[iwrock]

I'm just curious what kind of changes I'd see after I straightpipe the secondary cats. I'm sick of the American car burble and enjoy the smooth sound of the MB, so I'm going to try and keep that as much as possible.

I know that the exhaust will be louder, but how much? Would I hear more of a difference off idle or at topend? Are there any O2 sensors to deal with?

 

[exit2Ek]

no o2 sensors to deal with if straightpiping the secondary cats. it should be a little louder at idle but not excessive. other than that, chop away and slap those pipes on....

 

[iwrock]

Cool. That's all I wanted to hear :thumbup:

Going to have that taken care of within a few days.

 

[jangy]

Yup yup, I think you'll like it. i don't know how much back pressure the 350 needs, but I'd guess it is minimal, compared to the E55.

You consider cutting out your resonator, too and do a real straight pipe?

I want to do both to mine. I've done the resonator, but been scared of the secondarys, since I don't wanna loose bottom end.

 

[iwrock]

Yup yup, I think you'll like it. i don't know how much back pressure the 350 needs, but I'd guess it is minimal, compared to the E55.

You consider cutting out your resonator, too and do a real straight pipe?

I want to do both to mine. I've done the resonator, but been scared of the secondarys, since I don't wanna loose bottom end.

I wouldn't do both on this car, mainly because I hate how 6 bangers sound and I don't want to emphasize that. I talked to Vadim here on this board and he said straightpiping the secondaries is a better option because the resonator also keeps the pressure balanced.

As for backpressure, the 350's higher compression does help it, but I'm sure I'll still lose a bit off the line, since the powerband would move to a slightly higher rpm. I'm not too worried about it though, since 1st gear winds up pretty quickly (I launch it @ 1500 rpm), and from a roll I WOT it most of the time anyway....I don't let the car bog around at low rpm.