power ratings?
 

Hello everyone. Just a bit curious about the HP ratings on this LS3. I've seen 430 and 426, not sure which is acurate. But my question is, back in the early days many of these engines were "underrated", in some cases very underrated because of insurance purposes or whatever. Is it believed that the LS3 may also possess more than the advertised HP? Do car companies still do that?

It's officially 426hp. and yes it might be underrated.But we still don't know that

Don't care. This car is purdy. :wub:

With the SAE certification, it is impossible to "underrate" an engine. The only way is if the manufacturer chooses not to SAE Certify their engine (4.6 3v in the Mustang, 6.1 Hemi, etc.).

The LS3 and it's variances (GXP, Corvette, Camaro, etc.) are all SAE Certified.

The LS3 in the vette is rated 430 and 436. All other applications will most likely be lower. Example the Camaro is rated at 426.

Tom

BTW the 436 rating is with the optional Z06 exhaust.

It's not a Z06 exhaust. It has bypass valves like the Z06, but it is 2.5", the Z06 is a 3".

As stated earlier, the LS3 is SAE certified and that would make it impossible to underrate.

You don't understand engineers very well, do you? They say that the fastest way to get something done is to tell an engineer its impossible. Its a game for both sides. The SAE creates the rule book to even out the playing field. But like any other rulebook, its a paperback not chiseled in stone. There are ways to bend it which ever way you want. The manufacturers will try and get around the test procedure (in many cases, they help to write the procedure) and engines will be under rated (or over rated as the case may be). Then a new procedure will be created and the cycle will continue.

For reference, the 5.7L hemi in the Challenger (370 crank hp rating) dynos at about 335 to the wheel. The LS3 in the G8 has dyno'd 370 to the wheel (415 crank rating). This is approximately a 10% driveline loss. One of three this is going on here:

1. Those engines were unsually strong
2. They have very low drive line losses
3. They're under rated.

I'm leaning towards #3 because if you assume the standard 15% driveline loss from the 'regular' versions (390 hp Hemi, 436 hp LS3) you get . . . 332 and 371 which within error margin of what they dyno'd at.

10.83%:thumbsup:

yes . . .

i heard the gtr is underrated at 480 hp, i heard its really 500 plus hp

it could be. it's not an SAE certified engine.

Too bad no one said this to the GTR's tranny. LoL

GTR: Get Transmission Replaced

this is why i hate all this paddle shift, dual clutch, semi-manual crap.



if nissan just put in three pedals than they would of never had this problem.