2013 SS are we now at 430HP?

[CamaroSkooter]

Originally Posted by Jim968

If you're saying that the exhaust is not hooked up when testing flywheel hp on an engine dyno you're incorrect. Exhaust is most definitely hooked up.

I understand, but unless the backpressure difference from one to the other is just absolutely ridiculous, the change in flywheel hp is probably going to be negligible...

And trying to apply Corvette numbers to a Camaro is absurd to begin with.

Will there be a change? Possible. Is it going to be identical to the Corvette change? Doubtful.

[MLL67RSSS]

As long as there has been Camaro and Corvette, identical engines have always been rated less in the Camaro, the reason cited being more restrictive exhaust.
Take 1970 LT-1, in Corvette rated 370 HP, identical engine in Camaro rated 360HP. Now of course it could be just so the Corvette guys don't get pissed.

[BowtieBelle]

[JohnnyBfromPeoria]

Originally Posted by Jim968

If you're saying that the exhaust is not hooked up when testing flywheel hp on an engine dyno you're incorrect. Exhaust is most definitely hooked up.

AN exhaust is hooked up. It's not the one on your car, or anyone else's, though.

John B.

[fz4k98]

It is clear that the dual mode exhaust makes more power. In order to operate it you need to step on the gas more, so more power...

[JohnnyBfromPeoria]

Originally Posted by fz4k98

It is clear that the dual mode exhaust makes more power.

The exhaust doesn't make any power at all, technically. A different exhaust enables an engine to develop more power. Think that semantics don't make a difference? Watch the Presidential debates.

And, again, the vehicle's exhaust isn't the one connected to the engine during engine dyno testing, therefore, there isn't a difference in rated power.

John B.

[Jim968]

Originally Posted by JohnnyBfromPeoria

And, again, the vehicle's exhaust isn't the one connected to the engine during engine dyno testing, therefore, there isn't a difference in rated power.

That seems at odds with the definition of SAE net horsepower posted above. Here's another definition that I found that spells it out even more clearly:

"However, the SAE net power testing protocol calls for standard production-type belt-driven accessories, air cleaner, emission controls, exhaust system, and other power-consuming accessories. This produces ratings in closer alignment with the power produced by the engine as it is actually configured and sold."

Also, if they don't use the exhaust as sold on the car how does GM know that NPP makes 6 additional hp on the Corvette?

All that said, I've never witnessed an engine being dyno'ed on a stand, only in the car on a chassis dyno. If you have some sources or industry experience on how its actually done I'd like to learn more.

[1SSFever]

Originally Posted by Jim968

All that said, I've never witnessed an engine being dyno'ed on a stand, only in the car on a chassis dyno. If you have some sources or industry experience on how its actually done I'd like to learn more.

Plenty of Youtube videos of engines on dynos. First of all, instead of a transmission they bolt the dyno brake onto the rear of the engine. Most of the ones Ive seen they are using optimal exhaust (headers, length of tubing, mufflers if applicable.) Here's one video, as you can tell if the room was larger they could fit any exhaust they wanted on the engine.

It would be naive to think GM doesn't do extensive engineering and testing on their exhaust systems. They want to make the most power they can while still meeting noise and emissions requirements.

[1SSFever]

This one's pretty cool. "what inn theee hell?"

[Camarowguy]

Originally Posted by 1SSFever

This one's pretty cool. "what inn theee hell?"

Looks like a ford engine lol

[1SSFever]

Originally Posted by Camarowguy

Looks like a ford engine lol

They like to blow up.

Thats a BOSS429 copy though, it's bad ass and probably cost half what my car did.

[fz4k98]

Originally Posted by JohnnyBfromPeoria

The exhaust doesn't make any power at all, technically. A different exhaust enables an engine to develop more power. Think that semantics don't make a difference? Watch the Presidential debates.

And, again, the vehicle's exhaust isn't the one connected to the engine during engine dyno testing, therefore, there isn't a difference in rated power.

John B.

Well since we are going "technically", engines do not make power, engines provide an environment where a usable mixture of air and fuel along with spark can make power. And really horsepower is never made or created but calculated.

[oldfriend]

Originally Posted by SlingShot

When the engine was certified at 426Hp, it was with all pulleys attached. When the power steering pulley is disconnected, and replaced with an electric pump, the load is decreased. When the load on the engine is decreased, the certified Hp will in fact increase. The LS3 without all belts and pulleys, actually produces around 480 Hp.

The amount isn't all that great, but there is an increase of power.

I haven't seen a running engine without belts yet , but there always be a first time .

[Captain Awesome]

Originally Posted by SlingShot

When the engine was certified at 426Hp, it was with all pulleys attached. When the power steering pulley is disconnected, and replaced with an electric pump, the load is decreased. When the load on the engine is decreased, the certified Hp will in fact increase. The LS3 without all belts and pulleys, actually produces around 480 Hp.

The amount isn't all that great, but there is an increase of power.

The power steering pump being electric draws power from the electrical system in the car, which gets its energy from the alternator, which is connected to the flywheel. The electric pump may be a bit more efficient than the mechanical pump, but it doesn't create energy from thin air. Its power comes from the engine as well. Even if the pump were running from the battery, the power taken from the battery eventually needs to be replaced, and that energy comes from the alternator and hence from the engine in the end.