BirdsSince16

iTrader: (3)

After getting tired of scraping my low-hanging y-pipe on every bump and hump on Oahu, and hearing way too much rasp way too often, I bit the bullet on some custom true duals.

Went with double Borla XR-1 multicores. It's a different sound for an F-body, but I'm pleased. It's much quieter inside the car than the LTs to Corsa was, and of course has zero rasp.

http://i283.photobucket.com/albums/k...105_085818.jpg

http://i283.photobucket.com/albums/k...105_085758.jpg

Rise of the Phoenix

iTrader: (27)

Sounds good. I'm not familiar with Borla XR1 multi-cores. How do they differ from the Borla XR1 bullets? I thought about putting them on my duals setup, but opted for dual SLP Loud Mouth 1 resonators.

Fullblast

iTrader: (17)

Sounds really good man. Aggressive lope, but not too choppy. A video of a rev would be nice.

How much of a performance increase did you get over the y pipe? Is there any seat of the pants feel?

I really like the sound of my Borla adjustable with.almost no cab noise, but would like the performance increase of Tds.

Rise of the Phoenix

iTrader: (27)

I'd say going from a y-pipe setup to a free flowing true dual setup is good for at least 5-10 additional HP.

Fullblast

iTrader: (17)

I've read in a few places that you lose some low end torque of the y pipe, but gain more horsepower with the true duals. Any truth to that?

Rise of the Phoenix

iTrader: (27)

From dyno graphs I've seen, that's not been the case.

Fullblast

iTrader: (17)

So what is it exactly that causes the rasp in the exhaust in the first place?

Darth_V8r

iTrader: (4)

would it be fair to say it depends on the Y pipe? Good merge vs crappy merge? Catted vs OR?

I felt a huge seat of pants change from Y to duals, and i think it was the way my Y was done. Doesn't get much worse than this:

Rise of the Phoenix

iTrader: (27)

I personally feel that even the best designed Y-pipe with the very best merge is still not going to outperform a 3" true dual setup. You're constricting airflow into one pipe as opposed to two pipes on a dual setup. We all know the more air your engine takes in and how fast it expels it is going to equate to more HP. The only downside I see to a true dual setup is if you have clearance issues.

ragtopz28

iTrader: (57)

Maybe I'm getting old but....that must be the loudest MF in town!!

badbird

iTrader: (2)

How are you not deaf yet lol

I've got 2 bullets and 2 actual mufflers on mine out the back and its just about perfect.

Rise of the Phoenix

iTrader: (27)

The louder the better.

Darth_V8r

iTrader: (4)

I agree. My neighbors tend to disagree

Rise of the Phoenix

iTrader: (27)

Between the WS6 and my Silverado, I'm probably public enemy number one. Luckily though, all the mean age of my neighbors is 70 years old and they are all old ladies.

ss4chad

iTrader: (26)

In my opinion its the merge of two 3" pipes into one 3" or 4" pipe.

My personal proof is that I put an LS1 (stroked 383) in my '03 GMC Truck. Headers and a Y into a single muff out as dual's, similar to what was on my '02 Camaro. RASP same as the Camaro. I changed the exhaust to an honest dual system. I went with 3" to 2.5" reduced off the headers, dual's to a Magnaflow dual in/out muff out as dual's under the roll pan.

The rasp was eliminated at ALL RPM levels.

I am changing that set up with 3" all the way back and an X pipe into a Spintech dual in/out muff out as dual's under the pan when I get the Whipple SC back from rebuild. Should be 500+ at the wheels for a daily driver but I'm sure the sound results will be the same.

Plan on doing similar to my '02 Camaro. Installing a 447 CU/IN with a 4.125 stroke engine, big cam, heads etc..
I will run 3" round tubing to 3" Oval tubing into a Oval X Pipe and back to round just before the axles, then over and into two Spintech round muffs and under the bumper as slashed tips. Again I will get the RASP is 100% gone.

Chad

ss4chad

iTrader: (26)

Sounds great dude, well done!

Chad

ragtopz28

iTrader: (57)

Well that's the beauty of a cutout...stealth when I want to be, cracked at a cruise-in to hear the cam, and fully open at the track. A well thought out merge can be 90% rasp free.

BirdsSince16

iTrader: (3)

Thanks guys! As far as seat of the pants feel I replaced the torque arm at the same time so it's hard to say which made it feel better. I haven't been on a track or even done much racing since I had it done. No track out here.

The main thing is my ground clearance is better and sound is WAY better. Thanks for the replies everyone. Feel free to continue with your questions if you have any.

BirdsSince16

iTrader: (3)

The Multi-cores are quieter from what I've seen on videos at least, and they allegedly flow better. I really did want to quieten down from my previous setup and this achieved that. I'm not sure if the sportsmans would have had the same effect.

BirdsSince16

iTrader: (3)

I'll try to get a rev video when I think about it and I'm not sitting by myself at 11pm. Haha.