Hello!
What will be the best Manifold with CAT, for me to gain more power at low and medium speeds, for my R53 Cooper S?






Best Regards,
Nelson

 

my opinion:
modified oem ( if you have the tools and the time to do it yourself )

- increase the inlet ports if you have a modified head


- smoothen the part where the primary tubes connect to improve flow
original:

better:



- cut out the precat section and that weird restriction right before it and weld in a straight tube
above is the original, below the modified one notice the bend before the precat, and on the modified one: the precat is only show ( so it looks streat legal the pipe is going straight trough without any change in diameter ( that would produce turbulences -> restricting flow )

- i also changed the last pipe behind the main cat ( slightly bigger ) but i dont think thats needed

 

wow thats some pretty cool almost free modification

 

I noticed you plugged both o2 sensor holes. Are you using o2 simulators?

 

yes i use both, i just pluged them while working on it ( making sure nothing gets damaged or dirty )
and theres no engine light flashing

 

I've been thinking about removing my first cat but didn't want to throw any codes. Did you do anything different to avoid getting codes? I was under the assumption that if the first cat was removed I'd get a code.

 

depends on what kinda tune you have...
one, cooper, cooperS will probably trow a code, jcw usually doesn't

im using the jcw tune ( with a raised rpm limit and better adjusted dtc, otherwise stock jcw )

 

I have a RMW tune and my rev limiter is around 7400. I'm not sure what that has to do with the O2 sensor code though.

 

then you should ask rmw how the tune would react

 

I'm going to ask Jan when he re-tunes my car this month. I would have never thought to ask him about that until your post. Thanks