Rasp Galore?

[sabbanick]

Know hiflo cats and resonators serve two separate purposes, but do you guys think having some sort of secondary cats would eliminate the rasp?

[ScottinSSMD]

I've got the Aero Turbine resonators in place of the mufflers and they sound great! I don't have any rasp here.

[mfanatic325]

Originally Posted by sabbanick

Know hiflo cats and resonators serve two separate purposes, but do you guys think having some sort of secondary cats would eliminate the rasp?

Considering I got WAY more rasp after taking out my section1 (which as you know has the secondary cats in them), I'd be willing to put my money on it: that they help eliminate rasp altogether.

My setup prior to swapping out the section1 = JVT headers (no primary cats), and SuperSprint mufflers. That setup barely had any rasp at all, but noticeably more than before I had done the headers. Hope that helps!

[sabbanick]

ever consider just modifying your stock section one or going with a hiflo cat section one?

sadly i know that hiflo cats are much more expensive compared to catless, but i would pay extra to minimize the rasp.

[mfanatic325]

Originally Posted by sabbanick

ever consider just modifying your stock section one or going with a hiflo cat section one?

sadly i know that hiflo cats are much more expensive compared to catless, but i would pay extra to minimize the rasp.

Yeah, that is an option that I thought of. Was thinking about putting my SS section1 up for trade + cash. Buyer would trade me their stock section1 plus cash for my SS section1

[onebluemcm]

FYI regarding the custom Section 1 with race cats and resonators in Post #30

Those resonators are 9.5" long, 4" diameter. I don't have my OE section 1 in front of me with a ruler, but I think it is highly likely that two of them would fit in the forward part of section 1. With an aftermarket/euro/CSL header and removal of primary cats, more heat is getting back to the secondary cats. Adding resonators ahead of the cats should not absorb or hold as much heat as the primary cats would, so if people are not getting CELs with secondary cats alone (and proper wiring) I doubt that adding resonators in front of the secondary cats would do any harm....

[johanness]

Originally Posted by Roffle Waffle

try welding a small bracket between your exhaust pipes

You know this could work to eliminate some of the 'vibrations' causing the rasp. I may try this.

Ask me why I all of a sudden took a deep interest in this thread... :-|

I would suggest that on a European Z4MC... their Section 1 has a LARGER set of cats than the ones found in our Section 1. Because if they sound like this from the factory... then something's wrong.

Cats are rasp-eliminators. And I can say that there's a HUGE annoyance-factor when you're putting along in 3rd at 2500rpm, BARELY give it any gas, bog the car ever so slightly, and it sounds like your pipes are rattling against your heat-shield (or you have a small angry can of bees that get shaken momentarily).

Yeah. So my quest is going to involve returning to my STOCK X-pipe, and see if that changes things.

FYI, the deep bark, the power, the responsiveness is AWESOME. But I'm not willing to let my car sound like a $8K Civic just yet.

[ZStig]

Originally Posted by johanness

You know this could work to eliminate some of the 'vibrations' causing the rasp. I may try this.

Ask me why I all of a sudden took a deep interest in this thread... :-|

I would suggest that on a European Z4MC... their Section 1 has a LARGER set of cats than the ones found in our Section 1. Because if they sound like this from the factory... then something's wrong.

Cats are rasp-eliminators. And I can say that there's a HUGE annoyance-factor when you're putting along in 3rd at 2500rpm, BARELY give it any gas, bog the car ever so slightly, and it sounds like your pipes are rattling against your heat-shield (or you have a small angry can of bees that get shaken momentarily).

Yeah. So my quest is going to involve returning to my STOCK X-pipe, and see if that changes things.

FYI, the deep bark, the power, the responsiveness is AWESOME. But I'm not willing to let my car sound like a $8K Civic just yet.

you're getting all this rasp with just euro headers with a supersprint x pipe?

[johanness]

Originally Posted by Roffle Waffle

you're getting all this rasp with just euro headers with a supersprint x pipe?

That's what I said (meaning, I asked myself the same question). Doesn't make a lot of sense. It's certainly not as bad as Mfanatics... but it's not what I'm looking for. 1st step is getting this sucker on the hoist to see if something's up. But I'm almost positive it's good ol genuine rasp (as heard in Mfanatics video where he's going real slow and getting it at low rpm).
TBC...

[ZStig]

yeah thats strange, thats why I was double checking

[Thisisdudewhoru]

Originally Posted by Jbs

nothing wrong with a little rasp..

My car with cutouts sounds pretty much exactly like that....

[inTgr8r]

ttt..
Since a Euro Z4M cat section is so scarce, has anyone considered a modified Euro M3 cat section?
I'm thinking two things;
- more rasp reduction
- no bung modification to stock cat section
- better chance of O2 working (larger Euro cat)

I know they're not a direct fit, but wondering if they could be modified.
I haven't found anything conclusive, but from what I have seen posted they are different in length only?
If so it wouldn't take much to shorten them.

:EDIT:
NM
Upon further checking, it's more than just length.
The rear flanges are oriented differently.