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muffler decision

adamdrives

Member
Joined
Aug 9, 2010
Location
San Jose
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.
 
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.
 
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.
 

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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.
 
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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.
 
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.
 
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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.
 
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.
 
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