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The G92 Performance-Optioned 3rd Gen Camaro (Not Your Typical IROC-Z)

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John (Trae) King's rare 1990 G92 optioned Camaro with the 230hp 5.0 LB9 TPI 5-speed and the DX3 Decal & Stripe delete option.

John (Trae) King's rare 1990 G92 optioned Camaro with the 230hp 5.0 LB9 TPI 5-speed and the DX3 Decal & Stripe delete option.

Many believe that 1985-86 ushered in the rebirth of American Performance. With the introduction of GM's 5.0 liter 305ci small block TPI (Tuned Port Injection) and Ford's 5.0 liter 302ci small block EFI, the High-Output Ponycar war was in full force again.

By 1990, and with GM tired of the lighter 5.0 LX having its way with the Camaro and Firebird on the street and track, the G92 option was offered as a full "Performance Package" rather than simply a performance axle option (as prior to 1990) with G92 consisting of multiple performance upgrades and weight-saving options, and the manual 5-speed cars getting a revised and more aggressive camshaft that raised the 5.0-liter engines to 230hp.

GM and their F-body twin Ponycars were finally getting the upper hand on the street and getting revenge for all the 5.0 F-body automatic cruisers that were getting picked on by the infamously quick Fox-Body platformed 5.0 Mustang. The G92 code was GM's Ace up its sleeve! But Ford also had a secret weapon, the low-optioned and stripped down 5.0 LX Coupe (notchback trunk edition models) that could run documented low 14-second quarter-mile times, almost a half a second faster than the heavier and more common 5.0 LX hatch models, and almost a full second faster than the fully optioned and few hundred pounds heavier 5.0 Mustang GT. The only chance GM had against a 3,000 lb 5.0 liter Mustang LX Coupe (notchback) was the "trimmed of all fat" and low-optioned, 3,100 lb ultra-rare 1LE code Camaro. Motorweek tested a 1989 "bare-bones" 1LE optioned Camaro to the tune of a 13.9 1/4 mile time!

The 1LE was a special order Camaro reminiscent of the legendary COPO Camaros of the first Musclecar era. A very limited production Camaro that was GM's answer to the road racing Saleen Mustangs that were dominant on the showroom stock circuit. To order a 1LE performance optioned Camaro or Firebird, one had to know their way around an order sheet. By checking off the right items, you could get the hottest Camaro or Firebird to date. You had to simply order the "G92 performance package" and delete the creature comforts of air conditioning with the "C41 AC Delete option," which gives you the standard heater option. This triggered the "bare bones" version, 1LE Road Racing Performance Package. The 1LE option appears on the order sheet as a $675 "Special Performance Package" and consists of:

  • Twin Piston Z51 Corvette brakes
  • Aluminum Drive-shaft (prop)
  • High-Flow Exhaust (dual Y-pipe w/ dual catalytic converters)
  • Re-calibrated Engine PROM
  • Performance Axle Ratio (5.0 = 3.42 | 5.7 = 3.23)
  • Hardened Axles and Gears
  • Engine Oil Cooler
  • Special Swinging Fuel Baffle (prevents fuel starvation during hard cornering)
  • Special Calibrated Shock Absorbers
  • Fog Light Delete
  • Weight Saving Options

The 1990 model year, with manual 5-speed and equipped G92 and 1LE packages, included the fastest production models of the 1985-90 five-liter (305 cubic inch) version IROC-Z model years, as are the 1991-92 Tuned Port Injected Z28 models (as the IROC-Z ended in 1990 and replaced with Z28 in 1991). Here is more third-generation F-body knowledge and facts for newbies and/or Camaro enthusiasts looking for research, facts, specs, stats, and information on the third-gen Camaro and Firebird.

The 1985, which was the first year of the Tuned Port (TPI) system, actually outperformed the five-liter Mustang GT in Motor Trend's magazine road testing (this wasn't simply based on straight-line performance) and Motor Trend crowned the new Tuned Port Injection (TPI) IROC-Z to be the Ponycar king of the 1985 production year... the other hot performance optioned 3rd gen was the L69 H.O model which could be ordered with the 5-speed. The 5.0 Tuned Port Injection models could not be ordered with the manual tranny until 1987 (due to the high torque ratings of the Tuned Port Injection), which was also the first year for the new Corvette 5.7 TPI (L98/B2L) engines fitted in the F-body twins. But they, too, could not be ordered with manual transmission.

In 1986 GM changed the camshaft design for emissions purposes and lost power in the TPI engine from this cam change. Motor Trend's testing documented the 5.0 Mustang absolutely destroying the 1986 TPI Camaro IROC-Z and Z28 in road testing comparison. GM changed Camshafts the following year due to this lack of performance. The 1986 Tuned Port Injected Camaro was the least powerful of the 85-90 IROC Camaros, and road testing revealed the embarrassing 1/4 mile times for GM's Ponycar twins that particular model year.

1987 was the much-anticipated release of the Corvette L98/B2L 5.7 liter 350ci TPI motor for the Camaro IROC-Z, Formula 350, and GTA Trans Am. Motor Trend testing showed disappointing results for the 225hp 5.7 TPI Camaro with its identical 1/4 mile dragstrip times as the 5.0 EFI Mustang... handling & braking went to the LB9 optioned 5.0 powered manual 5-speed Camaro/Firebird, as usual, thanks to GM's more advanced suspension geometry and braking components over Ford's weaker handling/braking 5.0-liter Mustang. Both the 5.7 TPI Camaro and 5.0 EFI Mustang recorded identical 14.7 quarter-mile times and 140+mph top speeds with the Camaro edging the Mustang out slightly over 100mph due to its aerodynamic design.

1988 the Camaro and F-body cousin Firebird horsepower rating went up, as it did every year after... until 1990 when the TPI maxed out at 245hp for the 5.7 (L98) 350ci automatic and 230hp for the 5.0 (LB9) 305ci 5-speed with G92 and 1LE options (limited 1LE option F-bodies were built to compete with the Saleen Mustangs in showroom stock road racing competition) with documented 1/4 mile times of 14.6 for the 5.0/5spd model and 14.4 for the bigger 5.7/auto model, shows these were the best performing and fastest 3rd generation F-bodies produced to date. (Take note that this is not the TBI [Throttle Body Injection] 170hp Camaro or Firebird, as they were the "economy version" and had around 75hp less than the performance version 245hp TPI [Tuned Port Injection] equipped F-body versions, which was a big contrast in performance between the TPI and TBI models.) There were only four (6) 1LE models produced in 1988, with over 700 units being produced by the last year of the 3rd Gen run in 1992.

1989 and 1990 would prove to be the best performing IROC-Z models of the 3rd generation models. In 1990 the G92 option became a full performance "street" package that shocked many unsuspecting 5.0 Mustang of the time, with 230hp and 245hp, 3.23 gears or 3.42 gears, and similar 3,200 lb weight, the 5.0 Mustang guys were quickly finding out that these G92 optioned performance Camaros were a different breed from the earlier run-of-the-mill cruiser models.

Now, a note for all the newbies and/or young fellas new to the 3rd generation F-bodies, or those who may be thinking about restoring or building up a late 1980s early 1990s 3rd generation Camaro, Firebird Formula, or Trans Am. Just remember that TPI = good and TBI = bad if you are looking for horsepower or want to run with 5.0 Mustangs of the same era. The TBI will not get it done in factory or semi-modded form. You will need at least the LB9 optioned 5.0 TPI with the manual 5-speed or the L98 optioned 5.7 automatic (the 350ci cars were not available with the 5-speed transmission, only the 4-speed automatic). Also remember, factory stock for stock trim, the 1986 was the slowest year of production, and the 1990 IROC-Z and 1991-92 Z28 models were the most powerful 3rd Gen models, although the 1991-92 cars carried a little extra weight. Pound for pound the 1989 and 1990 IROC-Z and Formula were the best performing 3rd Gen models produced (of course that does not include ultra-rare models like the anniversary turbo Trans Am or SLP Firehawk).

The author of this article owns both Camaro and Mustang models from this generation, and I love them equally. But honestly, I believe that the Ford 5.0 liter 302 engine is a better all-around motor versus the GM 5.0 liter 305 engine. In terms of a balance of power, torque, reliability, dependability, acceptance to bolt-on modifications... and even sound. The motors are very close in specs, but the 302 has a larger bore, and many people don't realize that the Ford 302 actually has the same size four-inch (4") bore as GM's ever-popular 5.7-liter 350ci small block, but the Ford 302 has a shorter stroke compared to GM's 305ci small block. Another positive of the 305 is the fact that is almost a perfect square balanced motor, where the bore and stroke are very close to being equal, similar to Ford's durable 4.6-liter (281ci) engine, which produced a little over 300hp (naturally aspirated) in its final production years and 400hp (forced induction) in the legendary "Terminator SVT Cobras." The 305 unfortunately is remembered for all the non-performance economy versions through the years, which is a shame because the 230hp 5.0 liter 305 was a great little motor, and if weren't for GM guy's having the option for a larger displacement 5.7-liter 350 engine to turn to, the little 305 would have had the aftermarket support and loyal following just as Ford's little 302.

The featured white Camaro IROC-Z in this article is owned by the author, I figured I'd put that out there so you can't call foul by way of bias, towards the Mustang. These claims are simply my opinion from the years of experience I've had with these cars. As stated earlier, I have an equal love for both of these domestic Ponycars. Asking me to choose between Camaro and Mustang is like asking me which one of my kids I love more! Certainly, there is something good as well as something bad with both models. If I had to vote, judge, or award these cars from this era, I'd have to give straight line "Dragstrip" power, torque, and performance to the Mustang, and the "Corner Carving - Road Racing" abilities of handling and braking advantage to the Camaro/Firebird.

So there you have it, some random American Musclecar opinions from John @ nedaCFilms / Mustang-Town and And you know what people say about opinions—they are like !%$?&!

Thank you for taking the time to read my article. I hope you found some information to be useful. Feel free to ask any questions you may have by commenting below. Now, go buy American!

Car Craft magazine Dec. 2006

Car Craft magazine Dec. 2006

1990 G92 code IROC-Z Camaro

1990 G92 code IROC-Z Camaro

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.