[olrocker]

Just thinking about the old SAE gross ratings of the original muscle car era and I had a real mind blower…..

If our 455 hp LT1s were rated in gross circa 1963-71 it’d have been rated about 570 hp!!!

Those of you with the 650 hp supercharged LT4? 810 hp!!!!

Take that Chevelle SS396, Charger 440 Magnum and 426 Hemi, and Ford 428 Cobra Jet

[ctrlz]

Here's what he's talking about:
https://www.carscoops.com/2022/01/50...w-it-happened/

[JT6Speed]

Yeah it would be nice if it worked like that lol, but with electric fans, no power steering pump to turn, a much better exhaust, etc, you probably could take the 1 away from the 130hp.

[DaveC113]

LT4 is rated w/o SC losses so you get -100 whp vs -50 for the LT1. So LT4 is really only +150 hp, not +200.

Otherwise accessory losses aren't nearly that large on a modern engine.

[olrocker]

Originally Posted by JT6Speed

Yeah it would be nice if it worked like that lol, but with electric fans, no power steering pump to turn, a much better exhaust, etc, you probably could take the 1 away from the 130hp.

Well then, to equalize that you’d have to remove all 4 catalytic converters and every ounce of smog control on a modern engine.

Even with the advanced computers managing everything there would still be a substantial increase in hp on the modern engine.

[JT6Speed]

Originally Posted by olrocker

Well then, to equalize that you’d have to remove all 4 catalytic converters and every ounce of smog control on a modern engine.

Even with the advanced computers managing everything there would still be a substantial increase in hp on the modern engine.

Oh yeah there would definitely be a decent increase, but I'd be shocked if it was anything more than 500hp (so we're losing about 45hp or so). The tri-y style headers flow pretty well and so does our intake. That's why you really don't gain much by doing a no-tune cold air intake or a cat-back exhaust.

[Alan47717]

Originally Posted by olrocker

Just thinking about the old SAE gross ratings of the original muscle car era and I had a real mind blower…..

If our 455 hp LT1s were rated in gross circa 1963-71 it’d have been rated about 570 hp!!!

Those of you with the 650 hp supercharged LT4? 810 hp!!!!

Take that Chevelle SS396, Charger 440 Magnum and 426 Hemi, and Ford 428 Cobra Jet

Your point is well taken, however, you have to remember that the advertised horsepower ratings for most of that era's "King Kong" engines were pure fiction, mostly to pacify insurance companies. 430 hp for the L88? 375 hp for the Boss 429? Please.

[2SS Capt]

Originally Posted by Alan47717

Your point is well taken, however, you have to remember that the advertised horsepower ratings for most of that era's "King Kong" engines were pure fiction, mostly to pacify insurance companies. 430 hp for the L88? 375 hp for the Boss 429? Please.

However most didn't have the technology or capability to put that power down... Perfect example the 1972 Olds 442 bragging about "wider 14x7" wheels... Please... I had 9.5" wheels with 275's on the back of my 2020 SS and couldn't get traction... Finally with 11.0" and 305 summer tires I can finally hook with some sort of reasonableness..

[Number 3]

Also keep in mind, even with the newer SAE procedure, OEMs were fudging the test. Maybe 20 years ago there was a transition were Toyotas 4 cylinder engines were 200 hp one year and 165 the next. I think it may have been Dave Hill, Corvette Chief Engineer that had the details of the test changed. More consistent and reliable and if I recall correctly, witnessed.

Gets old when you know you’ve done great work and your competitor somehow is advertising wayyyyyy more up than you know is possible.

Another similar story from years ago on Hyundais as I recall. For EPA certification you don’t just give them a car and they drive it around. It’s actually a dyno test and the OEM provides the data for test. Again, GM as I recall asked how are they getting this incredible FE. Well they were sending in fake profiles for the dyno test that gave better results.

Lots of that going around. And even Toyota just admitted to fudging test data.

[Germansheperd1]

It is really funny when you put these stock old muscle cars on a rear wheel dyno. Then you really see what these “high performance” cars really made.

[clg82]

How much do you lose from crank to wheel horsepower? I forget the percentage...

[Dmoney2SS]

Originally Posted by clg82

How much do you lose from crank to wheel horsepower? I forget the percentage...

To my knowledge, for auto cars it’s around 12-15

[ZED SLED]

I saw a show on Speed channel several years ago where a team built a 1964 era 426 hemi, a Pontiac 421, a 409, Ford 427 and an L88 supposedly to original specs and dyno tested to see if they lived up to the advertised HP from back in the day. 409 came in at 409 as advertised, 421 was close to what it was advertised. The 426 was supposed to be rated at 426 but was way off. Came in around 830. Ford 427 was 600ish and L88 was like 530. Found part of it:

[olrocker]

Originally Posted by ZED SLED

I saw a show on Speed channel several years ago where a team built a 1964 era 426 hemi, a Pontiac 421, a 409, Ford 427 and an L88 supposedly to original specs and dyno tested to see if they lived up to the advertised HP from back in the day. 409 came in at 409 as advertised, 421 was close to what it was advertised. The 426 was supposed to be rated at 426 but was way off. Came in around 830. Ford 427 was 600ish and L88 was like 530

And that was using modern day SAE Net calculations?