r3gan

I've got a 2004 Mustang GT and I am hoping give her Magnaflow Catbacks (or "Magnapacks", I haven't decided yet) and I'm wondering how this will work and sound with the factory H-Pipe left on. I've read lots about X vs H pipe on this forum, and the conclusion I've come to is that H-Pipe will give a better sound at low RPM while the X-Pipe will be better at higher RPM. This being said, will it sound OK if I just throw on the Catback or Magnapacks and leave the stock H-Pipe in tact? I'd rather my car sound badder at cruising speeds or idle anyways.

I am also interested in whatever HP gains I can get from this. I live in Canada and I'm not quite sure of my provinces emissions laws, but I believe I'm ok to run catless. Will there be (at least) a 10HP gain from using a Catback or Maganpack set only, or will I need to get rid of the stock H-Pipe and use an Off-Road X-Pipe to notice any HP gains?

Thanks for the input.

Dan04COBRA

You really need to get rid of those 4 nasty cats you have on your car. I recommend using catted aftermarket mid-pipes, good for inspection and still somewhat ozone friendly [8D]

As for the cat-back, bolting it on without a new midpipe might get you an HP or two, but all the restriction is really in your mid-pipe.

Magnapacks sound awesome, really deep cruising around town, when you go WOT they keep their deep sound but have a neat high-pitched overtone, they are 100% unique, nothing sounds like them.

I HAD Magnapacks, but stupid circumstances forced me to take them off and now I have Flowmasters. I can tell you from personal experience that my old Magnapacks turned WAY more heads than my Flowmasters. Not to mention they looked great, no interior drone and the noise inside was much lower than my current Flowmasters.

Magnapacks and SLP Loudmouths are the best flowing catbacks and the LOUDEST offered. Quality is superb.

94Cbra

Come on now Dan, nobody buys a mustang to be "o-zone friendly" !! I would definatly run a catless mid-pipe if it was tolerated. A performance mid-pipe will also make a world of differnce with the sound of the catback you choose. I agree with Dan in the fact that Packs do sound awesome. It would make a good choice.

jishead

I put my pro-chamber on FIRST unlike most people. I put it on the same night as the 85mm MAF and Densecharger. I did make a heck of a feel and sound diff. I didn't dyno it till much later in the mods so it's all the feeling in the pants.

My Magnaflow sounds great. Got louder over time. Inside sounds incredible with little drone unless loading engine at low RPM. Outside sounds very low rumble. No high sounds at all. All very deep tones. My brother hears me coming from blocks away if I am running 2,000RPM or above OR I can sneek up on him if I am driving it econo (5-speed). I think that they would have sounded just a bit more mellow if I had the stock H pipe.

The quality of the Magnaflow system (welds, stainless, hangers, fitment) is great. I don't have much experience with other brands, but mine is great. I wish I could try another type just out of boardum but who wants to spend the $$$.

I'd be surprised if any midpipe performed any better that the pro-chamber on a barely mod'd GT. The pro-chamber sounds great, fit great and cost very little. Again, I'd love to try some other one just to hear and feel.

nanaki

yeah, as dan said, you'll get most of your gains from the midpipe.

i <3 SLP. i've owned the loudmouth 1s and 2s. the 2s are by far the best that i've ever owned and heard. the packs i've heard on stangs i didn't like at all. i think it's that overtone that dan was talking about. there's just something about them i don't like. i heard 2 stangs with them and meh..... LM2s are reeeeeeeeeeally deep and really loud. magnaflows sound good when you get on them and are OK when you're cruising around. just not loud enough for me.

Case

I currently have Packs on with my factory H-pipe. It sounds good, but I want it just a bit louder. My Magnaflow X is coming in about a week or so! Performance wise I hardly noticed a difference, if any, when I got the packs installed. I'm hoping the X-pipe will liven it up a bit.

r3gan

Thanks, all. And I have to apologize.... I have a 2002 GT, NOT A 2004.

That pretty much sums up what I was looking for. I actually don't know much about the Pro Chamber mentioned by jishead... I'm asuming that this will connect easily to the Magnapacks or will I need to get some extra stuff? The reason I was thinking of leaving the stock H-Pipe on was to save a little cash (I have to consider the exchange rate when buying stuff from the U.S.), but that Pro Chamber seems slightly cheaper than Magnaflow's X-Pipe. Would the Pro Chamber be a better way to go than the Mustang Tuning's Catted X-Pipe? The Mustang Tuning Catted X-Pipe is WAAAAAY cheaper than Magnaflow's, for example, so maybe I could go that route.

r3gan

I've another question too... concerning the MIL Eliminators. I noticed that MustangTuning.com sells "Steeda" MIL Eliminators for $59.99 but I also found some for $29.99 on www.mileliminators.com. I'm wondering what the difference is between these two and why the Steeda ones are 20 bucks more.

nanaki

there's no difference between the 04 & 02. performance wise anyway.

reason they're cheaper is cause they be aluminized baby!

you don't need them MILs unless you're running an off road H/X.

MustangZally

This is a sign from GOD. I just ordered Magnapacks for my 2003 GT and I hoped I didn't make a mistake. Thanks to all for your input.Now, I can sleep tonight. What after market midpipe would you recommend? I am going to pull it apart this weekend, and I would like to do it right the first time. Thanks, Mike