O2 Housing size with my new SBR G50

[Prodigyman]

So my FPBT28 went to a better place and I decided to update few things (check profile), just have a little question I still have my Hybrid Connection O2H from SBR which is 2.5” and just purchased SBR G50 turbo.
http://www.slowboyracing.com/shop.php?sid=&cat=1104 (the O2H)

I still have 2.5” DP and 3” CAT back so I was wondering if changing to 3” O2H will make any difference?

Also I am getting Electric Cutout valve so is changing to 3” DP really necessary since at the flip of the switch I can have 2.5” O2H and after 5” of downpipe path (after the bend) I have OPEN valves to atmosphere when needed most power?

 

[daren_p]

According to Forced Performance the 2.5 housing produced the same results as their 3" housing on one of their FP30 series turbos @ 540 whp so I don't think a 3" O2 housing will net you much if anything. As for the 3" DP, probably not necessary. The exhaust gases flow much better when they are hotter so you don't have to worry about 2.5" right after the turbo.

 

[DSMunknown]

The exhaust gases flow much better when they are hotter so you don't have to worry about 2.5" right after the turbo.

Daren, is that because the air molecules are moving at a highly-accelerated rate? Is it also because there are all the other hot molecules that are pushing them towards the nearest exit? In other words, since there is continuous exhaust gases leaving the head, does this force the exhaust gases to find the easiest exit and therefore make the flow of the gases much faster?

In my estimation, both things I have said seem to hold true (at least in theory). As we all know, driving on the road will put out more exhaust gases than when idling because there is more fuel being used and because the RPMs are higher. Therefore, because more exhaust gases are being emitted when the RPMs increase, we can say that the gases immediately leaving the head are pushing the rest of the gases out and down through the turbine housing and exhaust system.

 

[LA97GST]

Ok here's my take on this gas theory of travel. Hot gases expand. It's fact. If the gas is excited and expanding it is looking for the easiest way to get out. Hince the effect porting the wastegast opening has on preventing boost creep.