2" Centre Pipe

[FILVTR]

What's the benefit of getting a 2" centre pipe?

Does it increase gains at all as I'm sure I read on the GMC website that you need a box on the pipe to account for the back pressure (in waves or something)?

[VTS_16v_Boy]

There are alot of Different views on back pressure and its effect on performance. The way I understand it is:

A Twin Box system (Centre box - Back box) will produce more back pressure there by adding more torque to the lower end of the rev range.

Where as a Single Box system (Just Back box) reduces back pressure there by taking torque from lower down and moving it further up the rev range to give better top end power.

Most people remove their centre boxes for nnoise increases and the fact the exhaust is more likely to pop and fart without a centre box. Ground clearance issues is another reason for removing the centre box.

I noticed my S pulled better higher up the rev range mainly over 4k with a straight throuh centre but I had my manifold and back box changed at the same time so its alittle bit unclear what improved the performance in my case.

Look at this Group N system from OMP notice that it replaces the centre box and the cat but has a very small back box and tailpipe which increases back pressure there by increasing a certain area of performance.

http://i74.photobucket.com/albums/i277/turpin2000ad/OMPGroupNsystem.jpg

Somepeople say a Twin box system is better for track use as you need the torque low down for exiting courners etc and others a Single box system for strip racing as your going all the way up the rev range, but I dont think you will find a rock solid 100% answer to which is best for a standard or mildly tuned saxo either 8v or 16v