A 70-71 440 6 pack was rated 390 hp and 490 torque at either 3200 rpm or 3600 rpm, depending on the source. There are some some tests suggesting it actually made those numbers even when measured by the post 71 SAE net standard. An Olds 455 was up there too. One would need to conduct head to head stock tests to ever know the real world answer.
So you're saying the 70 Buick 455's torque rating was gross torque 510@2800rpm / GROSS TORQUE? And the 07 Viper's torque rating was 560@ 5000rpm / NET TORQUE? I'm not totally convinced on that yet? I've always thought that, that only applied to the two different ways that measured ratings were done in relation to horspower not the torque ratings? Huuuum? At 67 there's still time to learn in one's life! Anybody else want to chime in for the final word on this subject? Larry the Wizard or J.W. ?
Personally I don't know that I have ever bought into the net horsepower ratings. According to net ratings none of us had engines over 200hp. No way you could ever convince me that my 442 had 200 or less horsepower. My brothers GS 455 The same arguement. These numbers will never have a concrete answer.
Ok...I'm starting to believe... So I wonder where the net and gross torque ratings are being measured at? Could it be the same as where the two horsepower measurements are taken for net and gross? At the flywheel and the rear axle/wheels?
It is my understanding both net and gross are measured at the flywheel, the difference being gross horsepower is optimized for maximum power; no exhaust, no air cleaner, no water pump, etc. whereas net has all those items (and more).
Do not overlook drive train efficiency 50 years ago versus today. When measured at the the rear wheels, a stock 50 year old muscle car can make a lot less torque/horsepower than some of today’s muscle cars.
First, the "Fib Factor" https://www.stevelinden.com/blog/questions-and-answers-horsepower Second, Torque, Horsepower, and RPM are related by the following formula, Horsepower = Torque X RPM/5252, and Torque = Horsepower X 5252/RPM. If you know 2 numbers, you can solve for the other. Also, Torque = Horsepower at 5252 RPM. Look at any Dyno sheet and you will see this. Here is mine, If you graphed it out, the HP and TQ would cross at 5252 RPM. So torque is torque, just matters how it is measured. Both Gross and Net are measured at the flywheel. Just matters if all the accessories and exhaust are hooked up or not. Net will always be lower than Gross. Lets take our Viper, 560 ft. Lbs. of torque at 5000 RPM HP = 560 X 5000/5252 = 533 HP @ 5000 You can do that with any engine, but the figures are for Peak Horsepower, and Peak Torque, and they are at different RPM. A motor making peak HP at a certain RPM, will have less TQ at that RPM, and that same motor will have less HP at the RPM it makes Peak TQ. 1970 GS455 Stage1, 510 ft. lbs.@ 2800 RPM? That is 510 X 2800/5252 =272 HP@ 2800 RPM. So how do you compare our engines to modern engines? You can't really. 50 years of technological advances do produce more efficiency. Modern cars get more of that HP and Torque to the ground because of more efficient accessories and drive lines. But HP is still HP, and TQ is still TQ. And you can figure one from the other if you look at a specific RPM. So how were my numbers generated? Here's the motor on the Dyno, and the video, The motor isn't driving a power steering pump, water pump, fan, or alternator. It does have headers. So my numbers are Gross numbers, CORRECTED TO IDEAL CONDITIONS. So again, how do we compare our cars to modern muscle? You can't. All you can do is compare actual performance generated. My car has gone a best of 11.54, and my best trap speed to date has been 116 MPH at 4100 lbs. My best ET was generated on a great day at Cecil (1000' DA). My best trap speed came on a crappy day at Cecil (2057' DA). Modern muscle has Microprocessor controlled FI, that optimizes Fuel/Air under any conditions. We haven't even mentioned the Superchargers and Turbochargers combined with that FI. One more reason you can't compare our cars to modern cars. There is the butt Dyno though. I know my car makes me light headed and dizzy at times, when I am on it, it is hooked, and pulling hard. I have been in some Hellcats during some spirited driving. I think my car pulls harder. I have no doubt I would get spanked by one on the drag strip, it just doesn't feel that way in the car. IMO, modern muscle is civilized by the PCM(s) with their traction control, stability control, and Torque management. Our cars are just brute force. Anyway, those are my thoughts.
Thank you Larry! 602 hp/ 589 ft.lbs! That's quite a "slug"! Your answers are always food for thought! Now I'm an expert on torque!...not! When do I get my diploma? I love that video on the dyno!
The the best net HP in post #25 above, 305, is made by a Pontiac 455 H.O. To get to the RWHP knock off 15-20% for drive train loss. You are left with about 250HP net at the rear wheels. The modern muscle car with which I am most familiar is a 2014 GT500. It makes 600 RWHP with a supercharger. Its drive train loss is only 10-11%.
Interestingly, it was 310 for the A-body, 305 for the F-body. In 1972, it was 300 net for both. AFAIK, that was the highest of any 1972 engine save the 440 Six Pack, which was cancelled like a week into production.
