gutted primaries?

Fen335i · 07-11-2012, 01:23 AM

Has anyone here gutted the primary cats? I've heard of folks gutting their secondaries for sound improvements, but has anyone done the same with the primaries? Given that test pipes are hard to come by right now, I'm wondering if anyone has tried it. Seems pretty redneck, but I imagine some good gains could be made...

DJDeez · 07-11-2012, 02:21 AM

You're much better off having a local shop remove the stock cats and weld in their own test pipes. It would not be as simple to gut the primaries as the secondaries nor does it make any sense, financially or otherwise

THE TECH · 07-11-2012, 08:06 AM

Quote:

Originally Posted by DJDeez

You're much better off having a local shop remove the stock cats and weld in their own test pipes. It would not be as simple to gut the primaries as the secondaries nor does it make any sense, financially or otherwise

+1

Grail05 · 07-11-2012, 08:10 AM

DONT gut the primary cats. just replace it with a straight pipe for better flow. its too big of an opening if you gut the primary cat... the front is flat compare to the 2nd cat..

DARK_M3 · 07-11-2012, 09:20 AM

Test pipe = a piece of pipe. Those are hard to come by?

+1 on just having a shop weld in straight pipe.

THE TECH · 07-11-2012, 09:21 AM

Quote:

Originally Posted by DARK_M3

Test pipe = a piece of pipe. Those are hard to come by?

+1 on just having a shop weld in straight pipe.

Well in all fairness, the Turner ones were bolt in so no welding was needed.

m3an · 07-11-2012, 11:27 AM

Quote:

Originally Posted by Sean05

DONT gut the primary cats. just replace it with a straight pipe for better flow. its too big of an opening if you gut the primary cat... the front is flat compare to the 2nd cat..

lol wut... An oval pipe and a round pipe have the same flow charateristics (provided other variables are =)

DARK_M3 · 07-11-2012, 11:38 AM

Quote:

Originally Posted by THE TECH

Well in all fairness, the Turner ones were bolt in so no welding was needed.

JB Weld them in haha

I'm kidding

George///m3 · 07-11-2012, 11:40 AM

I gutted my primaries and saved myself $500.

Grail05 · 07-11-2012, 12:38 PM

Quote:

Originally Posted by talontid

lol wut... An oval pipe and a round pipe have the same flow charateristics (provided other variables are =)

ok whatever you say...

m3an · 07-11-2012, 12:40 PM

Quote:

Originally Posted by Sean05

ok whatever you say...

the OEM pipes are acutally really nice as they are hydroformed. While not being exacting I'm comparing it to a 3" oval to a 3" round pipe. THe ID remains the same, no?

That being said, I would only do this in a state with visual inspections as I don't see the point unless you also DIY then you'll def save some money while making power as well.. One thing I didn't like about my RPI x pipe was the thin walled construction which kind of gave it a tinny sound. The OEM pipes are nicely constructed

edwinm3 · 07-11-2012, 01:14 PM

Nothing special about TTP. You can get them made at a good muffler shop no problem, using the stock flanges

Grail05 · 07-11-2012, 01:52 PM

Quote:

Originally Posted by talontid

the OEM pipes are acutally really nice as they are hydroformed. While not being exacting I'm comparing it to a 3" oval to a 3" round pipe. THe ID remains the same, no?

That being said, I would only do this in a state with visual inspections as I don't see the point unless you also DIY then you'll def save some money while making power as well.. One thing I didn't like about my RPI x pipe was the thin walled construction which kind of gave it a tinny sound. The OEM pipes are nicely constructed

several tuners have gutted the primary cat and have tested that having a TTP or straight pipe is better results better flow with better gain compare to gutting the primary, they said that the flow is somewhat distorted in the oval shape and better to have the cat as is than gutting it. if you plan on taking the primary might as well go to some cheap muffler shop and have them weld a pipe.. even the regular muffler shop will tell you the same thing..

I understand that it will cover up and make it all look OEM but no matter what you will get a cel by gutting it... id take the TTP and call it quits.

Fen335i · 07-11-2012, 07:44 PM

The problem is no muffler shops up here will mess with it...even for off road. Touching cats is very touchy here. Also, Turner seems to have stopped making the test pipe and ACM who is rumored to be making them soon has yet to release them in mass.

Grail05 · 07-11-2012, 08:54 PM

Quote:

Originally Posted by Fen335i

The problem is no muffler shops up here will mess with it...even for off road. Touching cats is very touchy here. Also, Turner seems to have stopped making the test pipe and ACM who is rumored to be making them soon has yet to release them in mass.

OIC that is a problem... I guess im lucky to be in LA well goodluck just an FYI keep it and just wait for turner or the other vendor...

bollcosett · 07-11-2012, 09:45 PM

it make any sense, financially or otherwise

Pak317 · 07-12-2012, 10:46 AM

Check out Pina Motorsports in auburn

My brother had a custom straight pipe fabbed by them for his E46M!

Fen335i · 07-12-2012, 10:49 AM

^ Thanks Pak317! I'll give them a call.

crabman · 07-13-2012, 12:47 PM

I heard a rumour that any good shop that did work such as building custom headers would be willing to make a jig from your current mid section so long as it was brought into the shop in a separate vehicle and they didn't have to in any way modify the stock mid section. Not sure about the cost or time as I myself would never do anything illegal but at a guess I would say. roughly 280.79 dollars with WA state sales tax and about 3 hours and ten minutes.

chief · 07-13-2012, 02:12 PM

Quote:

Originally Posted by crabman

... Not sure about the cost or time ... but at a guess I would say roughly 280.79 dollars with WA state sales tax and about 3 hours and ten minutes.

Sounds like a realllyyy wild guess

tibra1 · 07-13-2012, 02:17 PM

People still gut cats?

Use some test pipes or straight pipes..if you take a look how much OEM cats are worth you would not touch them and you never know when you will want to return the car back to stock

THE TECH · 07-13-2012, 02:28 PM

Quote:

Originally Posted by tibra1

People still gut cats?

Use some test pipes or straight pipes..if you take a look how much OEM cats are worth you would not touch them and you never know when you will want to return the car back to stock

07-11-2012, 01:23 AM	#1
Fen335i Captain 107 Rep 805 Posts Drives: e92 M3 / X5d / Z4 M Roadster Join Date: Jun 2008 Location: Pacific Northwest iTrader: (0)	gutted primaries? Has anyone here gutted the primary cats? I've heard of folks gutting their secondaries for sound improvements, but has anyone done the same with the primaries? Given that test pipes are hard to come by right now, I'm wondering if anyone has tried it. Seems pretty redneck, but I imagine some good gains could be made...
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07-11-2012, 02:21 AM	#2
DJDeez Got my license back! 14 Rep 205 Posts Drives: TransLink Join Date: Jul 2011 Location: YVR iTrader: (2)	You're much better off having a local shop remove the stock cats and weld in their own test pipes. It would not be as simple to gut the primaries as the secondaries nor does it make any sense, financially or otherwise __________________ aFe cold air intake system (stage 2) ▫ Agency Power cat delete/section 2 midpipes ▫ Agency Power exhaust system ▫ Beltronics STiR Plus ▫ BMW M style (ZHP) weighted short shift knob ▫ CIC iDrive ▫ Clutch pedal spring removal ▫ Coding ▫ Evolve-R tune ▫ Laser Interceptor ▫ LUX H8 V3 Angel Eyes ▫ pickyeater334 clutch stop ▫ Rear fog lights (2011 light control switch assembly) ▫ T3 Alpha laser gun protection ▫ Turner Motorsport power pulley kit
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07-11-2012, 08:10 AM	#4
Grail05 Putcha ang ganda... 281 Rep 5,441 Posts Drives: 17 F82 M4 Join Date: Feb 2010 Location: Los Angeles, Brea CA. iTrader: (10)	DONT gut the primary cats. just replace it with a straight pipe for better flow. its too big of an opening if you gut the primary cat... the front is flat compare to the 2nd cat.. __________________
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07-11-2012, 09:20 AM	#5
DARK_M3 Banned 105 Rep 1,292 Posts Drives: 08 E90, 89 Grand Wagoneer Join Date: Mar 2012 Location: So Cal iTrader: (3)	Test pipe = a piece of pipe. Those are hard to come by? +1 on just having a shop weld in straight pipe.
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07-11-2012, 11:40 AM	#9
George///m3 Private 0 Rep 66 Posts Drives: 2008 m3 Join Date: May 2012 Location: Toronto iTrader: (3)	I gutted my primaries and saved myself $500.
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07-11-2012, 01:14 PM	#12
edwinm3 Brigadier General 980 Rep 4,001 Posts Drives: F82 Join Date: Nov 2011 Location: Broward iTrader: (32)	Nothing special about TTP. You can get them made at a good muffler shop no problem, using the stock flanges __________________ Grigio Telesto M4, 6MT. Coyote 5.0 F-150 991 GT3
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07-11-2012, 07:44 PM	#14
Fen335i Captain 107 Rep 805 Posts Drives: e92 M3 / X5d / Z4 M Roadster Join Date: Jun 2008 Location: Pacific Northwest iTrader: (0)	The problem is no muffler shops up here will mess with it...even for off road. Touching cats is very touchy here. Also, Turner seems to have stopped making the test pipe and ACM who is rumored to be making them soon has yet to release them in mass.
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07-11-2012, 09:45 PM	#16
bollcosett New Member 0 Rep 6 Posts Drives: bmw Join Date: Jul 2012 Location: 4tu iTrader: (0)	it make any sense, financially or otherwise __________________
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07-12-2012, 10:46 AM	#17
Pak317 Private First Class 27 Rep 138 Posts Drives: 2015 F80 Join Date: May 2010 Location: Bellevue, WA iTrader: (0)	Check out Pina Motorsports in auburn My brother had a custom straight pipe fabbed by them for his E46M! __________________ some boring white car....
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07-12-2012, 10:49 AM	#18
Fen335i Captain 107 Rep 805 Posts Drives: e92 M3 / X5d / Z4 M Roadster Join Date: Jun 2008 Location: Pacific Northwest iTrader: (0)	^ Thanks Pak317! I'll give them a call.
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07-13-2012, 12:47 PM	#19
crabman Captain 204 Rep 886 Posts Drives: 2024 X5M Join Date: Dec 2011 Location: WA iTrader: (0)	I heard a rumour that any good shop that did work such as building custom headers would be willing to make a jig from your current mid section so long as it was brought into the shop in a separate vehicle and they didn't have to in any way modify the stock mid section. Not sure about the cost or time as I myself would never do anything illegal but at a guess I would say. roughly 280.79 dollars with WA state sales tax and about 3 hours and ten minutes.
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07-13-2012, 02:17 PM	#21
tibra1 Banned 127 Rep 6,773 Posts Drives: 2011 ZCP M3 - 2007 335i crashd Join Date: Apr 2009 Location: NYC iTrader: (4)	People still gut cats? Use some test pipes or straight pipes..if you take a look how much OEM cats are worth you would not touch them and you never know when you will want to return the car back to stock
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