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      10-20-2012, 08:15 AM   #8
E46 + E90

Drives: E46 M3 + E90 M3
Join Date: Jul 2008
Location: Illinois

iTrader: (1)

Garage List
2009 BMW M3  [0.00]
2002 BMW M3  [0.00]
Thanks for sharing further documentation of your modding progress.

Once again proving that our stock full exhaust system pretty much sucks...hahaha

Enjoy the car and stay safe out there!

Originally Posted by pbonsalb View Post
You can make a little more or less boost just depending on atmospheric conditions. The blower spins at a fixed rpm, unlike a turbo, so it has zero adjustability. It can only compress what it gets, and what it gets is more or less dense depending on temperature and humidity.

The catless x-pipe reduces the restriction through the motor. This is why it adds power. On a boosted motor, boost is a measure of the restriction through the motor. Take the cork out of the backside and boost drops on a supercharged engine. Again, boost is fixed by the blower belt drive and has zero adjustability, unlike a turbo that will simply spool more or less fast to make the boost set by the wastegate.

Now raise the boost to ESS' specifications and you should see more power. However, I would first want to know why my installation made less boost than boost on identical kits on supposedly identical cars. There could be belt slip or a boost leak. Sometimes it is just a bad boost gauge, so I would want to check that as well against another reference.
As always, great information! Couldn't have said it any better myself!
E90 M3 DCT|Melbourne Red . Speed Cloth | My Build Thread
E46 M3 6MT|Jet Black . Black Nappa Leather | My Build Thread