[1LE Red Dragon]

Borla 60606 to me is a good combination with the stock NPP. It gets rid of the 2nd cat/resonator. When you find them on sale they can be had for $520 to $550 using Ebay 15% off coupons, or other online retailers that do 15% or 20% off sales. Just installed mine, and it replaces 70% of the entire exhaust system, for a little under $600 in full stainless steel. It bolts/clamps on right after the main cat, and replace everything up to 7" before the suitcase. It only works properly on Manual trans cars though. For the A8 cars, I think they make one with the AFM valves.

[cmitchell17]

Originally Posted by TJay74

When I had my 1LE I did the secondary cat deletes 1st, it sounded great and the car picked up some power. Then I put the ARH catless headers with the full system on it where it connects right before the NPP muffler, loud is an understatement for sure.

Personally I like the raspier sounding exhaust in the form of an exotic tone. I dont like the deep rumble like an old chevy pick up with Flowmasters on it sound. That is just my preference, others opinions may vary.

I hate the rumble sound too, but to me "raspy" is what a old truck with flowmasters sounds like, and I hate that sound. The sound of a straight pipe diesel minus the turbo sound is also pretty bad as well. I think it has to do with the firing order. I just don't get how exotic sounds raspy?

[ssmike]

[QUOTE=SkiRideDrive;10298328]Hey there.

I was pondering the least expensive way to get a bit more volume out of the NPP muffler when in full open mode. Some aftermarket companies have solutions in the 1200 dollar range and some folks have replaced the suitcase with aftermarket mufflers, etc.

I'm not sure if there is enough clearance under the car, but was thinking that maybe adding pipe to bypass the muffler for each valve could give a bit more volume for minimal investment. This would also allow the car to remain quiet in stealth mode. I have a super quality MS Paint drawing below with black lines showing where the theoretical bypass pipes would go.

Any thoughts? [quote]



That’s exactly how the Hooker system is designed.

[Dvs510]

Originally Posted by SkiRideDrive

Hey there.

I was pondering the least expensive way to get a bit more volume out of the NPP muffler when in full open mode. Some aftermarket companies have solutions in the 1200 dollar range and some folks have replaced the suitcase with aftermarket mufflers, etc.

I'm not sure if there is enough clearance under the car, but was thinking that maybe adding pipe to bypass the muffler for each valve could give a bit more volume for minimal investment. This would also allow the car to remain quiet in stealth mode. I have a super quality MS Paint drawing below with black lines showing where the theoretical bypass pipes would go.

Any thoughts?

I plan on doing that to my 18 1le in couple weeks.. gonna cut out and replace the crushed section and then y off that and bypass the muffler and tie back in right at elbo of npp valve.. the npp only sounds good when higher throttle because more pressure going through muffler allows more to make it by the baffled holes inside muffler. Under lighter load a good amount of exhaust is going through the baffles holes rather then making it all the way through to npp valve side... test it, when ur cars idling with valves open, cover both of the inner pipes and u can feel how much pressure is going through muffler rather then valve side... I’ll b sure to post a good before after video when it’s done tho

[avalonandl]

Replacing the crushed section does NOTHING for HP and sound.

Our cars have OEM tri-Y headers from the factory, thats why they sound so good.

[avalonandl]

OEM header

[Whocares05050]

Originally Posted by 1LE Red Dragon

Borla 60606 to me is a good combination with the stock NPP. It gets rid of the 2nd cat/resonator. When you find them on sale they can be had for $520 to $550 using Ebay 15% off coupons, or other online retailers that do 15% or 20% off sales. Just installed mine, and it replaces 70% of the entire exhaust system, for a little under $600 in full stainless steel. It bolts/clamps on right after the main cat, and replace everything up to 7" before the suitcase. It only works properly on Manual trans cars though. For the A8 cars, I think they make one with the AFM valves.

I think borla just discountinued the 60606 as well. Look on their site

[Buckscamaro]

you can always just add cutouts before the muffler?

However, I don't think I would be a fan of adding more weight to the already heavy npp.

[Dvs510]

Originally Posted by avalonandl

Replacing the crushed section does NOTHING for HP and sound.

Our cars have OEM tri-Y headers from the factory, thats why they sound so good.

I’m only removing the crushed section to get better flow. I’m aware it won’t add hp or noticeable sound

[Chris C 1SS 1LE]

Originally Posted by VinnAY

Too many people have said it get's raspy this route when I was thinking of the 2d cat delete option

60606 is great unless IN the gas. !F51 too. ATAK NPP on way. YMMV.

[Chris C 1SS 1LE]

Originally Posted by Whocares05050

I think borla just discountinued the 60606 as well. Look on their site

Wheelwell dot com

[cmitchell17]

Originally Posted by avalonandl

OEM header

I'm assuming the only reason GM went through the hassle of designing a separate header for the LT1 Camaro vs corvette is because of clearance issues. I know there are a lot of differences in the camaro vs corvette tune, just seems like they could have kept them the same and saved a lot of money.

[MAGAUSA]

Originally Posted by zoutlawss

Damn delete that big ugly thing and enjoy the Roar. I did the muffler delete and secondary cat delete and car sounds awesome. You can hear the results at the beginning and end of video. Also gives you before and after

LOL Everytime this stupid iphone pulls up Siri I cuss at her. F-ing useless.

[MAGAUSA]

Just by the videos, it sounds better at idle to me after the surgery.