Well, the 1975 Trans Am with 455 didn't make big power like the earlier and smaller Pontiacs did. It was one of the victims of the early EPA regulations and emissions requirements, causing a significant reduction in power from earlier 455 versions. The car also weighs a whole 1000 lbs more than a Fiero Formula. Power, weight, gearing, and traction would give the advantage to the Fiero Formula there.
Well, the 1975 Trans Am with 455 didn't make big power like the earlier and smaller Pontiacs did. It was one of the victims of the early EPA regulations and emissions requirements, causing a significant reduction in power from earlier 455 versions. The car also weighs a whole 1000 lbs more than a Fiero Formula. Power, weight, gearing, and traction would give the advantage to the Fiero Formula there.
The Fiero Formula also beats the GT due to more weight on the GT.
The fastest Fiero beats the slowest 455. Ok. The mid-70's were dismal performance years. The catalytic converter just came on the scene in 1974 along with stricter emissions. It took another decade before GM could figure out how to start making performance again with the emission controls. That '75 455 only had about 200HP, and 7.6:1 compression. It was the lowest output 455 Pontiac ever sold.
The fastest Fiero beats the slowest 455. Ok. The mid-70's were dismal performance years. The catalytic converter just came on the scene in 1974 along with stricter emissions. It took another decade before GM could figure out how to start making performance again with the emission controls. That '75 455 only had about 200HP, and 7.6:1 compression. It was the lowest output 455 Pontiac ever sold.
Almost 8 liters and it makes 50% less horsepower than my 2 liter Sky Redline. Yuck.
kinda miss leading as they didn't use a 455 super duty t/a
Yes the mid 70's 455 t/a "rated" published power was sad, but that wasn't the point of still offering it in the car.. g.m. knew they couldn't build a fire breather but, also still sold the earlier heads , the cams ,over the counter for the owner that wanted to bring it to life... one must remember the 2nd gen f-body t/a was not light.. 4200-4300 lb was the norm.. I'll take a 75 455 t/a as a swap for my 84 indy anyday..
Looks like the 1976 455 (non-HO) was rated at 200/330. My Sky makes 290/340. At the time I bought it, mid-2007, it was the highest per-liter output motor GM had ever put in a production car.
Looks like the 1976 455 (non-HO) was rated at 200/330. My Sky makes 290/340. At the time I bought it, mid-2007, it was the highest per-liter output motor GM had ever put in a production car.
FYI, after 1972 there was no "HO" 455. The mid 70's did have a 455 HO option, but it was the station wagon 455 with "455 HO" decals on the shaker. There was nothing different about it compared to the 455 in a Bonneville.
In '71 and '72 the last real 455 HO, they had a bigger cam, round port heads (same design as the Ram Air IV, but lower compression), and a 2 piece aluminum & cast iron intake with an 800 cfm Q'jet. '73 and '74 upped the ante with the Super Duty and that was the end of the high performance 455 Pontiac from the factory.
The mid-70's 455 had low compression, a tiny camshaft and a heavily restricted intake manifold.
Comparison of regular "D" port heads with "HO" round port heads. Super Duty also used round ports with even larger port volume.
Keep in mind too that when the '82 Trans Am came out, the LG4 V8 only had 145HP. The mid-70's to mid-80's were pretty dismal for performance cars. It was a big deal when the Tuned Port Injection came out in '85 as it was the first time in the 80's the F-body V8 got back up to the 200HP threshhold.
[This message has been edited by Formula88 (edited 08-14-2015).]
That was truly a bleak period for American muscle. So much gas burned to so little effect.
I am a child of and love the 80s, but not the cars. Though I still have an affinity for the C4 Vette with the digital dash. My aunt had one and let me drive it. First time over 100 MPH in a car...and first time over 120 I remember bemoaning that a car like that was truly lost on people too old to appreciate it...I'm sure I'm older now than she was then.
That was truly a bleak period for American muscle. So much gas burned to so little effect.
I am a child of and love the 80s, but not the cars. Though I still have an affinity for the C4 Vette with the digital dash. My aunt had one and let me drive it. First time over 100 MPH in a car...and first time over 120 I remember bemoaning that a car like that was truly lost on people too old to appreciate it...I'm sure I'm older now than she was then.
Not really that bleak , sure you couldn't walk into a dealer and roll out with 340hp, but performance cars were still being made, the oem's just left it up to you to build the hp.. it was bleak in the mid to late 80's and early 90's, as the oem were starting to figure out how to get the power back, the building your own hp into those cars, became a royal pain in the butt.. in the 70's you still could buy a f-body that handled just needed the go,, and the oem's still put big cube v8's in, the 80's cars, came with much smaller v8's that you couldn't just stab a cam into and headers, mill the heads and go from 220hp to 360+ . even in 2002 I was very limited as what I could do to my 86SS, dropping a 350 in was out.. and the old computers systems didn't like changes.. Now I can drop a big block in it if I want but while it was under the emission testing, no way.. People forget the 73-77 a bodys and to 81 f-bodys are the same basic car as the 64-up a body, and the 67 f body up.. same with ford and mopar.. what was odd, that g.m. never put the TPI in the SS or the trucks, as that efi is all torque, and should've been used in the trucks..
I remember bemoaning that a car like that was truly lost on people too old to appreciate it...I'm sure I'm older now than she was then.
