Interesting Article About Muscle Car HP

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I thought this article was informative, I'll toss it out there to see if the drag racers here think it is bunk...

https://www.hagerty.com/articles-videos/Articles/2013/08/13/Horsepower

Weird for me to think about an Edmunds driver only torturing an FXT like mine a little bit to get numbers somewhat comparable to a '69 Boss 302...

https://www.edmunds.com/subaru/forester/2014/road-test-specs1.html

I still haven't tried the trick of slapping the shifter from paddle to auto mode at redline and will probably never do a brake stand.
 
I had a 1965 Corvette that had a bad 327(non-matching numbers). I rebuilt and installed a 350 LT-1 out of a 70 Camaro Z/28. I used the 2.02 heads, original intake and carb, kept the same 11:1 compression pistons, and used a new TRW 30-30 cam. The engine should have had 370 horsepower from the factory. Unfortunately at school we only had an analog chassis dyno which measures rear wheel horsepower and pegs out at 200 rear wheel horsepower. I was certain that my car would peg the dyno; however, my car only made 155 rear wheel horsepower! Our instructor told us that about 1/2 of the engine horsepower is transmitted to the rear wheels. The car was fast but I never knew how much horsepower my car really had. In the early 1980's even 300 horsepower from an engine was a lot to me.
 
I grew up in the original muscle car ere graduating from high school in 1965 and college in 1969. I owned a number of muscle cars back then including a 1967 Firebird 400. A lot of my friends at the time had a variety of muscle cars including 428 Mustangs, 396 Chevelles, 427 Corvettes, 383/440 Mopars and the like. All of these were great cars and we loved them then and still love them now. However, in my view, there is no comparison to what is available now. I have owned a 2012 Mustang 5.0 (412HP), a 2012 Shelby GT 500 (550HP), a 2015 Challenger R/T (375HP), a 2015 Corvette Stingray (460HP), and now a 2016 Charger Scat Pack (485HP). There is no comparison. These new muscle cars will run circles around those in the 60's and early 70's. Cars like the ZO6 Corvettes, ZR-1 Camaros, Shelby Mustangs, Hellcats, and now the Challenger Demon put down insane power and performance with a factory warranty and good mileage to boot. Never would have predicted that back in the 60's. We ARE in the Golden Age of muscle cars. Enjoy it while you can.
 
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The net hp ratings are a fact. But, some engines were in fact down rated during the horsepower wars to get better insurance premiums (ie under 1 hp per ci of displacement).

While the Mopar 426ci hemi was rated at 425 hp gross, many believe it closer to 475-525 gross hp.

The Mopar 440+6 was rated at 390 hp, only 15 hp more than the 440-4v Magnum. That's nuts. The 440+6 gave the 426ci a run for the money, and was likely closer to 450-490 gross hp. Even the 340-4v at 275 hp (340-6v at 290 hp) and 383-4v Magnum (rated 335 hp) were probably underrated by 10% each. It's possible that the 440-4v was possibly over-rated at 375 gross hp. With the Hemi being the "cap," all the others had to line up.

The strongest GM 455ci engines of 1970-1971 were only rated at 450 hp. And those were likely closer to the 500+ hp range.

The 1966-1972 period isn't the only time the factory under-rated hp. The 4th gen LS-1 F bodies of 1998-2002 (346 ci rated from 305-325 hp w/o extra SLP options) were probably close to 350 hp. But that couldn't be assigned because the C5 Vettes had the "cap" at 350 hp. The best, 100% factory stock, 1/4 mile split of the 1998-2002 era (Vettes and F-bodies) is held by a plain Jane Z28....I think it was a 1999 too.
 
Some myths still persist, though, one being that the 1969-1970 Ford Mustang BOSS 302, which had a 290 hp gross rating, really had “around 400 hp.

Never heard that myth before. The identically rated 1970 AAR Cuda's and Challenger TA's were probably in the true gross hp range of 320-350. I never heard anyone claiming 400+ hp except for the 440/426/455 ci engines. Claiming 290 hp kept them comfortably under the 1 hp per ci measure.
 
Originally Posted By: 69GTX
The net hp ratings are a fact. But, some engines were in fact down rated during the horsepower wars to get better insurance premiums (ie under 1 hp per ci of displacement).

While the Mopar 426ci hemi was rated at 425 hp gross, many believe it closer to 475-525 gross hp.

The Mopar 440+6 was rated at 390 hp, only 15 hp more than the 440-4v Magnum. That's nuts. The 440+6 gave the 426ci a run for the money, and was likely closer to 450-490 gross hp. Even the 340-4v at 275 hp (340-6v at 290 hp) and 383-4v Magnum (rated 335 hp) were probably underrated by 10% each. It's possible that the 440-4v was possibly over-rated at 375 gross hp. With the Hemi being the "cap," all the others had to line up.

The strongest GM 455ci engines of 1970-1971 were only rated at 450 hp. And those were likely closer to the 500+ hp range.

The 1966-1972 period isn't the only time the factory under-rated hp. The 4th gen LS-1 F bodies of 1998-2002 (346 ci rated from 305-325 hp w/o extra SLP options) were probably close to 350 hp. But that couldn't be assigned because the C5 Vettes had the "cap" at 350 hp. The best, 100% factory stock, 1/4 mile split of the 1998-2002 era (Vettes and F-bodies) is held by a plain Jane Z28....I think it was a 1999 too.



How often do you see the old muscle cars (especially the multiple carburetor set-up's) tuned properly??? Much less kept in tune..... I work on all eras of performance cars & that's one thing that really Irk's me, The 6 Pack & Dual 4 guys always think they should outrun a single 4 barrel car. I've convinced a few Hemi & Wedge guys to run Holley HP's & Victor or Performer RPM intakes & they LOVE it, Even without a choke.....Get those plugs cleaned up!


On the LS1 front. C5 Corvettes have far better flowing factory exhaust, I agree with the rating bump that was given.
 
Originally Posted By: 69GTX
The net hp ratings are a fact. But, some engines were in fact down rated during the horsepower wars to get better insurance premiums (ie under 1 hp per ci of displacement).

While the Mopar 426ci hemi was rated at 425 hp gross, many believe it closer to 475-525 gross hp.

The Mopar 440+6 was rated at 390 hp, only 15 hp more than the 440-4v Magnum. That's nuts. The 440+6 gave the 426ci a run for the money, and was likely closer to 450-490 gross hp. Even the 340-4v at 275 hp (340-6v at 290 hp) and 383-4v Magnum (rated 335 hp) were probably underrated by 10% each. It's possible that the 440-4v was possibly over-rated at 375 gross hp. With the Hemi being the "cap," all the others had to line up.

The strongest GM 455ci engines of 1970-1971 were only rated at 450 hp. And those were likely closer to the 500+ hp range.

The 1966-1972 period isn't the only time the factory under-rated hp. The 4th gen LS-1 F bodies of 1998-2002 (346 ci rated from 305-325 hp w/o extra SLP options) were probably close to 350 hp. But that couldn't be assigned because the C5 Vettes had the "cap" at 350 hp. The best, 100% factory stock, 1/4 mile split of the 1998-2002 era (Vettes and F-bodies) is held by a plain Jane Z28....I think it was a 1999 too.



Percentage-wise, the Mopar 340 smallblock was probably the most under-rated. The high-performance 4-bbl version (not even the 6-pack) was recently dyno tested by Hot Rod, and it came up with about 320 horsepower in bone stock trim. Chrysler really pushed its numbers down so that it wouldn't eat into big-block (specifically 383) sales. The 6-pack 340 (1970 only) was over 350 HP.


http://www.hotrod.com/articles/bad-mopars-340-beat-ford-chevy-shocking-new-data/
 
I have the interesting perspective of owning a basically stock (except for electronic ignition) 1969 Mopar 440 powered Dodge Coronet, and a 2012 Challenger SRT-8 with the 392.

Yes, the Challenger is more powerful, and more civilized. Definitely more top-end power and more acceleration once you're above 70 mph. And 25 mpg highway when you behave... the Coronet *might* get 14 if I put a brick under the gas pedal. :-/

However, the way the 69 440 delivers power is a force to be reckoned with. It has *instant* huge torque at any RPM above 600. Right off idle, sheer unmitigated violence, and it wouldn't surprise me if I could get consistently better 60' times with the Coronet if I ever abused it at the track. That's one thing smallblocks, which by definition include all the Coyote, LS, and G3 Hemis, just can't deliver quite the same way. Probably the beastliest in stock trim was the 455 Buick unless it happened to blow the crank out the bottom... which was fixable with a block girdle, but that's how light they made that thing from the factory. Lighter than a contemporary Chevy 327/350.
 
Originally Posted By: 440Magnum
Originally Posted By: 69GTX
The net hp ratings are a fact. But, some engines were in fact down rated during the horsepower wars to get better insurance premiums (ie under 1 hp per ci of displacement).

While the Mopar 426ci hemi was rated at 425 hp gross, many believe it closer to 475-525 gross hp.

The Mopar 440+6 was rated at 390 hp, only 15 hp more than the 440-4v Magnum. That's nuts. The 440+6 gave the 426ci a run for the money, and was likely closer to 450-490 gross hp. Even the 340-4v at 275 hp (340-6v at 290 hp) and 383-4v Magnum (rated 335 hp) were probably underrated by 10% each. It's possible that the 440-4v was possibly over-rated at 375 gross hp. With the Hemi being the "cap," all the others had to line up.

The strongest GM 455ci engines of 1970-1971 were only rated at 450 hp. And those were likely closer to the 500+ hp range.

The 1966-1972 period isn't the only time the factory under-rated hp. The 4th gen LS-1 F bodies of 1998-2002 (346 ci rated from 305-325 hp w/o extra SLP options) were probably close to 350 hp. But that couldn't be assigned because the C5 Vettes had the "cap" at 350 hp. The best, 100% factory stock, 1/4 mile split of the 1998-2002 era (Vettes and F-bodies) is held by a plain Jane Z28....I think it was a 1999 too.



Percentage-wise, the Mopar 340 smallblock was probably the most under-rated. The high-performance 4-bbl version (not even the 6-pack) was recently dyno tested by Hot Rod, and it came up with about 320 horsepower in bone stock trim. Chrysler really pushed its numbers down so that it wouldn't eat into big-block (specifically 383) sales. The 6-pack 340 (1970 only) was over 350 HP.


http://www.hotrod.com/articles/bad-mopars-340-beat-ford-chevy-shocking-new-data/


I miss my old Duster 340. Only car I regret selling.
 
I worked every night after high school at a local garage (early 1960's). I ran Y block Fords, so the Chebie guys gave me a hard time. I had fun, I just was not as fast as the fastest Chebie's
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I had two cousins about the same age and they ran Chebie and ??? both were quick. One of my best buds ran a 63 Galaxie with 406 tri-power and 4.11's on the street. The ??? was my cousin Tony's 57 Ford Fairlane 2-door with a 383/TQ-flite under the hood out of a rolled police cruiser. That TQ-Flite fed into 3.70's ...

None of us opened a hood before a race. You heard it, you saw it, and you ran. On occasion we got beat, but not often.

So the fastest one I had was a G-2 Paxton blower 312 Y block in a 56 ranch Wagon with 4.11's. Had a C5AZ all-synchro three speed out of a pick-up (fairly wide ratio tough 3-speed).

My cousins Chebie was a 57 two-door with an honest 375 HP 327 with Rochester FI and four speed.

On a good day at Fremont Raceway, we could just barely touch the 12's. The 406 Galaxie was a solid 12.80 car. None of us had stock heads, cams or induction (except the FI 327). All the motors were clean-up bored and swinging 10:1 or better pistons. This was when you could buy 100+ octane Chevron White Pump any day, any town, for $0.35/gal
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Our ignitions were stout mostly running 36* advance all in at 2,500 with various fly-weights. Mostly dual point dizzy's. Headers were just becoming a big deal on the street. There were some decent high flow cast iron exhausts over the counter at the dealers and we all had dealer discounts available do to family business's.

So how much HP does it take to run 13's at 100 in a 3,300 ~3,600 pound car? Over 400 any day of the week. None of us shifted over 6,500 because crank breakage was a big possibility. I made it on 8~9 PSI blower pressure. Tony made it on neutral starts with the TQ-Flite and that 383 was a beast. Johnny could launch that 327 at 4,500 and go right to 6,500 and bang shift it 6,500~6,700. We all ran solid lifter cams and pretty big spring pressures (for the day).

These engines required constant maintenance - constant. Driveline and axle breakage were common. Clutch explosions were not unheard of ... These were not Date Night cars. If you wanted to go out on a date, you borrowed Mom's car. No fender liners, spartan interiors, etc.

If the girl was up for it, she could get a cheap thrill out at Capital Expressway (unfinished) or 4-Lanes on Hwy 1 north of Santa Cruz riding a serious street race with you. No wimps need apply. Mostly we rode alone ...

We could beat almost any dealer sold car - GTO's, Road Runners, RT Dodges, Chevelles and Novas. Unless they new how to re-build and tune, it was ours for run ... Occasionally we got beat, usually close. Once in a while bad
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Fastest car in the area was a split-window Vette with a big block on alcohol on the street, bright orange and named Plastic Toy. Close was another Buds 49 F-1 pick-up with a 425 Buick and a Muncie. That truck was scary quick and handful to drive.

Point being, that factory muscle cars were nice date-night cars that could pass most folks easily and run pretty good, but they were not serious fast.

Fast forward to today and see what A-bodies are doing in bone-stock classes. There are Buick GS's and Old's 442's running 10's with mufflers. I hear there is a 401 Javelin knocking on the 9's with mufflers. I know two engine builders that can get 550 honest dyno HP out of a reliable streetable 455 Buick for about $18K. They will run down your average dealer show-room hot car today ... It's all about the build. Always was, always will be ...

You want fast, talk to Saleen or folks like that
laugh.gif
 
Also remember that dynos can be programmed to lie. A manufacturer that is running an engine on an engine dyno now is following the SAE J1439 which is a recent standard, the first engine being run on it is the LS based LS7. Going to a shop with a dyno, you will probably get an accurate reading. However the person running it can move numbers using the software around to be whatever you want them to be. Also a Dynojet will give different numbers than other types of dynos.

That being said the old muscle cars have soul. I love my 2014 Mustang, has tons of power, stops great, handles great, sounds great. But there are thousands just like it on the road. A 1968 Mustang, even one that has been resto-modded, has a soul that the new ones just don't have. I think the best thing that explains this the movie "Love the Beast." If anyone hasn't seen it, it is well worth watching. Never thought I would get teary-eyed over a Falcon XB.
 
I had a 66 Chevelle SS 396 when I was 17 years old. It had the one year only 360 HP 396. I put a Crane Cams Z300-14 solid lifter cam and kit in it, ( 546" lift, can't remember the duration) with headers and a Holley 750 cfm carb and 410 gears. With uncorked headers and idling at around 900 RPM's it made some sweet music. 440magnum put it best, instant sheer unmitigated violence when the go pedal was pushed. Yes, today's factory hot rods are better in every way, but they don't have the character or soul or whatever the old 60's muscle cars had.
 
I worked as an engine builder in a big marina on Long Island in 1984-85. We had a full machine shop and a dyno on the premises.
Aside from doing lots of stroker big chevys for 39 foot Cigarettes and such, we did a ton of Chevy 305, 350 and 454s. The Mercruiser callouts for these engines seemed reasonable. The 305 was called a 220, the 350 was a 260 and the oval port 454 was claimed to make 330 hp. NONE of these came close. The 454 made 290 hp out of the box. The 350 made 225. I don't remember what the 305 made. Made me realize everyone had no idea what their engines in their cars made.
To make the 454 put out 330 actual hp, it needed the big oval port heads in place of the peanut ports, an Edelbrock or Weiand dual plane intake, Holley 750 carb, I forget what cam we used to install but it was a slightly hotter hydraulic flat tappet and good machining like carefully decking the block to get the quench right. Big stuff for me at 19.
I built a 440 Chrysler while I was there for myself. I carefully ported the heads as per Direct Connection's porting templates. I added bigger milodon valves, a DC 509 lift, 292 degree hydraulic cam, Speed Pro floating pistons, Edelbrock CH4B intake, headers, a Holley carb I cobbled myself out of an 850 base with a 750 body with the bores in the body blended to mate up to the 850 base. Worked awesome.
That engine dyno'd at 518 hp. My boss almost passed out. Only thing was, even though I had it running really good, like idling at 850 rpm, it still ran like a refugee from a race track. Today's stuff is so much better.

I am however beginning a build mixing old with modern. It's going to be a 68 roadrunner with a stroked 440 that will probably displace 512 cubic inches. I'll know for sure when I get the crank, rods and pistons. Roller cam, Multi point EFI on an Edelbrock Victor EFI, five speed manual transmission. I'm hoping to build a car that appears somewhat correct to the casual observer but will be comfortable on trips like Power Tour and maybe a landspeed run up in Loring, Maine.
My goal is to make a fun, dependable, enjoyable car. I considered a Modern Charger but the automatic trans kills it for me.
I'm going out on a limb by saying I expect 640 hp out of this engine.
The other thing is I need this car to make real power because it would just be wrong to have every guy with a new Challenger spank a real roadrunner. It just wouldn't be right. I know for sure if I did a stock resto 383, it would get beaten by modern V6 Camaros.
 
Originally Posted By: BrocLuno


So how much HP does it take to run 13's at 100 in a 3,300 ~3,600 pound car? Over 400 any day of the week.


GROSS? Because a 225HP Fox Body GT, which is in that weight range, would run high 13's on a tire stock. My '87 with underdrive pulleys and an aluminum driveshaft ran 13.8 @ 101Mph with like 270,000Km on it. Heads/cam/intake, it put down 270HP to the tires and was an easy mid-high 12's, cut 106Mph on the limiter in 3rd when I broke the transmission. It was a full-weight '87 T-Top.

That 270HP to the tires would be ~325HP NET to the crank. Roughly 100HP more than stock and more than a full second faster.

400HP (NET) in a 4,100lb sedan (my former M5) was mid high-12's in the 11xMph range.
 
I have a magazine that contains a compilation of '60s and early '70s road tests from the old High Performance Cars magazine. Most of the hallowed musclecars(which I love, by the way) couldn't break into the 13s without slicks, loosening the drive belts, and pulling the air cleaner. If they returned over 12 mpg on the highway that was a bonus. Today most every V8 ponycar can break into the 12s right off the showroom floor and average 20+ mpg without breaking a sweat. And as far as braking and handling goes, the new cars are infinitely more competent. My dead stock 2er runs the 1/4 in the high twelves and gets over 31 mpg cruising at 75+. So, while I still love the "hot" cars of the '60s(and rebuild the occasional Quadrajet), I much prefer to be able to drive and track the cars you can buy now- although I would also like to have a 1970 Z/28 or AAR Cuda in my garage as well...
 
Sox & Martin were my drag racing heroes in the sixties. Their shop in Burlington, N.C. was about 35 miles away. Their home track was Piedmont drag way which still operates today but is now a 1/8th of a mile track. I remember seeing Ronnie Sox beat Bill Jenkins in a best of three race in about 1971. Sox in a Hemi Cuba and Jenkins in a 427 Vega. I have a poster in my garage of a 1968 Sox and Martin Hemi Barracuda. It was a great time to be a teenage car nut.
 
I agree that today's cars are much improved and faster. I feel that the Buick Grand National set the pace for "technology making power" back in the 80's. That car, off the showroom floor, was dusting almost everything from 60's to then 1980's current muscle cars alike. It was very easy and cheap to modify. I still own my 87 GN I bought new and all I ever did to it was a better fuel pump, adjustable Fuel pressure regulator, ram air, slightly larger injectors and an ATR pitbull chip giving me 17-18psi of boost (stock was 13psi). I run low 12's all day long. That used to fast but today's technology has moved forward. I would love to own a new DEMON or even Hellcat.
 
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Originally Posted By: SilverSnake
We ARE in the Golden Age of muscle cars. Enjoy it while you can.


Yes we are.
And while my memory of driving a 68 Camaro with a 454 and rockcrusher 4 speed is as fresh as if yesterday, there are cars today that would leave that thing in the dust. It is so much easier to get performance now. Back in the day, it was change a carb, change a cam, advance the timing with lighter flyweights, all mechanical. Today, write a software mod, try it, gather data, lather, rinse, repeat.
I stumbled on this gem earlier today...
 
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Originally Posted By: SilverSnake
We ARE in the Golden Age of muscle cars. Enjoy it while you can.


Sort of ... For folks like me who would rather tinker than track a new'ish car, it's not really the golden age. I'm in my golden years. I don't have nostalgia for the old iron. I get how much better central door locks and temp controlled "climate" systems can be. But I hate working around modern ECU controlled engines. They either run, or you need a lap-top to diagnose the issue ...

I think I've gone as far forward as I'll go. My next car will be a
I get building the Road Runner with a punched 440. Dunno if I'd cross that magic 500 inch mark ... I don't get along with NHRA, but I see no reason to cross their magic number. You can make stupendous HP at 498 inches.

The modern thing I think I want is a P100D Tesla. 0-60 in 3 seconds, and no gas. That would be a decent family hauler and grocery getter
laugh.gif


But I like fooling with IC motors. 2-valve, 3-valve, 4-valve are all good. Maybe a BMW 2000ti with an M4 engine ... Or, the one in the back of my head for years, Opel Manta with an SBC ...

But I have grand kids to haul now, so I'll guess it'll be the Jeep and trails
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