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      08-27-2010, 01:57 PM   #1
Bob MG
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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
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Last edited by Bob MG; 08-31-2010 at 12:02 AM.
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      08-27-2010, 02:00 PM   #2
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Quote:
Originally Posted by Bob MG View Post
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!
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      08-27-2010, 02:12 PM   #3
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Quote:
Originally Posted by iBeJayKaying View Post
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
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      08-27-2010, 02:50 PM   #4
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Wow you sir are brave...
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      08-27-2010, 03:00 PM   #5
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sounds great!
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      08-27-2010, 04:42 PM   #6
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raising the bar again
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      08-27-2010, 05:45 PM   #7
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Quote:
Originally Posted by Bob MG View Post
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
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      08-27-2010, 06:36 PM   #8
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wish i had time for this stuff
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      08-27-2010, 10:09 PM   #9
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haha ur crazy.
That was a stoic way to get that done lol
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      08-27-2010, 11:08 PM   #10
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nice work!!!! ballzy
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      08-28-2010, 12:36 AM   #11
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You sir have a large set of attachments.


A Borat: "Very nice!"
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      08-28-2010, 12:38 AM   #12
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Quote:
Originally Posted by Bob MG View Post
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...
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      08-28-2010, 12:39 AM   #13
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Quote:
Originally Posted by J08M3 View Post
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.
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      08-28-2010, 12:41 AM   #14
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Quote:
Originally Posted by swamp2 View Post
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!

Last edited by Bob MG; 08-28-2010 at 01:18 AM.
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      08-28-2010, 04:23 AM   #15
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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!
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      08-28-2010, 06:22 AM   #16
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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
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      08-28-2010, 03:19 PM   #17
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Quote:
Originally Posted by Bob MG View Post
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.
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      08-28-2010, 04:18 PM   #18
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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 ...
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      08-28-2010, 11:36 PM   #19
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Quote:
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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?
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      08-30-2010, 08:31 AM   #20
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New sound clips of the cat removal

love it



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      08-31-2010, 12:19 AM   #21
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Hahahaha, you're nuts Good job!
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      08-31-2010, 06:33 PM   #22
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Nice going. Could you not order it without the cats?
Very familiar Austrian Village by the way.
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