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  1. #1
    GTP Level Member FriboRage's Avatar
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    Default SLP Powerflo Install Issues. (Solved)

    I think I got it, man is it really loud though. It sounds good, but its just way too loud.

    All the reviews said it needs a resonator and they're all right. Hopefully that tones it down, I'll be so disappointed if it's still so obnoxious.
    Last edited by FriboRage; 05-07-2017 at 07:09 AM.

  2. #2
    I can't car too good. SaukRapids's Avatar
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    Default Re: SLP Powerflo Install Issues. (Solved)

    They used to sell SLP's kit under "Loudmouth" name.

    I've been looking at some. Vibrant ultra quiet are supposed to be alright on a GP. There's cheaper options tho.

  3. #3
    GrandPrix Junkie spazzz's Avatar
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    Default Re: SLP Powerflo Install Issues. (Solved)

    I have had a SLP loudmouth catback since 08....it's loud when the car isn't even running.

    I did put a Magnaflow resonator on 2 years ago and it tamed it some.
    My muffler shop guy said it would always be loud with "those" on it. They do look nice though.

  4. #4
    Killa Bee Scottydoggs's Avatar
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    Default Re: SLP Powerflo Install Issues. (Solved)

    i heard a slp cat back on a stage 3 gsx regal a while back in person, why i went with a stock replacement off ebay. it sounded worse than the you tube vids out there. fart, pop, raspberry sounds. not my cup of tea at all.

    98 Buick Regal GS, F body brakes, Caddy STS wheels, tinted tails L36 bottom end, lightly ported heads, 1.95 roller rockers, headers, 2.8, FSIC, 42 lb injectors, a BrandonHall rebuilt trans, DHP tuned and AEM water/Meth injection https://goo.gl/gpV5kW

  5. #5
    GTP Level Member FriboRage's Avatar
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    Default Re: SLP Powerflo Install Issues. (Solved)

    Well, since I'm already in this deep I might as well see if I can fix it to my taste. Right now it's just a cat into a straight pipe to the mufflers.

    So as for a resonator vs a glasspack, I see some people arguing that they're the same thing, some say they're totally different in what they do.

    Which one will tone it down more? From my reading it seems a good resonator will quiet the volume and drone while filtering out some of the higher noise to leave behind a lower, nicer sound. So is it true that, in this case, the longer/bigger the better? Like magnaflow has 3"-7" round ones, from like 20"-27" long. So I feel like I should get the longest one I can fit.

    I already bought a magnaflow glasspack in anticipation of this, but now I'm thinking it's not going to be enough and I should just get my $23 back, then spend a little more on a resonator.

    Or maybe I should go to advance or something and see if I can find a 2.5" walker res... something designed to be factory which I think would probably end up being the quietest... what about zzp' whisper res they show?

  6. #6
    I can't car too good. SaukRapids's Avatar
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    Default Re: SLP Powerflo Install Issues. (Solved)

    I don't know if resonators and mufflers are the same. There's different internal designs when only looking at inlet/outlet size.

    Been reading too. It looks like it's a shot in the dark just from so many choices. To add to any confusion, people even try 2 resonators one after the other.

    My direction is also toward the longest that'll fit. Diameter of the muffler/case could be an issue for ground clearance. Dunno how much is too much there, but it looks like 6" might be alright. (2005 GP)

    Cost, do I get a cheap one and hope it does ok? Or, try and get a better one that might outlast my stock mufflers to use later?

  7. #7
    GrandPrix Junkie spazzz's Avatar
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    Default Re: SLP Powerflo Install Issues. (Solved)

    I have an old school father/son shop I go to.
    They hooked me up with what would be the best in my situation.
    Didn't cost a fortune either, like 125 welded.

    Get as big a resonator as fits and you will be happy.
    All 3800s sound like ass no matter whats on the pipe unless maybe big cam and turbo.
    But hell we all know that.
    Any muffler including stock sounds like crap noise just at different frequencies.

  8. #8
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    Default Re: SLP Powerflo Install Issues. (Solved)

    ^especially at 2000-2500RPMs when freeway cruising. IMO sounds like a bunch of gators having butt-sex.
    stock mufflers is the best sounding IMO when paired with headers and cat-deleted (because it's quieter lol).
    old setup-Z7 Turbo Kit w/T66, A2A I/C, stock cam & valvetrain/LS1 MAF/Ported 99TB/PowrTuner/AFC/Devils Own/LS1M Scanner/PRJ FP/42# Injs=12.3@118mph street tires -
    (Sold)BACK TO M90 Vs cam w/3.5" pulley/meth/25* timing+bolt-ons
    01 Z28 A4 HP-self-tuned, LTs, FTRA 13.1@110

  9. #9
    GTP Level Member FriboRage's Avatar
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    Default Re: SLP Powerflo Install Issues. (Solved)

    Well guys, I got the glasspack in and I drove it around last night and today. It doesn't sound terrible. It's way better than without the glasspack... tolerable even, but it's still a bit too loud and droney for my taste. It sounds like a riced out civic, just a little deeper toned.

    I like the exhaust to have some gurgle to it, and the stock setup sounded good to me, I just thought this would be that plus a little volume. This is just like one flat bass note that changes volume with rpm.

    I think I'm gunna try to sell this off to recoup some money and then get another resonator to reuse with my stock mufflers. The res was the only rottted part.

    One weird thing is that I noticed a lot more kr on my aeroforce now... I wonder if the vibration is setting off the sensor or something.

    Oh well, thanks guys.

  10. #10
    I can't car too good. SaukRapids's Avatar
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    Default Re: SLP Powerflo Install Issues. (Solved)

    Tough break, man. Someone will take it off your hands.

    Before I bought kits for my old cars, I heard SLP on a car around town. Tried Dynomax too. I liked Borla kit best, but it's expensive.

    This time doin' it like you might and cutting out old resonator.

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