MikeLsx

Was looking at getting a x pipe and new mufflers. But the OEM x pipe flows good enough. the only reason i see the need for one is to remove the secondaries. Just to complement the after market mufflers. (sound)

I would rather save the money and just cut and weld pipe where the cats once where. I nor does anyone on the street care about what my car looks like underneath. So putting that aside.

It doesn't look like much room to cut on the one side. Can this be done ?

Wormwood

You don't have much room at all. You got some good points & bad points about it. I took a couple of 3" 45° bent segments, cut them at the of the bend, flipped one half & then weld it back to make a slight S bend. On the OEM Xpipe I cut the cats right at the weld, replaced with the S bend & then measured & reattached the two flanges.

It may sound better with aftermarket exhaust & felt like there was a small drop in power ~2000-2500rpm. Not sure why may have been just me. Anyway I didn't like it enough to keep it on there so I put my original Xpipe back on...

Some members have tried gutting the cats, but I have no idea was the outcome was...

Wormwood

davekp78

[

Some members have tried gutting the cats, but I have no idea was the outcome was...

Wormwood[/QUOTE]

I gutted the cats in the X-pipe. Slight improvement in sound, no change in performance that I could tell. A lot of work, though.

neilvosko

how about just removing the OEM secondary cats ?

Kracka

See my post here: https://www.corvetteforum.com/forums...post1590606189

Kracka

From everyone I've talked to that has either attempted it or done it, was way more effort and time was required than initially thought due to the strength and durability of the metal honeycomb material. If you want to do it, my suggestion is get the best/largest hole saw you can find that fits inside the 3" inlet and go to town on it.

neilvosko

is the sound between the borla x vs corsa double helix that much different?

Mike Mercury

I did this on my 2002; the "precats" were near the end of the pipe. After unbolting the section, I took a long drill bit and started plunging holes into the material. At first all I got out were fine pieces, then chunks. I then went in with a rotating 2" wire brush on the drill and was able to remove the residual clinging to the inside surfaces.

I am now thinking of doing this to the 2015 sometime this winter.

robert miller

you will get the check engine light on all the time.

6Speeder

Nope, the O2 sensors monitor the FRONT, or primary cats, not the secondary ones, so no CEL.

mark mc williams

i know this is a old discusion, but i also lost low End torq on the Street with the added X pipe on my c7 z06.

Internets_Ninja

Aftermarket X Pipes are cheap and easy to install. I wouldn't spend the money chopping up the stock X pipe honestly. The only benefit of secondary cat delete is sound. I like it. Also, no worries about CEL.

mark mc williams

yes, i was very disapointed after installing the Borla 60547 and the attack mufflers, now i lost some bottom end when i punch it on the street, i really don't care about the dyno numbers, for me it is on the street half a block or so, now i have a louder sound, but less bottom end torq ,i called borla, one guy said you lose bottom end up to 2000 rpm or so, then one guy a week later at borla said give the computer time to adjust to it . it would have been nice to know this Before buying, when me and my friend race half a block or so were ussually neck and neck on the street now he gains on me at the begining, when before i slowly pulled away.
now i have 2000 in the borla mufflers and X pipe. mark

Internets_Ninja

The very sensitive LT1 knock sensors are known to have some false knock down low when you delete the primary or secondary cats. This is likely what is happening to you. I've seen it on my HPTuners datalogs before. I would see 2-3 degrees of timing getting pulled out. I tuned my car so I no longer have the issue.

If you only want sound, then I would suggest putting the stock x pipe back on and leaving the Borla rear section. Otherwise you will need a tune to regain your low end. On the bright side, you could get an AFE Intake and have the car tuned and you will pull away from your friend in block to block drags. (In Mexico of course)

mark mc williams

have you ever seen this problem on a LT4 factory supercharged, that is what mine is, 2017 z06. thank you.

Internets_Ninja

I don't have any experience with this on the LT4. But its entirely possible the LT4 would behave the same way as the LT1 and LT4 are similar sans the blower and fuel system.

robert miller

then let say this putting LT headers on the car & pulling the 2nd cats then put on Borla atka npp on the car. Check engine light was on until I got T/A kid to do a part tune on the car. Robert

Higgs Boson

the long tube headers relocate the O2 sensors and also are not compatible with factory primary cats, the Xpipe had nothing to do with the CEL.

C7/Z06 Man

Engine Setup: Stock Tune & AFE CAI with gray 'dry' filter installed.


Then I added: 3" Corsa X-Pipe with 2000 degree heat warp (spray painted silver) added just to shield the A8 trans area from heat.


Track Results: I lost ET & MPH in the 1/4 mile, so I removed the aftermarket X-Pipe and sold it.

Next Up: Gutted Cats.










Track Results: Not as bad as the 3" X-Pipe but still not as fast as the "Stock" pipe. So I reinstalled my original stock X-pipe and all is well.

PS: This is an example of what the stock X-pipe/stock tune with the AFE is capable of on a good day. I believe there is more to be found.



EDIT: IIRC, the time slip below may be with the 'gutted cats' at a different track and later date but as I said above its now back to the stock X-pipe.

mark mc williams

I lost bottom end Torq on my 2017 Z06 after adding the Borla X pipe and mufflers, sounds better though, but it dissapoin'ts me on the low End Torq loss i notice on the street.. i have over 2000.00 in the X pipe and attack mufflers, and lost Bottom End Torq. i cant believe it.