NIRVANA

I totally agree MOBE, the old cars were sweet. Before GM quit making the F-body, the only real muscle cars to choose from were the Camaro, Firebird, and Mustang. Back then you had all those plus the GTO, Roadrunner, Chevelle, Torino, Charger, GTX, etc. There were so many to choose from and they all looked great. Even though I'm not really a Dodge fan I'd love to see them do something with the new Hemi motor in the form of a rear wheel drive muscle car in the $30-$35K range.

TA Dave

Ah, but John I'm not talking about the Chevy's, of course they were slow...

The 73 SD TA ran mid 13's at 105. Also Most of the Pontiacs back then were close to or over 4,000 lbs. But the Performance motored Pontiacs did MPH over 100, most in the 103 to 105 range.

But all mag's were not equal back then. Most of the writers were not drivers, and the cars varied greatly between mag's...

Also remember, the Pontiacs has ton's of Torque! The 70 455 was rated at 360 HP and 500 lbs of torque!

Lt1plus

In Hot Rod,,, May of 1998 issue. They dynoed a 98 M6 T/A,,, it made 292.8 hp, 307.5 ftlbs,, to the rear wheels.. 98 M6 vette, went 285.6,, 301.2,,,, I am told rear and brake hp differ by about 40 horse give or take.

Dean-o

Drivetrain loss is around 15%. Take net hp and multiply by .85, take rearwheel hp and divide by .85 to get net hp at the flywheel. This is an average, not exact science.

Prior to 72, GM rated the motors on an engine dyno without accesories. That is called gross hp. Now they are rated in the car with accesories, which is net horsepower.

My 69 Stingray has a L36 motor that was rated at 390 hp and 460 ft lbs of torque. That is gross hp, so by the time you convert from gross to net hp and then deduct for drivetrain losses, it would probably dyno less than 280 rwhp.
In conclusion, the newer cars are more efficient. They have more power, better suspension and drivetrain, which equates to getting more power to the ground. They also get a lot better gas mileage.

I love my old car, but it doesn't hold a candle to my Camaro when it comes to performance. After all, engineering and automotive technology has come along way in the last 34 years!

Dean

Fulton 1

iTrader: (9)

As TA Dave eluded to, the thing that compounds matters with the old gross ratings is the fact that there was no standardization from manufacturer to manufacturer or even engine to engine. For example look at the old 455 Buicks - I saw one of those run mid-12's rated at 360hp while a SS454 Chevelle ran 13's rated at 450hp, both pretty much stock, auto, and similar in weight. Also saw a nice 302 Z28 (on radials) run high 14's at ~ 97 - still slower than my old low-rent (i.e. no options) and bone stock '93 LT1 Vette A4 running 14.1 @ 100.
Buddy of mine's dad had a relatively mildly built GN while we were in high school and I still remember him opening a can of whup-*** on a big block shoebox - couldn't even hear the thing run either.

White2000Z28

wow thanks a lot for all the info on this, yeah I understand it now, so the HP now you read about is actually the rear wheel hp, it's not talking about the gross hp, I guess this is the same for all vehicles then? like the new cobra with 390 hp? that's net power not gross? a few guys I work with have mustangs and they are always talking about these dammm cobras, drives me nuts.

Fulton 1

iTrader: (9)

Close, but not quite. Think of it this way:

There are essentially three different horsepower ratings that you'll run into -
(1) gross hp - the pre-1972 way of measuring hp at the flywheel in the US (Europe uses and has used DIN hp which is slightly different - but never mind that ). This method varied widely and there was little to no standardization. Many engines were dynoed without accessories, with open headers, etc., you name it.
(2) SAE net horsepower (or brake horsepower) - this is a way of measuring hp at the flywheel that keeps the engine in the same configuration as it sits in the car. It is standardized and much more realistic than gross horsepower ratings used to be. This is how engines have been rated since 1972.
(3) Rear wheel horsepower (or just wheel horsepower on a FWD or AWD) - this is the measure of horsepower at the drive wheels. It takes into account frictional and inertial losses in the drivetrain. This is the power that is actually being put to the ground and is the most realistic measure of hp.

Every manufacturer hp rating that you will see advertised nowadays is #2. Of course that's not to say that an OEM can't underrate a particular engine - as is clearly the case with the LS1's in F-bodies along with some other notables (1996 LT4, 1988 GTA turbo, off the top off my head).


EDIT Did a quicl google search and turned up this article that probably explains it better than I did: http://neptune.spacebears.com/opine/horsepwr.html

x phantom x

iTrader: (14)

Fulton got it exactly.

There are many reasons GM would underrate the F-bod's actual performance. Government standards, insurance compliance, Manufacturer MPG requirements, etc ... are all reasons to under-rate a cars hp.
I'm pretty sure the one that was the highest on the GM management was obviously keeping it away from the vette.

Nine Ball

iTrader: (38)

It wasn't the tires. I read a magazine article a couple months ago that destroyed that myth. They took some perfectly stock musclecars that a few collectors allowed them to borrow, gave them a little tune up with the timing light, put some real slicks on them and went racing. The results were not that impressive. I think the 70 LS6 454 Chevelle SS ran a low 13. A stock 68 Z/28 ran a high 13.

I've also seen some 454 Chevelles dyno and they only put down 320-330 rwhp on the Dynojet, but alot of torque.

My 69 Camaro is rated at "350 hp" with an almost stock engine (has headers and a mild cam) but I doubt it could clear 250 rwhp. It feels like a 14 second car. I'll dyno it for giggles later.

The only "Fast" old muscle cars were those ultra rare ones that nobody could afford back then. The ones with all-aluminum 427s (ZL1s), and those big block Vettes. The factory race cars that I wish they still made today

Tony

White2000Z28

Thanks for all the help on this question and the clear explanations, I appreciate it!

Cal

iTrader: (1)

In the 1980's we said "muscle cars were much faster back then" and this was a true statement at that time. But that has all been turned around now. When I bought my IROC-Z new in 1985, nobody thought '60s style performance would ever be back. Not only is it back and then some, but with great fuel economy as well. Yes, this is a great time we live in!

Pro Stock John

iTrader: (34)

Tony got a link to that article it sounds very interesting.

Old musclecars didn't get to benefit from the technology built into the LS1/ Gen III engines.

TA Dave

I agree today's technology is light years ahead of the 60's musclecars. The ability to run 12's with a basically stock car, with AC and 28 mpg is amazing.

I just took exception to the RAIV part, I'm an old school Pontiac guy, sorry for the rant...

y2k_ta

iTrader: (80)

Don't forget that GM also fudged the cubic inch displacement of certain engines. The one that comes to mind first would have the be the 396 which was actually a 402. I'm sure that certainly helped with insurance issues during the peak of the muscle car.

Then there's the 350 that's actually a 346.

WhitePheonix

You are 100% correct

Texfinn

iTrader: (39)

Pretty much so. Just to keep the government and Vette owners happy.

TS

NIRVANA

TA Dave, didn't mean to pick on the Ram Air IV Goat, I was just using it as an example since it's my favorite old Pontiac. I'm a big time old school fan too and plan to own a '69 GTO one of these days (my dad used to have a '68).

TA Dave

Hey Adam no problem at all.

There were a lot of games going on back then, just as now with HP ratings.

If you look at the 69 GTO's, the base 400 was rated at 350 HP, the RAIII was 366 and the RAIV was 370.
In reality there was probably 100 HP difference between the 350 and the 370 horse motors. Probably more like 250 and 350... (The 350hp over rated and the 370 under rated)

But the secret to Pontiacs performance was Torque...

Cal

iTrader: (1)

In the time period of 1979-1985 I ran two different '67 Firebirds, both with GTO engines: one was a 389 the other a 400, both built. Both cars were total animals; but I have to say the big-block Pontiac V8 was a lot of weight in the nose of an Fbody.

4thGENRETARD

Guys, Guys,
White 2000 Z28, if u want to know, put ur car on a dyno after a good tuning. u'll find out how much rwhp ur car puts out. And that is what matters. Now GM does under rate F-bodies. Check Aussie sites for Holdens they are true Ls1 rating.
Why do u think Camaros were phased out? Because they were better than vettes at 40% less cost.