COPO Tech: Prepping A Camaro For Factory Stock Showdown Racing

Despite all the race-only features built into the thoroughly engineered COPO Camaro, the limited-edition hot rod is not ready to win races in the highly competitive SAM Tech Factory Stock Showdown series when it rolls out of GM’s COPO build center.

We’re adding 150 horsepower over what the engine came with. -Todd Patterson, Patterson-Elite

Designed to honor the legacy of the original 1969 ZL1 aluminum big-block COPO Camaro while offering customers a safe, modern racecar, the COPO program was launched by Chevy Performance with the 2012 production model. The car features multi-link rear suspension, adjustable strut front suspension, race tires and safety gear certified to 8.50-seconds under NHRA guidelines. Six different hand-built engine packages have been offered over the years, with some 300 COPO Camaros having been sold. Unfortunately, many COPOs are rolled into garages by collectors, but there remains a strong contingent of COPO Camaros racing Stock and Super Stock.

The base car started as a 2016 COPO Camaro, #39 of 69 produced last year. Rolling out of Turnkey Performance where the COPOs are built, it came with the 5.7-liter supercharged V8 and 3-speed ATI automatic transmission.

The Factory Stock Showdown matches the fastest of the factory hot rods built by Chevy, Ford and Mopar for the FS/XX class sporting supercharged engines (2.9-liter Whipple) and weighing 3,550 pounds with driver. This is a heads-up class with a five-tenths Pro tree. For most of the events, the top eight qualifiers advance to the elimination finals. For the U.S. Nationals there will be a 16-car field.

Patterson-Elite sent the car to Brink Racecraft in Texas for a safety upgrade to SFI 25.5. The dash had to be removed for a crossbar that runs behind the firewall. A lighter steering column that is splined for a quick-release steering wheel is also installed, and the 2-step switch is mounted to the brake pedal. The steering shaft runs to the rack-and-pinion mounted on the aluminum K-member that is new for ’16 and ’17 COPO cars. A custom jack pad was fabricated (inset photo) for the alloy K-member to securely lift the front of the car in the pits.

The Patterson-Elite race shop is well versed in setting up COPO Camaros for competition. Before the start of the 2017 season there were six COPO Camaros that had won national events, and three were prepared at the Patterson-Elite shop in Augusta, Kansas. The shop also prepared two COPO Camaros that held NHRA class records.

Here’s the Funny Car-style hoop installed under the factory rollcage along with additional 4130 chromoly steel tubing to the rocker area and a down bar. NHRA also requires gussets in critical joints. Additional tubing tying the rollcage to the vehicle frame rails under the floorplan is also required. Note the extensive masking to protect the headliner and other interior trim pieces.

Patterson-Elite installs an Auto Meter brake-line pressure gauge in the factory HVAC vent. The seat is installed lower than normal to clear the Funny Car cage. Also note the custom window net. A Precision Performance Products shifter with all-forward shifting and clean neutral function is installed along with Advance Control Devices shift control.

Safety Measures For Running Quicker

Prepping a COPO Camaro for Factory Stock Showdown racing involves blueprinting the engine to gain upwards of 150 horsepower, setting up the transmission and suspension to transfer that additional power to the track, and upgrading the safety equipment to meet stricter SFI standards. The car, owned by Ted Hughes of Seward, Nebraska, featured in this build started as a 2016 COPO Camaro that was number 39 of 69 built that year. It was ordered with the 350 cubic inch supercharged V8 that NHRA rates at 580 horsepower. That engine is backed by an ATI TH400 3-speed automatic. Other engines offered that year include the 6.2-liter naturally aspirated V8 rated at 410 horsepower and the 427-inch naturally aspirated V8 rated at 470 horsepower.

A Racepak is installed. Besides monitoring engine functions, the data logger records suspension movement from sensors placed at the front and rear.

“Right out of the box it’s capable of running 8.60 to 8.70,” says Todd Patterson, shop manager at Patterson-Elite. “The way the car rolls out of the transporter, the chassis is certified to 8.50. If you go faster, you’re illegal. For anyone who’s serious and wants to race heads-up Factory Stock Showdown, one of the first steps is upgrading the rollcage.”

Patterson-Elite works with Brink Racecraft in Irving, Texas, to modify the existing rollcage and upgrade the suspension and brakes. The key element to the SFI 25.5 upgrade is the installation of a Funny Car hoop-style cage under the existing rollbar. Brink uses 4130 chromoly steel tubing and welds in gussets where required on critical joints. Additional tubing is also installed behind the dash, along the rocker area, and under the car to mate up with the unibody’s structural members.

Lamb racing brakes are swapped in at all four corners while the car is at Brinks Racecraft. Note that the rear brakes (left photo) are dual-caliper models to help hold the car on the starting line during staging.

Patterson-Elite swaps to 125-pound springs and installs new Lamb racing struts up front. The setup allows adjustability to ride height and weight transfer.

While the interior and dashboard are dismantled, Brink replaces the factory steering column with a lighter aftermarket unit. COPO cars don’t come with power steering, but a new aluminum K-member and improved steering rack on the Gen VI cars is making life easier for the drivers.

“There’s probably an extra 20 pounds of weight with the stock steering column,” says Patterson. “That’s weight in the middle of the car that we can move to the rear. Also, with the Gen VI K-member, it’s not only lighter but now you can drive with one hand on the steering wheel. With the old cars you had to arm wrestle around the pits. It’s not power steering but it’s like night and day compared to the previous car.”

The horsepower increase starts with tearing the down the factory engine and bringing the bore on the iron LSX block to .070-inch over, which is just under the .080-inch overbore allowed by the NHRA. Final bore is 4.135-inch. Patterson-Elite also installs ARP main and head studs, replacing the TTY hardware from the factory.

The engine comes with a Callies 4340 steel crank and Ultra H-beam series connecting rods. Patterson-Elite also uses a combination of Clevite and ACL coated bearings in the build. With the overbore, Patterson-Elite installs Gibtec pistons and Total Seal rings. Finally, the shop installs a steel main girdle for extra bottom-end strength.

Employing A Clean Neutral Option

Other interior changes include a quick-release Grant steering wheel, Auto Meter brake-line-pressure gauge and redesigned Stroud window net to fit the new rollcage. Patterson also installs a Precision Performance Products all-forward pattern shifter and a shift controller from Advanced Control Devices.

First Time Out

With Todd Patterson behind the wheel, the Omaha Track COPO Camaro qualified seventh at the opening round of the SAM Tech Factory Stock Showdown at Gainesville, Florida, during the NHRA Amalie Gatornationals with a time of 8.22 seconds. A total of eight qualify for the final eliminations. Despite nailing his opponent to the tree, .038 to .084 reaction times, Patterson lost in the first round to Stephen Bell, 8.412 at 162.59 to 8.304 at 165.15. Patterson had to change the engine following testing the week before racing Gainesville, and he estimated he was down some 40 horsepower to the field. And he says the torque converter was a little loose, possibly slipping 400 to 500 rpm through the lights. The winning time in the final was 8.131 at 168.47 by David Barton’s ’15 COPO Camaro.

“One of the first things we replace is the shifter and transmission. The valve body on the factory 3-speed transmission doesn’t allow a clean-neutral pattern where you shift into neutral and shut the motor off after the run,” explains Patterson. “We like to shut down because under deceleration the oil is rushing away from the pickup.”

The suspension makeover includes new Hyperco 125-pound springs and Lamb adjustable struts up front and new Precision Racing Shocks Penske coil-over shocks in the rear. Lamb brakes are also installed front and rear.

Adam Lambert valves the rear shocks specific to our application,” says Patterson. “The rear brakes are dual caliper. That’s a big factor for holding the car in the staging beams because of the torque these engines make.”

The engine upgrade starts with boring the LSX iron block .070-inch over and adding ARP main and head studs.

The short block includes an upgrade to a Cloyes timing chain, a Bullet camshaft that falls within the NHRA lift requirements, swapping to a Melling oil pump and the stock ribbed ATI damper.

The cylinder heads include Del West titanium valves and PAC valve springs. Not much else is allowed except a competition valve job. The heads are installed with Cometic MLS gaskets.

“You’re allowed by NHRA to go .080 over, and normally we would start at .070 to allow a .010 block life from rehones,” says Patterson. Now the engine already comes .060-inch over, so we just go .010 over to a final 4.135-inch bore.”

Patterson-Elite adds a steel main girdle to help support the Callies steel crank and rods. New Gibtec coated pistons wrapped with Total Seal rings are installed along with a combination of Clevite and ACL coated bearings. Compression ratio bumps up to 12.3:1 with the larger pistons. The bottom end is buttoned up with the stock Stef’s oil pan and new Melling oil pump. The custom Bullet solid-roller camshaft is ground within the NHRA lift restrictions and mated to a Cloyes timing chain. Jesel sportsman lifters are also installed.

Here’s the Stef’s oil pan and pickup assembly that comes with the COPO engine from the factory.

Few modifications are allowed to the LSX cylinder heads. They do receive a competition valve job to seat the Del West titanium intake valves. PAC springs are also installed. Stock rockers are used, although they get coated trunions. Since the rockers are not adjustable, Patterson-Elite relies on a combination of Manton pushrods and Jesel tips that uses shims to set the correct valve lash.

“We do have to shim each one individually,” says Patterson. “It’s time consuming but it’s very critical because the lash could be all over the place if you don’t check it.”

(Left) The factory rocker arms ride on coated trunions but are non-adjustable, so valve lash is set using shims between Manton pushrods and Jesel tips. In the future the team will switch to new Jesel rocker arms that are adjustable. The top-end assembly includes the factory 2.9-liter supercharger. (Right) Racers can switch to a 3.250-inch supercharger pulley to increase rotor speed, but that also puts a stress on the belt drive. Patterson-Elite upgrades to a billet tensioner from American Racing Solutions and also installs a stronger Gates ribbed belt.

Final assembly includes Cometic MLS head gaskets, MSD coil packs, Gates supercharger belt and American Racing Solutions billet tensioner before calibration work starts on the dyno.

“The old tensioner is cast, and we can lose 20 horsepower on the dyno just because the tension would back off,” says Patterson. “We have to use the Holley ECU. We start low and make quick, short pulls at low rpm to find how much more timing the engine will take. Then we start setting air-fuel targets.”

Patterson-Elite prefers a Coan Racing transmission and 8-inch, 6,500-stall-speed torque converter. The team won’t divulge the new gears but they’re definitely taller than the 2.48:1 low gear that comes in the factory ATI tranny.

Once the suspension and roll cage upgrades are completed, the engine is dropped into place. Note that the engine now sports MSD coil packs.

Moving weight to the rear

As mentioned earlier, a new Coan 3-speed transmission and torque converter are installed to allow for clean neutral shifting at the end of the race as well as gear changes to handle the extra power.

“We’re adding 150 horsepower over what the engine came with, and we’ve got a 9-inch tire restriction,” says Patterson. “There’s no way you’ll hook up with a 2.48:1 low that comes in the factory transmission.”

(Left) The car comes with wheelie bars but some teams have found them to be more of a hindrance than a benefit, so they’re usually set at the highest height to avoid interfering with the run. (Center) Part of the final prep brings in Scott Brown to design and apply the graphics and contingency decals. (Right) Patterson-Elite sends the Bogart Racing Wheels back to the factory for bead locks. The team also installs Mickey Thompson tires.

Patterson-Elite switches from a 4.30:1 rear axle ratio to whatever works best for the given track conditions. Other final prep work includes modifying the Bogart wheels with bead locks, adjusting weight balance and working with the factory wheelie bars.

“You’re lucky if you can get 49 percent of the weight on the rear with the iron block and supercharger up front,” says Patterson. “There’s really a fine line adjusting the struts. On a perfect run the car will pull the front wheels two feet into the air and barely hit the wheelie bars where it doesn’t unload the chassis.”

Following the car’s debut at the Gatornationals (see sidebar), it will run the NMCA Factory Super Car series in Atlanta before trying the Factory Stock Showdown again at Charlotte.

Final prep includes adjusting the suspension and ballast with a goal of 49 percent over the rear wheels.

Article Sources

About the author

Mike Magda

Mike Magda is a veteran automotive writer with credits in publications such as Racecar Engineering, Hot Rod, Engine Technology International, Motor Trend, Automobile, Automotive Testing Technology and Professional Motorsport World.
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