Secondary CATS delete

javol · 10-01-2011, 10:21 PM

Removed this mornig the secondary cat and... WOW!!

The sound is incredible!!
Especially the loud "TUM" on upshifting is gorgeous!!
A greet modify for 80 $.
I could not pare to drive and drive around

, listening to the upshift sound!!!

pbu06 · 10-01-2011, 11:39 PM

NEED SOUND VID!!!

Does it smell bad after taking it out?

///NWIE89 · 10-02-2011, 01:09 PM

please get a video of this!

javol · 10-02-2011, 09:15 PM

Quote:

Originally Posted by ///NWIE89

please get a video of this!

Here we are

:

1) on board video at:

2) gentle take off at:

Car is brand new (200 km), i shift @ 4000 RPM.

Completely stock except for secondary cats.

The exhaust tips are 4" applied to the oem mufflers, no more than that.

Bye!

pbu06 · 10-03-2011, 02:38 AM

Quote:

Originally Posted by javol

Here we are

:

1) on board video at:

2) gentle take off at:

Car is brand new (200 km), i shift @ 4000 RPM.

Completely stock except for secondary cats.

The exhaust tips are 4" applied to the oem mufflers, no more than that.

Bye!

Thanks for the vid!

Is the sound louder in general or just different when you upshifting?

javol · 10-03-2011, 08:53 AM

It is a bit louder in general, you can ear it in my 2nd video.
Just perfect for my taste.
But the best is the "bluuurrpppp" on upshifting and the rumbling on downshifting!

sDrive35i · 10-03-2011, 03:13 PM

Now you got me thinking about doing the same. Is there any power loss to this? Also can you put it back incase for inspection?

javol · 10-03-2011, 08:38 PM

Quote:

Originally Posted by sDrive35i

Now you got me thinking about doing the same. Is there any power loss to this? Also can you put it back incase for inspection?

No power loss at all.

For what concern "putting back" is tedious, not impossible.

It is a cut and weld work.

haspi · 10-15-2011, 12:02 AM

Quote:

Originally Posted by javol

No power loss at all.

For what concern "putting back" is tedious, not impossible.

It is a cut and weld work.

Any warranty issues?

Sorry for the stupid question but how do you do it?

az34 · 10-16-2011, 11:19 AM

Very Simple You Have To Cut At Each End Of The Cat Whit A Sawsall And Replace It Whit Straight Pipe

the infamous... · 10-18-2011, 02:02 PM

sounds great

bin karama · 10-23-2011, 09:23 AM

do you get any problems with the computer system ?? like engine check or an other problems ??

javol · 10-23-2011, 08:27 PM

Quote:

Originally Posted by bin karama

do you get any problems with the computer system ?? like engine check or an other problems ??

No problems at all.

Asbjorn · 06-11-2012, 09:49 AM

hi Javol

More than half a year has passed, was wondering if you still enjoy this mod?

javol · 06-16-2012, 02:06 PM

Quote:

Originally Posted by Asbjørn

hi Javol

More than half a year has passed, was wondering if you still enjoy this mod?

Completely

ymdd · 08-14-2012, 11:56 AM

Sorry if this is a stupid question but what's the difference between the secondary cats and the first cats?

javol · 08-14-2012, 09:41 PM

Quote:

Originally Posted by ymdd

Sorry if this is a stupid question but what's the difference between the secondary cats and the first cats?

In the N54 engine, the 2 primary cats are part of the downpipes, hence are practically located at 15-20 cm from the turbos. They are the most effective in reducing emissions and the most restrictive in term of exhaust flow, quitting power and torque. Removing the primary cats gan give you aprox 20-30 whp, depending on the chip tuning you run, and less turbo lag. The secondary cats are located aprox in the center of the car, welded to the midpipes. Removing them does NOT improve power and torque nor reduce turbo lag. Probably the emissions increase and it depends on how much severe are the laws where you live to go with this mod or not. For what concern the Z4 35i, I think this is the best mod to have a louder sound and an amplified upshift "TUM" @ very low cost, at least in Italy.

///MIKE · 08-19-2012, 11:50 AM

What about the iS?

javol · 08-19-2012, 03:39 PM

Quote:

Originally Posted by ///MIKE

What about the iS?

35i and 35is share the same exhaust parts and layout except for the rear end mufflers, sligthly different. This mod should give the same sound increase in both models.

castilla · 10-01-2012, 07:35 AM

i am thinking to do it on my z4 20i but i am curious about if there will be any error on screen ?

and i dont know how many cats does 20i ( n20 engine ) have

javol · 10-01-2012, 12:03 PM

Quote:

Originally Posted by castilla

i am thinking to do it on my z4 20i but i am curious about if there will be any error on screen ?

and i dont know how many cats does 20i ( n20 engine ) have

Here http://www.realoem.com/bmw/ you will find everything about your car

castilla · 10-01-2012, 02:18 PM

okay thanks but any ideas about error ? when i delete cat maybe some sensors will not work properly and it cause error on screen

10-01-2011, 10:21 PM	#1
javol Private First Class 17 Rep 154 Posts Drives: Z4 35i DCT Join Date: May 2006 Location: Italy / Chile iTrader: (0)	Secondary CATS delete - WOW! Removed this mornig the secondary cat and... WOW!! The sound is incredible!! Especially the loud "TUM" on upshifting is gorgeous!! A greet modify for 80 $. I could not pare to drive and drive around , listening to the upshift sound!!!
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10-01-2011, 11:39 PM	#2
pbu06 Enlisted Member 3 Rep 36 Posts Drives: 09' Z4 35i Join Date: Jan 2011 Location: Indiana iTrader: (0)	NEED SOUND VID!!! Does it smell bad after taking it out?
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10-02-2011, 01:09 PM	#3
///NWIE89 Private 7 Rep 75 Posts Drives: 2011 Z4 sDrive35i Join Date: Jul 2011 Location: Crown Point, IN iTrader: (0)	please get a video of this!
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10-03-2011, 08:53 AM	#6
javol Private First Class 17 Rep 154 Posts Drives: Z4 35i DCT Join Date: May 2006 Location: Italy / Chile iTrader: (0)	It is a bit louder in general, you can ear it in my 2nd video. Just perfect for my taste. But the best is the "bluuurrpppp" on upshifting and the rumbling on downshifting!
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10-03-2011, 03:13 PM	#7
sDrive35i Private 5 Rep 91 Posts Drives: 2011 Z4 sDrive35i Join Date: Jul 2011 Location: Brooklyn iTrader: (0)	Now you got me thinking about doing the same. Is there any power loss to this? Also can you put it back incase for inspection? __________________ 2011 BMW Z4 sDrive35i 2010 Nissan Maxima
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10-16-2011, 11:19 AM	#10
az34 Major 33 Rep 1,015 Posts Drives: 2009 z4sdrive35i 2008 x5 3.0i Join Date: May 2011 Location: montréal iTrader: (0)	Very Simple You Have To Cut At Each End Of The Cat Whit A Sawsall And Replace It Whit Straight Pipe
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10-18-2011, 02:02 PM	#11
the infamous... Relapsed Bimmerpost Addict 609 Rep 17,524 Posts Drives: like I'M BOUT THAT LIFE Join Date: Jul 2008 Location: PARADISE aka CANES COUNTRY iTrader: (0)	sounds great __________________ "simple is clean" -The ///ModFather [ iND ] - [ eAs ] - [ ACM ] - [ LTMW ] - [ AA ]
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10-23-2011, 09:23 AM	#12
bin karama New Member 0 Rep 9 Posts Drives: E89 - 2012 Z4 sDrive35is Join Date: Jan 2011 Location: United Arab Emirates iTrader: (0)	do you get any problems with the computer system ?? like engine check or an other problems ??
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06-11-2012, 09:49 AM	#14
Asbjorn Captain 24 Rep 730 Posts Drives: ESS twin-turbo roadster (E89) Join Date: Mar 2012 Location: European in China iTrader: (0)	hi Javol More than half a year has passed, was wondering if you still enjoy this mod? __________________ Little known facts about BMW: 1) The N54 is still in production and used in the current Z4 35i and 35is. 2) In a Z4 you can get sport+ steering combined with normal suspension etc by selecting DSC=off. (Update: DSC=off also offers sports steering in the M135i) 3) All Z4s with 19" wheels are still only offered with the worst performing OEM tires ever sold with a DCT equipped BMW (Potenza RE 050 RFT).
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08-14-2012, 11:56 AM	#16
ymdd Private First Class 4 Rep 107 Posts Drives: not fast enough Join Date: Apr 2012 Location: usa iTrader: (0)	Sorry if this is a stupid question but what's the difference between the secondary cats and the first cats?
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08-19-2012, 11:50 AM	#18
///MIKE Second Lieutenant 9 Rep 202 Posts Drives: E89 35iS Join Date: Sep 2010 Location: Hong Kong iTrader: (0)	What about the iS? __________________ 2012 E89 35iS
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10-01-2012, 07:35 AM	#20
castilla Second Lieutenant 28 Rep 218 Posts Drives: 2014 M4 Join Date: Mar 2012 Location: tr iTrader: (0)	i am thinking to do it on my z4 20i but i am curious about if there will be any error on screen ? and i dont know how many cats does 20i ( n20 engine ) have
	Appreciate 0 Quote

10-01-2012, 02:18 PM	#22
castilla Second Lieutenant 28 Rep 218 Posts Drives: 2014 M4 Join Date: Mar 2012 Location: tr iTrader: (0)	okay thanks but any ideas about error ? when i delete cat maybe some sensors will not work properly and it cause error on screen
	Appreciate 0 Quote

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