TOPAZ1+

Anyone have Kooks 1 3/4 lt headers with SLP 2 catback on a 2007
C6 automatic Coupe? Right now , I love the SLP 2, but I have to
live with a lot of drone at certain speeds that I have to contend with. Will the headers increase the drone to unbearable levels?
How does the headers and catback sound. How about horsepower
increase?

09_BSM_Z51

I installed SLP Headers but used the factory NPP mufflers, there is a touch of drone low in the rpm band when NPP mufflers are open but it doesn't bother me or cause any headaches in normal daily driving. Here is a youtube video of SLP Headers + SLP LM II's on a c6. See what you think. To me it sounds milder than NPP mufflers open so I don't think you have much to worry about. https://www.youtube.com/watch?v=lYk78V8AlKQ

So it will increase drone, but I don't think it will be so bad that you'll be disappointed.

The SLP headers I have make the car sound incredible, although a bit raw in the upper rpms. Keep in mind the NPP mufflers are straight pipes when open. The baffling in the LM II's will tame the rawness. No losses in power down low, only gains. Absolutely worth it, makes the car easier and more fun to drive. Also, it dropped atleast 25lbs of weight out of the car. I don't have a dyno, I had the car tuned using a diablosport handheld unit.

You will get cel codes for the rear O2 sensors after a few days of driving, they need to be disabled through tune. A full dyno session will be necessary. I don't recommend the handheld tuner with custom tune route that I use as it will cost just as much and not fully optimize the new modifications.

JimmyS5600

09_BSM what x pipe did you go with on your SLP header install,converters or non? Thanks

09_BSM_Z51

The SLP package includes cats, x-pipe, gaskets, and I think O2 extensions came as well. It replaces the entire exhaust from engine block to mufflers. It's sized 2.5" at exit to fit factory NPP, standard mufflers, or aftermarket 2.5" mufflers.

They are small racing cats. You can see through them, I'm positive they don't impede flow.

JimmyS5600

Thanks for your post. Iam now leaning towards a SLP header package

09_BSM_Z51

I think it's a great deal, I looked for what I felt was the best value. I was impressed with the quality when it arrived, the installers said it was as easy as any they've ever done. I've only gotten good parts from SLP.

Glad I can help.