SAE Gross, Net, and Certified

[amazinblue82]

If you folks have bandied this topic about in the past somebody just point me to it.

Something is fresh in my mind from my recent Interceptor auction. Someone wrote me "advising" (with #$*@ words) me of the "dark place" where my head was regarding horsepower today versus horsepower yesterday, and how his CV P71 would 'run circles in reverse" around my 429-PI

After going through the whole SAE "Gross" versus "Net" versus "Certified" thing, and basically conceding his point that 300 HP "gross" yesterday was less than 300 HP net today, I told him what I was reporting were the standards that existed when it was built. Engine technology/fluid flow etc., has allowed for all sorts of improvements i argued since it was built.

Unsatisfied, he still had a bone to pick so that's when I reported him after he basically told me that my "mother mated out of season" (80's movie line..which one?) and the discussion had to end.

Whole episode got me to thinking..in reverse. Anybody know what today's 6.1L Hemi at 425 Horses SAE "certified" today would be in SAE "Gross" of yesterday: 650-700 HP? The Hellcat almost 1,000HP?

Or is my thinking messed up on this look-back hypothetical as it makes no technical sense?

Whatever the answer it doesn't diminsh our "old iron" at all in my mind and probably none of your minds either. Appreciate anyone's views on the hypothetical question.

:sSig_thanks:

 

[cm23uoc]

On the other Hand the SAE gross numbers given by manufacturers, especially for the Ultra high Performance cars back in the day were most often underrated due to insurance reasons or even to undermine corporate brass legislation concerning hp in medium sized cars.
Best comparison will be today's SAE net, numbers for the old Hemi in stock form should be available I guess to compare.

 

[amazinblue82]

On the other Hand the SAE gross numbers given by manufacturers, especially for the Ultra high Performance cars back in the day were most often underrated due to insurance reasons or even to undermine corporate brass legislation concerning hp in medium sized cars.
Best comparison will be today's SAE net, numbers for the old Hemi in stock form should be available I guess to compare.

I read SAE 'net" in 1971 for 426 Hemi was "350 horses"...didnt notice anything about previous "understatement" by Chrysler on the "gross" as was routinely done by all the Big Three around that time.

 

[MrMoparCHP]

Also keep in mind that back in the day it was at the crank with no accessories, today it is at the wheel on a fully outfitted car.


Alan

 

[cm23uoc]

http://driving.ca/bmw/m5/auto-news/news/five-of-the-most-underrated-engines-and-their-true-power

Here is an article about supposedly underrated engines of the old days.

 

[amazinblue82]

http://driving.ca/bmw/m5/auto-news/news/five-of-the-most-underrated-engines-and-their-true-power. Here is an article about supposedly underrated engines of the old days.

.

interesting. so these folks say L88 under by 80HP, 426 Hemi under by 45HP, and 428 CJ under by 75HP, from original SAE "gross".

dyno sheet (source: allpar and footnoted not necessariy a production engine) attached at link below from Chrysler in July 1965 says 426 Hemi max HP of 463 at 6,000 rpm and max torque of 472 ft. lbs at 4,000 rpm. so maybe another confirmation of factory "underrating".

http://www.allpar.com/mopar/hemi/dyno-test.html

long story short, 426 (7.0L) Hemi may have still been at 425-HP SAE "net" (assuming you add back the underrate and have no compression change?) back then versus the 425-HP "net" out of the modern 6.1L Hemi mill today. Seems to make some sense improvements got equivalent HP out of less displacement.

 

[amazinblue82]

I still have some energy left around this topic:laughing4:

I may be "Don Quixote" tilting at windmills on this one, but everything I slogged through points me to the answer of my own question. Three reputable-looking sources and some of my buds in the OEM car business say roughly the same thing.

IF (given ALL the vagaries/conflicts within the test methods, the underrating, the overrating, technology improvements, displacement, compression ratios, etc.) you want to guess what today's "net" engine HP is compared to the old "gross" rating, you divide the net rating by 80% (round number, actuals vary by engine).

So our friend the Hellcat (if advertised accurately/tested without accessories, etc) might have been 875 gross HP back in the day. The current 6.1L Hemi may have been 530 gross HP.

Imagine that...guess it would have same jarring impact on our sensibilities -- 875 "gross" HP from the factory in 1970 -- as 707 "net" HP has on some of us today. Luckily we have better tires/suspension/stability control now versus then .. but maybe our driving skills now are no better judging by the green Hellcat smashed in 60 minutes of purchase.

Ah, today's crate replacement engines you say? Gross or net?

The various forums are full of conflicting, passionate views on this topic. For a fact I know one Big Three manufacturer's ratings are SAE "net". And that particular company is likely STILL "underrating" them (not sure why) given what people are seeing (engine shops and new car dealers with performance shops, etc.) at the rear wheels, let alone "accessorized' on engine-only dynoes, versus the advertised HP

For me, if the engine is original as well as the car in suficiently original shape too, and can be rebuilt I will tend toward the rebuild and I want factory performance to be regained/retained.

But I also have thumpin' crate "direct replacement" engines in stuff too..they are much stronger pieces than anything that was ever in the car from the factory as you would expect..if powertrain originality was not my goal.

thanks for your help folks.

 

[1978 NYB]

1971 was the last year of the big horsepower engines. From 1972 on the compression ratio (low 8's) and performance cam's pretty much dropped for emission standards.

 

[amazinblue82]

1971 was the last year of the big horsepower engines. From 1972 on the compression ratio (low 8's) and performance cam's pretty much dropped for emission standards.

yup thats right

I learned that whatever the power drop was for a particular engine from 1970 to 1972, 25% of the drop was test method with accessories and 75% of the drop was compression downgrades (round numbers, ignoring minor mechanical tweaks that might have also been done).

Not reporting those relative effects as the "gospel" but those proportions (assuming its true versus
"group think") were most often mentioned.

And then it was straight into the abyss .. powerwise compared to the go-go sixties .. for almost a decade as we all know due to the emissions-related stuff.

 

[commando1]

One thing you cannot deny.
Yes, a Metric Challenger may in actuality have better numbers and be faster but a stomp on the pedal full throttle in a '440-6 feels faster plus you look better doing it.

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[polara71]

Stan, have you ever driven or been a passenger in a new Challenger when under full throttle ( R/T. SRT ]?

 

[amazinblue82]

One thing you cannot deny.
Yes, a Metric Challenger may in actuality have better numbers and be faster but a stomp on the pedal full throttle in a '440-6 feels faster plus you look better doing it.

yes-sir.

done it (the "A" to "B" last summer, my '71 E body 426 and my friend's new Challey non-Hellcat). no fancy time traps and stopwatches .. just "old fashioned" eyes, ears, and seat of the pants.

there just there ain't nothing like the "old iron" for me, even though the "new iron" is extraordinary stuff that i dig too -- as they should be with 40 more years of vehicle evolution under their belt.

so, i am not arguing what car was "better"...just what i like personally:yes:

 

[polara71]

so, i am not arguing what car was "better"...just what i like personally:yes:

That's the feel good answer

 

[commando1]

Stan, have you ever driven or been a passenger in a new Challenger when under full throttle ( R/T. SRT ]?

I owned a highly tuned and dyno'd LS3 C6 that I brought to Bradenton for T&T's ( that's Test & Tunes, not Tilt & Telescoping ). I drove L-88's back in the day.
Nuff said?

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[commando1]

The feel of the engines is entirely different. It is physically impossible to make a 2015 engine feel like (or as good, AFAIC) as a 1969 engine.
'puters, EFI, CATS.. all make it so wrong in the feel. Yep, they're faster but the feel can not be recaptured.
Hell, ever look at the numbers of a new V6 6 speed Accord? Surprising. And it's a F%$#-ing Accord.
And memory enhances the old engines. If you weren't there, you don't have the advantage of the enhancement. A person who only has driven an RT8, no matter how he/she drives it can only have 1/2 the pleasure.

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[amazinblue82]

That's the feel good answer

"feel good"...not following you?

What I meant was newer cars enjoy technical superiority in many ways that are objectively undeniable so I wasnt going that direction with my point.

Subjectively, I am more partial to the stuff I grew up on..the sound, the feel, the look. Which doesnt change the objective (or subjective advantages people prefer) superiority of newer vehicles.

 

[polara71]

Don't know, never drove those . My experience is of the new Challenger and a nicely tuned 6 pack c body.


I'd rather drive the old iron but the gearing in the new cars alone make them run harder...

 

[polara71]

"feel good"...not following you?


What I meant was newer cars enjoy technical superiority in many ways that are objectively undeniable so I wasnt going that direction with my point.

Subjectively, I am more partial to the stuff I grew up on..the sound, the feel, the look. Which doesnt change the objective (or subjective advantages people prefer) superiority of newer vehicles.

That was my way of saying that's the right answer... In my opinion of course

 

[amazinblue82]

That was my way of saying that's the right answer... In my opinion of course

ah, i gotcha man. thanks for clarifying for me

 

[commando1]

And I'd like to thank AmazingInBlue for starting this thread.
Just thinking about how it used to feel makes the rest of the day a piece of cake.

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