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Old muscle car RWHP numbers....

12K views 32 replies 14 participants last post by  MizzouRT 
#1 · (Edited)
I found this article online while I was doing some surfing and it kind of makes you appreciate the power todays muscle cars produce. The 454SS Chevelle and Yenko Camaro’s rwhp numbers are below what our RT Challengers put out. It sure is nice to have all this new technology! I still would love to own anyone of these old muscle cars though.


Chevrolet Muscle Car Dyno Wars - 1970 LS6 Chevelle - Super Chevy Magazine
 
#9 · (Edited)
In stock form, the original muscle cars were 14 and 13 second cars, with a few limited models running 12's or better. Today's muscle cars are 13 and 12 second cars, with a few cars running 11's. To qualify for the original Dodge Scat Pack (and Plymouth Rapid Transit System) a car had to be capable of running a 14 second 1/4 mile in stock form.

Today's cars make far more RWHP in stock form. Many of the old cars had highly restrictive exhaust systems, and the manufacturer expected people to replace the factory exhaust with long tube headers, hi-flow mufflers and bigger exhaust pipes. The LS6 was notorious for choking with the factory exhaust.

How restrictive was the factory exhaust? I ran a very mild 440 with headers. The stock exhaust had to be pulling at least 50 hp from it. With factory mufflers and exhaust pipes behind the headers and mild cam, it was building up so much back pressure that a quick run thru the gears, let off the gas, and it was blowing tennis ball size holes out the back of the mufflers. After blowing out several mufflers, I switched to bigger exhaust and higher flowing mufflers, and the car was much quicker. Mopar Muscle did a test with a 500 hp street 440, and the stock manifolds were costing 70 hp. So while today's engines make lots more RWHP in stock form, the old engines had a lot of cheap, easy power gains with inexpensive bolt-ons. And no computers to make tuning difficult.

But even allowing for the easy power gains, the old school engines no longer have the clear edge in horsepower that held for decades. A mild 440 can easily produce 375 RWHP, but that is still less than a stock 6.4.

As for drag racing, as others have already pointed out, the original muscle cars were a lot lighter. In the Pure Stock drags, you have to run the stock carb, intake, exhaust manifolds, heads, cam specs and a full interior on factory sized street tires. They do allow low restriction air cleaners and hi-flow mufflers and 2.5" exhaust pipes. With careful blueprinting, the fastest cars are breaking out of the 11.50 limit and getting disqualified for not having a roll bar. So a carefully prepared L88 Corvette or 426 Hemi can make sub 11.50 passes in close to stock form on street tires, which puts them close to a Hellcat. The big difference is the old school cars are much lighter and require highly skilled prep to hit those times, while the Hellcat can do it turn-key from the factory.

http://www.moparmusclemagazine.com/techarticles/mopp_0106_manifolds_vs_headers/dyno_numbers.html

http://www.hotrod.com/muscle_car_review/1402_pure_stock_drags_2013/
 
#14 · (Edited)
Today's cars make far more RWHP in stock form. Many of the old cars had highly restrictive exhaust systems, and the manufacturer expected people to replace the factory exhaust with long tube headers, hi-flow mufflers and bigger exhaust pipes. The LS6 was notorious for choking with the factory exhaust.

How restrictive was the factory exhaust? I ran a very mild 440 with headers. The stock exhaust had to be pulling at least 50 hp from it. With factory mufflers and exhaust pipes behind the headers and mild cam, it was building up so much back pressure that a quick run thru the gears, let off the gas, and it was blowing tennis ball size holes out the back of the mufflers. After blowing out several mufflers, I switched to bigger exhaust and higher flowing mufflers, and the car was much quicker. Mopar Muscle did a test with a 500 hp street 440, and the stock manifolds were costing 70 hp. So while today's engines make lots more RWHP in stock form, the old engines had a lot of cheap, easy power gains with inexpensive bolt-ons. And no computers to make tuning difficult.


Manifolds Vs. Headers - Dyno Numbers - Mopar Muscle Magazine Page 3

Pure Stock Drags 2013 - Muscle Car Review Magazine
I saw and episode of "Graveyard Carz" where Mark was saying that a lot of the guys were taking the stock manifolds off the cars and replacing them with aftermarket headers. He then said that some of the stock exhaust manifolds flowed better than the aftermarket headers. I can't remember what Dodge cars he was talking about though.
 
#10 ·
One other factor is the switch from Gross to Net hp in the specs, so pre-1972 hp specs aren't directly comparable. If you convert the hp ratings of the different engines available in 1971 Challengers, for example, there are only 2 that rate higher than the 3.6L V6 of today.
 
#11 ·
I've only owned my '12 Challenger R/T Classic for 3 weeks. Besides the power, I've been really impressed with the way it puts it to the ground. I've been known to do some real classic burn outs in my past, and while a good one is possible with this car, it's one hell of a lot harder to do than it was in the old days.
Take a big block Chevelle, or a 440 Charger/Road Runner for that matter, especially with stock tires and suspension, mat the loud pedal, and drop the clutch. You'll lay rubber till you run out of 1st gear, powershift 2nd and you'll still be burning rubber when you come back around the block. A buddy in highschool had a dual quad 427 and a muncie in a '69 Nova, if you matted the pedal at 50mph the thing would go sideways.
This car, while still stock, has nearly 400 real HP, yet will idle down the street at 35 mph in 4th gear with the A/C on and gets 21mpg on my 19mi mixed drive to work.
Try that with the 427 above........it was a ball to drive too, got 4-6mpg, had no A/C at all, and handled like a broken tricycle.

Technology is damn fun some days!!
 
#12 ·
The manufacturer's push for fuel economy is also benefiting the new cars RWHP. The drivetrain losses seen with some of the new cars, the 6.4 Challenger in particular, are less than the old rules of thumb would suggest. Some people have interpreted this as underrating at the crank on the new engines, but another explanation is a lower than expected drivetrain loss. Given CAFE standards, seems likely the drivetrains are getting more efficient, resulting in better RWHP numbers for the new cars.
 
#19 ·
Yes, recall watching that video when it came out. Good stuff. Definitely a Motor Trend vibe. If Hot Rod magazine was doing the same video, they would probably also be noting how the computers are locked and all the low hanging fruit has been plucked on the new cars.

Here is a video of a 68 SuperBee in Factory Stock condition (basically allows less restrictive air cleaner, mufflers and 2.5" exhaust pipe) running an 11.03 @ 126 mph on street tires. In an article about the car, he modified the oiling system to run lightweight oil (like our modern cars do) and that was worth 20 hp alone.

His best time with this car is a 10.95. In the FAST class that allows internal changes like stroker kits, bigger cams, and head work, he has run in the high 9's with a hemi Road Runner. Watch how great this Super Bee launches. His sixty foot times have to be great.

Here is link to an article about the build:
Obsessive - 1968 Dodge Super Bee | Hemmings Motor News

 
#22 ·
Today I can't help but think these are the good ole days hot rodding wise. Look at the cars we can buy for the street, yeah 38K to 50K is a lot but back in the day $5,500 for a 396/375 hp Camaro SS/RS was a lot of money too. What I think about, and am glad about, is the fact that back in the late 60's early 70's when the horsepower wars were on we didn't kill too many of us because of the narrow, low traction, bias ply tires. If we had today's tires and the traction they provide, we'd have rapidly found out the brakes on those late 60's early 70's muscle cars were real lousy too. I wouldn't have an original muscle car from that time frame, I would rather have a clone 69 Camaro 396/375, or a clone 71 Hemi Challenger with a crate hemi and upgraded suspension. If you buy for LARGE dollars an original 71 hemi challenger, 69 396/375 Camaro SS/RS the worse thing you can do is drive it and add mileage to it, so I'll take an expensive 396/375 Camaro SS/RS clone, or a 71 Hemi Challenger clone and drive it like I stole it, and show the rice rockets what real horsepower is all about. Just my 2 cents opinion.
 
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#23 ·
There were plenty of wrecked muscle cars back in the day. There was a boneyard close to my house were they would display a different car every week that had been in a bad wreck with a sign on them asking if you could identify what make it was. I remember going over to look at one of the wrecked cars with a buddy and we finally found a piece of a GTO emblem----it was that bad. The big thing was there was no where close to the amount of traffic that we have now. I own 71 Challenger with a 472" Hemi and I drive it a lot more carefully them my new Challenger just because I can't replace it. I've been wondering how many wrecked Hellcat's there will be-----maybe it would be better if they are priced higher then everybody can afford. And by the way at the time our Mopar's had some of the best brakes and steering but you had to know what your were doing. These new Challengers can make you look like a hero. I also own a 98 Viper GTS which can get you into a lot of trouble if your not careful---no anti-lock brakes----I like it that way. It's more like driving an old muscle car.
 
#26 ·
Hands down, the good ole days were the mid 90's/early 00's. I bought plenty of cars for $5k & under such as '70 Challenger R/T, '70 Challenger conv, '70 cuda, '70 Barracuda, '70 AMX, '70 Sport Satellite, '70 Chevelle SS 454 clone, '69 Charger SE, '90 454SS, '67 Cougar, these were really nice drivers that could easily be in car shows, drove everyday & most would out run the new stuff at the time, all for around $5k each. Gas was $1.25ish a gallon & title transfers didn't consist of any taxing, now it does. Could swap/sell and title for $25. To me it was an awesome time & getting that Bargain Post on Thursday was great not to mention a trip to a neighboring state you had to get a Bargain Post to see what stuff could be had in other states.
 
#27 · (Edited)
I agree these are the good old days for performance. The old school engines remain formidable opponents even on the street, let alone the drag strip. But in terms of emissions, maintenance, and fuel economy, the new engines are so incredibly good.

The only edge the old school stuff has is how much easier it is for the average guy to modify. Bolt on mods are simple, cheap and produce big power gains. On the new stuff, the computer is locked and the exhaust is already very good from the factory, so you are left with spray, supercharging, or going inside the engine to add much power. The 5.0 Coyote already comes with shorty headers from the factory, and the 392 and Hellcat exhaust manifolds are much closer in design to a shorty header than the old school exhaust manifold.

Some may be unfamiliar with just how bad most of the old school factory exhaust manifolds were. See attachment for a comparison of 383/440 manifolds and long tube headers. You don't have to be a mechanical engineer to see those stock 440 manifolds are highly restrictive. The second picture is the factory shorty headers on a stock 5.0 Coyote.
 

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#33 ·
BBC makes 1,200+ hp on stock cast internal rotating assembly

In this month's (Oct 2014) issue of Car Craft, they tried to blow up a stock Chevy big block (CBB) by adding twin turbos. They bought a motor out of a junkyard 1 ton pickup and put new rings in the short block. It did have 4 bolt mains, but otherwise it was cast crank, cast rods, and cast pistons. The stock 8:1 compression was boost friendly.

To make some power before blowing it up, they added an intake, 850 Holley carb, mild cam and aluminum heads. The cam hurt them on power, with a street friendly 226/234 duration. Lift was restricted to .529/.525 because the stock pistons didn't allow much clearance, also holding down their power numbers.

With no boost, they got 442 hp / 447 torque, with performance held back by the low compression ratio. With the mild cam, torque was always higher than hp at every level of boost.

With twin 76mm turbos hp/ torque:

7 psi: 607 / 667
11.6 psi: 730 hp
14 psi: 814 hp
19.2 psi: 958 hp / 1,032 torque

At this point, they switched to race fuel and cooled inlet temps to a low 61 degrees before adding more boost, eventually reaching 29 psi and producing 1,237 hp / 1,322 torque.

They tried adding more boost to break the engine, but their fuel pumps were maxed out. So they never did blow it up, despite running cast internals and reaching 29 psi of boost and making 1,200+ hp. These numbers wouldn't be shocking if they used one of the factory high performance engines with 4 bolt main and forged internals, but I'm surprised the cast rotating assembly held up to this punishment.
 
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