I am trying to decide between the gm preformance exhaust and the magnaflow Has anyone here had experince with the gm exhaust and witht he magnaflow I see it comes with the resonator has anyone had an exhaust shop make them a pipe with out the resonator and then just hook that to the magnaflow muffler? What was the sound differnce when taking out the resionator? The reason I am asking is because I want to get he ost outta my exhaust with out sounding like total crap and by total crap I mean a 17 YEAR OLD with a honda civic. I know this I5 isn't going to sound like a v8 and don't expect it to but sounding deep and sounding like crap are two differnt things.
Also looking under my hummer I noticed up by the front where the manifold pipe comes down there is another little thing dunno what kinda looks a smaller resonator does anyone what that is?

 

Jackk:

The front "little thing" up front is a manifold CAT. New GMs and others use them to help emmisions when the vehicle is first started. An exhaust manifold CAT gets hot quicker than the main CAT farther back in the system and offsets the emmisions created by the rich fuel mixture of start up strategies used by the PCM when the engine is cold.

I really like my Magnaflow system, and it does not sound like a fart pipe. I could not justify the cost of the GM system that does not even come with tips included, the tips are like $180.00 more on top of the exhaust. I know several people on here have the GM system, let them tune in and give you some input.

IMO it is hard to beat a SS prefabbed system with lifetime warranty, but some local shops can do a nice custom sysytem for you.

 

well I was looking to get the magnaflow then having a custom shop make me a pipe from where the manifold pipe comes down and basically elimionate all the junk between the maifold pipe and the muffler will removing any of those items screw with the pcm or other computer on the engine?

 

My Gibson sounds cool..nothing like a tin can rice rocket. I havent heard the Magnaflow ( except online which does no good ).

I still need a pcm tune and an intake..maybe I should go for the Doc's intake[sm=smiley14.gif]

 

Try reading this and if it's not enough then do a search and you'll find some more information.

https://www.hummerforums.com/m_14380.../tm.htm#143804

 

Gibson is always a good choice, they have been making quality stuff for years. There are more, some do not yet show a 2008 part number for the H3 I5, but I believe all the 2006/7 H3 systems more than likely will fit without problem. The makers just need to confirm nothing has changed and expand their part numbers to the application.

Jackk: Here is a link to a prior thread wherethere was brainstorming about a gut the exhaust hypo for the Alpha. Some/most would apply to the I5 exhaust. Food for thought, just some ideas. RE: Alpha Exhaust... BIG DISAPPOINTMENT!



mfish, you know where to find me whenyou decide.

 

I installed an 07 Magnaflow in my 08...one exhaust hanger has changed from 07 to 08...It was fairly easy to remedy but I would wait till they offer an 08 part. I like the sound but have nothing to compare it to. It is after all a 5 cyl !

 

I have the Gibson and like it a lot - the sound is great, much, much closer to a V8 than a Civic. It's not great for wheeling (probably none of them are) as I've flattened the tips once. I have had one small impact point on the exhaust where the rear axle, or something coming off the axle, has hit and mildy marked the pipes.

 

Well you can do two things with the Exhaust Manifold, you can get a header Pic #1 or Gut the Catalyst from thestock exhaust manifold. I have the directions if you want them though it's not recommended if you are in a sniff test State.

Cat Back available: Bassani, magnaflow, Billy Boat, GM, Borla, Volant, Gibson, Corsa

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I just picked up my Magnaflow today and hope to install it this weekend, I will post a soundclip as soon as get a chance.