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Just wondering. I'm watching The History Channel about 60's and 70's musclecars. They talk about 405 hp on a 63 factory racer Pontiac Catalina 421 cu in. That's the old world hp figures. What would that equal in todays hp calculations? I think about the late 70's (?) the mfrs changed the way they figure hp? So our "500" hp SRT's would be 375 hp years ago or 600 hp? Any of you gearheads understand this? That's a compliment by the way. Thanks alot! :)
 

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My old Charger horsepower documentation stated that the HP was measured at the rear of the transmission with all accessories running. Back in those days, the manufacturers tried to help out with insurance by rating them that way.
 

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horse power rating

Back in
early 70s dynoed six pack 69-superbee,mild tune with fenderwell headers,at the rear wheels,276hp,car would run 12.50s with slicks and headers open, gearheadbill
 

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I was always under the impression that the 'old way'(Gross HP) would yield higher numbers than the 'new way'(Net HP). The way it was explained to me was they used to measure an engines power output WITHOUT all of the accessories hooked up. Today, and engine's power is measured WITH the alt., smog pump, pwr. steering pump, full exhaust system, etc. hooked up to the car.

Think about it. Many of the old muscle cars with 400+ cubic inch Big Blocks, and BIG hp numbers really only turned about the same trap speeds as say, an LT1 300hp Vette. Around 100mph give or take.

I just watched an American Muscle Car show on Speed Channel about the 426 Hemi Superbee's. They said that car was designed to go 100 mph +/-stock in the 1/4 mile. I'm not sure how accurate that is for completely stock, but weren't they rated around 425hp, at least? Now,take something like a ZO6 Vette with its 405 hp --->116mph in the 1/4! There can't be that much difference in weight to make that big of a difference in trap speeds.

ET's are a wash as there are way too many variables.


Back in
early 70s dynoed six pack 69-superbee,mild tune with fenderwell headers,at the rear wheels,276hp,car would run 12.50s with slicks and headers open, gearheadbill


As for this. IF it would hold together, a 405hp ZO6 with slicks, running 116mph through the traps, would be a mid-11 second car. SRT-10 Vipers with slicks would be in the TENS!! Until they both broke their halfshafts... :eek:

Of course, all of this is just my opinion. I could be wrong. :p :D
 

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horsepower rating

I hear what your saying, but those were the numbers,seems low ,
I had about every high horsepowered chevy or mopar in the late 60s,from 390hp to 450hp,from low 3000lbs to 3800lbs,all with gears headers,and igntion work,for the most part they were all middle to low 12 second cars with headers opened and with slcks
64 pro street dodge 330sedan 498cu in
72 py scamp pro sreet 470cu in all alu
94 supra TT
04 srt-10 ram 5.13s magnaflow k&n intake
gearhead bill
 

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Ford does this NOW!

They had a little mishap with the '99 Cobra and ate a lot of crow and lost their ass.
And they learned their lesson.

Now we have bone stock Lightnings making 369rwhp (factory rated at 380 at flywheel) (posted this week on a brand new truck)

The Ford GT is rated at "over" 550 horsepower. Well that is all nice and dandy, but they have been making over 560-570hp at the tires.

The new Mustang GT is claimed to have 300hp, yet the AUTOMATICS run a 5.1 0-60? the manuals should shave a .1-.2 off that time.
 

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In 1972, manufacturers began posting net horsepower ratings rather than the gross figures that were advertised through the 1971 model year. Net HP numbers were obtained at the flywheel but with all of the engine's accessories attached. I had several old muscle cars in the 70's including a 1970 Camaro SS396 and a 1968 Corvette, and none of them ran better than 13's stock. I am sure gearheadbill's cars were modified a bit to get to the 12's and there is no doubt that hundreds of 60's and 70's muscle cars have been modified to run 8's and 9's and even better. Most of the old muscle cars, in completely stock form though, were just not as fast as we remember them. In the current edition of Hemmings Muscle Car magazine, for instance, they print HP numbers and 1/4 mile times for the original Olds 442 and it ran a best of 15.5. I saw an article a couple of years ago, can't remember which magazine, but their tests showed that a Honda Odyssey minivan posted better times, both in the 1/4 mile and the slalom, than a completely stock 1957 Corvette.
 

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horsepower rating

All of the cars I speak of were not modifed internally,but like I said had headers,gears,and ignition work
Hemi roadrunner-425hp
427 L-72 425hp Biscayne
396-375hp camaro
superbee 440 sixpack
all very capable of middle 12s
with slicks and headers opened
Gearheadbill
 

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Although those aren't internal engine mods, headers, gears, ignition upgrades and, especially, slicks make a big difference, especially in older cars. My point was that modern muscle cars, including trucks like the SRT-10 and the Lightning are at least as potent as most of the cars from the muscle car era of the late 60's and early 70's, at least in stock trim. By the way, sounds like you had some great cars.
 

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horse power rating

I would agree with you,but open headers slicks nd gears on our trucks help just the same,never in my wildest dreams did I think that manufactors would be producing the cars that we have today,everytime I jump in my srt-10ram it reminds of the muscle cars of old,and believe me it always puts a smile on my face.
gearheadbill
 

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I certainly don't doubt you on the 12 second cars Bill, but what MPH were they turning?


427 L-72 425hp Biscayne
396-375hp camaro
superbee 440 sixpack


These are the types of vehicles I was referring to - Big Blocks with BIG HP numbers! All I'm saying is take a modern car, say a 4.6 liter 260hp Mustang GT. Open up the exhaust, install some steep gears for drag racing, along with a set of slicks, and I bet it'd run in the 12's!

It just seems like today's lower hp ratings do just as much as the 60's and 70's higher numbers did.
 

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horsepower rating

Your probably right,as for the mph,108-112,the only problem back then was stopping these cars with drum brakes!
gearheadbill
 
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