HFC or X-pipe

[GBX]

Indivudually, which yeilds more power gains and which is louder...while using stock muffler. I'm looking to get the more gains out and keep the car quiet w/ no drone, as its my daily driver.

So, if you had to choose, based on those requirements, would you get an HFC or X-pipe.

Still learning here with this motor. Thanks!

[J08M3]

the car comes from the factory with an x-pipe, and although it's not smoothly bent like the aftermarket ones it's still a x-pipe the advantage of the aftermarket ones is the elimination of the secondary set of cats. That will increase your HP. The biggest restriction is in the primary cats, so you'll find the best increase by eliminating them or swapping them with high flow cats.

[MrHarris]

With a stock muffler, you will have no drone whatsoever. When you're on the throttle, yes there will be more volume but when cruising at any rpm (besides the known 2k drone with stock setup) it will be just like stock.

Pick which x-pipe you like best, I'd suggest replacing the whole thing. Look into a quality manufacture (Gintani, Fabspeed, Akra) and see which one fits your budget.

[zamm3k]

I can help you with this as that's the setup I'm running know. Completely cat-less on stock axle back exhaust. If you decide to go completely catless you will gain power up top, but at the price of losing response down low. After months of driving it haven't been able to make up my mind whether I did lose some torque at lower RPM's or not. Physics would explain I did mainly because the turbulence inside the pipes is different now and the scavenging created by the X Pipes is different, therefore losing torque might be a side effect. However I can assure you that the power is noticeable up top.

As for sounds go..... its horrible. Dreaded...I can't stand it anymore and the only reason I haven't purchased the axle back is because I can't come to a decision as to which exhaust I want and whether I want a loud one or quiet one.

There's absolutely no drone whatsoever, but the car is louder at WOT, its obvious if you lose two cats and a pair of resonators. All in all I would advise you to spend your money on going fully cat-less if power is what you're looking for. But this will lead to having to get a flash. Again, if what you're looking for is power, a flash should be on you're mind already.

Hope this helps!

[LV-E92M3]

My set up was the Fabspeed HFC/X pipe with stock exhaust for a month.
There's no drone at all and making better sound + performance 20whp gain + no cell since I drove my car for 2k miles ( some people said it pops the engine cheek light, but mine doesn't ) You'll love the Fabspeed pack + stock exhaust system if you are fan of the stock exhaust. I hope you make a right choice!

http://www.m3post.com/forums/showthr...light=fabspeed

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[GBX]

Originally Posted by J08M3

The biggest restriction is in the primary cats, so you'll find the best increase by eliminating them or swapping them with high flow cats.

I just spoke with Fabspeed and they told me that the biggest restriction is the facoty x-pipe and i'll see the most gains there. Can anyone confirm one way or the other??

Originally Posted by LV-E92M3

My set up was the Fabspeed HFC/X pipe with stock exhaust for a month.
There's no drone at all and making better sound + performance 20whp gain + no cell since I drove my car for 2k miles ( some people said it pops the engine cheek light, but mine doesn't ) You'll love the Fabspeed pack + stock exhaust system if you are fan of the stock exhaust. I hope you make a right choice!

Sounds sick! 20whp on stock ECU or with a flash?

And any idea if i'll pass NYS emissions w/ their HFC's?

[J08M3]

Originally Posted by GBX

I just spoke with Fabspeed and they told me that the biggest restriction is the facoty x-pipe and i'll see the most gains there. Can anyone confirm one way or the other??

Did you ask them to clarify what the restriction is? I'm assuming they are talking about the secondary cats. Which you can easily eliminate yourself without buying their product. The main restriction is the primary cats though.

[J08M3]

Originally Posted by GBX

And any idea if i'll pass NYS emissions w/ their HFC's?

I'll have a real answer soon, mine is due this month.

[LV-E92M3]

Originally Posted by GBX

I just spoke with Fabspeed and they told me that the biggest restriction is the facoty x-pipe and i'll see the most gains there. Can anyone confirm one way or the other??



Sounds sick! 20whp on stock ECU or with a flash?

And any idea if i'll pass NYS emissions w/ their HFC's?

with stock ecu

[NatAsp-M3]

Originally Posted by GBX

I just spoke with Fabspeed and they told me that the biggest restriction is the facoty x-pipe and i'll see the most gains there. Can anyone confirm one way or the other??

Can't be, they must have misunderstood the question. It has to be the primary cats, I've tried to look through the stock primaries - you can't even see light through them.

[m33]

Originally Posted by NatAsp-M3

Can't be, they must have misunderstood the question. It has to be the primary cats, I've tried to look through the stock primaries - you can't even see light through them.

the xpipe includes the primary cats , no

[J08M3]

Originally Posted by m33

the xpipe includes the primary cats , no

well on OEM it does since it's all one piece, but not on the aftermarket systems. Most of the aftermarket x-pipe have you either take off the primary cats, or they have you cut the exhaust behind them and bolt on to them.

[M3 Montreal]

Originally Posted by J08M3

well on OEM it does since it's all one piece, but not on the aftermarket systems. Most of the aftermarket x-pipe have you either take off the primary cats, or they have you cut the exhaust behind them and bolt on to them.

+1

Although I think it depends on which aftermarket. AA is 2 pieces so you can go catless or HFC or CUT your stock pipe after the primary cats.

[M II]

Originally Posted by LV-E92M3

My set up was the Fabspeed HFC/X pipe with stock exhaust for a month.
There's no drone at all and making better sound + performance 20whp gain + no cell since I drove my car for 2k miles ( some people said it pops the engine cheek light, but mine doesn't ) You'll love the Fabspeed pack + stock exhaust system if you are fan of the stock exhaust. I hope you make a right choice!

http://www.m3post.com/forums/showthr...light=fabspeed

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Your car sounds amazing!

It's a great sound even with the use of the stock mufflers. Absolutely aggressive!

Originally Posted by J08M3

well on OEM it does since it's all one piece, but not on the aftermarket systems. Most of the aftermarket x-pipe have you either take off the primary cats, or they have you cut the exhaust behind them and bolt on to them.

On the aftermarket X-pipes, you can choose to run a cat bypass pipe or a set of sport catalysts. The OEM pipe does contain it on one unit, but with the aftermarket options you can play with it a bit in terms of setup.

[Fen335i]

Originally Posted by **********s II

Your car sounds amazing!

It's a great sound even with the use of the stock mufflers. Absolutely aggressive!



On the aftermarket X-pipes, you can choose to run a cat bypass pipe or a set of sport catalysts. The OEM pipe does contain it on one unit, but with the aftermarket options you can play with it a bit in terms of setup. The Fabspeed unit is nice since it slips on and off so easily between cats and no cats.

I didn't realize you can swap between fabspeed HFC's and cat-less with their system. What are the claimed gains with going catless w/Fabspeed's xpipe?

[M II]

Originally Posted by Fen335i

I didn't realize you can swap between fabspeed HFC's and cat-less with their system. What are the claimed gains with going catless w/Fabspeed's xpipe?

[IMG]http://www.**********s.com/images/Products/Fabspeed/dyno29.jpg[/IMG]

That's with the ECU upgrade though. You might have slightly different numbers without a tune.

[Fen335i]

^ that file is with the HFC's and xpipe....NOT catless, which is what I was looking to see numbers on. You mention in the thread that they offer a cat-less option where you can take the HFC's off and run without cats...at least that's how I read your post.

[M II]

Originally Posted by Fen335i

^ that file is with the HFC's and xpipe....NOT catless, which is what I was looking to see numbers on. You mention in the thread that they offer a cat-less option where you can take the HFC's off and run without cats...at least that's how I read your post.

I meant with aftermarket options you have a choice of a cat bypass pipe or a sport catalyst.

I'm sorry about the confusion as I was thinking about Fabspeed's E46 M3 setup, which does have a modular piece that switches back and forth.

I edited my post and sorry about the confusion.

[ryan@ActiveAutowerke]

The Active Autowerke X Pipe with HFC has been a proven performance enhancement for the E9X M3. Add a performance pulley and Active Software and your looking at anywhere from 23-27 rwhp. This has been dyno proven on a Mustand Dyno by a few M3 Post members. Eliminating the primary cats is where you will find the hidden power of the M3.

[BimmerRob08]

Hows the track record with CEL and this system? I've got an Encore Innovation x-pipe with HFC and throws a code about once a day now. Constantly having to resert it with the CANBUS reader I have. Starting to become a pain in the ass. I'm thinking of just slapping back on my stock exhaust mated to my Remus Sport that's on there.

[mfeltiii]

Originally Posted by ryan@ActiveAutowerke

The Active Autowerke X Pipe with HFC has been a proven performance enhancement for the E9X M3. Add a performance pulley and Active Software and your looking at anywhere from 23-27 rwhp. This has been dyno proven on a Mustand Dyno by a few M3 Post members. Eliminating the primary cats is where you will find the hidden power of the M3.

Do you mean eliminating as in replacing with this product (HFC) or are you saying that there is much more "hidden" power to be had by eliminating the HFC?

[ryan@ActiveAutowerke]

Replacing the primary with the HFC you will receive more power than having stock cats but eliminating the cats completely will give you the most power but a bit of a exhaust smell since there will be no cats.