How much HP does and exhaust add?

[unirok]

My 2003 automatic gt came with a flowmaster cat back exhaust and it feels alot quicker than the 2002 mustang gt with oem exhaust I drove?

 

[rangerboy101]

You don't know how to drive 5 speed that well making your automatic seem faster?

 

[unirok]

You don't know how to drive 5 speed that well making your automatic seem faster?

Actually you are right I suck at driving 5 speed but the other car i drove was a automatic too. mine is def quicker I am just curious as to why and how may hp an exhaust system adds. Even as small at 10 hp difference is enought o notice I just didnt think mods like that add much hp. btw my car has the stock factory air cleaner as well.

 

[Deleted member 38176]

5rwhp max, if that.

 

[rangerboy101]

AKA, not enough to make a huge difference.

 

[bradfier]

Keep in mind "feeling" is subjective, take it to the track and see what it does.

 

[unirok]

Yeah seat of the pants difference. My GT is not track ready fast so i would never bring it. thx

 

[Three50won]

unirok, what we hear can influence what we feel. So sometimes a slower car with a louder exhaust will "feel" faster than a quieter car...even if the quieter car is slightly faster. But still an exhaust upgrade after the X/H pipe does not make too much of a difference. The stock H pipe with it 6 cats is where most of the restriction is.

 

[unirok]

That makes sense and the other 2 gts i drove were with stock exhaust. thx

unirok, what we hear can influence what we feel. So sometimes a slower car with a louder exhaust will "feel" faster than a quieter car...even if the quieter car is slightly faster. But still an exhaust upgrade after the X/H pipe does not make too much of a difference. The stock H pipe with it 6 cats is where most of the restriction is.

 

[Noobz347]

Question:

How much HP does an exhaust add?


Answer:

None


Ideally, and exhaust system is setup to efficiently scavenge exhaust gasses from the motor. If it's too large, the efficiency is poor and you loose HP. If it's too small then you're restricting the exit of spent gasses and you loose HP.

Cat-backs in most cases, do little or nothing to remove restriction or promote efficiency. They change the exhaust note. That said, there are OEM cat-backs that are restrictive and are undersized for the purpose of meeting an emissions requirement.

If you REALLY want to improve exhaust efficiency, then get and install a set of long tube headers. Matched with the right cat-back, the efficiency will be improved and it has the added benefit of deepening the exhaust note.