In this edition of Muscle Car Milestones, we’ll turn back the clock and look at the 1985-1990 Chevrolet Camaro IROC-Z. The Camaro IROC-Z got its moniker from the International Race of Champions racing circuit. In IROC races, all cars are identically equipped and the outcome of the race is determined solely by the individual driver’s skill. The street version was a driver’s car as well, with plenty of engine choices to please almost any motorist. Let’s see what makes the IROC-Z a timeless classic.

1985: I Wanna Rock!

The IROC-Z was a $696 option package for the Z28. It included an upgraded suspension, 16 x 8-inch, 5-spoke wheels, and Goodyear Eagle GT tires. The package also included louvered hood inserts, ground effects, and IROC-Z graphics.

The IROC-Z was available with three engine choices. The base engine was the LG4 5.0-liter V8 with 155 horsepower and 245 lb.-ft- of torque. It was available with either a five-speed manual or four-speed automatic transmission. Next up was the carbureted L69 305-cubic inch V8 with 190 horsepower and 240 lb.-ft. of torque. The only available gearbox for this engine was a five-speed manual transmission. There was also a 305 cubic-inch Tuned Port Injection LB9 available with 215 horsepower and 240 lb.-ft. of torque. This powerplant was only available with a four-speed automatic transmission.

Hot Rod magazine put the IROC-Z with the LB9 TPI to the test for their February 1985 issue. The IROC-Z sprinted from 0 to 60 in 7.0 seconds and ran the quarter mile in 15.0 seconds at 92 mph. Hot Rod proclaimed “The IROC Camaro is a street fighter with all the right moves: it’s handsome, powerful, and agile with a gentleman’s finesse.” The magazine also declared the IROC-Z was one of the best Camaros ever built. Oh, in case you’re wondering, the IROC-Z was .08 seconds faster than the Mustang from 0 to 60 and .51 seconds faster in the quarter mile. It seems the Mustang’s dominance over the Camaro had come to an end. At least for now, that was the case.

1986: Second Time Around

The IROC-Z returned for 1986 with few changes. The most notable change to the IROC-Z was the detuning of the 5.0-liter Tuned Port Injection engine. Due to a camshaft change and emissions regulations, the TPI engine lost a whopping 25 horsepower. It did, however, gain 10 lb.-ft. of torque. Sadly, performance suffered due to the drastic drop in horsepower in the TPI engine. As a result, the automotive press was pretty unforgiving in their reviews. After Hot Rod raved about the 1985 IROC-Z being one of the best Camaros ever built, their opinion of the 1986 IROC-Z was a complete 360. The magazine stated “The bottom line is that the Camaro just lacks excitement for ’86. It still handles like a true race car, but that’s as far as it goes.” And much to the chagrin of the automotive enthusiast, the TPI was still only available with a four-speed automatic transmission. Needless to say, with the Mustang GT’s 0 to 60 time of 6.0 seconds versus the Camaro’s time of 7.3 seconds (with the L69 engine), it seems the Camaro brought a knife to a gunfight.

If there was a bright spot for 1986, at least Chevy ditched the 85-mph speedometer late in the model year in favor of a 145-mph speedo. Sales were also brisk with just over 49,000 IROC-Zs sold this year. 1986 may have been a low point for the IROC-Z, but positive changes were on the horizon.

1987: Back in the Saddle

For all the shortcomings the IROC-Z car suffered during the 1986 model year, 1987 was shaping up to be a good year. For starters, a five-speed manual transmission was now available for the LB9 5.0-liter TPI engine. This combination was good for 215 horsepower and 285 lb.-ft. of torque.

The big news for 1987 was the availability of the L98 5.7-liter TPI from the Corvette. This engine featured cast-iron cylinder heads (instead of the Corvette’s aluminum heads), cold air induction, and an aluminum intake manifold. A four-speed automatic was the only transmission available for this powerplant. It was rated at 225 horsepower and 330 lb.-ft. of torque. Muscle Car Review got down and dirty with the ’87 IROC-Z for their May 1987 issue and walked away with a 0 to 60 time of 7.09 seconds and a quarter mile time of 14.88 seconds at 92.87 mph. They commended the IROC-Z for its cornering and braking abilities. According to Paul Zazarine, acclaimed author of the article, “Every American male over the age of 35 should have the opportunity to drive the 350 IROC for at least a day. One turn behind the wheel is better than the fountain of youth, because every time we strapped on the IROC we became 18 years old again, shed 75 pounds and regained all our hair. And that’s worth the price of admission right there.”

For the first time since 1969, a convertible was part of the Camaro lineup. American Specialty Cars took cars equipped with t-tops and transformed them into droptops. A leather interior and Bose stereo were also offered for the first time on the third generation Camaro for 1987.

1988: The IROC-Z Stands Alone

A few changes were made to the IROC-Z for 1988. Chevrolet dropped the Z28 and made the IROC-Z the top performance trim for 1988. However, someone at the assembly plant must not have gotten the memo since interior badging still read Z28 IROC-Z. Also, the IROC-Z door decal moved from the front of the door to the back of the door. 16-inch wheels, which were standard equipment in 1987, were now optional.

The standard engine was now the LO3 5.0-liter EFI rated at a paltry 170 horsepower. Power for the other available engines was up slightly. The LB9 5.0-liter TPI was now rated at 220 horsepower with a manual transmission and the 5.7-liter, now dubbed the B2L, gained five horsepower over last year.

Road and Track tested the IROC-Z equipped with the 5.0-liter LB9 and manual transmission and garnered a 0 to 60 time of 6.9 seconds and a quarter mile time of 15.4 seconds at 91.5 mph.

Chevrolet started churning out the first batch of IROC-Zs equipped with the 1LE performance package this year. It wasn’t listed on any order sheet and was available only to racing teams. This package significantly beefed up the performance of the IROC-Z with performance equipment such as heavy-duty disc brakes, an aluminum drive shaft, and baffled gas tank. It was available with either the 5.0-liter V8 or the 5.7-liter V8.

1989: More of the Same

The IROC-Z carried over into 1989 with no significant changes. The IROC-Z did receive GM’s PASS-Key theft deterrent system and three-point rear seat/shoulder safety belts as standard equipment.

The 1LE option was still available this year. It still wasn’t listed in any brochure or marketing materials, but those in the know knew that by ordering the IROC-Z with the G92 Performance Rear Axle Package, you got the larger front brake rotors, aluminum brake calipers, and special springs and struts. Only 111 takers stepped up and ordered this ultra-secret package.

1990: End of the Road

1990 proved to be a low production year since a six-month production cycle produced roughly 35,000 Camaros. In fact, production of all 1990 Camaros was completed by the end of 1989. Since Chevrolet decided not to renew its contract with the International Race of Champions series, it had to produce all IROC-Zs before the contract expired on January 1, 1990. It was truly the end of an era for one of the most exciting third generation Camaros created.

Trims like the RS, SS, and Z28 span many generations of the Chevrolet Camaro. The IROC-Z is one of the few that was solely produced during a single generation. The 1985 – 1990 Camaro IROC-Z is also one that will always have a special place in the hearts of those that grew up in the 1980s. It was the Camaro that took us on first dates, graduations, and many road trips we’ll never forget.