muffler decision

adamdrives · 01-30-2021, 11:56 PM

Hey guys, I am building a 2.5" exhaust for my soon to be 15g swapped 240. I'm looking for the least restrictive muffler or resonator that will fit between the front and rear axle. From my reading it sounds like a lot of the resonators are louvered, which is not good for back pressure, even though the shape is more ideal. I'm not too concerned about sound, I just don't want to straight pipe it. Any recommendations? Quieter is better, but the main concerns are light and compact.

PCH · 01-30-2021, 11:59 PM

Why not just Cat and muffler?

adamdrives · 01-31-2021, 12:08 AM

It's going to be catless, and I'd like to make the exhaust as short as possible.

VB242 · 01-31-2021, 01:41 AM

I'm running an 11" glass pack on my 3" side exit, it's loud but not ear splitting loud

adamdrives · 01-31-2021, 03:47 AM

I saw a video of my setup with a cherry bomb out the back and I like the sound, but I'm not sure what size it is. 18" seems to be a common size so I think I'll go for that. It's got some nice crispy popping on decel.

https://www.youtube.com/watch?v=zavBTeTpLqQ

PCH · 01-31-2021, 09:58 PM

Quote:

Originally Posted by adamdrives

It's going to be catless, and I'd like to make the exhaust as short as possible.

On a street car? I sincerely hope that you reconsider.

2turbotoys · 01-31-2021, 10:01 PM

I am a big fan of Cherry Bomb Vortex mufflers, Thick steel, very free flowing, more sound deadening than a traditional Cherry Bomb, it's a full size muffler.

Watch what ya say about removing the cat here, a lotta hippies are gonna cry.

honeylake · 01-31-2021, 11:44 PM

Black widow?

kyote · 02-01-2021, 10:51 AM

Quote:

Originally Posted by PCH

On a street car? I sincerely hope that you reconsider.

The more bends, the more length, the less drone.

dbarton · 02-01-2021, 02:05 PM

Quote:

Originally Posted by PCH

On a street car? I sincerely hope that you reconsider.

CARB is the absolute enemy of common sense emission compliance. The result is more people going "underground" and breaking the rules. So keep your judgement on hold until you can see the bigger picture.

You can follow the rules and buy a grossly overpriced cat for your 240, which will still fail after a few years because CARB believes in a sliding scale for maximum emissions for older cars, reducing the max limits every few years until your car becomes easier to crush than register.

PCH · 02-01-2021, 02:12 PM

Dave, this has nothing to do with CARB. This is Federal Law.

dbarton · 02-01-2021, 02:23 PM

Quote:

Originally Posted by PCH

Dave, this has nothing to do with CARB. This is Federal Law.

So the Feds are causing CARB approved cats to be 5 times the price. Now I know.

PCH · 02-01-2021, 02:35 PM

Clean Air Act is a Federal Law- it doesn't deal with state specific pricing policies.

spock345 · 02-01-2021, 03:22 PM

Also most retailers will refuse to ship a non-CARB compliant converter to California. CARB is stricter than Federal regulations. There is an explicit clause in the Clean Air Act that allows CARB to set higher standards. Which funnily enough other states copy and use as their own emissions standards (with some common sense modifications).

The broken parts in it all are visual inspections for pre OBD-II cars that prevent common sense repairs (I was failed once for a butt splice with heat shrink on a MAF sensor wire), not tailpipe testing OBD-II cars even though we have evidence that cheating a computer only test can and has been done from the factory, and lastly the CARB EO number system that is the source of inflated prices.

Not running a catalytic converter in California is not a good idea and would land you in hot water if someone who cared found out. You could rely on VIN swapping or "knowing a guy" to pass you but that isn't much better. It wouldn't risk a trip to the smog ref in San Jose.

GeneralBurrito · 02-01-2021, 04:44 PM

I "upgraded" my NA from the stock 2" to the turbo piping (2.25" maybe just a tad larger) and swapped the rear muffler for I think a 14" Magnapack. Sounds good to me and you're also running one of the best mufflers, a turbo, so it should sound cleaner too.

adamdrives · 02-03-2021, 02:01 AM

I can't speak from experience, but according to my smog guy, in a worst case scenario where you are cited for having a modified/non-smog compliant car there are a number of days before the car is inspected. I'm not sure how that would work, they pull you over for a citation, and pop the hood? My guess is it's more a suspicion which makes you eligible for inspection. Has anyone in CA been in that situation? Regardless, he thinks the chances of a non-smog operator being able to tell the car doesn't have original emissions equipment in the wild are low, especially on an old (any?) volvo which is probably not a common violator.

edit: I went with the cherry bomb turbo glass pack. I'll upload some audio once everything is together. This isn't meant to be a discussion on the ethical/legal complexities of running a cat or not, I'm okay with my decision and would certainly urge others to know the consequences of not doing so.

Jack · 02-03-2021, 02:32 AM

Quote:

Originally Posted by adamdrives

I saw a video of my setup with a cherry bomb out the back and I like the sound, but I'm not sure what size it is. 18" seems to be a common size so I think I'll go for that. It's got some nice crispy popping on decel.

https://www.youtube.com/watch?v=zavBTeTpLqQ

WHAT?

VB242 · 02-03-2021, 09:10 AM

Revving your motor unloaded is hard on the bearings.

J_Jones · 02-03-2021, 02:28 PM

15g 245 that is as quiet as stock unless full-throttle: 2.5" all the way, dynomax bullet in front of rear axle, magnaflow offset/offset straight thru muffler in the back with tailpipe exiting in stock location. Paint the tailpipe black and hard to tell it isn't stock.

spock345 · 02-03-2021, 02:47 PM

Quote:

Originally Posted by J_Jones

15g 245 that is as quiet as stock unless full-throttle: 2.5" all the way, dynomax bullet in front of rear axle, magnaflow offset/offset straight thru muffler in the back with tailpipe exiting in stock location. Paint the tailpipe black and hard to tell it isn't stock.

This sounds like a good setup. If you are dead set on taking the risk of not running a cat it would be best to make it look as stock as possible to not draw attention to yourself.

Jack · 02-03-2021, 06:01 PM

Efi without a cat stinks worse than carbed engines

Dicktater · 02-03-2021, 06:14 PM

Quote:

Originally Posted by VB242

Revving your motor unloaded is hard on the bearings.

WHAT?........... I've been doing it wrong for a longtime, but but holeshot!

VB242 · 02-04-2021, 09:42 AM

Quote:

Originally Posted by Dicktater

WHAT?........... I've been doing it wrong for a longtime, but but holeshot!

You learn something new everyday.

adamdrives · 02-09-2021, 01:32 AM

Smell aside, it seems I would be in the same hot water with either no cat or non-CA cat if the car was reffed. Theres no way I'm spending a grand for an emissions device. I will consider a universal 2.5" if the smell is too much to bear.

cwdodson88 · 02-09-2021, 02:36 PM

Magnaflow CARB Cat, and Magnaflow straight through muffler. Just spend the money.

01-30-2021, 11:56 PM	#1
adamdrives Board Member Join Date: Aug 2010 Location: San Jose	muffler decision Hey guys, I am building a 2.5" exhaust for my soon to be 15g swapped 240. I'm looking for the least restrictive muffler or resonator that will fit between the front and rear axle. From my reading it sounds like a lot of the resonators are louvered, which is not good for back pressure, even though the shape is more ideal. I'm not too concerned about sound, I just don't want to straight pipe it. Any recommendations? Quieter is better, but the main concerns are light and compact. __________________ Feedback thread 78 242 DL 189k (For Sale) 83 245T+IC 136k 99 V70R 163k lazer blue 05 S60R 161k sapphire/nordkap 08 S80 V8 109k

01-30-2021, 11:59 PM	#2
PCH Board Member Join Date: Oct 2008 Location: Oxnard, SoCal	Why not just Cat and muffler? __________________ Feedback: http://forums.turbobricks.com/showthread.php?t=341280

01-31-2021, 01:41 AM	#4
VB242 Dann sind wir Helden Join Date: Sep 2011 Location: 4D space-time	I'm running an 11" glass pack on my 3" side exit, it's loud but not ear splitting loud __________________ "i will destroy all of you!" -Sheldon Plankton Booty Scooty https://youtu.be/i4oAOZ8nbq4

01-31-2021, 10:01 PM	#7
2turbotoys Salaminizer Join Date: Nov 2007 Location: Reading pa	I am a big fan of Cherry Bomb Vortex mufflers, Thick steel, very free flowing, more sound deadening than a traditional Cherry Bomb, it's a full size muffler. Watch what ya say about removing the cat here, a lotta hippies are gonna cry. __________________ Feedback thread https://forums.tbforums.com/showthread.php?t=144924 1978 242, 5.3 L33 1979 242, MS, R brakes 2006 V50 T5 AWD @ 17 PSI

02-01-2021, 03:22 PM	#14
spock345 Board Member Join Date: Nov 2016 Location: Santa Cruz, CA	Also most retailers will refuse to ship a non-CARB compliant converter to California. CARB is stricter than Federal regulations. There is an explicit clause in the Clean Air Act that allows CARB to set higher standards. Which funnily enough other states copy and use as their own emissions standards (with some common sense modifications). The broken parts in it all are visual inspections for pre OBD-II cars that prevent common sense repairs (I was failed once for a butt splice with heat shrink on a MAF sensor wire), not tailpipe testing OBD-II cars even though we have evidence that cheating a computer only test can and has been done from the factory, and lastly the CARB EO number system that is the source of inflated prices. Not running a catalytic converter in California is not a good idea and would land you in hot water if someone who cared found out. You could rely on VIN swapping or "knowing a guy" to pass you but that isn't much better. It wouldn't risk a trip to the smog ref in San Jose. __________________ 1967 122s, B20F, M40 1989 240 B230F (V15 cam, chipped EZK), M47 (Lost a fight with a Chevy express van) 2012 VW Tiguan 6 speed auto (oh the joys of carbon buildup). Last edited by spock345; 02-01-2021 at 04:45 PM..

01-31-2021, 12:08 AM	#3
adamdrives Board Member Join Date: Aug 2010 Location: San Jose	It's going to be catless, and I'd like to make the exhaust as short as possible.

01-31-2021, 03:47 AM	#5
adamdrives Board Member Join Date: Aug 2010 Location: San Jose	I saw a video of my setup with a cherry bomb out the back and I like the sound, but I'm not sure what size it is. 18" seems to be a common size so I think I'll go for that. It's got some nice crispy popping on decel. https://www.youtube.com/watch?v=zavBTeTpLqQ

01-31-2021, 11:44 PM	#8
honeylake Board Member Join Date: Jun 2017	Black widow?

02-01-2021, 02:12 PM	#11
PCH Board Member Join Date: Oct 2008 Location: Oxnard, SoCal	Dave, this has nothing to do with CARB. This is Federal Law.

02-01-2021, 02:35 PM	#13
PCH Board Member Join Date: Oct 2008 Location: Oxnard, SoCal	Clean Air Act is a Federal Law- it doesn't deal with state specific pricing policies.

02-01-2021, 04:44 PM	#15
GeneralBurrito Board Member Join Date: Nov 2017 Location: California	I "upgraded" my NA from the stock 2" to the turbo piping (2.25" maybe just a tad larger) and swapped the rear muffler for I think a 14" Magnapack. Sounds good to me and you're also running one of the best mufflers, a turbo, so it should sound cleaner too.

02-03-2021, 02:01 AM	#16
adamdrives Board Member Join Date: Aug 2010 Location: San Jose	I can't speak from experience, but according to my smog guy, in a worst case scenario where you are cited for having a modified/non-smog compliant car there are a number of days before the car is inspected. I'm not sure how that would work, they pull you over for a citation, and pop the hood? My guess is it's more a suspicion which makes you eligible for inspection. Has anyone in CA been in that situation? Regardless, he thinks the chances of a non-smog operator being able to tell the car doesn't have original emissions equipment in the wild are low, especially on an old (any?) volvo which is probably not a common violator. edit: I went with the cherry bomb turbo glass pack. I'll upload some audio once everything is together. This isn't meant to be a discussion on the ethical/legal complexities of running a cat or not, I'm okay with my decision and would certainly urge others to know the consequences of not doing so. Last edited by adamdrives; 02-03-2021 at 02:25 AM..

02-03-2021, 09:10 AM	#18
VB242 Dann sind wir Helden Join Date: Sep 2011 Location: 4D space-time	Revving your motor unloaded is hard on the bearings.

02-03-2021, 02:28 PM	#19
J_Jones Board Member Join Date: May 2005 Location: Lincolnton, NC	15g 245 that is as quiet as stock unless full-throttle: 2.5" all the way, dynomax bullet in front of rear axle, magnaflow offset/offset straight thru muffler in the back with tailpipe exiting in stock location. Paint the tailpipe black and hard to tell it isn't stock.

02-03-2021, 06:01 PM	#21
Jack junkman Join Date: Jul 2011 Location: The Ass Cheek Of History	Efi without a cat stinks worse than carbed engines

02-09-2021, 01:32 AM	#24
adamdrives Board Member Join Date: Aug 2010 Location: San Jose	Smell aside, it seems I would be in the same hot water with either no cat or non-CA cat if the car was reffed. Theres no way I'm spending a grand for an emissions device. I will consider a universal 2.5" if the smell is too much to bear.

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