What are the big differences between stock X-pipe and aftermarket?

I already have the Akrapovic slip on rear section for my e90 M3.

I find it a bit too quiet so I want more sound and have been looking at all the aftermarket X-pipes from: Akra, GTM, Supersprint, Dinan, etc....

Is the primary difference just the removal of the resonators? Reason I ask is I have access to a very capable muffler shop so I was thinking to just let them modify my OEM X-pipe...has anyone else done this?

Pros / Cons?

I was looking for pictures of stock X-pipe vs. the aftermarket but haven't found many on here.


thanks!

s4play wrote

I already have the Akrapovic slip on rear section for my e90 M3.

I find it a bit too quiet so I want more sound and have been looking at all the aftermarket X-pipes from: Akra, GTM, Supersprint, Dinan, etc....

Is the primary difference just the removal of the resonators? Reason I ask is I have access to a very capable muffler shop so I was thinking to just let them modify my OEM X-pipe...has anyone else done this?

Pros / Cons?

I was looking for pictures of stock X-pipe vs. the aftermarket but haven't found many on here.


thanks!

Check this out v v v:thumbsup:
http://www.m3post.com/forums/showthread.php?t=457202
http://www.m3post.com/forums/showthread.php?t=831443
http://www.m3post.com/forums/showthread.php?t=830895

s4play wrote

I already have the Akrapovic slip on rear section for my e90 M3.

I find it a bit too quiet so I want more sound and have been looking at all the aftermarket X-pipes from: Akra, GTM, Supersprint, Dinan, etc....

Is the primary difference just the removal of the resonators? Reason I ask is I have access to a very capable muffler shop so I was thinking to just let them modify my OEM X-pipe...has anyone else done this?

Pros / Cons?

I was looking for pictures of stock X-pipe vs. the aftermarket but haven't found many on here.


thanks!

IND has a good picture of the differences using Challenge as an example:



As an alternative option, Bypass Track Pipes are a good inexpensive way to rid of the restrictive primary cats at a fraction of the cost of an X-Pipe.

^thanks for the links!

Why does the "Street" version have shorter pipes that doesn't seem to reach the header?

Seems the Race version is what would fit me best but would this trigger any CEL without a tune? This would mate up directly to the Akra with no cutting right?

s4play wrote

^thanks for the links!

Why does the "Street" version have shorter pipes that doesn't seem to reach the header?

Seems the Race version is what would fit me best but would this trigger any CEL without a tune? This would mate up directly to the Akra with no cutting right?

The Street pipe retains the OEM Primary cats, you still get a CEL unless a tune is added.

Any of the pictured x-pipes will mate to the Akrapovic Slip-On.

You need to have adapters for the slip-on to attach to a stock exhaust type flange.

The stock X-pipe also has lots of kinks and bends in it compared to an aftermarket pipe. It probably doesn't really matter but there is a difference.

aus wrote

You need to have adapters for the slip-on to attach to a stock exhaust type flange.

The stock X-pipe also has lots of kinks and bends in it compared to an aftermarket pipe. It probably doesn't really matter but there is a difference.

yes tubing is also flattened out in several areas as well.

go for catless, akra sounds tame

or challenge sport and get rid of primaries so you pick up that horsepower.

aus wrote

You need to have adapters for the slip-on to attach to a stock exhaust type flange.

The stock X-pipe also has lots of kinks and bends in it compared to an aftermarket pipe. It probably doesn't really matter but there is a difference.

Where to find such adapters. I have the evo and I want to switch out my xpipe

Chriskm3 wrote

Where to find such adapters. I have the evo and I want to switch out my xpipe

They came with the EVO. I'm not sure if they were in the X-pipe box or slip on box. I saved mine and I'm glad I did since I'm considering swapping out the X-pipe too. I'm super sensitive to smell and it's a little more than I want with the 100cpi cats. I think I'd be pretty happy with 200 cpi cats.

For the OP. You won't gain much by deleting the secondary cats. Evolve did pressure studies and didn't gain much by deleting the secondary cats. You may gain some sound by getting rid of them, but I'm thinking you need to switch the rear section to something more aggressive sounding. The Akra just doesn't have that V8 snarl, but I keep it since it's very livable.

What do the adapters look like

aus wrote

They came with the EVO. I'm not sure if they were in the X-pipe box or slip on box. I saved mine and I'm glad I did since I'm considering swapping out the X-pipe too. I'm super sensitive to smell and it's a little more than I want with the 100cpi cats. I think I'd be pretty happy with 200 cpi cats.

For the OP. You won't gain much by deleting the secondary cats. Evolve did pressure studies and didn't gain much by deleting the secondary cats. You may gain some sound by getting rid of them, but I'm thinking you need to switch the rear section to something more aggressive sounding. The Akra just doesn't have that V8 snarl, but I keep it since it's very livable.

tom @ eas wrote

The Street pipe retains the OEM Primary cats, you still get a CEL unless a tune is added.

Any of the pictured x-pipes will mate to the Akrapovic Slip-On.

Are you sure you get a CEL if you get the street pipe? i bought it from a member that claimed it wouldnt give me a CEL and he used it for 20k miles.
I just installed it last week and so far no CEL
Im talking about the pipe that leaves the primaries but removes the secondary cats

JuRuKi wrote

Are you sure you get a CEL if you get the street pipe? i bought it from a member that claimed it wouldnt give me a CEL and he used it for 20k miles.
I just installed it last week and so far no CEL
Im talking about the pipe that leaves the primaries but removes the secondary cats

Yes, you will still get a CEL with the Street Pipe.

Tune or Delete-R will remedy this.

Chriskm3 wrote

What do the adapters look like

Adapters are the bell-shaped items in this image:

tom @ eas wrote

Yes, you will still get a CEL with the Street Pipe.

Tune or Delete-R will remedy this.



Adapters are the bell-shaped items in this image:

You keep the primaries with the street pipes. Why would you get a CEL?

I got worried and researched a little this is what i found:
http://www.***********.com/showthread.php?4555-%26%239600%3B%26%239604%3B-eas-Challenge-line-of-X-Pipes-for-e9x-M3

▀▄ eas | Challenge line of X Pipes for e9x M3
Gentlemen,

As an authorized dealer for Challenge, we are proud to announce that Challenge have just recently released new line of X Pipes, which will be the new standard in workmanship and performance for your e9x M3.




Street - OEM Catalysts
The Challenge Street X Pipe features 304 stainless steel piping and flanges, twin high flow resonators, and a precision fabricated X section. This pipe slip fits after your OEM cats, for easy installation with NO check engine lights! Best of all, no exhaust smell to alert the law at inspection. All bolts, gaskets, and stainless clamps necessary for install are included.

Features:
- Made in the USA
- Full stainless steel construction
- Laser cut and formed mounting brackets
- 2.5 in Piping
- Twin resonators for noise and drone reduction
- Retains factory primary cats
- No check engine light
- Flanged design for easy installation and upgrade options
- 10 wheel hp and 15 ft tq gains with factory exhaust
- Increased low end power

Moxie wrote

You keep the primaries with the street pipes. Why would you get a CEL?

It still appears after time. Would be best to ask Challenge directly.

On a different note, you won't notice much power gains (if any) from removing the secondary cats only, as the primaries are the most restrictive.

both Challenge and FabSpeed claim no CEL! I dont think they could advertise that if it wasnt true?
Im worried now... The only reason i got the street x-pipe was to avoid getting a CEL
Anyone running a street pipe that got a CEL?

If you plan to cut your OEM pipes, consider spending the extra cash and getting a whole new mid section. When it comes times to smog (if relevant) having an intact OEM xpipe with cats can be very helpful unless you know a smog shop owner very well.

If cost is a concern, you can just get test pipes from ACM or Turner for $400 which will extract most of the power from the exhaust. Of course this will also require modifying your stock pipe and will require welding to go back to stock. Another option is to get one of the ebay x-pipes, they may not be as high quality as the others, but fitment is usually pretty good. Here is one for $450 shipped made by topspeed:
http://www.ebay.com/itm/BMW-E92-E93-M3-08-11-Race-SPEC-Exhaust-Middle-Pipe-H-Pipe-Pipes-X-Pipe-Pipes-/230925197224?pt=Motors_Car_Truck_Parts_Accessories&hash=item35c436dfa8&vxp=mtr#ht_2542wt_1013

I had topspeed test pipes on my 350z and they worked great for several years. Resonators can be added on if its too raspy.

If money is no option, I see no reason not to go with the akra x pipe or a quad resonated setup like borla or dinan.

thanks for all the posts thus far! I guess I need to research a bit more, money is a factor but it's really not the main issue.

I have other cars that I mod like crazy and eventually it becomes a hassle just to drive it around town (sure some of you guys can relate) so I don't want the M3 to be another "show" only car.

I want NO CEL and simple bolt on for more sound but not so intrusive that my wife would yell at me as I have toddlers in the back seat sometimes.

So let me see if I got this right:


a) Cats closest to engine are my primary cats

b) Right behind primary cats is a clamp so this is how "Street" pipes attach thus maintain the primary cats

c) There are a total of x4 02 sensors that must be used to avoid CEL

d) Long shiny thick tubes closest to the rear are my secondary cats, not resonators?

e) Race eliminates primary cats but keeps secondary cats


These are slightly less money than the Akra X-pipe, I need to see what the Akra X-pipe does and I guess I'll pull the trigger on one of these.

tom @ eas wrote

The Street pipe retains the OEM Primary cats, you still get a CEL unless a tune is added.

Any of the pictured x-pipes will mate to the Akrapovic Slip-On.

The Street X pipe does not require a tune since the primary cats and sensors remain. I'm guessing this was a typo