How much whp/wtq would someone lose by choosing the Perrin with the stock o2 on a stock turbo and on a BBK? I can't seem to find the info anywhere of how much the bellmouth is actually worth on a dyno other than manufacturer claims.

Edit: with a catback exhaust and other bolt on's on the car too...just your normal bolt on evo x....interested in what the power difference is between the perrin turboback and the ams turboback if any...

Thanks!

 

Review of AMS Widemouth with Garrett GT3076:
http://blogs.insideline.com/roadtest...th-at-rre.html

In the comments, Shawn Church of Church Automotive adds in his results with a 02/DP with the FP Red.

 

Just to go a bit further with the original question.

I am in search of a new turbo-back for my car and I wonder which design is more fruitful:

-AMS' widemouth turbo outlet

or

-ETS/ATP's divorced turbo outlet?

It is said that divorced is better as the gases from the WG do not affect flow of the gases from the turbine.
Can anyone confirm it? Any tests somewhere?