We retrace five decades of Chevy’s most fearsome pony car
Australians may have waited half a century for an official ‘pony car’ Ford Mustang versus Chevrolet Camaro showroom war, but the Blue Oval and The General are making up for lost time in 2019.
While the earlier-arriving, recently-refreshed global Ford Mustang has dominated in dealerships so far, the team at HSV has now brought out the big guns with the $159,990 Chevrolet Camaro ZL1.
When we recently sampled HSV’s new-generation performance flagship, we concluded that it seems right at home in Australia. But just what does ZL1 mean?
50 years young
The inspiration for ZL1 started with a hyphen, the 1969 model year Camaro ZL-1 signifying something so special (and commercially unviable) that Chevrolet put the suffix on ice until 2012.
Chevrolet’s famed Central Office Production Order (COPO) system was designed for dealers to request specific changes to regular production – think specific-duty vehicle or parts requests.
Famously, innovative dealers such as Don Yenko and Nickey Chevrolet realised that Chevrolet’s Performance Division could technically approve special-build performance cars via the COPO system.
This process effectively bypassed the General Motors mandate that no ‘intermediate-size or lower’ passenger cars could have engines greater than 400ci (6.6-litre), Corvette excepted.
Dealers would simply order a 396ci (6.5-litre) Camaro, as well as a Corvette-derived 427ci (7.0-litre) iron-block engine, which would then be installed at the dealership.
This occurred from the start of Camaro production in 1966, for the ’67 model year. By the 1969 model year, Yenko had converted enough Camaros to convince Vince Piggins at Chevy Performance to install the 427ci monsters at the factory.
Another dealer, the Illinois-based Fred Gibb of Gibb Chevrolet, had used COPOs to build 1968 Novas with factory-fitted 396ci big-blocks, but had his sights set on something even grander than Yenko’s scheme.
At the time, back-channel factory-supported drag racing was the hot way to sell your muscle car to the newly-flush American youth. Gibb proposed a NHRA drag-spec Camaro that would use the ultimate Chevrolet engine: the all-aluminium 427 ZL-1 that was intended for Can-Am prototype racing.
Chevrolet accepted the ZL-1 Camaro (COPO #9560) proposal, on one condition: that Gibb Chevrolet would order 50 examples.
The guts of it
The donor Camaros were an interesting mix in themselves, starting life as big-block cars with the 375hp (280kW) version of the 396ci engine.
Added to the specification was ‘F41’, a V8-specific suspension option with heavy-duty springs and shock absorbers; ‘ZL2’ cowl induction hood; ‘G80’ 12-bolt locking rear differential with 4.1 ratio and mandatory front disc brakes.
Interestingly the popular ‘Super Sport’ trim package was deleted, reducing weight but lending the ZL-1 a ‘sleeper’ look.
The ZL-1 engine was based on the hardcore ‘L88’ specification 427 that was available in the Corvette, featuring aluminium heads but the usual heavy iron block.
For the aluminium block and head ZL-1, Chevy Performance stuffed a forged steel crankshaft in its belly, held by four-bolt main bearing caps.
The pushrods, connecting rods and camshaft were also forged to withstand a 12.0:1 compression ratio, and the whole lot was topped off by an aluminium intake and single 780cfm four-barrel Holley carburettor.
The ZL-1 was rated at the same 430hp (320kW) figure as the L88 Corvette, with 450lb-ft (610Nm) of torque, and was capable of running in the low-13s over the quarter mile, in bog-standard, narrow-wheel trim.
Tuned drag racers would hit the 10s with slicks. With its aluminium block and heads, the ZL-1 engine was around 100 pounds lighter than the all-iron 396 found in the top-spec ‘regular’ Camaro of the time.
Put another way, it was similar in mass to the 327ci (5.4-litre) iron small-block seen in regular production Camaros.
Obviously exotic, the program’s cost quickly blew out. Gibb, who had planned on the finished cars retailing for a tad under $5000, had to list them at over $7000 as development costs were passed on. Of the 50-unit allocation, he would sell only 13, with the first two arriving at the dealership on New Year’s Eve, 1968.
Thankfully, Chevrolet agreed to reacquire and redistribute the remaining stock. In total, 69 examples of the 1969 model year Camaro ZL-1 were produced: 47 with the heavy-duty four-speed manual, and 22 with a three-speed automatic.
Today, finding a genuine car is a bit of a minefield, thanks to the ZL-1’s legendary status and propensity for clones. Find an original Camaro ZL-1 with its ‘as-born’ engine today, and you won’t see change from one million American dollars.
Sleeping giant
After that single model year – the last of the first generation Camaro – the ZL-1 nameplate was shelved as an available option.
The timing appears right in hindsight, for the next decade’s fuel crisis and corresponding focus on improving fuel efficiency meant the muscle cars that survived at all were severely compromised from a power perspective.
Chevrolet did apparently use ‘ZL1’ in the 1970s, but only badged on a couple of design concepts. When ZL1 really woke up again was in 1994. It even dropped the hyphen.
Think back to the time: American muscle had nearly grown extinct through the late 1970s into the early 1980s, but as the engineers developed cleaner fuel systems and stronger understanding of electronic engine management, the horsepower wars slowly started heating up again into the 1990s.
As a precursor to the modern GM muscle car era – and the reignition of the pony car war against Ford’s Mustang – the fourth-generation 1994 Camaro ZL1 prototype was a spectacular opening salvo.
Powered by an all-aluminium 572ci (that’s 9.4 litres!) V8, the reborn ZL1 came from Chevrolet’s experimental ‘Specialty Vehicles Group’, under Jon Moss’s direction.
This 575kW/925Nm monster was showcased around drag strips all over America, and could run 11-second quarter-miles all day.
Back to basics
Come 2008, Chevrolet decided to celebrate the original ZL-1 by building the ‘Anniversary 427 Big Block’, an engine made available via its GM Performance Parts business.
These engines deployed the original ZL-1’s tooling, but were fitted with a modern hydraulic camshaft for ease of maintenance, as well as a more octane-friendly 10:1 compression ratio. Despite this less extreme specification, the 430hp output was quoted.
They came with a certificate of authenticity and engine bay tag, and today are worth around $25,000; small beans compared to what an original engine would command.
A triumphant return
Come 2012, the modern horsepower war was in full swing. It was enough to convince Chevy to green-light a fully-fledged, modernised ZL1 production return.
The fifth-generation Camaro was available as a ZL1 model off the showroom floor, housing a supercharged 6.2-litre ‘LSA’ V8 that was similar to the VF HSV GTS engine released later.
It featured a two-stage exhaust and produced 550hp (410kW) along with 550lb-ft (745Nm) – big, emission-friendly numbers that the 1969 cars could only have dreamed of.
It was backed by a six-speed Tremec manual transmission with stronger output shaft and housing so it could handle the torque, and ‘no lift shift’ and launch control were also included.
Stopping the ZL1 were six-piston Brembo front brake callipers with four-piston rears, and Magnetic Ride Control adaptive damping was employed. Interestingly, it was the only Camaro to use electrically-assisted power steering at the time.
Unlike the original, this ZL1 was trimmed as you’d expect for its place at the top of the Camaro tree. Suede was used for seats, steering wheel and shifter, as well as exclusive 20-inch forged aluminium wheels that apparently shaved 22 pounds of unsprung weight.
These were fitted with specific Goodyear Eagle F1 Supercar tyres, measuring 285/35/ZR20 on the front axle and 305/35/ZR20 on the rear.
At the time Chevrolet said one third of the parts on the ZL1 were upgraded or replaced over the Camaro SS, the car being capable of racetrack performance off the showroom floor with no additional modifications to cooling systems required.
Performance impressed, with a 12.3-second quarter-mile time and a top speed approaching 300km/h.
Up to date
Most familiar to Australians is the current-generation Camaro. It’s the first Camaro officially sold in Australia new, and keeps the HSV V8 dream alive.
The latest ZL1 range-topper was introduced to its homeland in 2017. At launch it packed a 650hp punch (485kW) from the latest ‘LT4’ 6.2-litre supercharged V8. Essentially this was a wet-sump version of the contemporary Corvette Z06 engine and generated some 880Nm of torque.
Mated to this awe-inspiring engine was a newly-developed 10-speed automatic transmission to go alongside the familiar six-speed manual, while Goodyear specifically developed a set of ‘F1 Supercar 3’ rubber – apparently trying out seven compound/construction combinations before settling on the final spec.
On the other side of the equation, the latest GM Alpha platform features several weight-saving advancements, so the 2017 Camaro ZL1 comes in nearly 100kg lighter than its predecessor, which was based on the same Australian designed Zeta platform as the VE-VF Holden Commodore.
Further developed adaptive damping can take 1000 road readings per second and an electronically-controlled limited-slip differential, augmented with five-stage traction control, ensures active traction management across the rear axle.
Variable-ratio electric power steering also debuted and all this fettling resulted in a Nurburgring lap time of 7:29.60 — a dozen-second improvement over its predecessor — as well as an 11.5-second quarter-mile; 0.8sec faster than before.
Today
Australian GM fans rejoice: the ZL1 is available right now, from $159,990 plus on-roads, in fully homologated, warrantied, factory-supported right-hand drive form.
Thanks largely to our low-quality fuel, the Australian-spec ZL1 has ‘only’ 477kW but matches the American with 881Nm. As such, it’s the most powerful GM product ever to be offered in Australia.
A half-century may separate the original and latest, but the truth remains: if you want a top-of-the-pile Camaro, you can’t do any better than ZL1. Over to you, Ford.
Keyword: Fifty fabulous years of the Chevrolet Camaro ZL1