"Street" X-Pipe Reviews: Who is using an x-pipe with primary cats in tact?

[grantmax]

All,

As the title states, I'm looking for some reviews/feedback from guys with "street" x-pipes on their cars. Preferably the Challenge Street X-Pipe.

I'm looking for general feedback on the following:
What muffler are you using with the x-pipe?
How is the sound? Any drone?
Did you experience an increase in power?
Is there a noticeable gas smell without the secondary cats?

FYI - Primary cats must be in tact for it to be considered a "street" x-pipe. This may not be the rule outside of this thread but it's what I'm looking for here.

Thanks

[tom @ eas]

One would ask: Why retain the most restrictive part of the system?

[jjettdunn]

Originally Posted by tom @ eas

One would ask: Why retain the most restrictive part of the system?

I think this is because they are not wanting to tune the ECU. As deleting the primary cats would throw a CEL light.

EAS, does eliminating both cats make the car un-driveable as a daily? I have the OEM exhaust (not the MPE) and I want both power and a good sound but I also don't want to drown out any passengers or sound like I'm in a track only car.

Thoughts?

[tom @ eas]

Originally Posted by jjettdunn

I think this is because they are not wanting to tune the ECU. As deleting the primary cats would throw a CEL light.

EAS, does eliminating both cats make the car un-driveable as a daily? I have the OEM exhaust (not the MPE) and I want both power and a good sound but I also don't want to drown out any passengers or sound like I'm in a track only car.

Thoughts?

You will get a CEL from removing primary cats, but it does not affect performance. A tune is required to remove the light.

With or without a tune, the car is easily a DD with the primaries removed, especially with the OEM exhaust still intact. There's very little performance gains from catback systems - most purchase aftermarket for either weight, sound and/or tip style.

[AlpineE92M3]

Originally Posted by jjettdunn

I think this is because they are not wanting to tune the ECU. As deleting the primary cats would throw a CEL light.

EAS, does eliminating both cats make the car un-driveable as a daily? I have the OEM exhaust (not the MPE) and I want both power and a good sound but I also don't want to drown out any passengers or sound like I'm in a track only car.

Thoughts?

Test pipes with a tune. I just did ACM TP's and BPM stage 2 tune( review coming). You will ask yourself why didnt you do it sooner. It makes the world of difference without it being "too much"

[jjettdunn]

Will I destroy my drivetrain warranty by removing the primary cats and cutting the factory x pipe?

[tom @ eas]

Originally Posted by jjettdunn

Will I destroy my drivetrain warranty by removing the primary cats and cutting the factory x pipe?

This is up to the dealership to determine, but i haven't seen a case of this happening yet.

[coloradoe92m3]

Zero point to xpipe that doesn't delete primaries. You get 5 HP from deleting secondaries and no real change in sound. Cat less or hfc or test pipes and OEM rear is the most under utilized setup IMO. Its truly the only zero drone system with same stock sound at low ROMs but the as throttle is applied you get a high pitch scream that is exotic, mechanical and raspy in good way

[jjettdunn]

Originally Posted by coloradoe92m3

Zero point to xpipe that doesn't delete primaries. You get 5 HP from deleting secondaries and no real change in sound. Cat less or hfc or test pipes and OEM rear is the most under utilized setup IMO. Its truly the only zero drone system with same stock sound at low ROMs but the as throttle is applied you get a high pitch scream that is exotic, mechanical and raspy in good way

Recommendations on doing one of the three:

1) A full x-pipe replacement either the gintani 4 resonator set up.
2) A cheaper two piece x-pipe.
3) Cut off the front cats and doing a test pipe set up.

I plan on keeping my OEM exhaust as there aren't any power gains. Also this is a daily so if a full x pipe is too loud or it actually has a bad exhaust smell I would not be interested. Thanks for all the help.

[M3ANMACHINE]

My car is my DD, and I have removed the primary cats and replaced them with TMS Test Pipes. I also have an AE Performance Exhaust and it is completely bearable.

[grantmax]

During the course of my mildly extensive research, I came across a thread about cutting out secondary cats. One clever member responded to the OP saying, "Don't be a squid. Delete the primaries." This phrase has stuck with me. It has haunted my mind for weeks. "You are not a squid", I told myself, "You're different." But the struggle was futile. In the end, this phrase has broken me down.

My decision: Test Pipes + Tune paired with an unmodified OEM muffler. Which pipes and which tune will be determined at a later date.

[kitw]

I tried a street x pipe. Actually 2 of them. All they added were drone, my dynos were all within dyno error.

If you want more power, get test pipes. If all you care about is more sound, the Street X pipe will give you that, but be prepared, it gives a lot of potential drone (depending on your rear section) without much change in the upper rpm sound. Kind of the worst of all worlds. I'd stick with a rear section or test pipes.

[thgem72]

I went Evolve x-pipe w/tune. No drone relative to stock and pick up in sound and performance. Dramatic? No. Expensive? Yes! They offer a test pipe option as well. X-pipe allows a direct swap.

[grantmax]

Originally Posted by thgem72

I went Evolve x-pipe w/tune. No drone relative to stock and pick up in sound and performance. Dramatic? No. Expensive? Yes! They offer a test pipe option as well. X-pipe allows a direct swap.

And now for the $1,000,000 question. If you could do it again, would you go X-Pipe or Test Pipes?

[thgem72]

X but I'm biased given easy swap for emissions testing when it comes time. There is a definite improvement in sound (very refined, but not real aggressive if that's what you're going for) that I assume has a lot to do with the x notwithstanding benefits of simply removing the primary cat. I had an RS4 prior and this is quieter than that in stock form. Had two different aftermarket exhausts on that and am somewhat familiar with drone, which this has none of. Think you'll get most of the performance with the test pipes from what I've read. Quality x-pipe and cats from what I understand.

Hope this helps!

[s85e90]

X pipe. No cats for me

[skate0518]

Challenge Street Xpipe no cat pair with Akrapovic catback (No drone at all) ~

[aus]

Originally Posted by grantmax

And now for the $1,000,000 question. If you could do it again, would you go X-Pipe or Test Pipes?

If you're in a state that requires a smog check, you're probably better off with an X-pipe so you can swap the stock X-pipe back.
The ideal would be cored primary cats stock X-pipe. You may still pass the sniffer if the secondary cats are hot.