Quieting down a 3" Exhaust with Headers
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Have you heard a exhaust that has silencers installed? Do you know if they work? As for the magna flows, I have thought of using them but heard there still loud at idle, which is what I am most concerned about. Has anyone tried Borla with headers?
X-pipe is worth about 2db reduction.
Pypes race pro mufflers are mellow at idle/cruise and really bark when you are on it.
2 1/2 tails will help with tips aimed down.
Pypes race pro mufflers are mellow at idle/cruise and really bark when you are on it.
2 1/2 tails will help with tips aimed down.
Goals uncompromising performance with highway patrol acceptable sound at part throttle or cruise with no drone.
1. Either an X or an H will help take a few decibels out. The X also smooths out the tone but the H is cheaper & easier. For practicality just get an H. Both are usually good for freeing up a couple HP. The little race mufflers in place of cats also works in addition or separately and will take a few more decibels out without sacrificing flow or costing you power.
2. Use the largest case "straight thru" type muffler that you can fit. Such as http://www.magnaflow.com/02product/universalmuffler.asp Muffler 12259 (5x8x18" case) will fit the gbody under the rear seat wells and most bolt up pipe systems for our cars. The equivalent Walker Ultraflow or off brand is generally ok. Although some off brands use a 3" inlet outlet but neck down to 2.5" inside so watch that if you don't want it to neck down until after the muffler.
Straight thru types have a nice idle and great WOT but mellow at cruise without drone. Flows far better than flowmasters which often drone. But no patented flowmaster sound. Flows better than chambered mufflers or cheaper "turbo" mufflers that make it flow thru an S and change the direction of exhaust flow twice. Ever see the little pictures marketing these with flow arrows that turn on the nice smooth curves. Exhaust does not turn it tumbles then has to be pushed the opposite direction twice. Turbo muffler designs are usually cheaper, flow decent and sound decent but often rust out generally are not 100% stainless and don't have welded seams.
3. Use tail pipes and make it 2.5"s especially if the rest of your system is 3". This is key to sound control. As Mega said it actually helps performance being after the muffler as it helps to keep velocity. This has been well proven on dynos. (This is because gasses shrink as they cool and slow which then have to be pushed out by the hotter faster moving gasses.) Also never neck down pipe and then go back to larger diameter pipe. This also kills flow and can easily be seen by putting a smaller water hose between two larger diameter water hoses.
The above system is what I used for the my 509 powered 442. It sounded great at idle part throttle or cruise, had no drone and sounded great at wot. Although some like it louder at wot.
1. Either an X or an H will help take a few decibels out. The X also smooths out the tone but the H is cheaper & easier. For practicality just get an H. Both are usually good for freeing up a couple HP. The little race mufflers in place of cats also works in addition or separately and will take a few more decibels out without sacrificing flow or costing you power.
2. Use the largest case "straight thru" type muffler that you can fit. Such as http://www.magnaflow.com/02product/universalmuffler.asp Muffler 12259 (5x8x18" case) will fit the gbody under the rear seat wells and most bolt up pipe systems for our cars. The equivalent Walker Ultraflow or off brand is generally ok. Although some off brands use a 3" inlet outlet but neck down to 2.5" inside so watch that if you don't want it to neck down until after the muffler.
Straight thru types have a nice idle and great WOT but mellow at cruise without drone. Flows far better than flowmasters which often drone. But no patented flowmaster sound. Flows better than chambered mufflers or cheaper "turbo" mufflers that make it flow thru an S and change the direction of exhaust flow twice. Ever see the little pictures marketing these with flow arrows that turn on the nice smooth curves. Exhaust does not turn it tumbles then has to be pushed the opposite direction twice. Turbo muffler designs are usually cheaper, flow decent and sound decent but often rust out generally are not 100% stainless and don't have welded seams.
3. Use tail pipes and make it 2.5"s especially if the rest of your system is 3". This is key to sound control. As Mega said it actually helps performance being after the muffler as it helps to keep velocity. This has been well proven on dynos. (This is because gasses shrink as they cool and slow which then have to be pushed out by the hotter faster moving gasses.) Also never neck down pipe and then go back to larger diameter pipe. This also kills flow and can easily be seen by putting a smaller water hose between two larger diameter water hoses.
The above system is what I used for the my 509 powered 442. It sounded great at idle part throttle or cruise, had no drone and sounded great at wot. Although some like it louder at wot.
I don't think the Magnaflows are too loud at idle. At least compared to the old exhaust, cherry bombs. The sound level at idle will have a lot to do with your cam and compression, so it's kinda hard to tell. This is mine, 2 1/2" x-pipe system with Magnaflows, hope it helps.
That was a huge help, great explanation too! I will take you word for it and that set-up.
jRM81bu- what do you have for cams and compression in your Malibu?
jRM81bu- what do you have for cams and compression in your Malibu?
Low compression, around 8.5:1. Cam has quite a bit of duration, 306* advertised, can't remember what it is at .050" lift. It is also on a 112* lobe seperation angle, wich helps to calm it down a little bit. I'm running a small blower, which explains the low compression and wide lsa on the cam.
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