gains from RPi 530xi exhaust?
11-09-2010, 02:24 PM
#3
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You might not notice it in auto mode so as much but will 100% feel it when you rev your can in sports mode
.I am actually going to quads now
, I shall have mine up for sale pretty soon. I am in Sterling,VA down south.Let me know if interested.
11-09-2010, 07:27 PM
#6
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Join Date: Sep 2009
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My Ride: '07 530iSport PackageLuxury Packagemore to come
11-09-2010, 08:52 PM
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11-09-2010, 11:51 PM
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My Ride: '04 530i 6MT
'04 Audi S4 6MT
Can someone explain to me the difference between the RPI exhaust and an aftermarket rear muffler? From the pics I've seen of what you actually get from RPI, it looks as if its just a rear muffler with about 3-4 feet of stainless tubing attached. Just trying to figure out the story behind the $800 pricetag when you can get a performance muffler for $150 and have any muffler shop bend up some tubing for less than $100. A shop local to me has a mandrel bender on site and can easily replicate the bends of the RPI unit. If my interpretation is correct, based on what some vendors on this site are saying, a rear muffler will net you 7-10 hp? Maybe I'm missing something???
Vs.
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Vs.
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11-10-2010, 05:10 AM
#10
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Can someone explain to me the difference between the RPI exhaust and an aftermarket rear muffler? From the pics I've seen of what you actually get from RPI, it looks as if its just a rear muffler with about 3-4 feet of stainless tubing attached. Just trying to figure out the story behind the $800 pricetag when you can get a performance muffler for $150 and have any muffler shop bend up some tubing for less than $100. A shop local to me has a mandrel bender on site and can easily replicate the bends of the RPI unit. If my interpretation is correct, based on what some vendors on this site are saying, a rear muffler will net you 7-10 hp? Maybe I'm missing something???
Vs.
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Vs.
+ Exhausts are not only about tubing or length, they are about superb chamber DESIGN. Any tom dick and harry can bend a pipe and throw in a muffler but the trick is scientifically designing an exhaust chamber (Amount of exhaust gas compression in a chamber before exit, a graph that dictates at what levels to force exit vs keep it free flow). This is different from car to car and from engine to engine. Coming up with a generic muffler design for all cars is seriously stupid.
I used to design exhausts a while ago. And let me say, you just cant imagine how much difference an exhaust can make on an engines performance.
If people believe free flow is the best exhaust they are completely WRONG. On the other side, too much filtration (adding catalytic converters, etc) is not so good as well.
In short, anyone can design an exhaust, but to design a performance exhaust is a big deal in terms of Research & Development AND Trial & Error