. Starting out as a small shop in Schenectady, New York specializing in Corvettes and other late models, Redline quickly became synonymous with the fifth-generation Camaro. When Redline got hold of its 2010 SS we were there to cover the drag test, and we even followed them as they went through the usual upgrades. Since then Redline established itself as a builder of OEM-quality special edition Camaro SSs, which can be purchased through a dealership, and has moved its operations down to Pompano Beach, Florida. As the 2012 ZL1 was released we found ourselves full circle, Redline had one on order and scheduled for an early delivery with drag testing and modifying in mind, and another dealership program on the horizon.

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Redline had certainly hoped to be the first ZL1 in the 10s, and had agreed to give us the exclusive coverage. Of course, the day we were at the track for baseline testing Lingenfelter Performance Engineering had already made their 10.79 run and beaten Redline to the punch. LPE's manual trans-equipped ZL1 was armed to the teeth and running on race gas, before the crew set its sites on another record. Meanwhile Redline's goal became to surpass LPE with their automatic ZL1 using pump gas and see how far they could push the revamped LSA. With a little luck, they could dethrone LPE and score one for the underdog. Follow along as Redline raises the bar at Palm Beach International Raceway, and became the fastest ZL1 (for all of 2 1/2 weeks).

Day 1: Baseline, Drag Radials & Cold Air Intake Drag Testing

After a snafu at the rental car agency, I arrived a half-hour late, around 11:30am in Jupiter, FL. Redline had already unloaded the ZL1 and was ready to go, as the crack staff at PBIR was prepping the track. The car sat bone stock save for the thermostat (160-degree used for dyno testing), a line lock kit for easier burnouts, and a removed washer tank (to make room for fabricating the cold air intake). At long last the anticipation was over, and on its first pass the ZL1 went 12.39 at 116mph with a sluggish 2.07 sixty-foot with all electronics turned off (such as traction control) in full automatic mode. Subsequent passes proved the manual shifting feature too sluggish to utilize effectively, using it resulted in either commanding the shift too early or bouncing off the rev limiter. The sophisticated traction control system (in Race mode), while great for "roll racing," can't recover fast enough to enable a good elapsed time. After the initial tire slip, there is a long pause as the motor ramps the timing back in and the clock ticks away. The (full automatic) Sport shift and Touring suspension mode with traction control off resulted in the best time of the day, a 12.24 at 116mph with a mere 2.03 short-time.

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Redline brought a set of lightweight 18-inch wheels from CCW that were an early prototype fitment. As it turned out, the front wheels just grazed the top of the steering knuckle, which was later trimmed for our next track session. However, the 18x11-inch rear wheels fit beautifully to wedge in the 305/45/18 Mickey Thompson drag radials. These tires were aired down to 16psi and immediately allowed the traction that the ZL1 so desperately needed. The slight increase in tire height slowed it to 115mph, but the added grip enabled a 12.04 with a 1.81 sixty-foot.

Master fabricator Jay Healy of Redline whipped up a 4-inch diameter aluminum intake with a 6-inch K&N air filter. By removing some of the baffling and silencing characteristics of the stocker, and increasing the diameter, the flow and volume increase would be substantial. The filter would also be grabbing air from the high-pressure area behind the front bumper cover, right next to the brake duct. Given the new location of the MAF and diameter of the tube, this required some modification to the tune. Redline calibrator Howard Tanner made adjustments to the MAF tables to compensate, otherwise leaving the tune (including the timing) alone. On Redline's Land & Sea dyno the results were an unbelievable 46 hp and 33 lb-ft of torque gain, from a baseline of 450hp and 447 lb-ft. Think it's BS? We definitely questioned it as well, but not after the crew swapped the intake over at the track and picked up 3.6mph and dropped .56-seconds. Best time on the day was an 11.68 at 118mph with a 1.73 sixty-foot. The larger intake increased boost by 1psi and even helped lower the rising IATs at speed, though it enhanced a noticeable bog at launch. After proving the merits of the intake, Tanner tried adjusting the timing in a few areas, but that proved a fruitless effort as the car could not best its previous run. The ZL1 was tapped out.

Days 2 & 3: Modifying, Dyno & Track Testing

That night we returned back to the shop, and started examining the LSA for teardown. Technicians Jay Healy and Mark Hoffman tag-teamed the wrenching with Howard lending a hand (excitedly) on occasion. Enhanced power would come from a custom camshaft from Comp Cams, upper and lower pulleys to increase boost, a ported blower snout, American Racing 1 7/8-inch long-tube headers with a catted X-pipe, and a custom calibration. Of course all of these components were matched to their appropriate upgrades such as Redline double valvesprings, Titanium retainers, Comp chromoly pushrods, Injector Dynamics 98 lb/hr high impedence injectors, ATI harmonic balancer, NGK TR6 plugs, and a shorter length HD belt. Redline wasn't looking to reinvent the wheel here, just use tried and true methods of upping the ante while still keeping it a ZL1.

While at the outset there was some anticipation of the factory TVS1900's limitations, when the final calibration helped the ZL1 belt out 624 lb-ft of torque and 654hp, a 200hp gain over stock, we all bowed to praise the LSA. With these numbers in hand, we knew the Redline ZL1 was destined for 10s. Also helping to lower track times, Redline planned to install a Coan 3600-stall torque converter, to improve sixty-foot times and get into the powerband, and a fabricated reservoir for the heat exchanger, to decrease heat-soak.

First pass at PBIR, Howard still had the stock trans calibration, which short-shifted at 5800rpm that allowed only a 10.73 at 132mph. Clearly there was a lot left in it, and after a 30-minute cool-down and some changes to the transmission tune-up, Redline filled the reservoir tank with ice. The stronger 1-2 shift and flat-footing it off the line enabled a 1.56 short-time on the way to a 10.37 at 134. The third pass proved the best with a 10.32 at 134mph, on a 1.54 sixty-foot, thanks to some additional spark advance and a heavy foot. Though elated to have shattered Lingenfelter's record, the transmission still needed additional tuning and Tanner knew there was still plenty left in the combination. Unfortunately, though, the Florida weather would not cooperate. With a tank full of race gas and a smaller upper pulley (730-rwhp), Tanner returned to PBIR, but couldn't manage more than a tenth of improvement due to the heat and humidity. A week later Livernois Motorsports became the first in the 9s with a similar combination, and Redline vowed to return to PBIR. If only mother nature would give them a hand...

60-ft 1/8-mile MPH 1/4-mile MPH
Stock 2.03 8.01 91.8 12.241 116.4
Drag Radials 1.81 7.79 91.2 12.048 115.7
Intake 1.73 7.54 93.9 11.689 118.6
Converter, Cam, Headers, 14psi & Tune 1.54 6.66 106.5 10.323 134.7

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