I asked a friend of mine who works at GM Engine Developement about the HP figuires on the LS7. He said that the engine is just about 500 on the nose. This is not RWHP, but at the flywheel. But without getting specific, he mentioned that other stuff on the way will make you smile even more.

As for the horsepower ratings, he's said that on the GM dyno's, other manuafcturers are under reporting their HP numbers by roughly 10% to 15%. GM is leading a spec with the help of the SAE to standardize horsepower numbers so what is publicized is the number that's really there. GM is playing the 'truth in advertising' game. Of course, if he's right about the 15% number, the Viper and Ram SRT/10 may be pushing over 560 HP(?)! And the Mustang GT would be around 340 HP.

 

The '05 Mustang puts around 265rwhp to the ground. If it's under-rated, it's not by much. It's probably around 310 at the flywheel.

 

Yeah like they did with the F-Bodies

 

That would be a funny commercial. A F-body rolling up next to a rice-burner, and you hear really loud piston slap...the ricer laughs, they both take off from the light, but the ricer wins because the guy in the F-body has to pull over because one of his T-tops exploded spontaneously all over him. And then he gets pulled over by a cop for street racing. That would be a good commercial.

 

ANY commercial would've been better than GM letting the F-body twist in the wind.

 

kinda off the subject but does any one know what the 05 GTO is putting to the ground?

 

Never mind. I guess the search button is your friend

 

Personally, I think power to weight ratio says a whole lot more then just brake horsepower or torque ratings. These really tell the story, especially when trying to compare them to other cars.

Just look at the famous LS6 1970 SS454 Chevelle--it said 450 hp when everyone knew it was closer to 500!

 

Red02Firehawk, couldn't have said it better myself. power to weight is more critical in acceleration than power itself. higher power will give you a better top speed though!

thanks Chris.

 

Underrated by 15%...on some vehicles.

Nobody is gonna tell me that a Hemi makes like 380 horsepower...that would be like the most catastrophic drivetrain loss ever...they dyno at like 260-270 that would be like 120 hp loss to the wheels lol

But doesn't that torque number seem kinda low? I would think that it would make 500lb/ft too.

 

There is info that directly contradicts your statements coming from the Corvette forums and those sources are a bit more reputable, IMO(long standing members with a history of good info). Anyway, the info is that each LS7 engine is being dyno tested to VERIFY at minimum 500 flywheel horsepower(the rating) and the current numbers seem to show that most LS7 are in the 520 to 530 flywheel range. Some of the low numbers reported where the 512flywheel that has been mentioned before.

I don't know where you get this 10 to 15% underrated crap about certain other makes, but the current Mustang is possibly right on in its numbers and it is true that a few Vipers seem to need more like a 530 or so horse number, but that certainly isn't 10%, much less 15%.

Todd

 

i think you will find that the HP "tolerance" on moderday motors will be much tighter than you think, although 10% does ring a bell as to what OE has to be within the addvertised amount.

 

Around 346.7 rwhp, 351.2 rwtq, with 218 miles on the clock.

 

around? that sounds pretty exact.

 

Wait till that thing gets broke in and I'd expect to see a 15 hp/tq increase at the wheels.

 

That is like the highest dynoing 05 anybody has seen yet........

Average seems to be in the mid 330 range.....

 

Why do manufacturer's even report flywheel numbers?? That means nothing to the consumer. Power to the ground is what counts. I have a feeling they do it so they can fudge the numbers a little and blame it on drivetrain losses. If they reported rear wheel numbers, they'd be liable to meet them more exactly. Ah, but I digress.

 

not everyone who buys cars is an enthusiast...they just like to say this car has 500hp...even though they will get smoke by a 450rwhp f-body..(well depending on the car)...normal people's braggin rights are in flywheel just cause it sounds better...if i'm not talking to someone who i know knows cars...then i give them flywheel because they don't know what rear wheel hp is...and they wouldn't understand...like how a full bolt-on 360rwhp f-body can beat a stock 390hp cobra...