Different exhaust hp gain or loss?

[Ateam]

So I am wondering if there are some dynos of people with just a muffler showing whether they gain, lose or do not affect the hp. I remember in the past some mufflers would actually lose power on other cars due to having the cat-back piping way to large of a diameter and would hinder exhaust velocity. However all of the available mufflers for this car keep the OEM connecting pipe size and I am guess it really does not matter what you do in a muffler that could effect power.

I definetly do not notice any difference for the one I got which is completely straight piping through which has to be the most free flow. Maybe overly free flow is bad and loses hp or gain hp or how do all these brands actually do hp wise?

[e92Mjunky]

our DRB Motorsports exhaust made 6whp and 6wtq from 4500-7000 RPM's...t
hat is where most people spend all their time in..plus a 27 pound weight reduction..

[Ateam]

Cool-thanks for sharing! Nice weight savings too! Congrats

[ysv]

poor gains, i my ss full system gave me 20-30hp... with stage2 ecu mod you will do way better

[pbonsalb]

Akra, which makes one of the finest exhaust systems around, claims about 3 crank hp for its rear section alone, but about 24 crank for its x-pipe and rear exhaust together. While even the best rear exhaust adds next to no power, some of them sound great and some of them drop about 10 lbs.

http://www.akrapovic.com/car-exhaust...3-e90-e92-e93/

[mshab356]

Exhaust upgrades are mainly for looks, sound and weight reduction. Minor power gains. If you really want to gain some power, get an X-pipe that deletes the resonators and the cats, then get a tune.

[Ateam]

actually deleting resonators do nothing to gain or rob power. They are totally straight through piping within a hemoltz chamber.

It is the cats being deleted that gives you the extra power

[Dave07997S]

Originally Posted by Ateam

actually deleting resonators do nothing to gain or rob power. They are totally straight through piping within a hemoltz chamber.

It is the cats being deleted that gives you the extra power

This...

[Dave07997S]

Originally Posted by e92Mjunky

our DRB Motorsports exhaust made 6whp and 6wtq from 4500-7000 RPM's...t
hat is where most people spend all their time in..plus a 27 pound weight reduction..
Attachment 616910

The hp gain looks like a wash, not to mention definitely within the margin of error for dynos. This is one of the lower dyno numbers I have seen even for STD vs. SAE.

There really is no to very little hp to be gained from just a cat back.

[mshab356]

Originally Posted by Ateam

actually deleting resonators do nothing to gain or rob power. They are totally straight through piping within a hemoltz chamber.

It is the cats being deleted that gives you the extra power

You're absolutely right. I don't know why I said deleting resonators increases power, as I know that's not true

[Ateam]

Originally Posted by mshab356

You're absolutely right. I don't know why I said deleting resonators increases power, as I know that's not true

I figured you misspoke and wasn't trying to piss on you or anything, just for lurking folks that read anything here as a definite truth will know they do not ahve to go cut out their resontors to gain 5hp