Muscle Cars Engines, Power
12-28-2007, 01:59 PM
#1
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Vehicle: 2006 Pontiac GTO
I've always wondered how muscle cars power ratings decreased so much over time, especially for engines with the same displacement. Take the 350 cid engine on the Camaro z28:
1970: it made 360 hp
1971: 300-horsepower rating (240-horsepower net)
1972: 255hp (net)
1973: 145hp or upgrade to 175hp
1974: 145, 160, or 185 hp
1975: 155hp
1976: 165hp
1977: 185hp
I read there was a problem with ratings, the older ratings were computed at the crankshaft with no accessories.. But what's really bothering me is: how badly can you build an almost 6 litre engine so that it only makes 145 hp?? That's 3 times bigger than a tib engine! Was the redline at 2000rpm or something? And if you could once build it to make 255, why suddenly build it to make much less? I guess there were emission laws tightening up or whatever, but still how can that affect the power output so much.. near-optimal AFR should be good for both power and emissions, it's not like they had to cut off half the fuel or something.. I don't get it...
1970: it made 360 hp
1971: 300-horsepower rating (240-horsepower net)
1972: 255hp (net)
1973: 145hp or upgrade to 175hp
1974: 145, 160, or 185 hp
1975: 155hp
1976: 165hp
1977: 185hp
I read there was a problem with ratings, the older ratings were computed at the crankshaft with no accessories.. But what's really bothering me is: how badly can you build an almost 6 litre engine so that it only makes 145 hp?? That's 3 times bigger than a tib engine! Was the redline at 2000rpm or something? And if you could once build it to make 255, why suddenly build it to make much less? I guess there were emission laws tightening up or whatever, but still how can that affect the power output so much.. near-optimal AFR should be good for both power and emissions, it's not like they had to cut off half the fuel or something.. I don't get it...
12-28-2007, 03:31 PM
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Vehicle: Turbocharged 2001 Hyundai Tiburon
See your focusing right in on the oil crisis years. EPA restrictions on emmissions and economy really made manufacturers tone down the engines.
as a result the muscle cars turned into 95lb weaklings that would get smoked by our cars stock-stock.
as a result the muscle cars turned into 95lb weaklings that would get smoked by our cars stock-stock.
12-28-2007, 05:24 PM
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Vehicle: 2001 Hyundai Tiburon
Yep emissions sucked. No manufacturers knew how to make power and get around emissions. Even still my brother had a 96 camaro with a V6 and auto trans. It was so much faster than a late 80s with a big V8 and manual trans. Rediculous.
12-28-2007, 07:04 PM
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big displacement...
Here is how it went down:
Carbs went from 4 and 6 barrel carbs.. to 2. Cams got shorter duration and less rise. Leaded fuel was phased out, which meant that they needed to refigure out how to lubricate the valves, so redlines got lowered. And in an attempt to lower NOx, they lowered compression down to what we would consider good for boost.. 7 or even 8 to 1 ratios..
This does not include exhausts with poor performing cats, and small pipes, Exghaust gas recirculation, little advance on the timing, leaned out carbs.. the list goes on and on and on.
Fuel Injection was the big boost in both power and emissions.
Here is how it went down:
Carbs went from 4 and 6 barrel carbs.. to 2. Cams got shorter duration and less rise. Leaded fuel was phased out, which meant that they needed to refigure out how to lubricate the valves, so redlines got lowered. And in an attempt to lower NOx, they lowered compression down to what we would consider good for boost.. 7 or even 8 to 1 ratios..
This does not include exhausts with poor performing cats, and small pipes, Exghaust gas recirculation, little advance on the timing, leaned out carbs.. the list goes on and on and on.
Fuel Injection was the big boost in both power and emissions.