davep_96

I see/hear a lot of conflicting opinions about this, so i hope someone can clear this up once and for all. I know that the ls1 is rated around 350 horsepower, but is that flywheel hp or rwhp? Also, when a car company gives you a hp number, is that usually flywheel or rear-wheel? I thought that the rating was at the wheels but on horsepower tv they dynoed a z06 and it had 4xx hp at the wheels and they said that is about right considering the 505 hp at the motor. So is the 505 really at the motor? And what about the ls1?

mycamaroSS

iTrader: (4)

flywheel, stock is around 315rwhp

02 Camaro SS

iTrader: (4)

Car companies always give flywheel numbers. The LS1 fbodies were rated at 305, 310, 320, 325, 330, 345 hp depending on what year/trim/slp options etc.. but they pretty much all made something like 370 at the flywheel and usually put 310-325 to the wheels for an M6 and 300-315 for an A4. They underrated the Fbodies so it wouldn't take sales away from the Corvette which would actually dyno lower at the wheels due to more drivetrain loss.

zracer323

iTrader: (12)

The car companies will give you the flywheel horsepower because it is more than the rwhp and it makes them sound better. Horsepower at the wheels is really the important number when determining how much power a car has.

'Trust'

iTrader: (24)

All true except the 370 at the flywheel part, these cars as a whole make about 350-355 flywheel HP from the factory.

DJ's 02' Z28

iTrader: (2)

I'm pretty sure drivetrain loss is around 15% for M6's and 18% for A4's. So a 355fwhp would put you at about 302rwhp for a M6, and 370fwhp would put you at about 315rwhp. Most '01 & '02's dyno at around 315 or higher at the rear wheels, seems pretty safe to say the later model LS1's are making 370 at the fly!

LS1crazy01

iTrader: (14)

All companies rate at fly wheel HP except for Porsche that I no of, they rate wheel hp.

1994Z28Lt1

iTrader: (1)

very true

it also depends a lot on the engine and the state of tune its in, lets face it there are some engines from the factory that even when new put down more power than some

i've seen ls1 m6's dyno anywhere from 280-325 at the wheels and i've seen Lt1's dyno anywhere from 235-275 at the wheels all stock

hell dead stock my car put down 271 at the wheels and its an m6 this puts me at about 315-320 at the flywheel

but yes GM and most manufacturers rate engines at the flywheel, people just get confused with the fbody's because often times they put down at the wheels what they are "rated" at the crank from the factory

hell from gm's point of view its a whole lot cheaper to put the same engines in the F and Y bodies than it is to detune one for the f-body other than intake and exhaust

reocamaro

iTrader: (5)

So are you saying when Porsche says their GT2 makes 530 hp on their site, it is making that to the wheels?

flintwrench69

iTrader: (11)

The LS1 has these different 305, 315, 320, 325, 330 & 345 HP ratings in the F bodys. Are any of these due to cam differences, cylinder head design, ram air, intake manifold, compression? Or just in the PCM calibration?

nssane

iTrader: (8)

98-00 z28s, formulas, and t/a are rated at 305. SS and ws6 from those years are rated at 320 due to the whole "ram air" thing. in 01 all ls1's got the ls6 intake manifold, but also got a slightly smaller cam. z's t/a's, and formulas were rated at 310 hp while the SS and ws6 were rated at 325 hp. some of the slp vehicles were equipped with a different exhaust set up and were then rated at 345 hp.


on a side note, i was thinking about dyno numbers and came up with this question. if an SS or ws6 gains hp from the air that is being channeled through the hood and into the intake, then logically it only gains this hp as the car is moving forward and air is being forced in through the openings in the hood. if the car is sitting still on the dyno, wouldn't the numbers be slightly lower than they would in real world driving situations?

Starz T/A 17

iTrader: (6)

^^^ I remember seeing something on here a while back about how the whole Ram air thing is overrated and really only has a LITTLE effect at speeds over 100 MPH. Also everywhere i know dynos cars with the hood open so that would take it out of the equation completely.

newton

iTrader: (4)

Where did you get this information?

To my knowledge, it is now standard for all car companies to rate power at the flywheel with all the essential peripheral accessories (full drive components, full production intake, full exhaust etc.). This is SAE net hp.

Benjamin Russick

iTrader: (1)

Porsche uses the same SAE numbers as everybody else.

CT15

Ram Air is more of a sales pitch IMHO based on everything I've heard. Better off buying a z28/formula and spending cash on your own intake. But damn, the extra cash is almost worth it just to have the WS6 hood. That thing looks like its coming to murder your family. In the end, if you have an LS1, you have one badass car with enough horse and torque to make the average car owner **** themselves.

300bhp/ton

I don't understand this ***** in the belief that people think manufacturers rate hp at the wheels.

THEY NEVER HAVE, not a single one of them EVER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

All car manufacturers the world over rate engine output as a flywheel reading.

It gets complex because there is imperial HP and metric HP (often seen as PS). They are similar but slightly different. You also have standards to how the tests are performed and how correction calculations are used. In the US this is typically SAE Net.

SAE = the Society of Automotive Engineers.

In Europe you'll often see DIN instead of SAE.

Again they are similar but can produce a variance of results, e.g.

Dodge Hemi SRT-8 425bhp SAE Net or 419bhp DIN.

Rolling road dyno's derive HP at the wheels. This causes a **** load of confusion

Mostly because drivetrain loss adds a large and unpredictable variable. Meaning even the same car will not dyno the same numbers even without any changes.

There are also different dyno types. Eddy current/load bearing dyno's (like the Mustang Dyno) and inertia dyno's (Dynojets). These both derive HP slightly differently as the measure torque differently. This means the same car can dyno totally different numbers on different dyno types.

You also have correction factors to consider on these. STD numbers mean what the engine was producing at the time, so hot weather would generally mean lower STD numbers.

SAE numbers should be corrected for many variables like temp, humidity and altitude. This allows you to compare dyno numbers more easily from session to session as it gives you a constant to measure against.

There's also a thing called graph smoothing which can also skew PEAK numbers and make it look higher than they actually are.

And this doesn't even consider user error and poor dyno maintenance.




As for the Ls1 Fbody, well they have been dyno'd from anywhere as low as 260rwhp to as high as 330rwhp. Both are correct and likely if you where to take both engines out and slap them on a proper engine dyno and test to FULL SAE Net standards they would be within 20bhp of each other.



-Manual cars will have a lower drivetrain loss = higher rwhp
-Post 2000 cars have LS6 intake manifold = slightly higher rwhp as a rule
-Some limited editions models (WS6/SS) have SLP Dual/Dual catback and Blackwing lid = slight higher rwhp
-Inertia Dynojet dyno's are not load bearing = slightly high results (but inreality same hp).


A stock LS1 in reality should be making 320-350bhp SAE Net (if you have to ask if this is flywheel or rear wheel )

300bhp/ton

Sorry mate, but that's a pile of total crap

300bhp/ton

Care to back that up?

02 Camaro SS

iTrader: (4)

What makes you say that?

300bhp/ton

Most of my post above explaining hp and dyno's.

Also there is not set amount as a percentage thru dirvetrain loss. Even tyre pressures can have an effect and according to Newton's laws of physics every action has an equal and opposite reactrion.

Also where are they getting 355fwhp from, not there really is such a thing as fwhp anyhow (also explained in my above post).

Also as Dynojets are very optimistic in deriving HP, figures from such dyno's should not be taken literally and converted into what someone believes the engine is making in SAE Net.