Thinking about an x-pipe...

[coogs08]

It began recently because I want to improve the exhaust note of my car. I was pretty set on just gettin an axle-back setup. However now, x-pipes have been on my mind due to the added benefit of decent power gains. I want to make the exhaust note louder, but not by much and definitely no drone.

If I go with an x-pipe only and keep the oem muffler, how will the exhaust sound? Will keeping the oem muffler cancel out anything achieved by a new x-pipe? I'm guessing that I would need an x-pipe that replaces the 4 cats with resonators, right? Is there a big difference in the power gains achieved by an x-pipe that is just straight pipe vs one with resonators? Also, I hear a lot about high flow cats on here, could someone please explain the adv/disadv of them to me? Sorry for being such noob, thanks for the help.

[THE TECH]

For the most gains, obviously a straight piped setup is the way. This comes at the detriment of sound. You will get a raspy sound which most don't prefer. To get the most gains and get rid of most of the rasp, you can just do test pipes which eliminate the front set of cats. It really comes down to what's most important to you as well as how much you want to spend.

[j2m]

I have a quad resonated X-Pipe and it sounds great. I also have an exhaust with a valve that I can close to minimize drone.
The drone of the X-Pipe can be minimized by choosing the right rear section. Main thing you want to consider, when going catless, is the smell. Some people are really bothered by the smell and end up going the HFC route.
IMHO choosing the right exhaust is one of the most important MOD's you can make to you car. A great sounding exhaust is important to me. I didn't change my exhaust for the added power but that is certainly a great by-product.
I'm not sure how the OEM rear section would sound with an X-Pipe but am guessing it might get a bit raspy.
I'd "second" adding test pipes, it will free up power and keep the 2 rear cats.
Here's a good thread with info and a couple VID's

http://www.m3post.com/forums/showthread.php?t=803719

[SflBimmer8484]

If you choose an X pipe like ours that includes resonators the sound only goes up slightly with a more aggressive tone over the stock exhaust. However you will still gain about 85% of the power of those with full exhaust systems. We have done quite a few of these setups for customers and I would say 70% eventually come back for the rear section as well. If you decide to go with the Hfc version it will be slightly quieter as well with slightly less power gains .

Stock Exhaust -Active Autowerke Xpipe With (Highflow cats)

[coogs08]

Thanks for all the help gents. It sounds like I'd be interested in an X pipe which replaces both sets of cats with resonators, or simply test pipes which will replace the top half & delete the primary cats. This will yield more power than replacing one or both sets of cats with HFCs, correct? So the only advantage of HFCs is to remove the smells that come with going cat-less?

[SflBimmer8484]

Originally Posted by coogs08

Thanks for all the help gents. It sounds like I'd be interested in an X pipe which replaces both sets of cats with resonators, or simply test pipes which will replace the top half & delete the primary cats. This will yield more power than replacing one or both sets of cats with HFCs, correct? So the only advantage of HFCs is to remove the smells that come with going cat-less?

Deleting all the cats would be best. If you see them off the car you would be amazed how air even gets through them. We use 100 cell Hfc's and their only purpose is to stop the smell.

The good thing about our X-pipe is that if you change your mind and want to go to straight pipes its only 4 bolts and 2 clamps away.

Please remember you will need to turn off the o2's via a tune with every option you have mentioned.

[M3takesNYC]

Some misinformation here.

Any x-pipe with no cats at all but with resonators will have the exact horsepower gain as a system without cats and without resonators. Resonators do not relinquish any power. So the 85 percent figure is not making much sense.

Second doing a test pipe and keeping the rest of the system stock will sound identical or very close to another aftermarket x-pipe with High flow cats and 2 resonators (one on each pipe) which AA and Fabspeed both offer.

The test pipes eliminate the primaries but leave the secondaries which are very close to HFC.

As someone who has had an x-pipe with HFC and a stock OEM muffler, I can tell you it has absolutely zero drone, it sounds like a race-car with much higher pitch and more raspy. Youtube M3 DTM car and it sounds identical to that only not quite as loud volume wise. It sounds amazing without being "boomy" at low speed or insanely loud. It gets nice and loud as the RPMS climb whereas rear sections tend to get drown out at high RPMS by the intake.

It is definetly the first step I would take. If you hate the sound you can than add a rear section but atleast you will have the power. If you like the sound which I do not see how anyone would not, then you save on not having to buy a rear.

Cheapest route is to buy test pipes. If you have the cash an AA setup seems nice with the HFC.

[///M Ryder]

Originally Posted by coogs08

Thanks for all the help gents. It sounds like I'd be interested in an X pipe which replaces both sets of cats with resonators, or simply test pipes which will replace the top half & delete the primary cats. This will yield more power than replacing one or both sets of cats with HFCs, correct? So the only advantage of HFCs is to remove the smells that come with going cat-less?

Say noob come to Cars and Coffee this Saturday and you can hear a proper set up .................Phil

[M3takesNYC]

AA, your site says you use 200 cell? Which just to clarify for the poster, using test pipes will likely produce a touch less power than a x-pipe with 200 cell HFC. Oem secondary cats are 200 cell but are ceramic which don't flow quite as well as the metallic 200 cell in a HFC.

If AA is truly 100 metallic it will definetly outflow test-pipes with the secondary 200 cell ceramic cat.

Smell will be eliminated either way and keep in mind this keeps your car legal. If you ever had bad luck and a cop stopped you (as it does smell even with HFC if you were stuck in traffic with a bike cop behind you), HFC still keeps your car legal in terms of a visual inspection. Won't pass emissions but that is not a crime but rather would need to simply change them out compared to running a catless car is a crime.

If you have the money and AA x-pipe is the way to go with the 100 cell HFC. All the power gain, almost no smell, legal and pretty good fitment, plus the benefit from a nice smoother x-pipe that is about 20 pounds lighter over a testpipe setup. A win-win if money is available

Originally Posted by Andrew@ActiveAutowerke

Deleting all the cats would be best. If you see them off the car you would be amazed how air even gets through them. We use 100 cell Hfc's and their only purpose is to stop the smell.

The good thing about our X-pipe is that if you change your mind and want to go to straight pipes its only 4 bolts and 2 clamps away.

Please remember you will need to turn off the o2's via a tune with every option you have mentioned.

[bgqkeneg]

I also have an exhaust with a valve that I can close to minimize drone.

[mkPOTO]

Originally Posted by bgqkeneg

I also have an exhaust with a valve that I can close to minimize drone.

I have the Evolve unit and I love it. I went with several different exhaust with several different xpipes as well. If you want to start you can try out a test pipe and go from there. I had a full catless xpipe and ae muffler and it was way to loud! I would go with a setup with resonators just to keep it tame and loud when you stomp on it. Why not try gong with some test pipes and go from there? (if you are looking to go a cheap route)

[Chriskm3]

Originally Posted by bgqkeneg

I also have an exhaust with a valve that I can close to minimize drone.

Every valved exhaust owner uses the same description:minimizing drone.
Op is inquiring about an xpipe oem exhaust combo with no drone.
I also had aa hfc xpipe with oem muffler. No drone. No boom but Under heavy acceleration it gets very raspy.
FYI. Two slip on exhausts that offer no drone that I have tested with aa xpipe were akra and Dinan. Good luck

[coogs08]

Originally Posted by M3takesNYC

Some misinformation here.

Any x-pipe with no cats at all but with resonators will have the exact horsepower gain as a system without cats and without resonators. Resonators do not relinquish any power. So the 85 percent figure is not making much sense.

Second doing a test pipe and keeping the rest of the system stock will sound identical or very close to another aftermarket x-pipe with High flow cats and 2 resonators (one on each pipe) which AA and Fabspeed both offer.

The test pipes eliminate the primaries but leave the secondaries which are very close to HFC.

As someone who has had an x-pipe with HFC and a stock OEM muffler, I can tell you it has absolutely zero drone, it sounds like a race-car with much higher pitch and more raspy. Youtube M3 DTM car and it sounds identical to that only not quite as loud volume wise. It sounds amazing without being "boomy" at low speed or insanely loud. It gets nice and loud as the RPMS climb whereas rear sections tend to get drown out at high RPMS by the intake.

It is definetly the first step I would take. If you hate the sound you can than add a rear section but atleast you will have the power. If you like the sound which I do not see how anyone would not, then you save on not having to buy a rear.

Cheapest route is to buy test pipes. If you have the cash an AA setup seems nice with the HFC.

Thanks for the very well thought out response, NYC. You addressed all my concerns.

Originally Posted by ///M Ryder

Say noob come to Cars and Coffee this Saturday and you can hear a proper set up .................Phil

Phil, I met you at the meet a couple months ago at Five Guys, not sure if you remember me. I had the jet black e92 with UH plates and asked you to rev your engine for me so I could hear your setup

Originally Posted by mkPOTO

I have the Evolve unit and I love it. I went with several different exhaust with several different xpipes as well. If you want to start you can try out a test pipe and go from there. I had a full catless xpipe and ae muffler and it was way to loud! I would go with a setup with resonators just to keep it tame and loud when you stomp on it. Why not try gong with some test pipes and go from there? (if you are looking to go a cheap route)

Yes I definitely do not want it to be too loud...you're right, I will go with either resonators or at least have some secondary cats (whether they're OEM or HFC)

Originally Posted by Chriskm3

Every valved exhaust owner uses the same description:minimizing drone.
Op is inquiring about an xpipe oem exhaust combo with no drone.
I also had aa hfc xpipe with oem muffler. No drone. No boom but Under heavy acceleration it gets very raspy.
FYI. Two slip on exhausts that offer no drone that I have tested with aa xpipe were akra and Dinan. Good luck

Thanks for the reply, Chris. Did you have HFCs in place of both the primary and secondary on your x-pipe? Or was straight pipe in place of the primary? I really don't want anything too raspy.

[M3takesNYC]

Its easy to find out level or rasp you like. Listen to DTM m3 race car on youtube. If you like that, that is what xpipe/HFC or catless xpipe with stock rear section will sound like. If you hate it than you will know to go with a different option.

[mkPOTO]

Originally Posted by M3takesNYC

Its easy to find out level or rasp you like. Listen to DTM m3 race car on youtube. If you like that, that is what xpipe/HFC or catless xpipe with stock rear section will sound like. If you hate it than you will know to go with a different option.

see here is my take on that. I have looked at over a 100+ different videos on different exhaust setups. There are some videos that come close to what they actually sound like.. but at the end of the day it was not like I expected it. Reason why I went through so many setups.

[SflBimmer8484]

Originally Posted by M3takesNYC

Some misinformation here.

Any x-pipe with no cats at all but with resonators will have the exact horsepower gain as a system without cats and without resonators. Resonators do not relinquish any power. So the 85 percent figure is not making much sense.

Second doing a test pipe and keeping the rest of the system stock will sound identical or very close to another aftermarket x-pipe with High flow cats and 2 resonators (one on each pipe) which AA and Fabspeed both offer.

The test pipes eliminate the primaries but leave the secondaries which are very close to HFC.

As someone who has had an x-pipe with HFC and a stock OEM muffler, I can tell you it has absolutely zero drone, it sounds like a race-car with much higher pitch and more raspy. Youtube M3 DTM car and it sounds identical to that only not quite as loud volume wise. It sounds amazing without being "boomy" at low speed or insanely loud. It gets nice and loud as the RPMS climb whereas rear sections tend to get drown out at high RPMS by the intake.

It is definetly the first step I would take. If you hate the sound you can than add a rear section but atleast you will have the power. If you like the sound which I do not see how anyone would not, then you save on not having to buy a rear.

Cheapest route is to buy test pipes. If you have the cash an AA setup seems nice with the HFC.

I was referring to the addition of an x-pipe and keeping the stock exhaust.. The x-pipe releases about 85% of the power while the rear exhaust releases another 15% or so. Im just giving an example so don't get to hung up on my figures.

[elim11]

Lots of good info. One question. In terms of loudness and exhaust note quality (which I understand is subjective), how does test pipes compare to resonated HFC X-pipe? Is it like 70% of the sound/loudness?

[mkPOTO]

Originally Posted by elim11

Lots of good info. One question. In terms of loudness and exhaust note quality (which I understand is subjective), how does test pipes compare to resonated HFC X-pipe? Is it like 70% of the sound/loudness?

Tests Pipes and stock exhaust


I have driven a car with test pipes only installed, its fairly quite when the car is warmed up from what I recall. If you add a exhaust mod or exhaust the sound gets louder. I would think if you just ran HFC it would be very similar to a test pipe (if your talking about no primary cats and resonators, like stock with test pipes)

[SflBimmer8484]

Originally Posted by elim11

Lots of good info. One question. In terms of loudness and exhaust note quality (which I understand is subjective), how does test pipes compare to resonated HFC X-pipe? Is it like 70% of the sound/loudness?

I would say on a scale from 1-10 and stock was a 3. Test pipes with secondary cats and stock exhaust would be a 4.5?

[kerkiraios00]

Originally Posted by M3takesNYC

Some misinformation here.

Any x-pipe with no cats at all but with resonators will have the exact horsepower gain as a system without cats and without resonators. Resonators do not relinquish any power. So the 85 percent figure is not making much sense.

Second doing a test pipe and keeping the rest of the system stock will sound identical or very close to another aftermarket x-pipe with High flow cats and 2 resonators (one on each pipe) which AA and Fabspeed both offer.

The test pipes eliminate the primaries but leave the secondaries which are very close to HFC.

As someone who has had an x-pipe with HFC and a stock OEM muffler, I can tell you it has absolutely zero drone, it sounds like a race-car with much higher pitch and more raspy. Youtube M3 DTM car and it sounds identical to that only not quite as loud volume wise. It sounds amazing without being "boomy" at low speed or insanely loud. It gets nice and loud as the RPMS climb whereas rear sections tend to get drown out at high RPMS by the intake.

It is definetly the first step I would take. If you hate the sound you can than add a rear section but atleast you will have the power. If you like the sound which I do not see how anyone would not, then you save on not having to buy a rear.

Cheapest route is to buy test pipes. If you have the cash an AA setup seems nice with the HFC.

Sorry ima butt in two sec.. So your saying go with an x pipe with a hfc instead of just a test pipe? Just curious bc I have a miesterschaft gt and I wanted to go with a fabe speed x pipe but was a afraid it might be too loud? I'm looking to get more power and louder note at higher rpm.. Bc my car gets quieter after like 6k? So would an x pipe with hfc be my best bet?