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Old 05-01-2012, 08:15 AM
stevelee203 stevelee203 is offline
Officially Welcomed to the 'Fest
Join Date: Oct 2011
Posts: 175
Mein Auto: 2006 BMW 650I CONV. Sold
Originally Posted by yorgi View Post
benefits of an x-pipe:
1) reduces rasp
2) slightly quieter exhaust than straight pipe (noise cancellation)
3) equalizes pressures on each bank of cylinders
4) the biggie: Causes a plunging/scavenging effect.

The scavenging results from the initial "pulse" of gases coming down one header then hitting the x joint. Now the gases have two pipes to travel down. This increases the speed of the gases. At the same time the other header will now experience lower pressure which causes the plunging effect (like a vacuum) and this sucks out the gases when the other bank of cylinders fire. This makes a big difference at higher rpms.

Moving the x-pipe to the rear is better for power but installing up near the headers sounds better. I went for the better sound option.
[/SIGPIC][/SIGPIC]2006 BMW 650I Convertible Black Saphire Metallic / Black
Premium Sound
Sport / Cold / Comfort Access
19" OEM
Logic 7 Premium
Sound HD Radio
Heads Up Display
Park Distance Control
K&N air filter
Aluminum Racing Pedals
6000k headlight upgrade
fog light upgarde

2010 MV AGUSTA F4 titanium/RED frame
2010 Audi Q5 S Line
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