DIY: How to butcher your Akapovic EVolutions Cats

Bob MG · 08-27-2010, 01:57 PM

In the spirit of achieving extra power without sacrificing drone and noise, I set about removing the insides of the 100 CPI HFCs that are standard on the Akrapovic Evolution full titanium system.

It took a leap of faith that the sound would not be too loud, or drone excessively.

It also took over two hours of brute manual labor

Tools required:
1. A tire iron (sharpened on a grinder)
2. A hammer
3. Perseverance
4. Time
5. Bravery to attempt this on a $6000 exhaust system

I am pleased to report that the sound is almost identical to before, maybe ever so slightly raspier, but still ZERO DRONE. It is not louder at all. It sounds fantastic!!

We managed to get every last bit of the fucking hard as hell bitching crap inside the cat chamber out. Fuck me I thought it would never come out, and a few times I was holding my head in my hands thinking what the hell am I doing?

Herewith pics, videos of the butchering and the final sound clip.

The car with the ESS VT2 600 is noticeably more responsive, and smoother to.

In fact I nearly crashed on the way home as I lost traction in third gear changing lanes, while accelerating hard

The car is so scary fast its insane!!! I loooove my ESS S/C

and all I can say is you must go catless if SC. otherwise its like boning with a rubber (just not the same)

Feels like at least an extra 20 whp to me

LateBraking · 08-27-2010, 02:00 PM

Quote:

Originally Posted by Bob MG

Tools required:
1. A tire iron (sharpened on a grinder)
2. A hammer
3. Perseverance
4. Time
5. Bravery to attempt this on a $6000 exhaust system

Bravery indeed BobMG

....Now get us some before and after dynos!

Bob MG · 08-27-2010, 02:12 PM

Quote:

Originally Posted by iBeJayKaying

Bravery indeed BobMG

....Now get us some before and after dynos!

Before not possible, but after do able

I think all the guys that are S/C with catless X Pipes are reporting around 20whp gain without cats

onefastman · 08-27-2010, 02:50 PM

Wow you sir are brave...

the infamous... · 08-27-2010, 03:00 PM

sounds great!

Brosef · 08-27-2010, 04:42 PM

raising the bar again

J08M3 · 08-27-2010, 05:45 PM

Quote:

Originally Posted by Bob MG

I think all the guys that are S/C with catless X Pipes are reporting around 20whp gain without cats

without the 100 cpi akra cats? I doubt 20hp from those. Maybe a couple. I can see 20 over other HFC's or OEM cats. But maybe, would be interesting to see

OMID INC · 08-27-2010, 06:36 PM

wish i had time for this stuff

Green///Hell · 08-27-2010, 10:09 PM

haha ur crazy.
That was a stoic way to get that done lol

DD GT3 RD · 08-27-2010, 11:08 PM

nice work!!!! ballzy

M3_WC · 08-28-2010, 12:36 AM

You sir have a large set of attachments.

A Borat: "Very nice!"

swamp2 · 08-28-2010, 12:38 AM

Quote:

Originally Posted by Bob MG

I set about removing the insides of the 100 CPI HFCs
...
It also took over two hours of brute manual labor

We managed...

Hmmm, is that you or your mechanic doing all of this terrible hard work...

Bob MG · 08-28-2010, 12:39 AM

Quote:

Originally Posted by J08M3

without the 100 cpi akra cats? I doubt 20hp from those. Maybe a couple. I can see 20 over other HFC's or OEM cats. But maybe, would be interesting to see

N/A I agree, but with FI I think it's close to 20whp?

Maybe Green Hell and others with FI and catless can comment on gains they got?

Definitely the right thing to do with FI.
I expected it to be louder and am relieved it's not!!

I'm sure this thread will get a few DIYs done.

Bob MG · 08-28-2010, 12:41 AM

Quote:

Originally Posted by swamp2

Hmmm, is that you or your mechanic doing all of this terrible hard work...

I was directing

Actually I was taking turns with the hammer and tire iron. I have tendinitis in my right elbow as evidence!

Extremley hard to do, took around 1 1/2 hours per cat!

BMRLVR · 08-28-2010, 04:23 AM

You sir are brave indeed!

The only issue is that those two big bubbles that used to be cats are going to effect exhaust velocity by creating turbulance because of their shape since they have no internals. The system will defenitely have less restriction than the cats would have had but will not flow as well as the Cat-less Akrapovic X-pipe.

Kudos again for the balls to do this but with the mods you have done to your car I would have expected you to buy the Cat-less Akrapovic X-pipe..... money don't seem to be an issue for you!

Bob MG · 08-28-2010, 06:22 AM

You probably right, but I have resolved to stop spending money!

The cat removal has made a performance gain without sacrificing noise levels, so I'm happy.

The sound is a little like the CSL exhaust note now. Quite raspy which I love

swamp2 · 08-28-2010, 03:19 PM

Quote:

Originally Posted by Bob MG

I was directing

Actually I was taking turns with the hammer and tire iron. I have tendinitis in my right elbow as evidence!

Extremley hard to do, took around 1 1/2 hours per cat!

That's cool. Just a small ribbing was deserved after all the complaining then seeing the video of your mechanic... Cheers. Nice mod.

m33 · 08-28-2010, 04:18 PM

Ballzy indeed bruh !
When I did my cat delete I noticed the power gain also , kinda like as if you took out 500lbs off the car ...

Bob MG · 08-28-2010, 11:36 PM

Quote:

Originally Posted by m33

Ballzy indeed bruh !
When I did my cat delete I noticed the power gain also , kinda like as if you took out 500lbs off the car ...

How's your new 625 upgrade?

Bob MG · 08-30-2010, 08:31 AM

New sound clips of the cat removal

love it

Mike S · 08-31-2010, 12:19 AM

Hahahaha, you're nuts

Good job!

GeorgeSmooth · 08-31-2010, 06:33 PM

Nice going. Could you not order it without the cats?
Very familiar Austrian Village by the way.

08-27-2010, 01:57 PM	#1
Bob MG Moderating Drives: like a muppet Join Date: Oct 2009 Location: Vienna Posts: 1,738 iTrader: (0)	DIY: How to butcher your Akapovic EVolutions Cats In the spirit of achieving extra power without sacrificing drone and noise, I set about removing the insides of the 100 CPI HFCs that are standard on the Akrapovic Evolution full titanium system. It took a leap of faith that the sound would not be too loud, or drone excessively. It also took over two hours of brute manual labor Tools required: 1. A tire iron (sharpened on a grinder) 2. A hammer 3. Perseverance 4. Time 5. Bravery to attempt this on a $6000 exhaust system I am pleased to report that the sound is almost identical to before, maybe ever so slightly raspier, but still ZERO DRONE. It is not louder at all. It sounds fantastic!! We managed to get every last bit of the fucking hard as hell bitching crap inside the cat chamber out. Fuck me I thought it would never come out, and a few times I was holding my head in my hands thinking what the hell am I doing? Herewith pics, videos of the butchering and the final sound clip. The car with the ESS VT2 600 is noticeably more responsive, and smoother to. In fact I nearly crashed on the way home as I lost traction in third gear changing lanes, while accelerating hard The car is so scary fast its insane!!! I loooove my ESS S/C and all I can say is you must go catless if SC. otherwise its like boning with a rubber (just not the same) Feels like at least an extra 20 whp to me Attached Images Last edited by Bob MG; 08-31-2010 at 12:02 AM.
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08-27-2010, 02:50 PM	#4
onefastman Major General Drives: 2009 135i 2011 e92m dct Join Date: Sep 2009 Location: Earth Posts: 5,702 iTrader: (15)	Wow you sir are brave... __________________ Legal Disclaimer: Anything I or anyone else says about my vehicle on this website(1addicts.com or any affiliated or nonaffiliated sites), pertaining to modifications, is only to gain acceptance from my/our peers, and does not actually represent anything actually existing on my car, and thus, cannot be held against me in any issues, i.e. warranty claims, that may arise.

08-27-2010, 03:00 PM	#5
the infamous... Lieutenant General Drives: like I'M BOUT THAT LIFE Join Date: Jul 2008 Location: PARADISE aka DAWNTOWN Posts: 16,890 iTrader: (0)	sounds great! __________________ "simple is clean" -The ///ModFather [ iND ] - [ eAs ] - [ ACM ] - [ LTMW ] - [ AA ]

08-27-2010, 10:09 PM	#9
Green///Hell Colonel Drives: E92 M3 6MT AW Join Date: Feb 2009 Location: Sydney/Chicago Posts: 2,587 iTrader: (5)	haha ur crazy. That was a stoic way to get that done lol __________________

08-27-2010, 11:08 PM	#10
DD GT3 RD Major Drives: 08 M3 DCT AW/Red Join Date: May 2009 Location: West Hollywood Posts: 1,252 iTrader: (1)	nice work!!!! ballzy __________________ 13 E92 M3 ZCP - WSIR 1:34:5 / BW C13 2:03:6 (stock besides wheels/tires R-s3) Past: Boss 302 - WSIR 1:32:8 / BW C13 2:02:00 C63 w/P31 / 997.2 GT3 / E92 M3 / B7 RS4

08-27-2010, 04:42 PM	#6
Brosef Lieutenant Colonel Drives: 2011 M Join Date: Aug 2009 Location: Chicago Posts: 1,509 iTrader: (3)	raising the bar again

08-27-2010, 06:36 PM	#8
OMID INC Lieutenant Colonel Drives: E70 X5 Join Date: Feb 2010 Location: Chicago Posts: 1,566 iTrader: (6)	wish i had time for this stuff

08-28-2010, 12:36 AM	#11
M3_WC Lieutenant Colonel Drives: M3 Join Date: Jun 2009 Location: CA Posts: 1,829 iTrader: (0)	You sir have a large set of attachments. A Borat: "Very nice!"

08-28-2010, 04:23 AM	#15
BMRLVR Grease Monkey Drives: 2011 E90 M3,1994 Euro E36 M3/4 Join Date: Apr 2006 Location: Fort McMurray, Alberta, Canada Posts: 2,013 iTrader: (3)	You sir are brave indeed! The only issue is that those two big bubbles that used to be cats are going to effect exhaust velocity by creating turbulance because of their shape since they have no internals. The system will defenitely have less restriction than the cats would have had but will not flow as well as the Cat-less Akrapovic X-pipe. Kudos again for the balls to do this but with the mods you have done to your car I would have expected you to buy the Cat-less Akrapovic X-pipe..... money don't seem to be an issue for you! __________________ 2011 E90 M3 ZCP - Individual Moonstone/Individual Amarone Extended/Individual Piano Black With Inlay:LINK!!! 1994 Euro E36 M3 Sedan - Daytona Violet/Mulberry:LINK!!!

08-28-2010, 06:22 AM	#16
Bob MG Moderating Drives: like a muppet Join Date: Oct 2009 Location: Vienna Posts: 1,738 iTrader: (0)	You probably right, but I have resolved to stop spending money! The cat removal has made a performance gain without sacrificing noise levels, so I'm happy. The sound is a little like the CSL exhaust note now. Quite raspy which I love

08-28-2010, 04:18 PM	#18
m33 Banned Drives: E92 VT650 MCB Individual Join Date: Dec 2008 Location: CT Posts: 2,677 iTrader: (5)	Ballzy indeed bruh ! When I did my cat delete I noticed the power gain also , kinda like as if you took out 500lbs off the car ...

08-30-2010, 08:31 AM	#20
Bob MG Moderating Drives: like a muppet Join Date: Oct 2009 Location: Vienna Posts: 1,738 iTrader: (0)	New sound clips of the cat removal love it

08-31-2010, 12:19 AM	#21
Mike S Private First Class Drives: A Car Join Date: Feb 2010 Location: The Stratosphere Posts: 101 iTrader: (0)	Hahahaha, you're nuts Good job!

08-31-2010, 06:33 PM	#22
GeorgeSmooth Lieutenant Drives: 2008 E90 335i AT Join Date: Feb 2008 Location: South Africa Posts: 559 iTrader: (0)	Nice going. Could you not order it without the cats? Very familiar Austrian Village by the way. __________________ 08 E90 335i AT RB Turbos -NX Wet Kit - Chiplogic Flash or Procede V5- M3 Diff - AE Exhaust- Forge Dv's - Helix Intercooler - AR DP's - P3 Boost Gauge - Vishnu Meth- Stett Chargepipe and CAI 09 C63

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