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-   -   Which Mufflers? (https://67-72chevytrucks.com/vboard/showthread.php?t=349100)

MrBlue 06-18-2009 08:17 PM

Which Mufflers?
 
Greetings,
The 72' we purchased has 3" exhaust with glass packs from the headers to the tailpipes. Sounds nice (& loud). But with the law, I'm sure my son would surely would draw some red-light attention. So we need to install mufflers. We like the Flowmaster and Magna Flow. Anyone have any suggestion(s)?
Thanks
Victor

fiyaweed06 06-18-2009 08:22 PM

Re: Which Mufflers?
 
I love the sound oh!;) i mean the price of the Thrush Welded mufflers i have them on all my cars except the stang.:lol:

piecesparts 06-18-2009 09:23 PM

Re: Which Mufflers?
 
Just a small $.02 worth. Unless you have a big block engine and you are driving it hard, that 3" exhaust maybe costing you some gas mileage and performance. Is the exhaust a single pipe or duals? If it is duals, then exhaust companys will tell you that the exhaust flow may be to slow or "Lazy" and is causing you some reversionary losses in your system.

The idea is for the exhaust to move along "Cooling" as it exits from the engine. That cooling effect is causing a slight vacuum effect pulling the gasses away from the headers and making the exhaust scavenge the fumes from the cylinders. Flowmaster will tell you that for a modified 350 to 383 cubic inch engine a dual 2 1/2" exhaust is the borderline for the amount of gases you will create, from that point on you are walking in an area of losses being more than gains. If it is a single exhaust system, then the 3" tubing is well worht the effort.

I prefer the Flowmaster sound to the Magnaflow sound, myself.

70cst 06-18-2009 09:41 PM

Re: Which Mufflers?
 
Quote:

Originally Posted by piecesparts (Post 3367701)
Just a small $.02 worth. Unless you have a big block engine and you are driving it hard, that 3" exhaust maybe costing you some gas mileage and performance. Is the exhaust a single pipe or duals? If it is duals, then exhaust companys will tell you that the exhaust flow may be to slow or "Lazy" and is causing you some reversionary losses in your system.

The idea is for the exhaust to move along "Cooling" as it exits from the engine. That cooling effect is causing a slight vacuum effect pulling the gasses away from the headers and making the exhaust scavenge the fumes from the cylinders. Flowmaster will tell you that for a modified 350 to 383 cubic inch engine a dual 2 1/2" exhaust is the borderline for the amount of gases you will create, from that point on you are walking in an area of losses being more than gains. If it is a single exhaust system, then the 3" tubing is well worht the effort.

I prefer the Flowmaster sound to the Magnaflow sound, myself.

Very good point piecesparts... I will have Spin Tech's with factory manifolds connected to 2 1.2" pipes once my project is out the door. Flowmasters will be lower cost than Spin Techs ...but I just liked the sound of Spin Techs better but flowmasters will do you just fine.

ZombieWeinerDog 06-18-2009 10:11 PM

Re: Which Mufflers?
 
spintechs or flowmaster series 40's

if i had a big block (and Money), i would have a cutoff that i could switch between straight pipes and mufflers. best of both worlds

1968SWBBigBlock 06-18-2009 10:23 PM

Re: Which Mufflers?
 
The spintechs sound very nice especially with big blocks
I just put on Goerlich mufflers on mine - they sound quite wicked -
3" true duals back to the rearend with turndowns
As mentioned above pipe diameter makes a big difference the larger the pipe the more noise it will make


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