Exhaust Performance Upgrade Questions:

I have a 2008 LS3 Z51 6MT, I am the second owner and the car only has 18.5K on it.

Unfortunately it appears to have a very slow rear main seal leak. (engine to bell housing connection). The leak is not major and only produces a few drops of oil on the floor every two weeks or so now that the weather is warm and I am driving it more. I noticed the issue over this winter and it seems the leak is slightly more active when the car is sitting and the weather is cold.

That being said, to repair this leak the exhaust and other components will need to be removed/moved around and I figured that it makes sense to save in labor and order some performance upgrades at the same time. My plan of attack is below:

Option #1
Headers/cats/mid pipe combo = American Racing - ARH C6E34W/C
Keep my Factory NNP Exhaust
Tune = Professional tune

Option #2
Headers = Kooks headers
Mid pipe = Corsa Mid Pipe
Keep my Factory NNP Exhaust or replace with Corsa exhaust
Tune = Professional tune


I love the Corsa exhaust sound, but I think I want to retain a stock appearance on the outside of the car and keep my NNP exhaust system and NNP exhaust controller. I wanted to see if anyone had a similar setup and if the combination of parts will correctly bolt to my factory mufflers/NNP system without any fitment issues or cutting/welding required.

I realize there is much more I could do but I think this is where I would like to start but I am open to additional recommendations if the cost to power ratio makes sense to me, although I am not looking to go down the road of FI, CAM, or anything that major, at this point…

Also while the seal is being replaced I am having the transmission fluid changed and rear differential fluid changed. I was planning on using Royal Purple (Synchromax #12512) for the transmission and GM factory differential fluid.

 

I think the question is more how you feel about an 'always loud' sound? If you don't think you'd ever care to have the car quiet, I see no reason to keep NPP. I understand wanting to retain the stock look...but honestly, I don't know that anyone has ever said the bigger tips look worse.

Personally, I had the NPP (to quiet...period), B&B PRT (loud when you got on it, nearly dead quiet at cruising speeds...more so then NPP open), and now Corsa Xtreme. I'm actually installing a set of Headers thursday along with a catted xpipe.

My suggestion... ARH headers/xpipe and Corsa exhaust w/ tune.

I know that wasn't exactly one of your options, but I'd rather go ARH then Kooks but it's all a matter of opinion, either are perfectly fine.

Tune is a must with headers. Do it. If you don't have a great tuner in your area, then you can look at going the mail order route through someone like DiabLew Tunes- he does great work. All the magic happens with the tuner- don't half *** it.

Oh...and since you asked, there is no reason a set of headers and xpipe won't bolt up just fine to your NPP if that is the route you want to go. Honestly, the axle back is the least of your problems, so it's easy to start by keeping your NPP and swap it later if you want.

 

AR or Kooks with the C6Z catback or Corsa as you like if I am the one who gonna chose I'll go with the Z catback cause I can enjoy the Mild to wild.

 

I, too am looking at headers/ crossover w/cats to hook up to a Callaway Double D axel-back on my '12 GS. Whichever brand you decide on-- get the headers coated--keeps heat lower for one thing. There is also the maybe small possibility that standard headers could get hot enough under certain circumstances to damage the stock plug wires. Some packages include new plug wires. That's the feedback I'm getting from owners of all kinds of cars. Just my 2 cents for what its worth.

 

I have had about 10 different combinations on my C6 with American Racing headers, Zo6 manifolds, stock manifolds. My car had a decent sized cam on a 112lsa.

I found Corsa to be by far the best sounding, and when they say ZERO drone....they mean it but without cats it might be a touch too loud for day to day. If you are doing cats, go Corsa!!!!!

Akrapovic sounded amazing at WOT, otherwise I didn't care for them.

B&B Fusions are my #2 overall choice. Not a huge difference between the 2-modes though, but enough to make it worth while.

Zo6 axleback: Quiet cruising, but not very good tone (open or closed).

If Corsa had a design with small mufflers in the midpipe, combined with the drone killing design of the "mufflers" it would be AMAZING.

 

As for coating the headers.... DO IT! HUGE difference in under hood temps and the more heat retained in the pipes = faster exhaust velocity.

Jet-Hot
Swain
Cerkakote

 

dK_C6_LS3

All of the mods that are on the lists you provided are all parts that we use on our own installs. Can you PM me your information, and I will put together a quote for you that has the parts, labor, and tuning for the parts that you desire and I will email it over to you.


Brandon

 

At only 18K I was not expecting this leak, but I will do my best to make the best of it... I'm going with ARH, and now just have to decide if i want to give up the ability to push the quiet button. I have a local shop that does quality work and tuning. as of now it is looking like end of June or end of summer for me to get in there, so I have some time to figure out the mufflers... youtube surfing...

 

This is what I found when i noticed the drops a few months ago...

 

My 2008 vett w/ 17,000 miles has the same problem. Haven't noticed it actually drip but it looks damp. Ive read the oil pans seals tend to leak and a few guys have simple re-torqued there oil pans. Im going to re-torque and hope for the best.

 

The shop cleaned up the pan and the area in the picture. They then put dye in the oil. I drove it for about 2 weeks and brought it back. They were able to identify that the slow leak seems to be coming from the rear seal.

 

I'm tryng to be optimistic lol. I thought the same thing when i first was the dampness. Im installing LG Gt2 coilovers the weekend so re-toqueing oil pan is worth a try while i have the car jacked up.

 

I hear you, good luck to you, I hope a re-torque does the trick for you