13 August 2013

Muscle Car Horsepower – How Exaggerated Was It?

Forty years after the end of the “classic” muscle car era, there is still some confusion over horsepower ratings, especially how they relate to today’s cars. Let’s try to clear it up.

Prior to 1972, American carmakers used the SAE (Society of Automotive Engineers) “gross” measurement of horsepower. Gross meant the figure was taken from an engine running on a test stand, with no air cleaner assembly, accessories or exhaust system connected.

By 1971, carmakers began reducing compression in many engines in order to meet upcoming emissions requirements and to use unleaded fuel. General Motors and Chrysler began advertising both gross and SAE net figures in 1971, derived from an engine tested with air cleaner assembly, accessories or exhaust system connected.

The net ratings, which were applied across the board for 1972, must have been a shock to some customers. Suddenly, muscle cars appeared to lose 100 hp or more.

For example, the Corvette’s optional LT-1 350 cu. in. small block V-8 had 370 gross hp in 1970 (with 11:1 compression), then a 330 hp gross rating (with 9:1 compression) for 1971-1972 with a 255 hp net rating. The mighty Chrysler 426 cu. in. Hemi kept its high compression and 425 hp gross rating for 1971 and showed 350 net hp.

Jim Campisano, editorial director of Muscle Mustangs & Fast Fords and Super Chevy magazines, has revisited the classic muscle car horsepower topic numerous times over the years. The magazines have compared old and new muscle cars and have also put classic models on a chassis dynamometer to record rear-wheel horsepower.

“Rear wheel horsepower was at least 30 percent lower than the reported gross figure, in some cases even more,” Campisano said.

Some Super Chevy readers must have been stunned to see that an LS6 Chevelle SS, with 450-hp rating, put down 288 rear wheel hp in the dyno test. That would have put a net hp rating at around 350 hp for that legendary big block.

You don’t need a dynamometer to estimate net horsepower for classic muscle cars, or to check claims of current models. Roger Huntington, the renowned technical writer who penned articles for many car magazines into the 1980s, developed a formula to show the relationship between quarter-mile performance and power output. Others have refined those formulas and developed calculators, in which you can use performance figures and vehicle weight to get estimated hp. (To check hp figures for this article, we used calculators at http://www.stealth316.com/2-calc-hp-et-mph.htm.)

Keep in mind that some muscle cars came specially prepped from press fleets, sometimes with non-factory supertunes. That’s one reason that making comparisons using vintage road tests can be sketchy. Different axle ratios, testing methods, drivers, test conditions and other variables also affect results.

But we can try anyway.

In 1970, Car & Driver tested a Pontiac Firebird Formula 400, which had a 330 gross hp rating and was equipped with a fairly tall 3.07 axle ratio. They recorded a 14.78-second ET at 98.9 mph. A 1970 Trans Am with the same engine, but with a 4-speed and a 3.55 axle ratio, was tested by Muscle Car Review magazine in 1995. That car burned the quarter-mile in 14.68 sec. at 97.17 mph, quite close to the C&D test 25 years before. Pontiac gave that engine a 255 net hp rating for 1971.

Now, let’s add a later model into the mix. When C&D tested a 1979 4-speed Trans Am with the emissions-controlled W72 400 engine, the one with a 220-hp net rating and the “T/A 6.6” decal on the shaker hood scoop, it ran a 15.3 second ET at 96.6 mph. That car had a 3.23 axle ratio. As a drag racer will tell you, the mph figure is the better indicator of horsepower than ET. So, the 35 net hp deficit from the 1971 engine seems accurate, and not nearly as bad as some might have thought three decades ago.

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.” Vintage road tests show mid-to-high 14-second ETs at 94-97 mph for a car weighing about 3500 pounds with a driver and test gear. That’s about 100-150 pounds less than the 400-powered Firebirds cited above. Given those figures, the BOSS 302’s 290 gross hp rating seems accurate, pegging net hp closer to 240.

Contrast that with the 2012-2013 Mustang BOSS 302.

Ford rates the modern BOSS with its DOHC 5.0-liter V-8 at 444 hp. Car & Driver, driving one the way most drivers would (not powershifting), recorded a 12.8-sec. ET at 113 mph. Muscle Mustangs & Fast Fords, with hot shoe Evan Smith banging off full-throttle powershifts and the car running on drag radials, scorched the quarter-mile in just 12.07 sec. at 114 mph.

Those similar mph figures easily substantiate the car’s 444 net hp rating and leave no doubt that the 1969-1970 BOSS 302 was at least 200 net hp below that.

To be clear, debunking myths does nothing to tarnish the place that classic muscle cars hold in our hearts and garages.

“We still love the old ones,” said Campisano. “They’re cool looking, fun to drive and fun to look at. It’s just a different performance world today.”

79 Reader Comments

  • 1
    tommy taylor TX August 21, 2013 at 13:06
    By '69 the GM HP number on our Camaro SS was way under the number generated by speed at the end of the 1/4. Lower insurance rate!
  • 2
    Hal Heindel Webster, NY August 21, 2013 at 13:08
    That's about as honest and realistic a comparison of old versus new I've ever come across. Kudos, Jim. I used to own the original factory Dragonsnake CSX2019, which I sold at the Mecum Spring Classic in 2006. Some of the proceeds bought a new 2006 Ford GT and a new 2006 Corvette. Much earlier I had bought the 1970 Boss 302 and 1978 W72 400 Trans Am mentioned in the article. Still own both. "Much earlier" means I bought them new in the wrapper. Back in their day, the Boss and T/A seemed potent enough, but stepping from the modern plain vanilla 400-hp 'Vette into either one of the two is an eye-opener. They're still fun on a Sunday morning, don't get me wrong, but fast? Not any more! Thanks for the reality check. I'm printing copies to shorten future discussions with my die-hard muscle car friends.
  • 3
    Scott Tennessee August 21, 2013 at 13:48
    The older cars gave you that feeling of almost uncontrollable power, because a lot of them were almost uncontrollable. Tires, suspension, brakes, safety equipment, etc... it's all come a LONG way since the late 60's/early 70's. I believe that is the reason that most people feel like the older cars had so much more power... they were harder to control, corner, and stop than modern musclecars, and felt like it. The old cars defintely had personality, though, and also a loyal following. You had to be able to DRIVE to get some of the older cars to perform to their potential.
  • 4
    John Northern Colorado August 21, 2013 at 14:00
    Nice write up. Those of us who grew up living and racing a mile high had to deal with another 20-30% loss due to the thin air. MPH still best indicator of horses. It can't be fudged or corrected, its the same at sea level or 6000'.
  • 5
    Joe Richmond, VA August 21, 2013 at 14:04
    I know that many V6 sedans would hand a classic muscle car its lunch at the strip. Heck, my Mini Cooper S has a working scoop on the hood and runs 0-60 in 6.2 seconds. But classic Detroit muscle captures something no modern ride can: a gone America that was on its way to the Moon with slide rules and Tang. A nation burning rubber as The Yardbirds or Black Sabbath blasted out, innocent of limits, slashed budgets, polluted skies, and practical family matters, like young gods playing with their newfound power. It was just flat-out cool. And finally, doomed. That makes it all the cooler to me and cannot be reduced to numerical comparisons. By the time I got my license in '76, the thunder was rolling off into the distance, then gone.
  • 6
    Jeff So. Cal. August 21, 2013 at 14:50
    That would explain a lot about how my '58 Ford Custom 300, with a balanced/blueprinted 352 C.I, with a 406 solid lifter cam, 10:1 comp. and a toploader 4-spd was kicking butt on both 348 and 409 Chevys, 383 C.I. Mopars, whom I guess now, were lying about H.P.. I had RWHP of 310, pushing my 3800 lb. tank around. So I guess honesty is the best policy.
  • 7
    Kirk Aldrich Genoa,Oh. August 21, 2013 at 14:59
    I had two friends that bought Chevelle's. The 1st.was a 69 396 375 h.p.4 spd.4:10 gear. He added headers,slicks,ran 12.72@ 107 mph. The other was a 70 454,450 h.p auto w/4:10 gear. He added a Eldlebrock hi-rise intake,headers,slicks,4:88 gear and ran 11:88 @ 112 mph. Much better than people give those cars credit for,but still no match for the new technology. I had a 2008 Z06 that ran 11:98 @124 mph.bone stock. I have a friend with a 2006 Z06 w/long tube headers,drag radials,goes 10.98 @ 128 mph. New cars are amazing!!
  • 8
    dan colorado August 21, 2013 at 15:03
    We bought a 2012 Rousch stage3 Mustang last Christmas. I've driven most the supercars over the years and this car does everything alot better. I still have a 64- 440 drag car and a 70 dart. Fun, but no comparison to the new cars
  • 9
    Randolph Jon Geminder Amityville, NY August 21, 2013 at 15:27
    I am the original owner of a '72 Camaro, insured by Hagerty. It was delivered in December of 1971. Those were the days when you ordered YOUR car, with accessories a la carte. I didn't have the money for the SS or the Z28, but I purchased it with the best extras I could, which were: 7" ralley wheels (with white- lettered Tiger Paws at the time), the spoked steering wheel, the four-speed on the floor, and the 350 v-eight. Also (for an additional $100!) the instrument cluster, including all gauges and tachometer. Including taxes, the car cost $3300 - just about one dollar a pound. Though simply called the Sport Coupe, and by no means a "muscle car," it still stands out in a crowd, and runs like a top. Couple that stick with that 350, and by today's standards, it is quite muscular. There are 122,000 original miles on it - onlookers these days inquire as to what kind of car it is, thinking it's some exotic new vehicle!
  • 10
    gary quilliam Freeport, NY August 21, 2013 at 15:44
    I have a '72 340 Duster with a hp rating of 240. As i'm not about to take it to the drag strip, what I'd like to know is if the 72 340 was rated the same way the 71 was rated (at 270 hp) what would the '72 be rated at; apples to apples?
  • 11
    Richard Columbus Ohio August 21, 2013 at 17:28
    I have a 71 Camaro Z/28 350 ci 330 hp , 4sp 410 gear I also have a 2006 Pontiac GTO 364 ci 400 hp 6 sp The Z/28 is real fast but the GTO will fly>>>>>>>technology is amazing>>>>lol
  • 12
    Barry Tiegs Eganville On August 21, 2013 at 17:30
    Well I am a baby boomer and had Chevy SS's ; RoadRunners, Duster 340's and a Camaro in my time plus 2 74 Corvettes- still have one convertible. So I had lots of fun with those vehicles in their time. For their time they were great cars ; especially in a straight line. Of my bunch only the Corvette had better handling and braking for 1974 era. I have driven the new generation Mustangs Camaros and Challengers and am of the opinion that they are much quicker; faster and immensely better handling than the pony cars of my generation; plus the electronics now that in my day was almost non existent. I love the the pony cars of my generation BUT I wouldn't want to be racing for ownerships against the new breed
  • 13
    Andrew Miami, Fl. August 21, 2013 at 17:30
    The old musclecars had a lot of room for improvement internally without ever changing the camshaft. Muscle Car Review once dyed Ram Air III and IV engines. Rated at 366 and 370 hp, they produced 370 and 400 hp respectively with fresh refunds and unported heads. So Pontiacs ratings were honest.
  • 14
    Keith Miller Cypress, TX August 21, 2013 at 17:58
    I am interested in why everyone thinks the muscle cars started in the 1960's when they actually started in the 1950's. Pontiac put some real horse power in their 1957 and 1958 cars. 1958 was golden anniversary for Pontiac and they put a lot into their cars that year. The 370 cu in engine came in 4 different ways from the factory: 2 barrel carb., 4 barrel carb., fuel injection or 3 - 2 barrel carburetors. The car generally came with a 4 speed hydro-matic transmission but could also have a three speed standard transmission. One engine did not make the brochure which showed the maximum horse power at 300 hp. but was a special NASCAR Engine which produced 330 horses and with the 3 - 2 barrel carburetors could make it through the quarter mile in under 13 seconds with a car weighing over 4000 lbs. Something you might want to look into. When did the muscle cars really start appearing?
  • 15
    Brian Pensacola Florida August 21, 2013 at 18:13
    Great article that provides an ability to make an apples to apples comparison. And, as an owner of a 1970 Firebird Formula 400 (335hp, or is that 290?) I'd like to get that 1970 article. Thanks for the good info.
  • 16
    Mr. J home August 21, 2013 at 19:26
    Your numbers sound right to me, especially the Pontiacs. I had a '77 TA 6.6 4 speed 3.23 back in the early 1980s. Though giving up 20 hp to the '79 C&D tested I ran the same mph, 96-97 at 15 flat-14.90s. I did have true duals (no cats) and lighter advance springs in the distributor, pretty much what Pontiac did to get the extra horses IIRC. I then added 1970 RAIII heads and 1.65 rockers, tweaked the secondaries and changed the metering rods, also opened the shaker (for the most part making the engine 1970 specs) now running consistent 13.80s at 100-101 with a 13.78 best. I think the old gross hp figures are useful to show the 'potential' of the engines with some basic mods. Of course we also gave to take into account the well known secret that the manufacturers played games with hp ratings for various reasons.
  • 17
    George Young Loudon, N.H. August 21, 2013 at 20:51
    Hummm, I own a 1969 Boss 302 and have had the horsepower conversation with many people over the years about my car. Your article helps clear up a lot of misunderstanding on my part and any one else who thought the horsepower ratings from that era were under rated. Thanks
  • 18
    Rich C Phoenix, AZ August 21, 2013 at 22:34
    As I've told people over the years, the stories of the 60's & early 70's muscle cars were highly exaggerated and the source or many urban legends. As the article states they were mostly one off, special tuned models for bragging rights and marketing. Today's go fast cars are faster, better handling, stop shorter and don't need the constant 'tuning; the older one's did. I was the one who was doing the 'tuning' on these in the 70's. Carb's, breaker point ignitions I don't miss them.
  • 19
    bob burgett portville ny August 21, 2013 at 10:56
    i own a 70-rs-ss 396 4 speed car and getting ready to restore it. i had a lot of fun with it over the years. last year i bought a 2010 camaro with the 6.2 rated at 426hp, 6 speed. i really love the car and it really runs great. overall i have the best of both worlds, old and new, i love both of them. thanks bob
  • 20
    gerry larrivee erda, utah August 21, 2013 at 23:03
    No mention of the weight : hp ratio?
  • 21
    Don Granger St. Louis August 21, 2013 at 23:30
    I've got a 66 Fairlane GT 4-Speed, 3.25 locker Convertible who's 390 was rated at 335 HP. My daily driver is a 2010 BMW 335 wagon. Both have similar rated HP, and truth be told, the wagon would probably win the drag race between the two and would win a road course race hands down. But... the Fairlane delivers a bigger kick in the pants. There's just something about the old raw delivery of performance that cars of that era had.
  • 22
    Tim Taylor Ogden, UT August 21, 2013 at 11:50
    A related myth is the one that the horsepower rating for the 1969 Shelby GT500 was understated at 335-hp (some say for insurance reasons). It will be interesting to apply this cited formula to calculate horsepower for it. Thanks for the interesting article!
  • 23
    steve the OC August 21, 2013 at 12:02
    The attempts to use modern dynos, old(or cosmetically restored) cars in unknown condition and an absolute lack of tuning really do the old muscle a huge disservice. Hemis, LS6s, Boss 9s,etc still make big power. The claim a properly tuned L88 only makes a few hundred net horsepower is simply ridiculous. In today's age of computer controlled engine management that always keeps the car in perfect tune, its easy to forget that the classic muscle required an enthusiast owner. An hour spent dialing in the old engines could produce big gains-it would still be stock, just set up to run as designed. Another aspect of "the old days" ignored by this test, is that many of the factories that produced the old warriors knew and expected that the stock exhaust, air cleaner, tires,etc would be immediately trashed. Running a COPO 427 Camaro on a dyno with its tiny single exhaust certainly doesn't reveal the true power of the engine. Nor does a Hemi Dart produce any power with an exhaust never intended to be run on the car. When GM tested the ZL1 Corvette way back in 1969, it ran 10s with an open exhaust and sicks and an auto trans. Stock motor-seems like 500+ horsepower to me(yet rated 425). A huge reason for todays great quarter times is fantastic traction management and launch controls. While todays motors undoubtably are better and produce big numbers, trying to claim the legends of old are wheezing relics is nonsense. Let me get a few of the old guard together with a couple super tuned musclecars and we'll show you a true indicator of their power.
  • 24
    Rocco Southampton NY August 21, 2013 at 12:07
    I have a 67 Camaro with a 427 L88 rated at 435hp ,properly tuned has 527 dyno hp ,it run 11.0 in a 1/4 mile all day long
  • 25
    Denny Chicago August 21, 2013 at 12:15
    You missed the BIGEST One the 1967 Corvette 427/435 or L-88 I just bought a GM crate 427 Gen VI and the words they chose was "Conservative" 460hp in the paper work. Enjoy your car! Denny
  • 26
    Suzi Findley Roanoke, VA August 21, 2013 at 12:16
    I own a '70 Chevelle, SS Ragtop with a 396 (402), 4 speed that I recently had bored with more than 375 hp now. Just one question. Why don't you include the '70 Chevelle SS's as muscle cars when they are/were truly some of the top dog muscle cars?... especially if they have the 445 engines in them. Looks to me like some people are Ford biased. Just saying.......
  • 27
    David San Jose, CA August 21, 2013 at 12:18
    I love the classic muscle cars and in fact I have a few in my corral. But there is no disputing the advances in recent years. For example most tests put a 1970 Boss 302 Mustang at 14.8 in the 1/4 mile, at 95mph. Contrast that with a 2013 base V6: 14.0 at 103. Not to mention that the new Mustang will get 30mpg on the highway. That's real progress! (But I will take the '70 Boss 302 over the new one, all day long!)
  • 28
    Bob Magee Butler, NJ August 21, 2013 at 12:22
    When your vehicle is covered by the insurance co. they rate your cost by the horsepower. If it says it's more you pay more. Like motorcycles, some are rated by "CCs" If you have a BSA 650 CC you will pay one rate. If you look the spests up in the factory manual, the actual CC is 648. That s in a lower rate. Always check your factory manuals for the correct HP or CCs.Bob
  • 29
    John Buban Washington State August 21, 2013 at 12:33
    I would think that the true hobbiest of muscle cars would understand the horsepower ratings of muscle cars, and would not be blinded by the change in rating specifications. As an example, Chrysler, for the enthusiast back then, did not give horsepower increases with added performance parts. Chrysler created tables during the 1960's on how to gauge the performance of their cars for the drag strips in changes to both ET and speed. The performance enhancements also included changes in weight as well as suspension changes. A horsepower increase could be ascertained from the increased performance at the drag strip. If you look at the factored horsepower for the various classes of drag racing back then by NHRA, you will see that typically Chryster cars were factored up relative to their claimed horsepower while GM cars were factored down. This was an attempt to level the playing ground. This factoring actually made many B-body cars by Chrysler no longer competitive. So here is another arena where horsepower gets confusing. I personally know that cars are more powerful today than in the Muscle car era. I know they handle better (much of that is due to tire technology). I believe the mistique of the past is a good thing. Finally, I believe the muscle cars of their day out performed everything around them just like performance cars today out perform the grocery getters of today.
  • 30
    Travis Williams San Diego, CA August 21, 2013 at 12:41
    Great article! I own a 1971 Chevelle SS 454 (LS5). Something very interesting to me since I have translated some of these horsepower numbers myself. As mentioned in your article, the change in the way horsepower ratings were measured is a math problem for us that want a real comparison for cars made in 1972 and after. I find it difficult to compare the muscle cars from the 60's and 70's to the modern day muscle cars. Truly "two different worlds!" Regards, Travis
  • 31
    Evan Phebus Scottsdale, AZ August 21, 2013 at 12:50
    Another great article.
  • 32
    Robert Jordan Arlington VA August 21, 2013 at 12:57
    Another point to add in regards to leaded gasoline's used prior to 1971 was the available octanes offered. I can remember 100 Ethel octane was required for all muscle cars of that period. Being that higher octane levels allowed for less advanced timing to burn fully on the power stroke. Once they removed the lead and 100 octane level that's when pre-ignition issues came into play requiring reduced compressions. The other issues showed up 'over time and after many miles' on the eroding of top compression rings and valve guides with the lack of lead causing more blow-by and making less horsepower.
  • 33
    Jimmy Gaines Austin, texas August 21, 2013 at 12:59
    This article is very misleading. At the same time the change from using Gross ratings to Net ratings occurred, Compression ratio was lowered considerably, in some cases cam timing was retarded, more restrictive exhaust was added, cam profiles were changed, all resulting in the engine itself absolutely making much less horsepower. And as far as the Boss 302 engine goes, the only stock quarter mile times done in magazines used very stock cars with high axle ratio and street tires. It is simply impossible for this motor not to have been well over 300 horsepower ( this engine used 351 cleveland heads , which are some of the best flowing factory heads ever made.
  • 34
    Ian @ Jewel or Jalopy Portland, ORE August 22, 2013 at 01:52
    It's also not just about the peak number, it's about how much power you have throughout the usable RPM range. You don't drive a car at one engine speed.
  • 35
    Vern Virginia August 22, 2013 at 19:55
    My '03 Mustang Cobra just dynoed 468 HP at the wheels. with bolt on mods and a tune. My '74 vet L 48 is a rated at ,I think,, 195 HP net. Both are fun cars but from a different time.
  • 36
    Harvey Mushman South August 22, 2013 at 08:51
    Myths indeed. Not hardly. I was there!
  • 37
    T. Saxe Grand Rapids August 22, 2013 at 09:37
    I have had a few muscle cars (insured by Haggerty, too) and never restored them to the low HP factory specs. They looked factory, but with my 1968 KR Shelby Mustang, I left off the snorkle and smog equipment. With my Buick GS 455, I had the engine built to Stage 1 specs with modern pistons, cam, valves and so forth. Vintage muscle cars are indeed all fast and fun, but I sincerely believe that we are presently in the golden age of horsepower.
  • 38
    rex morley Rose Hill, Ks. August 22, 2013 at 12:33
    In 1989, we took our 70 LS6 Chevelle (about 18,000 miles on the clock then) to the local strip (WIR), to see what it could do, validate it's ability, and with heat wrapped 2 & 1/8" hooker headers (closed), with full 2 & 1/2 half standard bent bent exhaust piping in stock configuration, with so called "Turbo" mufflers, a carb base heat shield (homemade and polished aluminum 2024 - T3 .040 plate), along with L-70 x 15 (on mags, stock was 14" rims), Goodyear tires turning the 12 bolt 3.73 posi gears, 4 spd M22, and ran a best of 13.23 @ 113.xx mph in the quarter. I don't recall the 60 foot figures, but at the time, we saw that the 60 foot times sucked for the outcome from lack of any decent traction for at least 120 +/- feet. Except for the above mentioned mods, the rest of the vehicle was stock, as it is today, and still powerful feeling at 44,xxx miles and while we have a couple of more modern performance cars that I'm sure would best this beast on any surface, that feeling from the old LS6 under WOT is still hard to beat.
  • 39
    Ron Wahl Michigan August 22, 2013 at 12:39
    We owned a 1970 BOSS 302 and loved the look, but not the lack of torque down low, especially with a 3.50 gear! The new '13 BOSS literally blows the original away, performance wise, with a similar look! Way to go FORD!
  • 40
    Hal Thayer Santa Rosa Calif August 23, 2013 at 13:22
    I have a 1967 Camaro RS , I don't have a clue what the Gross/Net HP is ,the gear ratio or original specs were....don't care !! At the time it had only the 210 HP , 2 barrel carb 327 motor and it still had plenty of "Power" ...I know because I used to drive it to High School...yeah ,there were a couple Mopar and Big Fords around at the time but the the RS jerked my Head and put a smile on my face. Luck would have it my Mother was the original owner and " Repossessed" it from me ! Now , 46 years later , it still has the stock block , but I put a 4 barrel with an Eddelbrock manifold , Headers and Flowmaster Exhaust...it still jerks my Head and puts a smile on my Face !! As far as the New Camaro , I don't even like them...feel like I am cooped up in a tiny Box,can't even enjoy the better Technology and specs...and though the Style is Retro Cool, it still ain't "as" Cool !! Wouldn't trade my car for 2 new ones...OK maybe 3 or 4 of em ! My Mucles aren't what they were at the time but the Cars are.Muscle Cars of that time were, are, and always will be "The Best" . O to 60...who cares, its all good ! Know Mom would still be proud of her Baby , ( got her name on the Plate) and proud of me for not letting her "Get Away"
  • 41
    Norm Kentucky August 23, 2013 at 06:03
    Were the test on the original Boss 302's done WITH the factory rev-limiter still connected? Makes a difference!
  • 42
    billcamino San Diego August 23, 2013 at 10:29
    1970 Trans Am had a 455.. not the same 400 as the Formula..
  • 43
    Chuck Klim Newton,New jersey August 23, 2013 at 22:34
    Great article, I had one of the most under rated muscle cars, a 71 Boss 351 that I bought new. This car ran 13.4 @ 106 mph and was bone stock except the rev. limiter was disconnected. It was rated at 330 hp at the time. Today I have a 2003 Mustang Cobra That runs 11.61 @ 121 mph and can get 25mpg, just love the modern tech. I have this car and 2 old tractors insured by Hagerty.
  • 44
    Harold Johnson San Francisco bay area calif August 25, 2013 at 03:55
    Unequal comparisons ! Old school got it done with; heavier cars that had a REAL rear seat and trunk, way fewer gears ( 3 or 4 ) vs 5 or 6 speeds today ! Tires were not as preformance constructed. etc etc. My 1974 z28 4 speed has surprised me AND many modern "computerized" vehicle owners during a throw down on the freeway from 50 mph to as far as we dare take it---even though I changed the 3.70 rear gears to 3.08 for better fuel economy !! I know for a fact that it's not just hp to weight ratio, BUT if my 74 camaro had a 6 speed manual with overdrive, both off the line and mpg numbers would be awesome !!! Anyone with an overdrive tranny would get lousy gas mileage if they drove at 65 mph in 1 to 1 tranny drive instead of 1200 rpm 6 th gear !! I still toy with the idea of putting my spare 496 cu in square port bb chevy in my z28 -- can't decide between a road race 5 speed or 6 speed tremic with those super low 1 st gears --- can you see a dodge viper owner thinking twice ??
  • 45
    Jack United States August 26, 2013 at 22:32
    I am a former Chrysler power train engineer. The 426 Hemi ran between 485 and 510hp on the dyno with air restriction (dyno inlet and filter), water pump, alternator without load, and cast iron headers. Tuning and and prep had Jerry Stahl's '66 B body running low 10s in factory stock. Every once in a while, one of these engines would come from the factory close to blueprint specs, and some lucky person had a nice ride. By the way, I own a 4spd '68 Hemi Charger R/T with 13k miles. Eat your hearts out!
  • 46
    John Kranig canton michigan August 27, 2013 at 18:02
    In comparing acceleration performance of today's cars with ones of 40 plus years ago it must be remembered that the tire technology has had a major impact on vehicle performance as well. For instance a 1970 Boss 302 with modern tires would have much better acceleration numbers. I know that basically stock 1970 Boss 302's with slicks would run in the mid 13 sec. quarter mile times just due to the ability to transfer the power to the road surface. I have talked with one of the Ford Boss 302 engine development engineers from the 1969-70 years and he quoted the gross dyno hp as being in the 370 hp range with the Ford "B" curve hp in the 315-325 range which is nearly net except for exhaust system power losses which were not to much on the Boss 302 exhaust system. So the 290 hp advertised maximum wasn't far from the true net value I believe.
  • 47
    Peter Clark Newmarket Ontario, Canada August 29, 2013 at 12:29
    Power?? to scare your pants off and make your knees turn to jelly? That was my 69 Dodge Coronet RT with its 426 HEMI & Isky 550" Solid cam & MT Headers & DANA 60 456 Gears on only 15" Cragar SS wheels and bias ply tires, it ran 11.6 in the 1/4 mile at 125MPH and 180 MPH on the stock 3:23 gears when I changed the neck-breaker gears. Today my new '13 Challenger SRT-8 392 (6.4L) HEMI has 492 HP with all the gizmo's I would liked to have had back then and it winds up real fast and I suspect not much will beat it! But give me back my ''68 Hemi and I'll give her a hug like I did back in the day Maybe it's the tires & hyd suspension and steering that seems to calm the performance today but even though I love the new MOPAR, not until Chrysler stuffs a modern 426 HEMI with that secret dual overhead cam will the performance world see the most blazing engine that wass ever built!! Yeah, I' still living in the past because we were the pioneers of street & strip racing and because we were the first, it seems nothing else can ever come second. MOPAR or no car!! FORD (Fix or Repair Daily) and GM's I'm just sick and tired of everybody bragging about their small block Chevy 350's, there are too many of them, I was never beaten by any of the competition, quite honestly and yeah I had a few of them too.
  • 48
    Garrett Pierce Michigan August 30, 2013 at 22:06
    One thing you neglected to mention here is the quality of gasolines available for modern engines today vs. those required for the musclecars of yore. Different world indeed, since many of the strongest musclecar engines from 40-45 years ago would struggle to run on the modern "junk" gas available today. Sure you can do things to compensate, but it's still not the same as what was available back in the heyday of those old cars. Horsepower ratings have always been a huge debate among those who believe their car to be better or more powerful than others, but the speed calculator never lies. It is what it is. I do find it very interesting that when i go watch "Pure stock" musclecar drags, the times being recorded by many of these original old cars is still substancially quicker than what was ever recorded back in the old days, which is saying something since many of these supercars are running on original type rubber(Firestone wide-ovals/goodyear polyglass GTs) since the group here in Michigan doesn't allow running slicks. Although most of the quick cars are dyno tuned, you can't argue with 11.0s and around 120mph from L-88 Corvettes, high 11s from L-78 Novas and Camaros, plus lots of GTOs and other cars running in the mid to high 12s all on original rubber from 45 year old engine designs. Today's cars are nice, but the expense of them sure makes them just as prohibitive to younger car buffs as those old ones did. That much will likely never change.
  • 49
    Don Misler East coast August 31, 2013 at 07:06
    It's personally what the individual wants, like a lot of us that for any reason, couldn't afford or didn't buy the "original" then, but enjoys it now! For me my "72" stingray (year I graduated) takes me from (almost) 60 to 18 in about the time it takes you to smile. Enjoy what you own! Own what you enjoy!!
  • 50
    Tominator Cahokia August 31, 2013 at 22:47
    I lived through the days of SAE v. NET Hp ratings....made a good read but as some alluded to it was the reduced compression that stopped the HP wars...I lust after my Olds Starfire BTW...10.25 ratio proudly displayed on the air cleaner.Those old cars were slow regardless of HP rating compared to the CID of today. I've had over 75 cars trucks and motorcycles and dragged raced many of them and even set some track records. I miss them but also embrace the technology that makes those old Muscle Cars relics! Enjoy them and restore them but accept the fact that old is slow........Damn! I want my 428 Cougar back.....but my HHR SS does EVERYTHING better......including the 1/4! Oh, that's my DD.....My Ranger does 12.5s in the quarter and still retains every amenity know to man......brag all you want...today is much better...now where's my HEMI cup holder?
  • 51
    Anthony Brooklyn January 4, 2014 at 11:43
    So basically what you're saying is 70% of people are lying about what their cars did back then? Only one way to prove it. Bring the cars to the track with a good set of tires and high octane gas. Slowly detune or tune from there depending on results. The end. I like both old and new muscle cars but this debate is getting dull after all these years.
  • 52
    Mark MQ1 Cottonwood Ca July 28, 2014 at 13:03
    Time marches on. We are living in the best of times right now, and yet I yearn for my 67 Mustang GT. Red/Red. 390, 4 speed. A brute! No A/C. No pwr. steering. AM radio. Power disc brakes, though! Pass anything but a gas station! That car set me back in the seat like nothing before or since. I miss it, and I miss the time.
  • 53
    Robert Crase KS September 29, 2014 at 15:23
    Then can someone tell me what my 69 charger with a rebored 440 magnum that has a few modifications that allow it to have the dual imaged twin turbos the super charger and blower the last Dyno test said 3600 hp and 3400 torque with a 3.41 rear gear ratio.
  • 54
    kevin berry st.thomas ontario October 2, 2014 at 07:23
    I own a 1971 Torino GT 351C 4v bone stock ,if I was going to run it against my 6000 pound Ford F150 (2010) 4X4 with duel exhaust ,cold air and programmer the truck wins hands down . The rated 285 10.7:1 comp just seams anemic in comparison esp the trucks rated hp for the 5.4 litre is 320, but in saying that nothing is as cool as an old car
  • 55
    Shawn Atlanta December 11, 2014 at 15:38
    Easy to solve. Take your car to a dyno. My 67 corvette tri-power 435 hp dyno'd 405 hp at the wheels. If you tune the carbs, tweak the timing, let the car breath by removing the old exhaust manifolds, you will be surprised how much these old engines produce. I made minor changes that can be easily brought back to stock: Sanderson Headers, MSD ignition, K&N air filter (took off the terrible foam), 100 octane gas, etc. Today's gas is a joke, performance cars in the day required higher octane. I think some cars are an exception to the topic of the article: 302ci in the Z28 (let that motor breath and watch out), 427 tri-powers, L88 corvettes, Hemi Cuda, Max-Wedge, etc. to name a few. I also have a 2009 Z06 and that car will blow the doors off the 67. Still the old classic can hold it's own.
  • 56
    slashfan New York January 8, 2015 at 13:49
    However 1/4 mile times back then were on crappy bias ply rubber. Put modern radials on them and the big block cars soar into the 12s and dare I say 11s.
  • 57
    DocJ PNW January 21, 2015 at 18:04
    Rented a V-6 Camry the other day and my jaw dropped when hitting passing gear-this thing honks! Checked the specs later on the 3.5 liter and was shocked to see the thing turned 101mph in the 1/4 mile and a little over 14 ET! Can hardly tell engine is running at idle! It'll get 30mpg at 80mph too! Note: the 4 cylinder Camry of today will give a 1976-80 V8 Vette a run for the money :) We've come a long way baby!
  • 58
    phil S. Madison AL February 4, 2015 at 11:34
    I own three Boss' Mustangs a 1969 (Aculpulco Blue) Boss 302, a 1971 (white) Boss 351 and a 2012 (Kona Blue) boss 302. Here is the truth: With the 69 G code Boss 302 the magazine and newspaper tests at the time (all were conducted with a 70 Boss 302 because too few 69's were made to warrant an in-depth test) were conducted totally stock with the infamous rev limiter installed keeping the engine revs down to 6250 rpms. My car is perfectly stock 64789 miles on the odo, no add on's no headers no lopey cam, stock Goodyear F-60x15s the whole bit. The numbers (dynod in 2008) are in the 305-309 range for rear wheel HP at 6248 RPMs. Remove the rev limiter and accelerate to 7850 rpms (if you dare) and that jumps to high 370s rwhp (see sept 2011 muscle car mag) Now the 0-60 and 1/4 mile stats for an unmolested 69 Boss (6.89/mid 14s) are on the money. But, remove the Rev Limiter and the world changes. Now for the Boss 351 that was the shizzle. 351 Cleveland w/335 HP...ya right. I believe I got 412 hp out of it. That car accelerates to 60 in 5.8 seconds and runs the quarter in low low 13s stock! like Hot Rod magazine said in 1970...no one saw that coming
  • 59
    Doug Canada February 25, 2015 at 14:47
    Here's my study of the 351 Cleveland as per the factory literature I have. 1970: VIN H; 351 2V, 2 bolt mains, flat top pistons, 9.5:1 compression using 76.2cc (averaged) open chamber heads, small ports, 2.04 intake/1.65 exhaust valves, 250 gross HP @4600 rpm, 355 ft lbs gross torque @2600 rpm. 1970: VIN M; 351 4V, 2 bolt mains, flat top pistons, forged steel connecting rods, 11:1 compression using 62.8cc (averaged) closed chamber (quench) heads, large ports, 2.19 intake/1.71 exhaust valves, slightly better cam & valve train, 300 gross HP @5400 rpm, 380 ft lbs gross torque @ 3400 rpm. 1971: VIN M; 351 4V, 2 bolt mains, flat top pistons, 10.7:1 compression using 66.1cc (averaged) closed chamber (quench) heads, large ports, 2.19 intake/1.71 exhaust valves, slightly better cam & valve train, 285 gross HP @5400 rpm, 370 ft lbs gross torque @ 3400 rpm. 1971: VIN Q; 351 4V, 2 or 4 bolt mains, flat top pistons, 9:1 compression using 75.4cc (averaged) open chamber heads, large ports, 2.19 intake/1.71 exhaust valves, Cobra Jet cam, spread bore carburetor, 280 gross HP @5800 rpm, 345 ft lbs gross torque @3800 rpm. 1971: VIN R; 351 4V BOSS, hi nodular iron block w/ 4 bolt mains selected for hardness, selected hi nodular iron crankshaft, forged pop-up pistons, conrods shot peened & magnafluxed w/ 180,000 PSI bolts, 11.3:1 compression using 66.1cc (averaged) closed chamber (quench) heads, large ports, 2.19 intake/1.71 exhaust valves, solid lifter cam & valve train, spread bore carb on hi-rise aluminum intake, 330 gross HP @5400 rpm, 370 ft lbs gross torque @4000 rpm. 1972: VIN M & Q; same as ’71 Q except for camshaft retarded 4 degrees, 266 net HP @5400 rpm, 301 ft lbs net torque @3600 rpm. 1972: VIN R; 351 4V HO, same as ’71 R w/ the following changes; forged flat top pistons, 9.2:1 compression using 75.4cc (averaged) open chamber heads, solid lifter cam (retarded 4 degrees) & valve train, 275 net HP @6000 rpm, 286 ft lbs net torque @3800 rpm. 1973-74: VIN Q; 351 4V, 2 or 4 bolt mains, dished pistons, 8.2:1 compression using 78.4cc (averaged) open chamber heads, large ports/small valves, 2.04 intake/1.65 exhaust valves, Cobra Jet camshaft retarded 4 degrees, spread bore carburetor, 248 net HP @unknown rpm, unknown ft lbs net torque @unknown rpm. I mention the VIN H 351C 2V only once (1970) as a base reference. It was avail in other yrs w/ only slight changes fr ’72 on. Note that VIN H in these yrs can also mean a 351W (Windsor) engine; a completely different block & design. VIN H in any Ford can be either Windsor or Cleveland during the ’70 thru ’74 model yrs. Note that Ford never built the same 4V Cleveland 2 yrs in a row; save for ’73-’74. Every yr there were small differences even using same VIN codes as previous yr. Also, I am certain that compression dropped on the '72 M & Q engines compared to their '71 versions but see no documentation of that in the Ford literature I have. I also want to state something about HP. I believe Ford, for the most part, used conservative gross ratings. In some cases HP did not lose much when Ford switched to SAE net ratings (compare '71 to '72 Q code). But it is misleading to think that similar engines between different yrs would be as close in performance as published factory ratings seem to indicate. Many automotive journalists of the time agreed that the BOSS 351 was very close to, if not in excess of, 400 gross HP. Yet Ford rated it at 330HP. Anyone who drove these cars (GM & Mopar incl) during the yrs compression dropped & camshafts were retarded to meet emissions specs knows that the newer engines were pale imitations of the former. In some cases they weren’t even close; unless you chose to be blinded by factory ratings.
  • 60
    Brian Samuels Washington, DC March 19, 2015 at 19:41
    Honestly I prefer old school muscle over modern muscle. When I drive my 68 impala 2 door HT coupe. It feels like a man's car. I just dropped in a NA 496 big block stroker that dynoed at 561hp and 585tq on 9 to 1 compression. 3-speed th400 transmission with 3.36 rear gears. It takes skill to drive it fast. No help from a computer, plus it's all 50 years old. I doubt if modern muscle can last for a good 10 years with out falling apart. All that cheap plastic and stuff. Plus its highly overpriced. New cars are meant to be recycled not collected like old school muscle.
  • 61
    Phil Island lake,il April 29, 2015 at 20:12
    The only similarity between old and new Detroit iron is the shape. It's almost the same as comparing a Tesla to a Ferrari there's almost nothing in common. It was indeed a simpler time when a good start for young man was used Chenille for 800 bucks and the exhaust note alone was intoxicating.
  • 62
    Dino Minneapolis, MN June 14, 2015 at 00:03
    I don't know about the new cars, but I modified a 1970 Roadrunner with a 383 and stuck an Edelbrock Torker manifold with an 800 double pumper, Mallory dual point, Accel super coil, 727 Toqueflite with an 11" torque converter and manual valve body, Dana 60 rear end with a 3:23 gear, and Mickey Thompson L-60 tires (and a few other parts), but that car would be just over idle going down the highway, getting 16 m.p.g. and I could drop it into 2nd gear and chirp the tires @55 m.p.h. and take it up to 110 in 2nd gear and when I hit 3rd it would finally release you from pushing you against the back of the seat, and it would easily climb past 150 m.p.h. I did that in 1981, and those cars are going for quite a pretty penny these days. I'll never forget the time I dusted off a Ferrari on the highway. Of course I built that car for top end speed and not quarter mile performance. But it was easy to build up a car to 500 H.P. back in the '70's and into the '80's. Parts were more easy to get and to swap out, and you could do a modification in your garage, one at a time, on the weekends. I guess that's what made it so much fun. The performance game is just so out of reach today for the average person. That, and the laws have changed so much over the years, it almost isn't worth it.
  • 63
    Peter Pleitner Ann Arbor, MI July 15, 2015 at 20:27
    A bone stock 1968 Camero Z-28 was dyno'ed at the rear wheels in Cologne, Germany in 1998 or so at the TÜF for an importer. It recorded 400 DIN hp @ 6500 rpm (+/- 3% not certain but close about that). It was later written up in an article for Klassic Auto magazine.
  • 64
    Dean M Detroit, mi July 17, 2015 at 16:35
    While working on the Viper program, I was asked if I'd like to bring my 1971 396 nova along when we were testing at Milan dragway. We brought SRT challengers, an SRT charger, and a few vipers. I fired up the nova, which has a lots of camshaft and sounds quite wicked. Everyone liked it. I cranked out several 13.50 runs at 103 mph. We put the intern, who had never seen a dragstrip before, in the scat pack charger, and told him to push on the gas when the bottom light turns geen, then let off the gas at the little timing light down at the end of the track. 12.20 at 107.
  • 65
    Dennis Tampa, FL July 18, 2015 at 07:32
    Yes, the new cars will out perform the old ones in every measure. But the old cars are way more fun to drive. My 1963 Ford Falcon with a 164 hp Challenger V-8 and two-speed Ford-O-Matic transmission puts a big smile on my face every time I get behind the 17-inch steering wheel. It makes my commute back and forth to work each day something to look forward to.
  • 66
    Michael Lansing August 19, 2015 at 14:48
    Just finished replacing 427 with 502 Ramjet fuel injected high rise manifold, etc crate engine from Chevy Performance. Oh yeah in 66 Corvette convertible. I own a 5 series and a 7 series BMW and have access to a 911 SC Porsche and am familiar with several other high performance rides. But I'm telling ya when I fire this thing up and roll her out there is no feeling quite like it.
  • 67
    Mike D Newark, De September 11, 2015 at 23:35
    I own a 70 Boss 302 with a bone stock motor(.030) and a set of hooker headers and with 486 gears I ran consistent 12.50's with one 12.40 at 109 mph. Using one of the horsepower calculators on line showed 375 hp. Gross of course, but the "myth" that they really produced around 400 is pretty much in line. Sure the gears helped a lot in the quarter, but the horsepower is what it is. I could see it running 14's with 350 gears as it has no low end. I saw another Boss 302 in one of those Hot Rod Magazine present day pure stock meets run very close to mine. It's all in the tuning. Sure the new ones are much faster(I just bought a Hellcat, and WOW), but some of the oldies really did make the power(or more) that they advertised.
  • 68
    Jack Brewer United States November 19, 2015 at 06:48
    This article misses a huge reality regarding engine power output and power bands . Perfect Example is the original Boss 302. It absolutely made big HP but at very high RPM . It was never a 1\4 mile engine by design. Huge ports and big valves dont lend themselves to low end performance. It's power certainly cant be measured accurately using 1\4 mile time or mph reached in that 1\4 mile . You simply cannot measure power by 1\4 mile .
  • 69
    Bob NC December 26, 2015 at 14:00
    Chevy still uses pushrods, and 2 valves/cylinder in their V-8s, lagging way behind Ford with their DOHCs, and 4 valves/cylinder. The Camaro Z-28 makes 505HP with 7.0L, while the Mustang GT-350 makes 526HP with 5.2L. Both engines are normally aspirated.
  • 70
    Scott Drummond Georgia January 11, 2016 at 11:27
    I agree with a lot of the comments posted previously. There have been quite a few topics touched on. I have been building and working on cars for more than 30 years. I owned a shop restoring and modifying them for 18 of those years. I own a 2006 Charger SRT8. It is impressive in almost stock form (K&N cold air intake and Magnaflow exhaust). Of course, factory HP ratings are 425. Keeping in mind that I have built many pretty wicked and powerful cars for street and race use, the performance of the Charger indicates ACTUAL power numbers in the 500+ range. Though it is impressive to be able to claim how much your engine dynoed at, there is nothing that compares to seat of the pants feel and actual performance figures. There have been many tests run, over the years, to get exact gross power numbers from stock engines, both old and current. It seems to me that the numbers have always been advertised on the conservative side for whatever reason. In every write-up I have read, the gross power measurements have been a good bit higher than what the OEMs have claimed. As for SAE gross vs net, one way to look at it, that might make more sense, is gross would be the total amount of power at the crank with no accessories, and net at the rear wheels in a fully dressed street car. Where the debate of old vs new is concerned, take a look at the advertised power numbers. Today's advertised, net numbers are generally higher than most advertised gross numbers from the muscle car era. Then take into account that today's gross ratings would be even higher. I agree with the statement posted that today's cars are made to be recycled. I call them "throw-away cars". There are only a handful of today's cars that will be around in 30-40 years. It's a shame to think that our younger generations might not have the opportunity to restore or modify a car that defined a bygone era and a simpler time. I know I am trying to pass that passion on to my children and expose them to that while i still can. It makes me proud that my 12 year old son has asked me to find a suitable 69 Camaro to restore with him as his first car. Just think... he could want a Honda.
  • 71
    Scott Drummond Georgia January 11, 2016 at 11:48
    I just want to clarify something I wrote in my previous post, before anyone takes it out of context. I made a statement about a simple way to look at the gross and net comparison. I don't want to give the impression that I think the rear wheel horsepower is the net figures being used. I'm just saying that is a way of trying to help understand how different the two numbers can be. Just wanted to clarify.
  • 72
    Russ California March 2, 2016 at 01:32
    I own a 1969 chevy Nova that was bought by my father in 69 it was my high school car. I restored it and love how people will stare at it and want to talk to me about it. It has all the modern tech that no one can see. I have a racing suspension and fuel injected 350 with a tremec 6 speed i usually suprise the other guy when i can beat him in cornering as well as the straight line so keep your cooky cutter
  • 73
    wayne australia May 8, 2016 at 02:40
    You can definitly get a rough HP estimate with a Moroso Power speed calculator. This is just weight moved over time.Simple,easy quick.It will give you a fair estimate on HP. I have done thousands of power runs on hundreds of engines in the time that i have worked for GM. GM power figures are on full complete engines with all accessories, full vehicle air cleaner and full vehicle exhaust system.Power figures are recorded after a full 4 minutes at each speed starting at 1200 to 6800 rpm WOT (max rpm depends on engine type) .What you end up with is a power run that can last up to one hour, the readings are then corrected to whichever standards that they wish to advertise and that will be your published figures.Different countries have different standards. HP is never obtained by the BS tests that you see at shows or on you tube.A ten sec transient power run is very inaccurate, giving only glorified overrated figures.I hope that this comment gets you thinking, if a stock engine can handle high rpms for such a long time on a dyno, can mine?
  • 74
    Doug Adam Canada May 17, 2016 at 18:37
    Seems to me that the gross vs net HP relates to NA vs European practice, of 'look good for sales' figures vs real life. Same applied to power ratings of audio receivers & amplifiers. My NA Motorola was advertised at 300 watts output by using peaks and adding both channels, whereas using European measuring methods it ran about 20 watts RMS/channel.
  • 75
    mike california July 4, 2016 at 16:37
    I grew up in Norcal in the 70's, and my neighbors and best friends' family owned a speed shop and raced at the old Fremont Raceway for many years. We drove properly set up (bigger carbs, hotter cams, headers, and larger wheel/tire combos) and correctly tuned muscle cars on the drag strip many times and their ETA's were at least 2 and sometimes as much as 4 seconds lower than published figures. Yes they were not stock, but the motors themselves were only lightly massaged using mostly bolt on components. Just as an exemple, we tested a 1970 Hemi Challenger, and found that properly set up and tuned for the strip and using 103 octane gas, it was putting down 521 HP at the rear wheels. A far cry from 425 at the crank, as was advertised at the time. Several things come to mind here... 1) a brand new engine bench tested without load on a dyno will produce anywhere from 5-8% less horsepower than a properly broken in and race tuned motor under load will. 2) You cant deny physics. If you have a 6-8 liter V8 motor running 12:1 or 13:1 compression with a free breathing intake and free flowing exhaust, you will create big horsepower. Period 3) octane will increase horsepower, not a ton but some. Using 103 octane gas will add about 3% to high compression motors, and 108 octane race fuel will add at least 6%. I realize modern cars dont need the stuff, but older cars, especially with high compression motors, were designed to use high octane leaded gas. 4) suspensions and especially tire size and compounds were very different in the late 60's and early 70's. Even some of the highest horsepower muscle cars had very simple suspensions not designed to put all that power down on a strip, and certainly not on a public road. Stock tires were seldom over 12 inches wide and never more than 14 inches on any car of that era that I know of. Nowadays you can buy family Hondas and Toyotas with tires that wide. The grip of muscle-era tires was also nowhere near as good as todays compounds. Put 24 inch modern soft compound tires on those old Ram Air IV's, Hemi's, SS's, L78's, Boss 429's etc with a modern suspension set up, and I guarantee the quarter mile times would rival most modern high performance cars.
  • 76
    Griz Oklahoma July 21, 2016 at 00:00
    The author of this article conveniently forgot to mention that the tires on performance cars today are infinitely superior to the tires used in the 1960s, both in tread width and in the rubber compounds used. So comparing the acceleration times for the muscle cars of the 1960s to today’s cars is like comparing apples to pineapples. A good example: a friend of mine raced a 1963 Ford Galaxy with the 425 horsepower 427 cubic inch engine in it in “A” Stock class at the drag strip in 1963. It typically turned 13.3 seconds at 113 mph on the 7-inch tread width tires used back then. The miles per hour is a much better indication of the engine’s horsepower than the elapsed time. That same car with the wider tires and better rubber compounds used today would be without a doubt, turning in the high 11-second bracket at the drag strip, about 1.4 seconds quicker than it did in 1963. When you factor that fact in, those cars were not really as slow as the author is stating, compared to the cars of today. If we’re going to make a reasonable comparison, let’s be realistic and fair. If you put 1960s tires on the performance cars of today, they would be significantly slower on zero to 60 and quarter mile acceleration because of the harder rubber and the narrow tread widths used back then.
  • 77
    Derek Stewart Tigard Oregon October 25, 2016 at 04:32
    I am a Professional Engine builder by trade and I have done a Ton of Engine dyno then chassis dyno comparrisons. Older auto trannies, TH400,C6 typically show a 19-22% loss Older 4 speed manuals almost always show a 15-16% loss Newer AT cars, Camero, firebird 12-15% New manual trans is 8-11% New auto 4x4 truck is 25-28% These are verified over 20 years of testing, so far I can tell if something is really wrong or if the hp claims were bs. Many of the BAD Big Blocks were really Bad! In a good way, most all were designed and tested with free flowing exhaust, the LS6 the L88's, the 375hp 396's, the W30 455 Olds, the RAM AIR 4 Pontiac's all made a Ton more power when used and operated as intended. Back then people didn't just buy a car they were entusiasts! They beat on them, Dealers were told,shown, and carried the parts necessary to really make your LS6 an LS6 ! I have done a Ram Air 4 400 Recently and in totally stock configuration it made 422hp 445tq, with Headers it made 454hp 490tq On the Mustang Chassis Dyno it put down 384hp and 412tq so pretty darn close. One last thing, most of the ET's were ran by magazine people and usually 2 or more people were in the car and they had crap tires, so I'm trying to put things in a more realistic sense, there is a reason some are legends, in totally bone stock form not man were fast, not like today where most people just wanna hit a button and go!!!
  • 78
    Rich McQuiggan Mansfield, MA November 2, 2016 at 01:53
    I agree that our memories are sometimes clouded and what we thought was fast wasn't as fast we remember. However what was never mentioned here was torque. All the big blocks of the day produced HUGE amounts of torque. They might not be as fast in the 1/4 mile as we thought they were but torque is what kicks you back in your seat, not HP. It was not uncommon to see torque figures in the 400/500 range in many of the big blocks during the 60's. Only recently am I seeing these numbers starting to reappear. I agree that the new cars are quicker (stop and handle a whole lot better as well) but the old cars had to contend with bias ply tires (zero traction), 4 gears (if you were lucky) and transmissions that were parasitic hogs. Take one of these cars out for a ride around town, go about 20mph and punch it. They might not have the legs of the new engines but you'll be smiling all the way to 70 or 80mph and then you'll remember why we thought they were fast
  • 79
    Cara Herrs Washington KS November 13, 2016 at 22:05
    What is the approx. Horse power on a 1950 flat head Ford with a Mercury crank with aluminum Edelbrock heads, 3 carbs and dual exhaust?

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