Pontiac Firebird Trans Am 455 Super Duty specs

Please delete the top speed of 170mph

The point here is this was one of the fastest cars u could buy in 74 so pay it some respect and yes the mopar hemi’s were cool but u couldn’t get one n 74 and who wants to drive around with a 4ft wing on there car I don’t care how fast they are ugly and that’s the only way mopars could out run ford in nascar #429boss

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Utilizes it's power better than an early nineties 911 turbo...not. 0-100 in 6.5 and 155 which was beast back in those dark days.

For all other Muscle cars, it can reach higher max if only using long ratio gearbox but it's only give not too much boost of speed depend on power rating.

@ Bijan : Charger Daytona can run faster because it has better aero and more power. in this link: http://en.wikipedia.org/wiki/Chrysler_Hemi_engine
It has 433.5 Hp and 472 ft-lbs in purely stock form. I think, it might be refer to 1968-1970 model since i heard it's not too underrated (still using some racing part. The 1964-1966 had more crazier performance since it's not underrated. 1971 model had 350 Hp net.).

@ Viking: Try to read this at 1973-1974 model http://en.wikipedia.org/wiki/Pontiac_Firebird
There's no link to that magazine but since it posted in wikipedia, i think it's a little accurate but not too accurate.

Some of those top speed data are come from the manufacture. But some of it come from people who claim ever test it. The only top speed that i'm pretty sure it's true is 1969 Dodge Charger Daytona R/T Supercharged. First, the driver who test that car in Chrysler Proving Ground Buddy Baker and Charlie Glotzbach claim it can reach 200 mph with only using small 4 barrel.
http://en.wikipedia.org/wiki/Dodge_Charger_(B-body)
Second, it using Supercharged to give about 575 Hp output. I think it's enough to reach 190+ mph with that if using 3.23 final.
Third, good aero but not that good. Most people though that was performance for standard Daytona R/T.

Actually 1994-2004 Mustang GT models had roughly a 0,34 Cd, but 1979-1993 had roughly 0,40. The retro 2005-2009 had 0,38. When the 2010 came out it had 0,36 and 315 hp so Ford added a governor to keep it down to 151 mph. I think the governor was lowered to 146 mph in 2011. It is silly to have a governor on a performance car, and quite annoying to those who live where it is sometimes safe to go faster. As for the Ford Boss 302, I believe the standard 302 might have a governor at 160, but the Laguna Seca (LS) model has no top speed governor.

Are not Boss 302s limited to 160Mph? But correct me if im wrong, but dont the 2000-2004 Mustangs have better aerodynamics? Cd.34 around there?(Not sure) and cars lke th 5.0 should never have a Governor, 420Bhp and you limit what it can do? they have the tyre tech, its stable, i never understood that, GreenPeace? TFO here, but most limiters dont even kick in at the tamed speed, i know the 2007 XKRs didnt, Unlimited top speed for the 420Bhp models was 180Mph, and most didnt kick in till 173mph..kinda redundant.

In the past the gearing or the aero or both were bad on Mustangs. When Ford redesigned the retro looking Mustang in order to improve the aero for the 2010 model year they added a governor to limit the top speed. When they introduced the new Coyote V8 and getrag 6 speed transmission Mustang owners discovered how quickly they would hit the top speed governor. I don't speed much since I am not in Germany, but I have come close to hitting the limiter myself. Only the Boss 302 LS is unlimited in stock configuration (as far as I know), everyone else with the Coyote 5.0 has to get a tune to eliminate the governor.

Mustangs can get good top speeds, but Ford Restricts there capabilities, wether its gearing(Like too damned long in the GT500)(Or the crap 6th economy gear shite) not particularly drag itself, and tyres sometimes, the 1st Gen GT500 hit a tested 183-192Mph depending on the room and source, the Saleens were pretty good at top speed to. but since emissions and sometimes safety regulations, along with economy(Atleast your economy lol) Its put a bit of a limitation on them, that or there just short geared in the lower range for better accel, having never oned a Stang i cannot say for sure.

Thanks BR2' for the info. I had hypothesized at one time that it was capable of 179 mph given enough room and optimal gearing. The 3.73 rear allows sixth gear to be okay for top speed. At 179.2 mph depending on tire wear, the rpm would be somewhere around 5531 to 5600. In any case, the power band levels out so that it would be producing 96 percent of maximum horsepower. So it seems quite possible to me. I will look for the YouTube video sometime, my German is still pretty good. Thanks.

@Viking

Unfotunetly i dont have any info other then the YouTube video which was back in late 2011, and strangely enuff it was a German in Germany who did the video, and at the end of the run the Box listed 288Kph. Know, the 2 patrons in the car said it was stock, there were engine and interior pics posted, i dont think they have a reason to lie, i think with enuff room the 5.0 can get to 179, its got the Bhp, and enuff aero, dunno bout gear ratios though, and im fairly confident its had the 3.73.

@ Viking my friend : Agree with you , you completely right , FastestLaps is not a good source for Top speeds , especially the American Muscle Cars , 64-74 and some important classics .

@Shaggy I also completely agree with you. Your numbers are completely believable, and realistic given the gearing of those four speed manuals. @Bijan LOL clearly that website "FastestLaps" is just not a good source for top speed info. :)

@ Shaggy : I'm so glad , and I Completely agree with you , you are correct , and in my opinion all of these Top speed claims are incorrect , but you really don't know from where I get these figures ????? really ??? all right , I tell you , I get all of these and several more from this site , fastestlaps .
I know all of them had 4-speeds and poor cd , Completely know .
But Shaggy look at these :
From Cougar 429 to Torrino Talladega , and Cobra 427 s/c to 1969 Charger 500 and 79 Mustang king cobra 139 hp :

www.fastestlaps.com/models/mercury-cougar-eliminator-429-boss

www.fastestlaps.com/models/mercury-cyclone-spoiler-ii-429-boss
www.fastestlaps.com/models/ford-torino-talladega-429-boss

www.fastestlaps.com/models/shelby-cobra-427-s-c

www.fastestlaps.com/models/ford-mustang-boss-429-special

www.fastestlaps.com/models/ford-mustang-ii-king-cobra

www.fastestlaps.com/cars/dodge_charger_daytona_rt_special.html

www.fastestlaps.com/models/dodge-charger-r-t-500

And even this !!!! AC 428 frua , Only few Magazines Road Tested this car , Two British , AutoCar and Motor .... and they tested and get Top speed about :
In 9/1968 Motor get 139.0 mph Top speed .
Auto Car can reach 141.0 mph in july 1968 , and look at this :

www.fastestlaps.com/models/ac-frua-428-coupe

I don't know these figures and claims came from where ? which Magazine ? which book or any Documentary facts ..... sorry about this comment Shaggy but this is it .

@ Biajan: With all due respect, all of those top speed claims are incorrect, The 1974 Pontiac Firebird Trans Am 455 H.O. will do about 145 MPH, the 1970 Mercury Cougar 429's top speed is about 140 MPH, a 1969 Mercury tops out at about 135 MPH, a 1969 Ford Torino Talladega can do around 140 MPH, a Ford Shelby Cobra Daytona's top speed is 185 MPH, a Shelby Cobra 427 tops out at 165 MPH, it'd take more than just a racing carburetor and manifold to make a Ford Mustang Boss 429 capable of 180 MPH, a 1979 Ford Mustang King Cobra will only do 117 MPH at the most, 139 horsepower in that car just isn't enough for 132 MPH, a 1970 Dodge Charger Daytona RT Special is capable of 145 MPH, not 206, and a 1969 Dodge Charger 500 is capable of around 142 MPH. I don't know where you get your specs from, but they're wrong, most of the cars you mentioned have close ratio 4 speed manual transmissions and a close gear ratio usually sacrifices top speed in favor of acceleration, And the Mustang King cobra is just an underpowered pretentious piece of crap.

@Bijan I don't believe most of the top speed claims for cars unless the source is carefully documented. The Cobra Daytona was clocked at 182 mph on the straight at LeMans so I believe it. A book I used to own claimed the Plymouth SuperBird could reach 160 mph with 426 Hemi and 3.23 rear, and had enough evidence to support it. A 0.34 Cd is quite good (estimate based on appearance I think), so a high top speed is possible, I just haven't seen enough evidence yet to be fully convinced. I am just being cautious, and skeptical as usual. I just crunched some numbers, and my current estimate would be 162 mph with 310 net hp and 172 mph with 371 net hp, assuming gearing was made to reach those velocities. My numbers are based on some Car and Driver tests of some Camaros and Firebirds of the 1990s and early 2000s. Car and Driver is rather weird in that they always average the speed of two directions (not the right way to do it in my opinion) so you could be right with 175+ mph if the net hp really is 371.

The only magazine test of an ungoverned Mustang 5.0 was Car and Driver's test of a Boss 302 LS. On a hot and windy day they reached 165 mph in one direction, and 157 mph in the other. Not much power difference between the Boss 302 and Mustang GT at only 5000 rpm. VMP tuning once did a back to back dynojet test of a Boss and GT. At 5000 rpm the rear wheel hp of the Boss was 330.80, the GT was 328.76. (Above 6000 rpm much different story of course.) So top speed with 3.73 rear should be roughly the same between Boss and GT.

@ Viking : My friend when some of my friends say that a Daytona or Cobra 427 can do 180-200 mph , can you believe ? or 155 mph for 1970 Cougar 429 ? or 168 mph for 69 Cyclone with 3.50 rear end ? or 171.1 mph for 69 talladega 429 and 3.25 ? or 180 mph for Boss 429 only with a racing Carb and manifold ??? or even 132 mph for 1978 Mustang king cobra ? with 139 hp ??? 206 mph for a Daytona R/T special ??? 172 mph for 1969 Charger 500 ????

If you think that these data is right and the 175 for a car with 7000 plus rpm and long 3.08 ratio and slightly better cd than above 60' Muscle cars , is wrong ..... in my opinion its sadly " FASCISM " .

@BR@' thanks for the info on the youtube Mustang GT 5.0. Do you know what axle ratio they were using? I had seen a fellow in Germany post a you tube video with GPS, but since he was running the performance 3.73 rear he only reached 167 mph in sixth gear at roughly 5150 rpm. At 5150 rpm the stock Coyote 5.0 engine is producing only about 90 percent of peak power, I think. Based on that video I had theorized that with optimal gearing 172 mph would be possible. 179.2 mph would be very cool, if we could trust the YouTube poster being honest that the Mustang was stock (other than having a tune to remove the governor).

I "Think" th fastest stok GT 5.0 Mustang with Govenor removed hit 179.2Mph with VBox(YouTube) but we can be sure how accurate a YT video can be.

Not too confident this would hit 175Mph, 70s tech, with a 4-Speed, and that much Bhp, and a CD of about Cd.34?

@Bijan 175+ mph? That would make it faster than my 412 hp Mustang with the governor removed. What is the co-efficient of drag and frontal area of a 1973 Pontiac Firebird?

@Super8 could you post a link for the article in High Performance Pontiac magazine where they determined the true net output is really 371 hp? The '73-'74 SD 455 was certainly the most powerful engine available when it was introduced. I also know that it is easily modified for more power, in an original test of a '73 SD 455 stock it reached the end of the 1/4 mile at 104 mph, and after a couple quick changes for better traction and power it reached 107 mph. Certainly it produced over 300 hp net, but I am not sure 104 mph indicates 371 hp. I believe the factory ratings for the '73 was 310 hp, and the '74 was 290 hp if I remember correctly. I am curious about the High Performance Pontiac rating, and how they determined it.

With 175+ mph and 13.5 seconds in 1/4 mile , this is really " The Last true Muscle Car " , and The Last of the Fast cars , that Car and Driver said .

Pontiac said that the 73 SD455 capable to reach near 8000 rpm that RA V can do ( 8200 ) , but in my opinion the 73 SD455 can reach to 7300-7500 rpm .
And the 74 SD455 can reach to 7000 rpm %100 . look at my posts in this place :
www.fastestlaps.com/models/pontiac-firebird-trans-am-455-super-duty

@ Super 8 : Thanks to add this beauty , and thanks about point to 371 hp , that I say that in before .
As I say before , the 73 SD is slightly faster than 74 SD .
When you speak about the mighty Daytona HEMI , you say that capable to 180 mph with 3.00 , as you know the red line of the 426 HEMI was 7000 rpm , but in this page you say 7000+ 74 SD455 can do only 170 mph with 3.08 , why ?

The true Output is 371 Hp net from source High Performance Pontiac magazine.

Most of the people think that 1974 455 SD had only 290 Hp Net but actually the earlier 1974 model had Ram Air IV camshaft just like 1973 model. It's the fastest Pontiac in both 1973 and 1974 and capable to reach 170 mph with 3.08 ratio as the fastest recorded top speed that ever made by Firebird after 400 Ram Air V. It's even faster than Corvette L82 that offered in that day. I'll pretty sure you can bully De Tomaso Pantera GTS with this.