1981 Pontiac Trans Am 5.0 Liter – Glimpse into the Future

1981transam50-s2.jpgAt the beginning of the 1981 model year, the Trans Am was entering into its thirteen year of production and its twelfth year on GM’s second generation F-body platform. The Trans Am had been successfully updated every few years during the second generation’s twelve years and even though the basics were still the same since 1970, it looked a lot different by 1981 due to the modern front-end and rear-end styling which had been introduced for the 1979 model year. However by 1981 the Trans Am was really showing its age, most cars underwent massive shrinkage during the 1970s however the Trans Am was left untouched. By 1981 it was a heavy full-size 2+2 sport coupe with a curb weight of around 3,500 lbs which was way out of touch with the 1980s which demanded smaller, lighter, and more efficient cars. GM was well aware of this, even though they had dragged their feet with releasing a third generation Trans Am. And who could blame them with the Trans Am hitting a historic peak of 116,535 units produced for the 1979 model year (as a comparison 1969 had seen the production of only 697 units), there wasn’t much of an incentive to change a good thing. For 1981, Trans Am production dipped to 33,313 units – a big sign an all-new Trans Am was needed. 1982 would see the release of a new third generation Trans Am that was smaller, lighter, and utilized much improved aerodynamics. Sales would climb again.

By 1981, the Trans Am was a declawed tiger. The car looked like it could go 200 mph standing still, but a choice of a 150 horsepower 4-bbl 4.9 liter (301 CID) V8 or a 200 horsepower 4-bbl turbo 4.9 liter (301 CID) V8 just wasn’t enough to match the powerful large displacement motors offered on previous Trans Ams. 1979 was the last year for the large displacement V8 under the Trans Am’s hood, the "6.6 T/A" (400 CID V8) W72 package which gave the Trans Am a 1/4 mile time on the average in the low-15 second range. Unfortunately the 200 horsepower turbo 4.9 liter V8 powered 1981 Trans Am took on the average 1.5 seconds more to run down the 1/4 mile. The turbo 1981 Trans Am was just too heavy and didn’t have enough power to provide the punch past Trans Am buyers had become accustomed to. Of course the Trans Am’s competition was in the same boat, and provided even less horsepower. For instance the 1981 Mustang’s hottest motor was a 120 horsepower 2-bbl 4.2 liter V8. For 1979-1980, the Trans Am was available with the 4-bbl 4.9 liter V8 and 4-speed manual transmission combination, so there was some semblance of performance for 1981transam50-1.jpgthe Trans Am buyers who wanting to manual change gears. For 1981, the Pontiac 4-bbl 4.9 liter V8 unfortunately could not be equipped with a manual transmission and the turbo 4.9 liter V8 also entered its second year of production with the mandatory 3-speed automatic transmission again. However there was light at the end of the tunnel for those wanting a manual transmission. Pontiac offered an engine delete option on the 1981 Trans Am which consisted of Chevrolet’s small-block LG4 5.0 liter (305 CID) V8 with a mandatory 4-speed manual transmission and standard 3.08 rear gears. It wasn’t the first time another GM division’s V8 was found under the hood of the Trans Am. When Pontiac was forced to end production of the 6.6 liter (400 CID) V8 in 1978, Pontiac saved a little more than 8,000 of these 400 CID V8 engine blocks for the 1979 Trans Am and Firebird Formula. Pontiac used Oldsmobile’s small-block 6.6 liter (403 CID) V8 as the standard motor for the 1979 Trans Am – the 403 V8 was first used on all California sold 1977-1978 Trans Ams (in order to meet California’s CARB emissions standards). With GM ceasing 403 V8 production at the end of the 1979 model year in order to meet the EPA’s Corporate Average Fuel Economy (CAFE) standards, Pontiac then switched to Chevrolet’s LG4 4-bbl 5.0 liter V8 as the 1980 Trans Am’s new standard motor in the California market only. So Pontiac offering the LG4 V8 as an engine delete option for those wanting a manual transmission equipped 1981 Trans Am, made perfect sense.



Buyers didn’t know it at the time, the LG4 V8 was the way of the future for the Trans Am. GM made the decision to pull the plug on the Pontiac 4.9 liter V8 at the end of the 1981 model year, which didn’t fit into the new GM corporate engines policy. Under the new policy Pontiac was tasked with producing only the 2.5 liter Iron Duke 4-cylinder motor 1981transam50-4.jpgfor GM vehicles – only Chevrolet, Oldsmobile, and Cadillac were given the green light to produce V8s starting in 1982. With no Pontiac V8 on the Trans Am option list starting in 1982 with the release of the all-new third generation Trans Am, the LG4 became the Trans Am’s base motor from 1982-1987. The LG4 may have been a delete option on the 1981 Trans Am, however it sold in much higher numbers than you would expect, 6,858 were sold which was about 20% of 1981 Trans Am production. It showed there were still buyers out there who wanted a manual transmission equipped Trans Am. The good was the LG4 was a light V8 – a few hundred pounds lighter than Pontiac’s old 400 V8. The bad was this motor only produced 150 horsepower which in a 3,500 lb Trans Am caused the small displacement V8 to be pretty heavy taxed. The ugly was there was only 240 lb-ft of torque which looked mighty paltry when compared to the 340 lb-ft of torque of the 1981 Trans Am’s optional turbo 4.9 liter V8. Still this was 1981 which was the bottom of the barrel for American performance cars, and 150 horsepower wasn’t so bad when compared to the competition. In fact with the standard 3.08 rear and 4-speed manual transmission, acceleration was actually spirited. The 5.0 liter 3.08 rear was open by default, RPO code G80 had to be ordered to convert the rear axle to limited slip. A 3.42 open rear was optional with the 5.0 liter which could also be had with a limited slip setup if the G80 option was checked off on the order sheet. Also ordering the WS6 or WS7 suspension package with the 5.0 liter V8 converted the 3.08 and 3.42 rear axles to limited slip.



The engine made all the right tones which included the familiar wail of a Rochester (4-bbl) Quadrajet – only the speedometer needle took a little longer to move along its circular path during wide open throttle than the larger displacement V8 powered Trans Ams from yesteryear. 1981transam50-8.jpgUnfortunately even with a very skilled driver, low-17 second 1/4 mile times were about the best you could expect to obtain with the LG4 equipped 1981 Trans Am. However there was one hidden advantage to the LG4 Trans Am, which the standard 4.9 liter and turbo 4.9 liter V8s didn’t have, and that was a plethora of aftermarket performance parts. The Pontiac 4.9 liter V8 which was first introduced in 1977 as an economy V8 had no aftermarket performance parts to speak of. It didn’t share any common parts with the standard 1955-1979 Pontiac V8 family which used the same engine block design that utilized different displacements from 287 to 455 CID. So with 4.9 liter V8 production only being from 1977 to 1981, there weren’t enough units produced for companies to be interested in developing and offering aftermarket performance parts for this  motor. Most Pontiac performance fans pulled the 4.9 liter and replaced it with a Pontiac 400 or 455 V8, which yielded large doses of horsepower and torque. The downside with this engine transplant was weight was added above the front wheels hurting handling. The 5.0 liter V8 on the other hand could be cheaply and easily modified to produce over 200 horsepower, since it shared many parts with Chevrolet’s other small-block V8s. An aftermarket performance cam, performance intake manifold, set of performance heads, and a rejet of the stock 4-bbl carb; would easily wipe away a minimum of 2 seconds off the quarter mile. Throw in a performance exhaust, exhaust headers, and aftermarket ignition timing and you would easily have the 5.0 liter Trans Am yielding impressive traditional muscle car era performance times. For the unbelievers, Popular Hot Rodding magazine took a run of the mill Chevrolet 305 V8 and built it up with some performance parts for street use and yielded an impressive 372 horsepower at 6,000 rpm. A 305 build up like this in the 1981 Trans Am would easily hold its own against the most powerful Trans Ams from yesteryear including the 1973-1974 Trans Am equipped with the Super Duty 455 CID V8.



All 5.0 liter equipped 1981 Trans Ams had a "5.0 LITRE" decal on each side of the shaker hood scoop. Worth noting, Pontiac used the "LITRE" designation on its Trans Am decals and some related product 1981transam50-6.jpgliterature at the time which was the international spelling versus the American spelling of "liter". Very oddly Pontiac had decided that the 5.0 liter equipped Trans Am would use the Camaro Z28’s exhaust setup which consisted of a dual outlet exhaust setup with one pipe on opposing sides under the rear bumper. The 5.0 liter (for California market use) 1980 Trans Am also had this same exhaust setup. This was a real blow to Trans Am fans who liked the traditional quad chrome splitter exhaust system which had two chrome outlet pipes under each rear quarter panel. This setup was found on every other 1975-1981 Trans Am – even the Oldsmobile 403 V8 powered 1979 Trans Am used this setup. The 5.0 liter Trans Am’s use of the Camaro Z28 exhaust system was probably a cost savings measure since the setup was already used on 1981 Camaro Z28 which used the LG4 as its only manual transmission equipped engine for that year. Pontiac probably figured the added cost of engineering the Z28’s exhaust system that was unique to the 5.0 liter V8 (and the Z28’s small-block 5.7 liter V8) with the Trans Am’s twin chrome splitters wasn’t worth the cost.

The LG4 5.0 liter V8 option was available with any Trans Am color and even the black and gold SE (Y84) Trans Am. The only exception was the Nascar Pace Car edition Trans Am which was standard with the turbo 4.9 liter. A buyer could 1981transam50-7.jpgload the 5.0 liter Trans Am with as many options including T-tops, power windows, power door locks, etc. The 1981 Trans Am kept the captivating engine turned aluminum decor around all the dashboard gauges. There were still the base vinyl seats and optional were attractive custom vinyl bucket seats which hadn’t changed since the 1978 model year. And for 1981 there was a new optional Millport cloth interior which used the same seat pattern design as the base vinyl seats. Also new for 1981 were upscale Pimlico custom cloth seats which used the same seat design and pattern as the custom vinyl seats. With the Pimlico custom cloth seats the Trans Am took on a sporty luxurious persona. There was no denying the fact that the dashboard design and other interior themes which dated back to 1970 (even with minor updates over the years) were a little long in the tooth by 1981. However comparing the Trans Am to its other rivals in 1981 including the Mustang, the Trans Am interior still was desirable and modern enough to keep most buyers happy.

The exterior of the 1981 Trans Am was a carbon copy of the 1979 Trans Am (the last Trans Am to receive an exterior update) which had an aerodynamic front clip and a rear design that consisted of one big 1981transam50-5.jpgblacked-out tail light bar which only turned red when the brake pedal was applied. The only real change from this overall design was the addition for 1981 of a bird insignia in the center of the big tail light bar. This area where the insignia resided, had a door that opened to allow access to the gas tank cap.   

Even though the 1981 Trans Am was big by 1980s standards it was a great handling car that was very light on its feet. The base Trans Am suspension handled the curves well. With the 5.0 liter equipped 1981 Trans Am all the different style of Trans Am wheels were available: 15 x 7 inch Rally II steel wheels, 15 x 7 inch Snowflake aluminum wheels, 15 x 8 inch Snowflake aluminum wheels, and 15 x 7.5 inch Turbo Cast aluminum wheels. This was a big change, since the previous year the 15 x 8 inch Snowflake and 15 x 8 inch Turbo Cast aluminum wheels were only available when the WS6 suspension package was ordered. For 1981, the WS6 suspension package could only be had with the 15 x 8 inch Snowflake or the 15 x 7.5 inch Turbo Cast wheels. The following items also came standard with the WS6 package: 4-wheel disc brakes, limited slip differential, thicker anti-roll bars, stiffer shocks, and a tighter ratio steering box. The end result was a WS6 equipped 1981 Trans Am easily obtained .81 g on the skidpad which made it the best handling American car for 1981. The WS6 was so much better than the standard suspension it was worth the $372.00 to $580.00 extra versus 1981transam50-2.jpgthe standard suspension. And for those who didn’t want to pony up the extra money for the WS6 but wanted to have 4-wheel disc brakes with the standard Trans Am suspension, Pontiac offered the J65 option which added only $167.00 to the Trans Am price tag. Worth noting, Pontiac also offered a WS7 handling package which included all the items the WS6 offered except for 4-wheel disc brakes (the WS7 used rear drum brakes).    

With the 5.0 liter V8, Pontiac was able to give its 1981 Trans Am customers a list of good performance goodies and a mandatory manual transmission. It may not seem like a big deal now, but back in 1981 it was quite the berries. And because the 5.0 liter V8 was a delete option, Trans Am buyers were given a $140.00 discount on the window sticker – it was a win-win situation for Trans Am buyers since they paid less and got more. The 5.0 liter 1981 Trans Am also had the added benefit of warming up Trans Am buyers to future Trans Ams that would be standard with the 5.0 liter V8. The 5.0 liter 1981 Trans Am was a glimpse into the future, the second generation body style would be permanently put out to pasture at the end of the 1981 model year, but the Chevrolet produced 5.0 liter V8 would remain the new primary motor for the third generation 1982-1992 Trans Am. There would be jokes and barbs about the 5.0 liter V8, from Pontiac purists during this transition period. Yet most Pontiac fans eventually warmed up to the idea of a Chevrolet small-block V8 being the Trans Ams sole power source. And with the 5.0 liter 1981 Trans Am, this is where it all started (the 5.0 liter 1980 Trans Am was a last minute "California market" substitute). Unfortunately being first has its disadvantages, the biggest of which is the 5.0 liter 1981 Trans Am has been forgotten by most Trans Am fans and car collectors which is a darn shame – even today it’s a special breed with a high potential for collectibility once it shows up on car collectors’ radar. Until then it will remain a forgotten Trans Am.  

Written contents in this article – © 2012 Pete Dunton – All Rights Reserved