High flow cats recommendations?

///M Kidding · 10-24-2016, 01:03 PM

Hi guys,

I currently have the challenge street xpipe, and I want to switch the OEM primary cats to high flow cats if possible. Any one has any experience with these stuff? Any recommendations? Also, are there any downside switching the OEM cats to HF cats?

Thanks in advance.

dparm · 10-24-2016, 01:20 PM

Downside is the car will get a bit louder, depending on which specific cat you go for. A "larger" cat (e.g. more volume) will tend to be quieter since it has more mass and material to absorb the sound. It will also change the tone of the exhaust, and possibly not for the better -- they tend to get tinny and raspy.

You should also check into your local state laws about this. If there's a visual check as part of emissions inspection, you will fail. It's illegal in all 50 states to modify or remove a functioning emissions device, as I understand it.

///M Kidding · 10-24-2016, 01:45 PM

Quote:

Originally Posted by dparm

Downside is the car will get a bit louder, depending on which specific cat you go for. A "larger" cat (e.g. more volume) will tend to be quieter since it has more mass and material to absorb the sound. It will also change the tone of the exhaust, and possibly not for the better -- they tend to get tinny and raspy.

You should also check into your local state laws about this. If there's a visual check as part of emissions inspection, you will fail. It's illegal in all 50 states to modify or remove a functioning emissions device, as I understand it.

Thanks for the input, the main thing I'm after is the power gain. As for the sound, I don't think it's going to be too bad right? Because a good amount of people run HFC here on the forum.

As for the state law, I think I will be fine

SYT_Shadow · 10-24-2016, 02:30 PM

I run the ESS HFC Xpipe. Very nice, light and it sounds wonderful. Having an xpipe actually reduced the drone at 3200rpm!

dparm · 10-24-2016, 02:31 PM

Quote:

Originally Posted by ///M Kidding

Thanks for the input, the main thing I'm after is the power gain. As for the sound, I don't think it's going to be too bad right? Because a good amount of people run HFC here on the forum.

As for the state law, I think I will be fine

I see that you have a Challenge X-pipe and Akrapovic exhaust. I would talk to both of those companies and see if they offer matching high-flow cats and explicitly ask them about the sound (e.g. "is your cat converter designed to complement the exhaust, rather than being a generic off the shelf one").

This is the problem when you piece together an exhaust: you never know what it might sound like.

///M Kidding · 10-24-2016, 02:37 PM

Quote:

Originally Posted by SYT_Shadow

I run the ESS HFC Xpipe. Very nice, light and it sounds wonderful. Having an xpipe actually reduced the drone at 3200rpm!

Good to know, what did you pair with?

///M Kidding · 10-24-2016, 02:39 PM

I will try to contact them but I think they will just tell me to buy the xpipe from them since they both have their own HFC xpipe mass produced lol

dparm · 10-24-2016, 03:15 PM

Quote:

Originally Posted by ///M Kidding

I will try to contact them but I think they will just tell me to buy the xpipe from them since they both have their own HFC xpipe mass produced lol

Ask them point-blank why you should buy theirs versus someone else's.

///M Kidding · 10-24-2016, 03:34 PM

Quote:

Originally Posted by dparm

Quote:

Originally Posted by ///M Kidding

I will try to contact them but I think they will just tell me to buy the xpipe from them since they both have their own HFC xpipe mass produced lol

Ask them point-blank why you should buy theirs versus someone else's.

Lol not sure it's the best thing to ask, I just did some research and found out adding HFC in the stock primary cats' position does not add a lot power...

:

KRZ3 · 10-24-2016, 04:57 PM

Tried the Akra Evo full line. Too much drone and lots of torque lost in the low rpms. Now on ESS HFC and mufflers. No drone, torque is back and the M sounds like an Aston Martin, very sophisticated. I just love it.

///M Kidding · 10-24-2016, 05:01 PM

Quote:

Originally Posted by KRZ3

Tried the Akra Evo full line. Too much drone and lots of torque lost in the low rpms. Now on ESS HFC and mufflers. No drone, torque is back and the M sounds like an Aston Martin, very sophisticated. I just love it.

Yeah I've heard the akra evo drones a bit, glad you like your new setup

SYT_Shadow · 10-25-2016, 01:10 PM

Quote:

Originally Posted by ///M Kidding

Good to know, what did you pair with?

Evolve valvetronic catback

///M Kidding · 10-25-2016, 01:31 PM

Quote:

Originally Posted by SYT_Shadow

Quote:

Originally Posted by ///M Kidding

Good to know, what did you pair with?

Evolve valvetronic catback

Why didn't you choose evolve's HFC xpipe? I heard their xpipe is pretty good.

SYT_Shadow · 10-25-2016, 02:47 PM

ESS is the only one that maintains the HFCs in their original position, and I've worked with ESS in the past and have a lot of trust in them.

If they built a valvetronic rear section I would have gone with them. Mind you, the Evolve has worked out well

///M Kidding · 10-25-2016, 02:52 PM

Quote:

Originally Posted by SYT_Shadow

ESS is the only one that maintains the HFCs in their original position, and I've worked with ESS in the past and have a lot of trust in them.

If they built a valvetronic rear section I would have gone with them. Mind you, the Evolve has worked out well

Doesn't it kill power if the cats are located at where the stock cats were? At least that's what I've learned from previous research.

loveskiing · 10-25-2016, 03:55 PM

Another vote for ESS X-pipe with HFC, but it's wedded to the Corsa axle back. Zero drone and IMHO, the best sound of all that I've heard.

SYT_Shadow · 10-25-2016, 04:04 PM

Quote:

Originally Posted by ///M Kidding

Doesn't it kill power if the cats are located at where the stock cats were? At least that's what I've learned from previous research.

Their xpipe shows nice gains. OEM cats are restrictive and around 4x the volume of the hfcs ESS uses

///M Kidding · 10-25-2016, 04:11 PM

Have you run a dyno comparison? Got any numbers? Or, it's the feeling that there's obvious power gain after installing the xpipe?

SYT_Shadow · 10-25-2016, 06:13 PM

Quote:

Originally Posted by ///M Kidding

Have you run a dyno comparison? Got any numbers? Or, it's the feeling that there's obvious power gain after installing the xpipe?

There was clear and unmistakable power gain from this. I'm sure someone did the dynos. Many supercharged cars are running this setup

///M Kidding · 10-25-2016, 07:12 PM

Quote:

Originally Posted by SYT_Shadow

Quote:

Originally Posted by ///M Kidding

Have you run a dyno comparison? Got any numbers? Or, it's the feeling that there's obvious power gain after installing the xpipe?

There was clear and unmistakable power gain from this. I'm sure someone did the dynos. Many supercharged cars are running this setup

Cool, good to know

SYT_Shadow · 10-26-2016, 05:41 PM

Quote:

Originally Posted by ///M Kidding

Cool, good to know

Here you go, they claim 20hp. Given their ample experience with BMWs, I have no reason to doubt them
http://esstuning.com/ess-e9x-m3-exhuast-full-system/

Best part of their hfc is you maintain emissions readiness

10-24-2016, 01:03 PM	#1
///M Kidding Captain 93 Rep 661 Posts Drives: E92 M3 DCT Join Date: Feb 2015 Location: PA iTrader: (5)	High flow cats recommendations? Hi guys, I currently have the challenge street xpipe, and I want to switch the OEM primary cats to high flow cats if possible. Any one has any experience with these stuff? Any recommendations? Also, are there any downside switching the OEM cats to HF cats? Thanks in advance. __________________ 11 E92 M3 DCT \| Evlove Stage 2 Tune \| Evolve Test Pipe \| Akrapovic slip-on \| MS Stage 2 Intake \| Ohlins R/T \| Vorsteiner VFF-101 \| OSSdeisgns \| Exotics Tuning
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10-24-2016, 01:20 PM	#2
dparm Stop the hate, get a V8 3850 Rep 8,625 Posts Drives: C7 Corvette GS, AMG C63 S Join Date: Jun 2013 Location: Frisco, TX iTrader: (1)	Downside is the car will get a bit louder, depending on which specific cat you go for. A "larger" cat (e.g. more volume) will tend to be quieter since it has more mass and material to absorb the sound. It will also change the tone of the exhaust, and possibly not for the better -- they tend to get tinny and raspy. You should also check into your local state laws about this. If there's a visual check as part of emissions inspection, you will fail. It's illegal in all 50 states to modify or remove a functioning emissions device, as I understand it. __________________ Now: 2017 Corvette Grand Sport, 2021 AMG C63 S sedan Past: 2011.5 M3 sedan ZCP
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10-24-2016, 02:30 PM	#4
SYT_Shadow ///M Powered for Life 11462 Rep 10,328 Posts Drives: E90M/E92M/M4GTS/M4GT4/X5M Join Date: Sep 2010 Location: Greenwich, CT iTrader: (2)	I run the ESS HFC Xpipe. Very nice, light and it sounds wonderful. Having an xpipe actually reduced the drone at 3200rpm!
	Appreciate 0 Quote

10-24-2016, 02:39 PM	#7
///M Kidding Captain 93 Rep 661 Posts Drives: E92 M3 DCT Join Date: Feb 2015 Location: PA iTrader: (5)	I will try to contact them but I think they will just tell me to buy the xpipe from them since they both have their own HFC xpipe mass produced lol __________________ 11 E92 M3 DCT \| Evlove Stage 2 Tune \| Evolve Test Pipe \| Akrapovic slip-on \| MS Stage 2 Intake \| Ohlins R/T \| Vorsteiner VFF-101 \| OSSdeisgns \| Exotics Tuning
	Appreciate 0 Quote

10-24-2016, 04:57 PM	#10
KRZ3 Private First Class 23 Rep 139 Posts Drives: E90 M3 Join Date: Dec 2015 Location: Home iTrader: (0)	Tried the Akra Evo full line. Too much drone and lots of torque lost in the low rpms. Now on ESS HFC and mufflers. No drone, torque is back and the M sounds like an Aston Martin, very sophisticated. I just love it. __________________ '09 E90 M3 DCT EDC, ESS VT2 625, ESS HFC, GTS DCT, D2R BBK, B16D, VORSHLAG CP, DELRIN SUB, TE37SL '00 996.1 GT3 CS
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10-25-2016, 02:47 PM	#14
SYT_Shadow ///M Powered for Life 11462 Rep 10,328 Posts Drives: E90M/E92M/M4GTS/M4GT4/X5M Join Date: Sep 2010 Location: Greenwich, CT iTrader: (2)	ESS is the only one that maintains the HFCs in their original position, and I've worked with ESS in the past and have a lot of trust in them. If they built a valvetronic rear section I would have gone with them. Mind you, the Evolve has worked out well
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10-25-2016, 03:55 PM	#16
loveskiing Lieutenant Colonel 966 Rep 1,612 Posts Drives: 2011 M3 E90 Join Date: Aug 2012 Location: Portland, OR iTrader: (0)	Another vote for ESS X-pipe with HFC, but it's wedded to the Corsa axle back. Zero drone and IMHO, the best sound of all that I've heard.
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10-25-2016, 04:11 PM	#18
///M Kidding Captain 93 Rep 661 Posts Drives: E92 M3 DCT Join Date: Feb 2015 Location: PA iTrader: (5)	Have you run a dyno comparison? Got any numbers? Or, it's the feeling that there's obvious power gain after installing the xpipe? __________________ 11 E92 M3 DCT \| Evlove Stage 2 Tune \| Evolve Test Pipe \| Akrapovic slip-on \| MS Stage 2 Intake \| Ohlins R/T \| Vorsteiner VFF-101 \| OSSdeisgns \| Exotics Tuning
	Appreciate 0 Quote

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