Muffler vs. Cat-back...

migpilot · 03-17-2008, 12:22 AM

Just purchased my Pure '07 Sol NA A/T 3 weeks ago today. After almost 2k mi. I'm loving it more each day.

Even off the lot I wasn't crazy about the sound of the stock exhaust thus some (remedial) questions about an upgrade.

1) What are the main advantages of a cat-back system (say a Magnaflow MLF 16646) vs. the much less expensive alternative of a muffler swap (a Magnaflow 40 perhaps)?

2) The sound clips I've heard (thank you all for the work putting it together) all have stationary revving of the engine in common. With an automatic I won't be doing any of that (nor putting my car in a 'show' or racing for that matter). Anybody have experience with these driving specs and can help me in deciding the benefits of the various after-market exhaust offerings?

3) Aesthetics aside (duelies do look very sporty), is the performance gained (HP and gas savings) from dual-in/dual-out system objectively worth the $$$ outlay?

4) Perhaps a CAI or headers ought to take priority (for a performance bump) vs. addressing the exhaust tail alone?

Thanks for helping me work through these arguments...

J.-

SmokinSolstice · 03-21-2008, 08:08 AM

Wow four days and no one responded?!

I think its all a matter of what you want and money. I think the muffler is the main restrictve part so meaning a muffler swap can help. I am not so sure if there is much advantage performance wise between a muffler swap and a catback full exhaust. However headers and maybe even a hi flo cat should be included to completely take advanatge of the exhaust. There are lots of people on here who have done muffler swaps and love it. I myself went with a catback and headers as well as the CAI. Don't forget solo they are outstanding.

Red Rider · 03-21-2008, 09:00 AM

I agree with SmokinSolstice the header and cia will give you a boost, the exhaust is debatable between a muffler replacement or a full replacement but I think I would still go with the dual cat back or similar setup. If you scan the "for sale" forum here you may be able to find some good deals on a dual rear fascia and I have seen some shorty headers for sale also along with cia's.

Aspenrose · 03-21-2008, 09:57 AM

I was going to go with just a flowmaster muffler, but after discussin' it with my local exhaust guy, I went with the full cat back magnaflow. His point was after a muffler swap, the muffler, or it's connections would be the weak link-the full cat back kept the exhaust as all stainless, no rust out points.

With all the issues of blown header gaskets, no way Jose. I got all I need out of my NA with the CAI, magnaflow cat back, and ECM tune.

Envious06 · 03-21-2008, 10:39 AM

Well heres my two cents...You are starting with a stainless exhaust system. If you cut it three quarters of the way back, weld in a custom SS "J" pipe for a side inlet muffler such as a Flowmaster 40 or my favorite, the Solo Storm. Mount the muffler with the OEM rubber and some stainless rod (muffler shop will be glad to help if you don't weld) cut off the existing tip on your OEM exhaust at the muffler exit, weld it to your new muffler and there you have it, "the po mans special". Around $250 at most muffler shops and still 100% stainless steel. There are plenty of threads on this subject. Chemist has some great photos of a proper installation. You could PM him for them. I used Solo's Storm big can. The owner welded on the proper mounts for me, all I had to do was cut, mount, clamp or weld in place, done deal, sounds great, seat of the pants dyno felt more powerful. (Thanks Jeff) As for the CAI, save your money, they are worthless. Throw a flat panel K&N in the stock box (Don't listen to the stories about the oil screwing with your MAF that only happens to loogans that put way to much oil on the filter when they clean it) and drive away. You might want to consider an ECM reflash, that money that you saved by not buying the CAI will come in handy here. This is a mod that will actually net you a power increase while a CAI just looks like it should. Oh well, I guess that was more like five cents. Next best mod, replace the tires, but I won't even go there. Good luck with your new ride. Keep the rubber side down.

RevmanII · 03-21-2008, 10:50 AM

I'm going to have to agree with AR and Envious on this one. While I really like my complete Solo exhaust, and my AEM CAI did look pretty cool

, it's not cheap and you can count me as one of the guys that is going to have to deal with a leaking header this spring before I put the car back on the road. If your on a tight budget do the muffler replacement and seriously consider the ECM tune

Red Rider · 03-21-2008, 11:46 AM

Quote:

Originally Posted by Aspenrose

I was going to go with just a flowmaster muffler, but after discussin' it with my local exhaust guy, I went with the full cat back magnaflow. His point was after a muffler swap, the muffler, or it's connections would be the weak link-the full cat back kept the exhaust as all stainless, no rust out points.

With all the issues of blown header gaskets, no way Jose. I got all I need out of my NA with the CAI, magnaflow cat back, and ECM tune.

There is no header gasket to blow that I know of. I had the Clear Image header on my 07 N/A and no gasket was on the head from the factory or when the header was installed.

Aspenrose · 03-21-2008, 12:18 PM

Quote:

Originally Posted by Red Rider

There is no header gasket to blow that I know of. I had the Clear Image header on my 07 N/A and no gasket was on the head from the factory or when the header was installed.

It's at the other end-where the header connects to the cat. LOTS of blown gaskets.

Red Rider · 03-21-2008, 12:27 PM

My bad I was thinking of the connection to the head.......................I just installed the Solo Cat on my GXP I don't know if the gasket can be bought separately but it may be worth a try. It has a was better seal to it than the stock gasket that I used on my NA. I am pretty sure the bolt pattern is the same. I would get a hold of Jeff at Solo and see what he thinks.

RevmanII · 03-21-2008, 01:23 PM

There is a metal gasket between the head and the header/manifold. Not sure if my leak is there or at the cat. To me it sounds like its at the head, but until I pull the supercharger off I won't be able tell.

Red Rider · 03-21-2008, 01:40 PM

Quote:

Originally Posted by RevmanII

There is a metal gasket between the head and the header/manifold. Not sure if my leak is there or at the cat. To me it sounds like its at the head, but until I pull the supercharger off I won't be able tell.

Unless the gasket was put there because of the Solo header or the super charger the original factory build has no gasket between the exhaust manifold and the head. I did the High Flow Cat from Solo install on my GXP and you really have to get the bolts between the cat and the manifold tight as that gasket will compress to make a good seal. Assuming it is the same one that came with my cat install. Also I did a shorty header install on my 07 NA and had to remove the bracket the held the cat to the engine because it would not line up without putting pressure on the exhaust system. I never had any leak problems with it and I had 6700 miles on it when i traded it. I removed the header when I traded it in and the gasket was still intact. I also reinstalled the bracket at that time.

Critterman · 03-21-2008, 04:28 PM

My 06 N/A had a gasket between the head and the manafold, I replaced it with the one provided by FocuzTech

SmokinSolstice · 03-21-2008, 04:51 PM

Quote:

Originally Posted by RevmanII

There is a metal gasket between the head and the header/manifold. Not sure if my leak is there or at the cat. To me it sounds like its at the head, but until I pull the supercharger off I won't be able tell.

If your leak is at the engine block and header is the gasket stock? If so how many times have you unbolted it? I hear the stock gasket is good for one off after that you need a replacement.

RevmanII · 03-23-2008, 04:00 AM

Quote:

Originally Posted by SmokinSolstice

If your leak is at the engine block and header is the gasket stock? If so how many times have you unbolted it? I hear the stock gasket is good for one off after that you need a replacement.

Too many obviously. Let's see, it's been re-used 3 times. I do have a fresh one from Pontiac I bought last summer along with the nuts sitting in the garage if that turns out to be where it's leaking.

Quote:

Originally Posted by Redrider

Unless the gasket was put there because of the Solo header or the super charger the original factory build has no gasket between the exhaust manifold and the head. I did the High Flow Cat from Solo install on my GXP and you really have to get the bolts between the cat and the manifold tight as that gasket will compress to make a good seal. Assuming it is the same one that came with my cat install. Also I did a shorty header install on my 07 NA and had to remove the bracket the held the cat to the engine because it would not line up without putting pressure on the exhaust system. I never had any leak problems with it and I had 6700 miles on it when i traded it. I removed the header when I traded it in and the gasket was still intact. I also reinstalled the bracket at that time.

RR, I can't speak to the GXP, but your 07 NA certainly should have had the gasket at the head.

Red Rider · 03-23-2008, 06:44 AM

Quote:

Originally Posted by RevmanII

Too many obviously. Let's see, it's been re-used 3 times. I do have a fresh one from Pontiac I bought last summer along with the nuts sitting in the garage if that turns out to be where it's leaking.

RR, I can't speak to the GXP, but your 07 NA certainly should have had the gasket at the head.

All I can tell you is that I had it off the car 2 times and at no point did I see a gasket between the head and manifold......................not saying there was not suppose to be one there just didn't have one.......................maybe that is the fix try putting it back without the gasket