In the rearview mirror: 1980-’81 Turbo Trans Am

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Let’s dial back the clock a quarter century and return to the wee hours of the Reagan Era, when Pontiac made a desperate, last-ditch effort to keep the Trans-Am from becoming completely toothless via the engineering Viagra of turbocharging its flaccid 4.9 liter V-8.

It was spring 1980 – and things were looking dim for the Trans-Am. The last of America’s big-engined muscle cars had finally lost even the big engine. (Big horsepower had been gone since 1974, last year for a true high-performance V-8 in the form of the now-legendary SD-455, hilariously under-rated at 290 hp but in reality producing more than 330 hp. Because 4,000 pound Trans-Ams don’t run low 13 second quarter miles on 290 hp!)

1979 was the last year for both the Pontiac-built 6.6 liter “T/A 6.6” 400 V-8 (producing 220 hp) and the Oldsmobile sourced 403, which also displaced a still-impressive 6.6 liters – even if it only made 185 hp.

Both engines, however, could nor survive the one-two punch of ever-tightening fuel efficiency and emissions control requirements. Pontiac had actually stopped building the 400 in 1978, leaving a relative handful for installation in a few lucky ’79s.

The 403, too, was an engine that had outlived its usefulness.

As the 1980 model year approached, it seemed there would be nothing bigger than 4.9 liters in the TA’s engine compartment – in the form of the new 301 V-8. This engine, though still Pontiac-built, did not share a block or heads or crank or intake manifolds or any other major parts with the previous 400. Or any other Pontiac V-8, for that matter. It was designed to be a lightweight, high-efficiency engine – period.

With the downsized displacement would come downsized power. The little 4.9 liter V-8 that became the TA’s standard engine for 1980 was rated at a truly embarrassing 140 hp at 4,000 RPM. An optional “T/A 4.9” upped that to 155 hp at 4,400. This represented a drop of 30 hp over the ’79 Trans-Am’s weakest engine, the 6.6 liter Olds – and a loss of 65 hp compared with the ’79 TA’s optional 220 hp Pontiac 400.

The famous “chicken” decal on the hood seemed to be screaming in pain as a result of the cruel plucking the TA was being subjected to – not as a sign of the performance that beckoned.

But Pontiac had one last card to play – a way to literally breathe life into the wimpy 301.

Turbocharging.

In the mid-late ’70s, several automakers were turning to the turbo as a way to maintain a semblance of performance – on demand – while delivering decent gas mileage the rest of the time. Buick was fiddling with turbos as a way to goose the output of its 3.8 liter V-6 (and would achieve great success with this as the ’80s progressed). Ford put a turbo four in the Mustang II.

No one, however, had thought to bolt a turbo onto a V-8. Not since the 1960s, anyhow (when Oldsmobile briefly toyed with the idea).

No one, that is, except for Pontiac.

Turbocharging appeared to be the salvation of the 301. A specially reinforced block and other internal improvements laid the foundation. A unique cam was installed – and of course, turbo-specific exhaust plumbing.
Capping it off was an AIR Research turbo that fed compressed air to the engine through a specially calibrated Rochester Quadrajet four-barrel carb.

Net result? 210 hp at 4,000 RPM and even better, 345 lbs.-ft. of torque at 2,000 RPM.

On paper, this looked solid. The 301 turbo’s rated output was only 10 hp off the rated output of the previous year’s 400, despite the loss of 100 cubic inches of displacement (as well as a similar amount of dead weight off the front end of the car; the 301 was a “light casting” that weighed about 100 pounds less than the 400). And the 301 turbo’s rated torque output was actually higher – and came on sooner (345 lbs.-ft. at 2,000 RPM vs. 320 lbs.-ft. at 2,800) than the 400’s.

Actual performance, therefore, ought to be very close, ’79 vs. ’80.

Unfortunately, as we know now, there were some flies in the proverbial soup. For one, the ’79 TA’s L78 400 was (like the ’74 SD-455) almost certainly underrated. The published peak hp of 220 and the ’79 TA’s low 15 second quarter miles times and 130-plus top end don’t line up. The T/A 6.6 400 was likely making closer to 250-270 hp. Meanwhile, the 301 turbo’s 210 hp rating was much more honest, if the 1980 TA’s gimpy 0-60 and quarter mile time slips are any indication. It was considerably slower than the ’79 400 Trans-Am, waddling through the quarter in a so-so 16 seconds. Top speed, at 118 mph or so, was also about 10-15 mph off the pace of the ’79 T/A 6.6 Trans-Am

Strike one.

The turbo TA suffered another handicap, too. It was not offered with a manual transmission – whereas the ’79 400 had only been sold with a 4-speed manual. Reason? Pontiac could not “emissions certify” the 301 with a manual transmission – though mighty efforts were made to get it done. The best it could do was to fit a “performance calibrated” THM350 automatic to the car.

Strike Two.

Another problem with the 301 turbo was that it was carbureted. Carbs and turbos don’t work well together, in part because carbs can’t meter the fuel as precisely and also because the turbo must “blow through” the carburetor – and carbs are by design intended to operate under vacuum, not boost. The final nail in the 301’s coffin was its not-ready-for-prime-time electronic controls.

Like early jet engines, the 301 was still going through its teething phase when it was put into a production car. It had tons of potential, but that was hard to see through the enfeebled performance (even when things were working right).

But had Pontiac been given time to massage the technology, the 301 turbo almost certainly would have matured into one of the most formidable engines of the ’80s. Doubters should look across the aisle to the miracles Buick eventually worked with the 3.8 liter turbocharged V-6. EFI, intercooling and digital controls turned this engine into the most powerful production engine GM made in the mid-late ’80s, when it was installed in Regal Grand Nationals and the 1989 20th anniversary Trans-Am.

These were cars capable of high 12 second quarter mile times and 150 mph top speeds. Indeed, the ’89 20th Anniversary Trans-Am with the turbo Buick V-6 engine was the first Trans-Am in 15 years to beat the performance stats of the ’73-’74 SD-455 Trans-Am.

Pontiac clearly hoped it would get the chance to develop the 301 to its full potential. When the redesigned 1982 Trans-Am appeared, it had an offset “turbo bulge” hood scoop, just like the ’80-’81 Turbo Trans Am. The car’s front subframe was designed to accommodate the Pontiac V-8, too. In the smaller, lighter third generation Trans Am, a 250-300 hp turbocharged 301 would have been absolutely ferocious. Probably, it would have been quicker and faster than the Buick Regal Grand National given the same advances in EFI/intercooling but with two more cylinders and more displacement to bring to bear.

A five-speed equipped mid-1980s Turbo Trans-Am would have been a memorable ride. And with a true Pontiac V-8 under its hood, it would have retained its Pontiac personality – as well as assured its future collectibility.

Unfortunately, GM management decided to kill the development of the Pontiac V-8 altogether. The 301 would be the last-ever Pontiac V-8. Beginning with the ’82 model year, all Firebirds would have the same engines as the Chevy Camaro. V-8s would henceforth be exclusively Chevy-built, so that from ’82-up, there was no meaningful difference under the hood between a Camaro Z28 and a Trans-Am.

It was a “Pontiac” in name only.

Arguably, this helped kill off the Firebird line itself. After all, why bother with the (so-called) Pontiac when the same car was being sold for less money at the Chevy store? Yes, there were exterior and interior differences, but these were superficial. The Pontiac’s still-beating heart had been ripped out of its engine bay – and the transplanted Chevy mill could never provide more than artificial life support.

How different it might have been – the saddest six words in the entire English language.

Throw it in the Woods? 

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37 COMMENTS

  1. I’ve read that a Pontiac engineer was a teacher on the side, tasked his students to come up with a solution for the 400 to 300, 25% reduction in engine size and how to replace the 50 odd horsepower loss. The solution had no R&D development time to even find out the problems, not to mention solve them. Probably only a few months for a two model year lifespan.
    I never could understand the rear located turbo concept at all outside of the cooling effect of the long journey back to the engine which killed response.
    Two things about diesels, they normally only operate in a 2000 revs per minute powerband .5K to 2.5K whereas some gasoline engines can be three times wider. That’s a better match to what turbos boost generating short powerband. Diesel engines must have a much stronger recirculating parts, block and heads read heavier. 30 pounds boost plus lower revolutions in the gasoline engine usually means one word BANG! Too much power(read expansion) for each stroke of the piston, higher revolutions each stroke only has to develop half the horsepower. To my understanding anyway, anybody please feel free to chime in.

    • ******WHOOPS******

      sorry I meant to reply to another statement, and pressed the wrong button. If an administrator could delete this reply and the one above. Thank you

  2. Please take some constructive criticism. The Pontiac 301 turbo was a draw-through turbo system. The article erroneously assumes that it was a blow through system.
    Also, carbs and turbos/superchargers work beautifully together. Look at the ’63 and ’64 Studebaker Avanti R2s, Gale Banks’ kits, engines and whole cars sold from the late 70s into the 80s, and any of the modern blow through cars being built today by countless guys all over the world.
    Blow through systems are an awesome way to make smooth, reliable power, and get good mileage as well. Draw through systems however, are plagued with problems, and have never been an ideal way to make serious, reliable power.
    Most carbs can be set up easily for boost, and these days at the drag strip it’s not unusual to find blow through holleys and Edelbrocks boosting upwards of 30 psi.
    With the right know how (read, proper tuning skills), the cars start idle and drive like modern day EFI cars.

    • Hi Dave,

      Certainly!

      IIRC, one of the issues with the 301 turbo was that the turbo was poorly suited for the application. I believe it was basically the same unit Ford used on its four cylinder turbo of the same era. And of course, the 301 – like all the engines of the era – was hobbled by crude emissions control devices grafted onto it rather than designed in tandem for it.

      The tragedy is these issues would have been sorted out, given development time.

      • It is unfortunate that it turned out the way it did. It could have been so much better!
        Ahh well, at least we learn from past mistakes. 🙂

        • Yup!

          Just look at what Buick did with its 3.8 V-6. Initially, it had teething problems, too. But Buick sorted them out and by the mid-late ’80s, that engine was among the best performance engines available – and not just in an American car.

          • You bet!
            The 3.8 will always be respected. It has earned that reputation time and again in everything from street cars, to full on drag cars knocking down unbelievable ETs! Was ahead of it’s time, really.

          • I loved the 3.8. It was the best car V-6 GM ever had. They never had a great tranny to match up with it though. IMO, the 4.3 V-6 was the among the best truck/van 6’s ever made, if not the best. The combination of power and mileage was hard to beat on both of those engines.

            The 3.8 was replaced by the 3.1, 3.4 and 3.5. All garbage. Ticking time bombs for head gasket issues. I had a few vans with the 3.4’s and a car with the 3.1. I can’t even describe how much I hated those vehicles.

            • Hi Ancap,

              Actually, the GM 2004R (four-speed) automatic is a good tranny, if built properly. It has a number of clap-worthy attributes relative to other GM automatics, including no got-damned computer (just a single 12V line to control the lock-up converter) and no need for an adaptor plate to make it work with non-Chevy engines. It directly bolts up to the Buick/Olds/Pontiac (BOP) bellhousing.

              I have one in my TA and it has held up to the torque of a fairly “built” 455 with no problems for going on ten years.

            • Sorry but I don’t really care much for the 4.3 as it was a 350 wit 2 cylinders loped off. The result was a very unbalanced engine which needed a balance shaft to even things out. These were parasitic in nature and a band aid IMO. The 3.8 however was one of the best ever produced by GM especially in its later years (Series II) when the engine was revised. The shorter connecting rod’s, nearly oversquare bore produced 205hp and 230lb.ft in a very compact and quick revving package. I have read where Pontiac had intended the 1980 and 1981 Turbo Firebirds to be available with a manual 4 speed transmission, but they were unable to clear EPA regs for some unknown reason. This would be a very good project IMO. I have read so many ways in which these cars can be made to perform, but I would love to see what they would do with these mods and a standard shift transmission.

              • Due to the 90 degree crankshafts on both the 4.3, and 3.8 V6s, and the odd number of cylinders per 1 revolution, both engines require balance shafts to smooth them out. The higher rotating mass of the 4.3 makes it the more “shaky” engine, but is still a great stump puller to stick in trucks. Mileage though, not so good.

            • ancap, that’s weird about 3.1’s. There are still countless cars out there with 3.1’s and and not a problem one engine wise. I see them all the time with 300K on the clock and the worst thing about them is the electronics of the cars. 3.8 wasn’t nearly as smooth and I don’t know any that really lasted as long as the 3.1. the 3.4’s definitely had problems but I’m ignorant of 3.5’s. I’ve seen 4.3’s run quite a ways and do some hard duty doing it, esp. when stuck in large pickups that people tended to use just like they were V-8’s. But like the old saw goes, Thanks, I’ll have a V-8.

              Anyone ever had any dealings with the GM 8.1 L? Now they have an 8.8 L gasoline/CNG engine capable of producing 1,000 ft. lbs. or torque. Put that in your Winnie.

              • The 3.1 is the next iteration of the 60 degree 2.8 V6. Externally they are identical. The stroke of the 3.1 being about an 1/8″ longer, which gave it more torque.
                I really like the 3.1! Since it’s a 60 degree engine with a cylinder firing every 120 degrees, no balance shaft is required. They are smooth little compact engines that sound great too! Much different than the 90 degree engines.
                The main problem with the 2.8 through to the 3.4 of the 93-95 Camaro years was crankshaft breakage. In one month we had a customers 2.8, my 3.2 (stroked and bored 2.8), and another customers 3.4 come to the shop all with broken cranks. The reason? The fillet radius on the rod throws, and mains is very small. If these cranks are ground with more radius they won’t propagate cracks in that area, and will live forever.

                • I had no idea the 3800 used a balance shaft, learn something new every day. Anyway the 3800 was on “Wards best engines” list from 95 to 97. Speaking of the 60 degree V6, I had a 81 X11 Citation with the true “HO660” LH7 V6. Little is known about these engines but they used a higher lift cam, bigger va;ve heads, high volume oil pump, higher compression, low restriction intake with a 2 1/2 inch exhaust. In fact, the cam was of such a high lift Chevy had to install a vacume pump to run accessories at low RPM’s. This was a GREAT engine that made great power all the way up to the redline which I think was around 6500rpm. This was all packaged in a 2500lb car with a Saginaw 4 speed….it was a great package that literally would fall apart in front of your eyes……but I digress. My apologies for going off script a bit.

                  • Randy, I looked up the X11 Citation and really liked the car, and the engineer who lead the project. I’ll bet it handles great, even considering the era it came from! A Getrag 5-speed would make it a great all around car.

                • Dave C, I didn’t know the origins of the 3.1 or I’d never have given it a try. But most of my experience with a 2.8 was in an S-10 and the only good thing I can say about those trucks is I’m glad they’re gone. I could never understand how a company that made the longest lasting pickup could make such a POS as the S10. The four’s didn’t work out at all. Hook that four to an automatic and it had its work cut out to attain the PSL. Lots of loyal GM truck owners that were loyal because of the quality of their previous trucks got burned bad. Ford laughed all the way to the bank…..with way more money than a Ranger could haul. You rarely see a mid-size Dodge so they must be just as good as most Dodge’s from that era.

                  • Eightsouthman,
                    I had an ’87 S-10 Blazer that had just about 113k before she slung a a rod right through the block. This was just after the auto trans wouldn’t shift up to third. A 1000 mile trip that day that ended with a night’s sleep in a motel, and a U Haul truck and car carrier the next morning to complete the trip!
                    I’ve had the L99 Fieros, and they take a turbo well, but I eventually installed a 327 small block and went to the next level. Boy that car was FUN!!

    • What is really scary, is how similar our taste in 70’s iron actually run.

      Having owned a 72 GTO, and a Can Am (the Holy Grail of Pontiac’s) the 301T is the last “gotta have one” for me. Although Pontiac had a great idea…they stopped a bit short in order to placate the fed’s I believe. This car was never meant to run with the W72 IMO, but I believe Pontiac was trying match the performance of the 403 Trans Am of 79 with a 301 cube mini V8…….I could be wrong but I bet I’m not. Once you understand the limitations of this motor, simple mod’s can be made that make them really fun to drive. The biggest problem with this engine was the poor gasoline on the market circa 1980. The TT/A was equipped with a “spark knock sensor” which effectively retarded the ignition timing whenever said detonation was detected. It has been published that these cars really come to life with Shell 93 in the tank. This along with some other very simple mods which reduce the operating temp of the car (heat is turbo enemy)and allow it to breath better (remove CatConv)can make this a very respectable street car. While I am not one for cutting up nice original cars such as these, I am all for updating those design flaws which were brought about by aforementioned federal agencies (see EGR).

      Another great job by Pontiac when nobody else really cared IMO.

      OK Eric……time to review a W72 CanAm?

      • Yup!

        And: The story of the 301 turbo is tragic… .

        Pontiac, like Buick, saw turbocharging smaller engines as the best way to maintain (and build) performance while still achieving acceptable fuel economy (a big issue in the late ’70s/early ’80s).

        The 301 turbo was intended to deliver performance comparable to the 1979 W72 220 hp 400 – with less weight on the nose of the car (the 301 being much lighter than the 400) and better fuel economy. On paper, it looked good. 200 hp (and IIRC 345 lbs.-ft. of torque – lower in the RPM range than the ’79 400). But, in practice, it didn’t work out. The turbo was not well-engineered for the application and had to work through a carburetor rather than FI. The exhaust system was a nightmare. Pontiac was unable to EPA-certify the four-speed manual so all the ’80-’81 turbo cars were automatic.

        These cars ran 16 second quarters.

        But… Pontiac intended to develop this engine. Had they been given time to do so, the results could have been spectacular. The Buick 3.8 V-6 started out as a slug, too. But by 1987, it was propelling the Regal GNX to quarter-mile times not seen since the late 1960s/early ’70s. Imagine the 301 with a turbo designed for a V-8 (not the Ford four, as the ’80-’81’s turbocharger was) with port fuel injection and an intercooler. I have no doubt the 301 turbo could have been developed to 300-plus hp by the mid-late 1980s, which would have made it one of the strongest production engines available at the time.

        So, what happened?

        GM pulled the plug on Pontiac’s V-8 engine program. The last Pontiac V-8 was built in 1981. The 301 turbo was slated for the new ’82 Trans-Am (hence the similar-to-’81 off-center hood bulge) but as everyone knows, the ’82-up Trans-Ams got the same Chevy 305s (and later, 350s) as the Camaro.

        The loss of its unique, Pontiac-specific engines is one of the reasons why Pontiac became irrelevant and eventually got the needle.

        It’s too bad, for what might have been!

        One of the cars on my Jay Leno List is an ’80 or ’81 Turbo T/A – pace car or Daytona 500 in white and charcoal. They were gorgeous cars, whose full potential was never realized.

          • Hi Eight,

            IIRC, it was the same AirResearch turbo Ford used on its four of the same era; in the Pontiac boost was 4-6 psi… I think!

            • Thank you, love the article. I have owned a bunch, mostly 1980 Indianapolis pace cars, yes, the white/charcoal spoken of earlier. Sold the last one five years ago. My nickname was Tommy TA, from 81 to 08. I always had a 79 400 bandit Black and Gold and the white indy. The 6.6 worked flawlessly, the Turbo sorry to say basically was a dog, crappy gas in the 80s kept the timing retard working overtime. That tied with nasty fuel mixture horror story brought on by the vacuum created between the Turbo and the carburetor.
              But boy do I love the Turbo Indy. The problem was, when the Turbo came on song, it created massive vacuum after the carburetor, which freezes the air, causing fuel droplets to get cold and to literally fall to the bottom of the pendulum. Pontiac addressed this by running coolant to that pendulum in an attempt at warming the fuel vapor. If you’re following along, you would realize warming that vapor causes more temperature to develop on the compression cycle, causing, yes, detonation, causing, yes, timing retard even with the far superior gasoline available today. My solution would be put a small Turbo on the driver side pushing a very small boost into the carburetor. This would make normal driving great, but causing a massive restrictions on the top end. As you can see I spent decades learning about chemical reactions with regard to compression and vacuum, Turbo vortexes, and all how it relates to heat.
              The Turbo Trans Am came with a “special” larger T-3, compressor and exducer, and it was called the T03. It was designed to produce boost in the midrange to try and make at 301 “feel” like a 400. Technology today realizes that Turbo’s have such a short “powerband” where they produce boost, top end power is a way better match. Superchargers are for low rev power. Turbo’s don’t cost power to make power, superchargers do, so miles per gallon suffers all the time on that route. Sorry for the disjointed few paragraphs, but I’m trying to keep the explanation short and not use too much technobabble. Mustang, four cylinders had so much Turbo lag caused by the large Turbo in relation to the engine (exhaust volume), causing only high rev, boost levels. Whereas the Turbo Trans Am had massive turbo lag because the massive travel the exhaust had to make before entering the Turbo, losing almost all “gas expansion” power and none of the upper rev range boost. Of course, the students of Michigan (actually came up with the Turbo idea) knew nothing of this so-called “gas expansion” power production, and designed the whole system around pumping forces. Turbos make most power when they are located closer to the exhaust valve.
              Feel free to rewrite this in more readable English If you like, I’m too tired right now. Keep up the good work, Tommy TA

              • Thanks, Tommy!

                I’ve always though the ’80-’81 Turbo TAs (especially the Daytona Pace Car and the Recaro Edition) were stunning to look at and – had they 301 turbo been sported out – could have been fantastic cars.

                I’d like to have one – it’d look nice parked next to my ’76 TA!

                • I had one of those for years, I bought the car around October 88, from a guy who had an 89 Indy pace car, 20th anniversary on order. It was beautiful, 33,000 miles, the guy had the car in a garage because it wasn’t running right, kept eating spark plugs, never found out why. I rebuilt Trans Am’s as a hobby on nights and weekends, but “cash money” Cars took priority, and the NASCAR pace car was for me, my personal toy.
                  Every time you want to start it, it required a new set of plugs. Cleaning, sanding, didn’t work. Probably something to do with the massive swing from rich to lean going from washing out to burning out the plugs. That was one nice mint condition Trans Am. Fourth of July 2001, neighbor was setting off fireworks, a rocket misfired came over the fence, 5 feet tall and into the open window, melted a few things before the fire was put out. Could never get it to run again, got MS, and unfortunately a wheelchair replaced all my toys. I had dreams of what that would be like years after, right about now actually.
                  Imagine, being at a car show with three Trans Am’s, 79 bandit, 80 Indy, 81 NASCAR, all with 35k? I bought them when they were cheap, all the work that didn’t cost me anything. But disability took away the storage, and thus my toys. I can’t believe how much they cost now. The 81 NASCAR was the crème de la crème of the good old “obnoxious”, “stand out from the crowd” car the Trans Am was.

                  • Hi Tommy,

                    Very sorry to hear about what happened to the cars – and to you. Sucks. I still have my ’76 – which (like you) I bought when they were still cheap. I paid $5,400 back in the early ’90s for a one-owner car with 54,000 miles; strong “#2” condition, with very nice factory Carousel Red paint, near-perfect factory interior. This car is loaded with options (power windows and locks, AC, the fairly rear electric rear defrost, Honeycomb wheels, 8-track). I will never sell it.

                    • When I bought the NASCAR, a coworker said to me, he had a Trans Am in the garage at his mother’s house would I be interested in it. 10 years in storage. A beautiful low mileage 76 white Trans Am with a tan interior. Purchased it on the spot, a very light compound and came up like new. Fixed everything with new bulbs on all around. I remember I even compounded the gauge plastic ultrafine and came out like new to match the perfect engine tuned dashplate. The car came out mint.
                      I told him to come see the car, telling him how amazed I was at its condition, he did, and he wanted it back because he loved the car. I understood and handed him back the title. We both were happy

                    • Beautiful story, Tommy!

                      Prior to my current ’76, I had another ’76… one of the 50th Anniversary LE cars (without T-tops). But it had the 455/4-speed. It was a “driver” but would have been much more… had it not been for the Clover who blew through a completely red light, T-boned the TA and totaled it.

                      I still have the shaker with the German script “455” callouts…

                    • eric, I was just perusing a 50th anniversary TA and it turns out the non-t-top LE was a $450 option compared to the Hurtst t-tops on the LE that were $1100(gee, 1976 money, quite a chunk of change). A few got made with the gold rear splitter instead of black and they’re really rare. Alas, the gold lettered Goodyears were never made. Now that would have been a sight. The only gold Blackie ever had after I shaved it was a gold Bowtie that looked good in the center of the black grille. That’s one way car companies get you if you want the better looking grill. Either pay over $300 more than the standard grille, then have to prep and paint the new unpainted one or pony up the extra for a GMC. TANSTAAFR. I misspoke. it had a gold 3500 on the side also. I almost pinstriped it in gold too. But it was stealthier just being black……all over.

                      My buddy with the 15th anniversary silver t-top has factory(GM produced)t-tops that were much better but not infallible. When his car was still new and had leaked a bit he asked a knowledgeable person how he could keep them from leaking. Don’t use them the guy said, simple, never take them off. Not really wanting to ruin that nice interior he used some clear GE silicone sealant and put them on permanently or close to it. They didn’t leak and he still has the car.

                • By the way, I know the Daytona pace car, Recaro edition, the one with the black and red interior as the NASCAR edition, as it had a big NASCAR emblem on the rear quarter. The embroidered burden on the door panels and rear seat really stood out. Gaudy, lipstick on a prostitute, or other descriptions of it, but I love it.

              • Tommy, sure looks like anyone trying to work with any gas would immediately become aware of Boyle’s Law and have that affect every thought from that point on. Maybe GM lost their only engineer with any sense of physics after the turbo Corvair. That’s why I’ve always looked askance at those add-on turbo systems that run to the back of the car where the turbo is located.

                Every piece of equipment I operate has the turbo mounted at the collection point of the exhaust manifold.

                I often wonder if auto builders are simply trying to keep things cheap with the amount of boos they run on even fairly exotic applications. Rarely do you see any pressure beyond 8-10 lbs. but as many who comment here can tell you engines for big rigs often run between 25-30 lbs. of boost expecting over a million miles before overhaul. I see all types of equipment with a life of over 100,000 hrs and some times much more, all turbo diesel powered. Those engines normally have the boost come on quickly.

                • I’ve read that a Pontiac engineer was a teacher on the side, tasked his students to come up with a solution for the 400 to 300, 25% reduction in engine size and how to replace the 50 odd horsepower loss. The solution had no R&D development time to even find out the problems, not to mention solve them. Probably only a few months for a two model year lifespan.
                  I never could understand the rear located turbo concept at all outside of the cooling effect of the long journey back to the engine which killed response.
                  Two things about diesels, they normally only operate in a 2000 revs per minute powerband .5K to 2.5K whereas some gasoline engines can be three times wider. That’s a better match to what turbos boost generating short powerband. Diesel engines must have a much stronger recirculating parts, block and heads read heavier. 30 pounds boost plus lower revolutions in the gasoline engine usually means one word BANG! Too much power(read expansion) for each stroke of the piston, higher revolutions each stroke only has to develop half the horsepower. To my understanding anyway, anybody please feel free to chime in.

                  • I think you made my point for me. A diesel, for the most part, has wet steel cylinder liners, and most nowdays have forged cranks and some really high strength connecting rods plus the extremely greater strength alloy pistons.

                    We’re now seeing the same thing in production gasoline engines but only the pricey versions. I recall 25 years ago and his name has slipped my feeble mind but a hotrodder built a turbo ‘Vette to the tune of 1200hp. It wasn’t the first SBC to be built to that power but it was a serious street/race car. He drove it to mid-Ohio on street wheels and tires, replaced them with racing slicks and did a few laps at over 250mph. Changed tires, drove it back 20 some odd miles to the shop, topped off the gas and had an overall 18 mpg.

                    I got my first good education in turbocharging in ’69, not at the college library of a major university, but by ordering a book by Ak Miller. He’d been doing it for 20 years at that point and fairly much had it figured out. After that book I realized his stance on mostly blowing through the carb was the best answer at the time. Of course there’s a downside of using a good enough carb to stand the boost air running through it but that wasn’t that big of a deal once the carb was brought up to quality.

                    As an aside to that, I think the old GM Turbo diesel is a great bugout vehicle. An extra lift pump and you’re fairly much set for anything. And the lift pumps weren’t a problem on the mechanical injection engines.

                    • We’re on the same page, you’re talking about saving money in engine parts, exactly. They want to slap together totally unstressed engines to last a few days past warranty.
                      Were also on the same page when it comes to learning from being a grease monkey to studying manuals at night trying to answer questions that were sitting right in the garage.
                      It seems that Miller was a kind of Turbo hot rod pioneer, my baptism Came with “Maximum Boost” by Corky Bell. Mostly manipulating OEM turbochargers like twin 4 cylinder T-3 on a 5.0 Mustang.
                      How the hell did he make that power on a stock block, that’s crazy. I have a an 81 and a Martin kit, never could get it running right that sent me on a blow, draw through rabbit hole of information;)

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