No cats vs. High flow cats

Discussion in '2005 - 2009 Specific Tech' started by UrbanRedneck, Jun 25, 2008.

  1. I want my car to be a bit louder, but I am not sure about whether or not I want to go to a full off-road pipe. I was wondering, is there any benefit (performance wise) to high flow cats, like the bassanni X? Is there much of a gain if you have no cats vs. high flow cats? And are high flow cats louder than stock? Almost as loud as no cats?

    Lastly, has anyone had warranty work on their cars with an off-road or high flow midpipe? Did the dealer care?
  2. Hi flow cats sound much better and decently louder than stock and as far as how loud I guess would depend on your mufflers. No cats is of coarse much louder and more aggressive. I have Bassani X pipe w cats and I am satisfied and keeping it until my pockets are deep enough to buy longtubes then I will change to off road.
  3. I recently purchased and installed the MAC prochamber with high-flow cats, and noticed that my Pypes Violators definitely sound deeper, and are also slightly louder over the stock catted H-pipe. Perhaps it's just me, but it also seems like there's been a significant reduction in drone as well.

    But most of all, I've also noticed a significant increase in both low and mid-range torque. So it appears that MAC's prochamber design, really does improve torque by merging exhaust gases evenly into a single collective.

    All in all, I've been very pleased with the catted prochamber, and has by far, exceeded my expectations. :nice:
  4. How many cats do the new mustangs have? If they got 2 these things must be restrictive as hell because on the sn-95's i have had if i put aftermarket mufflers on it is considerably louder. On my new GT its not loud at all with the FRPP stingers.... :shrug:
  5. The factory cats (2) are far less restrictive, and flow much more efficient over the previous SN-95 models.

    That being said, unless your just looking for improved sound quality. There's very little to be gained from a performance or HP standpoint. However the reason for my improved torque gains, is because of the MAC prochamber, and not from replacing the cats !
  6. I have stock headers, Magnaflow O/R x-pipe and Magnapack's full cat back..I LOVE the sound..Even slowly accelerating it is deep and sounds insane at higher rpm's with the Vortech..I may change mufflers later just for a change if I start to get bored withthe magnapacks...But as of right now, I love it, and get alot of compliments too:D
  7. Hmm, so they aren't quite as loud as no cats, but much louder than stock.. Anyone know from good evidence wether there is a performance gain to no cats vs. high flow?

    I don't know what I want to do, stick with stock, get a high flow catted X pipe, or an offroad X or H pipe. I have a violator axleback.

    And what about the warranty question, has anyone had work done on their car with an aftermarket midpipe?
  8. How loud do you want it to be? Violators sound awesome with an off road H pipe, but it's extremely loud. A high-flow catted H or o/r pro-chamber would be best for sound/loudness.

    I just replaced my Violators with Magnaflow chambered axlebacks because the Violators were just too loud with the off road pipe for daily driving. The Magnaflows are very deep, but not nearly as loud as the Violators. I hope they break in, actually, because they're kinda quiet at idle, though they get decently loud at WOT. Someone was nice enough to sell me a set with 500 miles on them for $100 :) I couldn't pass that up.

    But if you're happy with the Violators and just want them louder, a high flow catted H or pro chamber is definitely your best bet.
  9. I have the FRPP GTA's and was thinking about getting the Pypes off-road H because I want a little bit deeper sound and would like it to be louder as well. The thing I worry about is adding the O/R H going to make it obnoxiously loud? Like loud enough that it will bother the neighbors in the morning and such, because that is not really what I want to do.
  10. I want it to be louder but I'm not sure how much. Too bad you don't live a little closer so I could hear yours.

    Does anyone even make an H pipe with high flow cats?

    I was thinking about buying a used Bassani X with high flows, but I don't know if I'd like the raspier tone you get with an X pipe.
  11. haha, seems like we are more or less in the same boat.
  12. Stock cats vs no cats is about a 2-4 rwhp gain. High flow cats vs no cats is about a 0-2 rwhp gain.
  13. MRT makes a h with high flow cats.
  14. It's fairly loud outside the car, but not annoyingly so. My g/f was in our other car the other night driving next to me with her windows down and she said it was a bit loud when I got after it, but was almost like stock when I was cruising. It also has a very old school growl, with just a hint of sexy rasp and NO drone, unlike a lot of axle-back kits.

    In my oppinion this is the best bang for the buck exhaust mod there is. It costs about 180 shipped from brenspeed, is actually a nice fit/finish, adds noticable power and sounds killer.
    No other exhaust mod can do all these things and this is less than any axle-back kit.
  15. Stock mufflers with off road H sounds decent, but is way too quiet. Of course this is my opinion. But the only time you can really hear it is at WOT. I'm very happy with the Magnaflows I just threw on. In fact, my fiance just took off and I was surprised at how deep it was. It's still not nearly as loud as the Violators were, but it's quite a bit deeper.

    I think GTAs or Magnaflows + off road H are probably the best combinations for sound quality without being overly loud or quiet.
  16. Sold! :D

  17. Do you work for a bomb sqaud, or at a gun range...maybe a very loud factory that doesnt provide hearing protection?

    I only ask that because if you think the stockers w/ o/r h pipe are only audible at wot then you must be missing at least half of your hearing. Mine start to growl fairly loudly at about 1/4 throttle and get nasty at anything over half. What I do like about this setup is that you can keep them at a decent level while cruising in a quiet neighboorhood and while cops are around. But it doesnt take much to get them to loud.
  18. Lol no. Just used to loud cars. Our '05 has straight thru magnaflow side exhaust with off road x, and the '07 had Violators (basically a straight thru louvered tube) and off road H. So putting the stock mufflers back on made it extremely quiet in comparison.

    My fiance left today, and I faintly heard her pull out of the garage today in the '07, and could only hear her about 500 feet down the road. (she wasn't really getting on it, though). So, I wouldn't consider that loud. At WOT, they get pretty loud, but again, nothing like the Violators. When I ran my car on the dyno, the dyno guy plugged his ears and mouthed (That's *****ing loud!) I guess it's just all in what you're used to. But I do think a chambered muffler with off road H is pretty tame, though sounds very good. The Magnaflows I just put on are crazy deep.