4'' DP needs to quiet down ALOT!!
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From: San Diego/ from the 316
4'' DP needs to quiet down ALOT!! just finishing up my build and getting the car on the road. right now its an open DP at the rear. we ran out of 4'' bends to finish it out the back wit my hooker max flow. with oout the muffler its LOUD, and raspy.. put the muffler up to it and it changes the tone and takes some rasp out . but really doesn't quiet it down much
so, what can I do to get it even more quiet for street driving.. there is a cutout so no super worried about it flowing like 100% open but still want it to make some good power while being ever sleeperish..
so, what can I do to get it even more quiet for street driving.. there is a cutout so no super worried about it flowing like 100% open but still want it to make some good power while being ever sleeperish..
More mufflers 
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From: San Diego/ from the 316
LOL. yea its finding one that fits. car is lowered and being 4'' limits whats available.. how much would going to a 3in after the cutout affect things
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From: San Diego/ from the 316
I do.. ill have to look at clearance though... bigger drive shaft and big exhaust make space a premium.. and being lowered doesn't help either.. I think I have a place or two I can fit something though.. even if its small race mufflers it might help....
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Once it isn't dumping under the car anymore it will be half as loud trust me.
You still running the 04 single exit style exhaust?
Just put a 4 inch dynomax bullet where a cat went and then another where the oem 04 muffler was and then another right before the bumper exit where the 05/06 mufflers are located normally.
With 4 inch all the way and bullet straight through mufflers it isn't going to affect flow at all imo only deaden sound like it should.
What did skinnys run on that ltd? 6 mufflers lol.....and that was how it was ran at the track and turned impressive times.
You still running the 04 single exit style exhaust?
Just put a 4 inch dynomax bullet where a cat went and then another where the oem 04 muffler was and then another right before the bumper exit where the 05/06 mufflers are located normally.
With 4 inch all the way and bullet straight through mufflers it isn't going to affect flow at all imo only deaden sound like it should.
What did skinnys run on that ltd? 6 mufflers lol.....and that was how it was ran at the track and turned impressive times.
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Thread Starter
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From: San Diego/ from the 316
oh its quieter then it would be without turbo for sure.. it used to be cammed with LTs single chamber flows.. and that was LOUD!! its more silent then that ever was even wth no muffler right now.. and im sure once the exhaust is done with the muffler I go it will be even better but I want it factory quiet or less.. without too much restriction.. I will probably throw a few bullet mufflers in the mix after the cutout
I liked these "neckless" mufflers. They are really easy to angle and install anywhere you have a straight section of pipe. They use to have 6" ones as well, But I don't see them anymore. Built an exhaust system with 2 of these per side on a 468. Sounded nice and was quiet, on the heavy side though.
http://www.ebay.com/itm/300715159916?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
http://www.ebay.com/itm/Blank-In-Out-50-Series-5-00-In-Dia-Case-4-0-In-Core-A5024B-400-Glasspack-Muffler-/371042778728?pt=Motors_Car_Truck_Parts_Accessories&hash=item5663df7e68
http://www.ebay.com/itm/300715159916?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
http://www.ebay.com/itm/Blank-In-Out-50-Series-5-00-In-Dia-Case-4-0-In-Core-A5024B-400-Glasspack-Muffler-/371042778728?pt=Motors_Car_Truck_Parts_Accessories&hash=item5663df7e68
I liked these "neckless" mufflers. They are really easy to angle and install anywhere you have a straight section of pipe. They use to have 6" ones as well, But I don't see them anymore. Built an exhaust system with 2 of these per side on a 468. Sounded nice and was quiet, on the heavy side though.
12" Long Packed Diesel Muffler No Necks 4 inch I O Fits GM GMC Dodge Ford | eBay
12" Long Packed Diesel Muffler No Necks 4 inch I O Fits GM GMC Dodge Ford | eBay
These are what I planned to run on the bird if it's too raspy (which I believe it's going to be). These straight through designs are great for our setups and come in larger sizes.
Definitely take the advise about not having the exh exit under the car if you can. Makes a massive difference if you carry it out the side or the back. My open 4" downpipe was crazy loud when I had it dumped under the car. I ran it up through the hood and it cut the sound in the cab down by half or more.
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I'm saying find some of those in the longest lengths you can fit and put 3 of them on the car and it will be quiet. Also they are not going to restrict flow what so ever and with the gto you can make an almost straight exhaust, there are no sharp bends after the dp under the car so I wouldn't even bother with the cutout unless you wanna have that race car sound still every once in a while.
4 inch tube with bullets is like having a straight pipe 4 inch exhaust.
I can tell you this I have a cut out on my turbo car right at the bend going back to the rest of the exhaust towards the back of the car and with it open it will wake the dead. I thought it was going to be quiet but is damned loud, really damned loud.
My vote would be for a 4" downpipe, cutout, then a 4" to dual 3" flowmaster Y to split em out the back in stock muffler configurations - even 2.5" in/out mufflers. Maybe try and find a pair of corsa mufflers or similar - something with some case diameter to it and some packing to kill the noise for street driving. Flip the switch and have the 4" cutout dump under the car.