Tuning, Exhaust question L99

[Switchback700]

I am getting a set of Kooks 1 7/8 LT's, Hi-flow cats, CAI, and a tune. Right now I have an axleback GMPP (Borla Touring??) with AFM tuned off.

Should I just get the Headers and keep the stock resonator back (I want it on the quiet side, 530 am to work with neighbors, and can always get louder) with the first tune and then add catback later?.

Or will adding a catback later benefit from another tune, if so, maybe I should do all of it at once. Just a little concerned of being too loud at early morning and highway cruising.

[d69chris]

Corsa cat back is a great fit. Better flow and nicer than the stock resonator. Not too loud.

I have the Corsa cat back and am adding the Kooks LT & high flows + tune!

[Switchback700]

Is that the L99 Corsa? Do you have AFM still on? LT Headers will add quite a bit of volume, I have read a lot of posts of guys getting a new exhaust after LT's trying to quiet it down.

[StlRomAniaN]

Corsa's too raspy for me. SLP Powerflo for the win. Quiet at warm-start up, quiet idle, and roars at WOT.

[Blacknight11]

I hv headers, cai, and just got a tune. Had a borla and went to acorsa, it sounds good just could be a little louder. I love the fact that it has no drone. I am selling mine and probably going to a magnaglow.

[y2k king]

i've got l99 with solo hi-flos and corsa catback and the sound is just right.

[Switchback700]

StlRomAniaN,

Corsa is a little raspy for me too, I like the Borla and Magnaflow deeper sound, but unfortunately it seems like the drone comes with the deeper exhausts.

Blacknight11,

What Borla exhaust? Touring, S type, Attack? What Corsa exhaust? LS3, l99? What Magnaflow exhaust? Street, or Competition?

y2k king,

Corsa for LS3 or L99 with the resonators?

Thanks guys for the input, I'm getting closer to making a decision and all of your input just helps.

[agkelly73]

I have Doug Thorley Tri-Y long tubes (cat delete) and GMPP axle backs as well (street legal version). I decided to leave the stock resonator in place to see how loud it was. To me, it's perfect! Not too loud on start up (IMO) and when you stomp on it, you definitely hear it!

[mlee]

If you want it a bit quiet then go with LT headers for the added power gains and keep your stock exhaust (paint the trash cans black or something). Adding both LT and Catback will be pretty loud.

I also crank up at 530AM w/ Corsa + LT and it's way loud. Then I added TC and big cam and it's just rediculous loud now. Scares the hell out of me to start it up.

[Switchback700]

I am going to get the Kooks LT's with cats and add the Borla X Pipe to my existing GMPP axle back (be about the same as Borla Touring catback). From all the clips I've heard this shouldn't be too loud. I would rather have 1 tune without the monster resonator there. I'll add video clips of before and after.

[JANNETTYRACING]

Originally Posted by Switchback700

I am going to get the Kooks LT's with cats and add the Borla X Pipe to my existing GMPP axle back (be about the same as Borla Touring catback). From all the clips I've heard this shouldn't be too loud. I would rather have 1 tune without the monster resonator there. I'll add video clips of before and after.

Any changes to the exhaust behind the cats has ZERO affect on Performance or the Tune.

If you want it quiet Keep the Stock Resonator X pipe, Yep it has an X pipe inside it.

We have made 670 RWHP through the Stock L99 Exhaust.

Ted.

[Switchback700]

I don't see an X pipe in the L99 resonator...... looks more like a boat anchor there to hide the AFM terrible sound when in 4 cyl mode, which was the first thing I got rid of

[JANNETTYRACING]

Originally Posted by Switchback700

I don't see an X pipe in the L99 resonator...... looks more like a boat anchor there to hide the AFM terrible sound when in 4 cyl mode, which was the first thing I got rid of

It essentially accomplishes the same thing but quieter.

[Switchback700]

Looks like a bad heat build up going on in there too........ I do want to be on the quiet side but I'll take my chances getting rid of the resonator for the Borla X pipe and then go from there. If I hadn't already taken the stock mufflers off I might go for just headers and stock cat back because I think the Helmholz J pipe in the stock mufflers will help with drone more than the resonator, but I already put an axle back before investigating, my bad.