[Ventmaster]

Computational fluid dynamics aside, gentlemen- there is a difference in sound. Significant enough that some people may prefer the stock pipe.

[gippy87]

All science behind I cant figure out why GM would have done this anyways. I see no added benefit there is plenty clearance in all directions.

[1LE Red Dragon]

I also used to work for an OEM exhaust manufacturer in Toledo Ohio. Typically, the OEM and aftermarket replacement systems are not designed for power, they are designed for sound. Different baffling arrangement, resonator etc are used in OEM to get desired sound. If a crushed pipe has no affect on airflow, then the laws of fluid dynamics that have existed for many years, are all bogus. This is not the case. The velocity of the air will increase as the area is decreased through the crush section, and the flow rate stay the same. This will cause increased back pressure. This is fact.

Q=V*Area. If Area goes down, then Velocity, V must go up to keep Q (flow) the same. Increased velocity through this crush section and additional frictional losses.

If this were not the case, then no mandrel bent exhaust system or straight thru muffler would ever have added horsepower or torque. This is also not the case. NA motors are not as sensitive to back pressure issues as a turbo or supercharged car. Turbo being the most sensitive to back pressure because of the backpressure in the turbine housing which has a very small area.

Put both setups on a flow bench and you will see a higher air flow rate through the smooth diameter pipe compared to the crush diameter pipe. However if the crushed sections air flow rate when run on the car is still capable of flowing the amount of air needed for the airflow being moved by the engine, then the HP increase will be insignificant. But make no doubt the air flow potential of the fully circular area is greater than the crushed pipe and its reduced area.

[Sub]

With all that said, one of the exhaust manufacturers did a study on the crushed pipe and found zero difference in horsepower. It may restrict flow, but its still not affecting performance. Save your money.

There is a video out there somewhere. I'm too lazy to search for it.

[SSDanny]

But is there a significant difference in sound? lol

[oneredry]

Originally Posted by SSDanny

But is there a significant difference in sound? lol

Crushed vs non crushed. No.

[Redlinez]

Hooker designed this BlackHeart crush pipe delete kit for the 16-17 Camaro SS to eliminate the crushed, factory mid-pipe that GM skimped out on. By replacing the inferior pipes you will gain up to 12.84 horsepower and 17.28 lb/ft of torque (tests were recorded on a dual mode NPP Camaro). This offers great bang-for-the-buck as the kit costs less than a few tanks of gas.
Sure would like to see the proof of this.

[SSDanny]

Originally Posted by Redlinez

Hooker designed this BlackHeart crush pipe delete kit for the 16-17 Camaro SS to eliminate the crushed, factory mid-pipe that GM skimped out on. By replacing the inferior pipes you will gain up to 12.84 horsepower and 17.28 lb/ft of torque (tests were recorded on a dual mode NPP Camaro). This offers great bang-for-the-buck as the kit costs less than a few tanks of gas.
Sure would like to see the proof of this.

I honestly can't see those gains being possible. Did they disclose if a tune was done?

[oneredry]

I would agree with this.. wonder if more flow was offered with the mufflers. Something in this equation is missing. you simply don't had 5 HP let alone the claimed numbers by just simply replacing the crushed pipes, of which has been noted many of times that it makes NO difference in HP or sound rating by just replacing that section. They do it for a reason.

[KingLT1]

I am guessing since the crush pipes are so far back in the exhaust system where velocity is greatly reduced, the restriction is not that big of a issue compared to if it was up by the cats.

[wildchevy]

you think for one minute GM spent a dime crushing those pipes for no reason?

[arpad_m]

Originally Posted by wildchevy

you think for one minute GM spent a dime crushing those pipes for no reason?

What I read is the vert requires them to ensure clearance for the underbody cross-braces it requires for rigidity, and GM decided to save some cash by not having separate parts for the vert and the coupe, they simply installed the crushed pipes on both.

[EDFHOBBIES]

If that adds 12hp than a CAI must close to 30 LOL!

Probably another scenario where a tune was factored in with the mod!

[Umbriel]

So there is no point on doing a cat back exhaust just buy an axle back?