Exhaust question from beginner
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This is a discussion on Exhaust question from beginner within the Engine Modifications forums, part of the Tech & Modifying & General Repairs category; Hi all, I've been wanting to upgrade my exhaust looks and sound for awhile now and I think I've settled ...

  1. #1
    Registered User degobah77's Avatar
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    Exhaust question from beginner

    Hi all,

    I've been wanting to upgrade my exhaust looks and sound for awhile now and I think I've settled on;
    Axleback, Quad Tip

    Now I'm not looking to sound like a Harley, but I do want something a bit more than stock. After listening to a dozen different exhausts, I've found the Perrin sounds very reasonable, a nice upgraded rumble at idle, not ridiculously loud under 3k RPMs, but nastier if wanted above that. And the 3.5" slant cuts should look so much better.

    I've never made any such mod to a car before, so after some research, I have some assertions and questions that maybe an experienced one can verify/answer;

    • A CBE does not add any extra power, so would there be a reason to get a CBE when I can just get an axel back and have everything I am looking for - upgraded sound and rear aesthetics?
    • With 3.5" tips, is there a concern about heat and melting the bottom of the bumper or not? I read that with 4", you should install a heat shield, but is there any concern for 3.5" tips?
    • The installation guide says to check local laws because these are sold for off-road and racing purposes only. Is this just a generic statement or am I really going to get pulled over with a better looking, slightly louder exhaust?
    • My local laws limit vehicle noise to no more than 90db over 35mph and less than 86db under 35mph. I can't find any noise measurement specs for Perrin. Is this something you think would be posted somewhere, or something I should just not worry about, unless I was going with a TurboXS CBE or something else notoriously loud...?
    • An axel back (or CBE for that matter) does NOT change emissions whatsoever, so I'd have no reason to worry about state inspections or anything.
    • I plan on doing the install myself as it doesn't really sound all that difficult, is there anything I need to be careful about here?


    Hope I don't sound like an idiot, I have a feeling this is a non-issue for people who are really into cars, but I have to admit I'm a bit nervous about making the change.
    Last edited by degobah77; 09-08-2013 at 10:25 AM.

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  3. #2
    Master Baiter EJ257's Avatar
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    Have you heard the exhaust in person? Online clips are pretty meaningless due to the quality of the recording device, the compression that YouTube (or other video hosting sites) perform during the upload process, and the recording technique. Without hearing the exhaust first-hand, you're still pretty much guessing.

    1) On a relatively stock car, a catback is not going to net you any real power. The reason most people go with a catback is that for the price of an axleback, it's only a little bit more for the full catback. If you don't really plan on going far in terms of mods with the car, an axleback is perfectly fine for you if it fits your needs.

    2) This is something to bring up with Perrin. Some manufacturers (e.g., Kartboy) sell extended-length exhaust hangers, but Perrin should be able to tell you if their product would run the risk of damage. That's part of the support you're paying for with their product.

    3) That is a "cover their ass" statement. Some areas do not allow for you to legally tamper with the exhaust in a way that increases noise output (NY, for example).

    4) Again, this is a question for Perrin, as part of the support of their product. Find out from them if they have that information already available, or if they're willing to get that information for you.

    5) There is no impact on emissions with a catback or axleback, so there should be no issue from that standpoint.

    6) Installation of a catback/axleback isn't too difficult. Likely, the most difficult part of the install will be the exhaust hangers. WD40 I've found works pretty well in terms of lubing up to make for easier removal. Any "seal" you break, make sure you replace the gasket to avoid the chance of leaks.
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  4. #3
    Registered User degobah77's Avatar
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    I have not heard it in person, but I have listened to many recordings from different perspectives. I like the SPT and the Perrin the most. The SPT has the advantage of being OEM which would make me far more comfortable with the whole thing, and after a few more listens, actually stands out quite a bit and gets very favorable reviews around the net. *NOTE: I HAVE heard the SPT in person...

    It's currently a 50/50 toss up between the SPT CBE and the Perrin AB.

    My biggest concern is what the actual laws are in my area. I can't find a damn thing about Washington, DC laws for aftermarket exhausts, only decibel levels. The surrounding states all have explicit laws stating exhausts can't be modified to increase noise levels, but I can't tell you how many massive exhausts I see driving around so it can't really be strictly enforced.

    I'll ask Perrin for more info tomorrow. Thanks for the reply.

    EDIT: Updated impressions and decision
    Last edited by degobah77; 09-08-2013 at 05:31 PM.

  5. #4
    Registered User degobah77's Avatar
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    Update, just purchased the Perrin CBE - should be here by Friday, bolt on Saturday fun coming up...

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    Master Baiter EJ257's Avatar
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    Quote Originally Posted by degobah77
    Update, just purchased the Perrin CBE - should be here by Friday, bolt on Saturday fun coming up...
    Did they answer your questions about dB levels and issues with the rear bumper?
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  7. #6
    Registered User degobah77's Avatar
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    They couldn't tell me any db levels but they did confirm no issue with the rear bumper and an easy fitment to existing pipe.

    Chatting with the RSD guys is what led me to choose Perrin. I wasn't hearing too many good things about SPT, so I started checking out Cobb (too loud for me). RSD suggested the Q300 (4" tips!), then the Perrin...

    Edit: Forgot to add that when I asked Perrin about the db levels, the second half of the response was, "not much louder than stock". I'm assuming that means at idle, because what I've heard online is far from stock when hitting upper rpms. That said, every recording was a bit different, so who knows...

    Got a tuner shop scheduled to install it next week. Hope it's not a cop magnet...
    Last edited by degobah77; 09-10-2013 at 04:14 PM.

  8. #7
    Master Baiter EJ257's Avatar
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    Quote Originally Posted by degobah77
    They couldn't tell me any db levels but they did confirm no issue with the rear bumper and an easy fitment to existing pipe.

    Chatting with the RSD guys is what led me to choose Perrin. I wasn't hearing too many good things about SPT, so I started checking out Cobb (too loud for me). RSD suggested the Q300 (4" tips!), then the Perrin...
    Perrin, in my experience, has been louder than SPT.
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    Pro Manscaper Mikie13's Avatar
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    Quote Originally Posted by EJ257 View Post
    Perrin, in my experience, has been louder than SPT.
    But a much better tone to it...deeper IMO.

    I think Perrin was a solid choice. They are probably my front runner for when I look for an exhaust.
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  10. #9
    Registered User degobah77's Avatar
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    Hi y'all...got the CBE installed this afternoon. Initial impressions; much louder than stock, not a little. A lot of bass rumble at start up, quiet at idle, so far no droning at highway speeds - it blends in with everything else. Not obnoxiously loud at all, but sounds so much better than stock. Will definitely turn heads if I punch it, such a low end growl. Very sexy if I dare say so.

    UPDATE: for the first 3 or 4 days, this was a very loud (for me) exhaust, cabin noise and drone were just a bit too much for me after a 4 hour road trip. However, after about a week and about 500 miles later, the cabin drone has completely, and I really mean completely, gone away - overall the exhaust vibrations have really quieted down. It's still louder than stock (if stock is a 0/10, I'd give this about a 4/10) and all that deep growling boxer bass rumble is still there, but it's all the way in the back now. Sounds great tearing away from a stop. Overall, I am extremely pleased now that it has "burned in" a little bit.

    Last edited by degobah77; 09-24-2013 at 02:31 PM.

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