Dyno results of full exhaust vs stock?

[Dzl210]

Saw a video a while back on YouTube that was basically a glorified sales ad with no actual numbers or anything to back up their statements. There was a lot of points made about areas where the stock exhaust is choked down so the Boxster is less of a competitor with the 911 and their exhaust creates huge gains because of removing these bottlenecks.

Some points seemed valid, but like I said, seemed like they were spouting off glorified sales talk.

So

What do dyno sheets look like? I haven't found any on Google and posted on that video a few months ago asking for a dyno graph with no reply.

[Dzl210]

Did find this eventually on Google, I guess close enough to get an idea of how these motors react to full (i'm assuming) exhaust...11hp.

987RaceExhaust.jpg Photo by FabspeedMSP | Photobucket

[KRAM36]

This the video you're looking for?

[Jake Raby]

According to the system purchased you may make LESS power than stock. Very few of these systems do more than make noise, reduce weight, and look cool. That eye candy and ear candy is what sells them.

As part of my research I have tested every system I could get my hands on, back to back on stock and altered engines. I haven't seen much that impressed me at all, and some systems that cost 3K or more can cost you 27RWHP.

Believe nothing that you hear and only 1/2 of what you see, the advertisements are usually very, very far from reality.

[Porsche9]

If you want a little more sound delete the secondary cats and for more sound either make your own PSE and find a good used one. I little more growl is nice when you step on it but neither are going to wake the neighbors or create any drone.

[edc]

I dyno'd my old S. I used the same dyno and had all the modified plots overlayed on the standard plot.

http://986forum.com/forums/performance-technical-chat/47555-tuned-modified-2000-boxster-s.html

[rfuerst911sc]

I have a 2002 S that is slightly modified from stock ( head work ) . Jake Raby is in my back yard so I have been dealing with him on the slightly modified heads. When he had a used exhaust system available I purchased it. This used system was a set of aftermarket headers with attached high flow cats not sure who the manufacturer is. Jake also had a Dansk performance banana muffler that I purchased. So we removed the OEM exhaust which had four cats and replaced with a " high performance " system with two cats and bypass pipes. Jake was very up front that this was not going to make huge gains but would make a difference. We had dyno data of before and after and if I remember correctly we made about 5-7 additional horsepower. So we made some extra power, decreased some weight and improved the overall sound. Am I happy ? You bet. Did I gain 20-30 hp as some would claim ? Not even close but in reallity I never expected that type of gain. Lets face it Porsche did not leave a lot on the table for bolt ons to make a dramatic increase. But a little here and a little there adds up. I really can't see a better exhaust than what I currently have. It is not intrusive, has ZERO drone and has some bark when you rev her up. Plus it's lighter than stock what's not to like ? I just need more power but Jake and I are working on that also.

[thstone]

Here are the dyno results for my cat-back exhaust system. Back to back testing, apples to apples.

http://986forum.com/forums/general-discussions/51783-top-speed-pro-1-catback-exhaust-hp-increase.html

[Dzl210]

So yeah, sales pitch. I'll stick with stock exhaust because I like the way it looks, not worth changing it for basically 10hp max.