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Thread: Exaust System

  1. #1

    Default Exaust System

    Hey guys, iv got a 95 silverado as you can see in my avatar and i would like to remove the mufflers.

    but i dont know if it is legal in the state of Oregon, of course i would leave the Cat's on, it would be dumb to remove thoes, they pose as spark arrester.

    Thanks for your help

  2. #2


    Quote Originally Posted by Thundare View Post
    Hey guys, iv got a 95 silverado as you can see in my avatar and i would like to remove the mufflers.

    but i dont know if it is legal in the state of Oregon, of course i would leave the Cat's on, it would be dumb to remove thoes, they pose as spark arrester.

    Thanks for your help
    check ur emission laws for oregon!
    2005 GMC Sierra 1500, reg cab, 4.8 ltr, 5 spd, 4X4, Flowmaster 40 series w/3" exhaust pipes & 4" tips. ReadyLift torsion bar keys(part#66-3000), K&N air filter (soon to be getting a AFE Pro Dry S airfilter), & airbox mod .

  3. #3


    Quote Originally Posted by devilsalmostfree View Post
    check ur emission laws for oregon!
    agreed .. its probably not legal though

    2002 Jeep Wrangler Sport 4x4 (the Yellow Jacket)
    4inch suspension 3inch body
    Straight 6 (383 Stroker within a year)
    36inch SuperSwamper TSL.
    Detroit Loccers
    Daily Driver Weekend Wheeler
    much more...

    2004 Sierra crew cab, 2wd, 5.3 V8
    2inch Daystar Leveling kit
    single dumped Flowmaster 40 sieries exaust(removed)
    Mb Blitz Chrome wheels
    Leer Bed Cover(for sale)
    50k miles

  4. #4


    i wouldnt bother unless you really enjoy going to the gas station and having a pretty gutless truck i ran mine for a week without a muffler just to see what it did..the fuel mileage went way down and it had almost no torque and it just sounded like a$$..flowmasters sound good but they arent the best for power output there are a few mufflers i can quote with dyno numbers and db levels that are much better than flowmasters or even an open exhaust
    99 silverado 4.8l with 6.0 throttle body,full tci rebuild with shift kit transmission with no reverse,eaton posi,flowmaster exhaust
    97 s10 350 pushing 350hp,5 speed trans,headman headers...kenwood in dash double din touch screen dvd,kenwood 6 disk changer-just a project truck

    Ricer: from the latin word Ricarius meaning to suck at everything you attempt

    A person who makes unnecessary modifications to their most often import car (hence the term "rice") to make it (mostly make it look) faster. The most common modifications are (but not limited to):

    - Huge exhaust that serves no purpose but to make the car louder
    - Large spoiler on the back that looks like something Boeing made for the 747
    - Lots of after-market company stickers they don't have parts from, but must be cool
    - Expensive rims that usually cost more than the car itself
    - Body kit to make the car appear lower, usually accented with chicken wire
    - Clear tail lights and corner signals
    - A "performance intake"- a tube that feeds cold air to their engine usually located in areas of excessive heat (behind or on top of the engine)
    - Most of these riced cars (a.k.a. rice rockets or rice burners) are imports; Honda Civics, Accords, Integras, CRXs, RSXs, Del Sols Mitsubishi Eclipses, Lancers, Subaru Imprezas, however there are some domestics such as Chevrolet Caviliers, Dodge Neons, Ford Focus; small, slow, economy cars designed specifically to go slow. Please note that some 3000gt's Supras, Skylines, WRX's and other higher performance imports are designed to go fast, and are therefore not always considered rice, but it really depends on the severity of the case.

    (courtesy urban dictionary)

  5. #5


    The results in HP order:
    1.Flowtech Warlock (open) 374.2 hp/ 333.1 tq
    2.Bassani Real Street 373.7 hp/ 333.8 tq
    3.Hooker Maxflow 373.5 hp/ 333 tq
    4.Borla XS 373.3 hp/ 332.6 tq
    5.Magnaflow 372.8 hp/ 332.5 tq
    6.MAC 372.3 hp / 331.5 tq
    7.Flowtech Afterburner 372.3 hp/ 330.1 tq
    8.Hooker Aerochamber 372.1 hp/ 330.4 tq
    9.Bassani 372 hp/ 333.5 tq
    10.Spintech 371.6 hp/ 332.2 tq
    11.Edelbrock Performer RPM 370.9 hp / 331.3 tq
    12.Borla XR1 370 hp/ 334 tq
    13.Flowtech Terminator 369.5 hp / 331.3 tq
    14.Dynomax Ultra Flo 369.4 hp/ 333.2 tq
    15.Flowmaster 369.4 hp / 331.8 tq
    16.Flowtech Warlock 366.3 hp / 325.3 tq
    17.No muffs 365.2 hp / 330.1 tq

    Sound Off in Quietest to Loudest (Decibels):

    1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT.
    2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT.
    3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT.
    4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT.
    5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT.
    6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT.
    7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT.
    8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT.
    9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT.
    10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db).
    11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT.
    12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT.
    13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT.
    14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT.
    15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT.
    16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).

    And I have listed here a muffler shootout test done by CAR CRAFT, they show the best bang for the buck, and show the db's

    The Mufflers
    SUMMIT Turbo 630125 $14.75
    THRUSH Magnum Glasspack 24214 $16.50
    THRUSH Boss Turbo 17718 $23.95
    HOOKER Competition 21006 $25.95
    DYNOMAX Super Turbo 17733 $28.50
    DYNOMAX Race Magnum 24215 $31.95
    HOOKER Super Competition 21106 $35.95
    SUMMIT Fully Welded 630325 $38.69
    FLOWTECH Afterburner 50322 $39.95


    MUFFLER Flow at 28-in H20
    DynoMax Race Magnum 528.64 cfm
    Thrush Magnum Glasspack 507.40 cfm
    Summit Fully Welded 343.38 cfm
    Flowtech Afterburner 342.20 cfm
    DynoMax Super Turbo 333.94 cfm
    Hooker Competition 232.46 cfm
    Hooker Super Competition 320.96 cfm
    Summit Turbo 331.16 cfm
    Thrush Boss Turbo 297.36 cfm

    MUFFLER Idle dB WOT dB
    DynoMax Super Turbo 89 123
    DynoMax Race Magnum 94 133
    Flowtech Afterburner 92 124
    Hooker Competion 92 122
    Hooker Super Competion 90 125
    Summit Turbo 89 124
    Summit Fully Welded 92 125
    Thrush Boss Turbo 90 123
    Thrush Magnum Glasspack 92 128

    All mufflers were dyno-tested on a 355-cube SBC with 10.0:1 compression, Air Flow Research 190 aluminum heads, a CompCams 292 hyd. a Victor Jr. intake, a Holley 750-cfm double-pumper, and 1 5/8 Headman headers.

    MUFFLER HP TORQUE 2,500-6,000rpm Average
    Hooker Competition 397.4 381.1 286.8hp/351.9 lb-ft
    Thrush Boss Turbo 407.1 384.9 292.1 hp/357.5 lb-ft
    DynoMax Race Magnum 409.5 394.3 298.8 hp/366.9 lb-ft
    Flowtech Afterburner 409.7 391.2 294.8 hp/361.7 lb-ft
    Thrush Glasspack 409.5 389.8 297.7 hp/365.3 lb-ft
    Summit Turbo 411.5 386.3 291.5 hp/357.4 lb-ft
    DynoMax Super Turbo 412.7 387.2 292.6 hp/358.6 lb-ft
    Hooker Super Comp 413.8 387.2 292.8 hp/359.0 lb-ft
    Summit Fully Welded 415.4 390.7 295.6 hp/362.4 lb-ft

    i have another test here on my computer but i don't know how to upload it onto this site because it is in a adobe pdf file.

    more numbers for ya'll who like numbers.

    All tests via an independent lab
    All tests @ 15 wc

    2 Straight Pipe 283 CFM
    2 Straight Pipe 365 CFM
    2 Straight Pipe 521 CFM

    2 Typical Bent tailpipe 268 CFM
    2 Typical Bent Tailpipe 417 CFM

    2 Inlet/Outlet_ Glass Pack Tips- No Louvers- Smooth 274 CFM
    2 Inlet/Outlet- Glass Pack Tips-Louvered 133 CFM
    Same as above set for reverse flow 141 CFM
    2 Cherry Bomb 239 CFM
    2 Cherry Bomb 294 CFM

    2 Inlet/Outlet Dynomax Super Turbo 278 CFM
    2 Inlet/Outlet Ultraflow Bullet 512 CFM
    2 Inlet/Outlet Gibson Superflow 267 CFM
    2 Inlet/Outlet Flowmaster ( 2 Chamber) 249 CFM
    2 Inlet Outlet Flowmaster ( 3 Chamber) 229 CFM
    2 Inlet/Outlet Thrush CVX 260 CFM
    2 Inlet/Outlet Maremount Cherry Bomb 298 CFM
    2 Inlet/Outlet Hooker Aero Chamber 324 CFM
    2 Inlet/Outlet Hooker Max Flow 521 CFM
    2 Inlet/Outlet Borla Turbo 373 CFM
    2 1/2" Inlet/Outlet Magnaflow 284 CFM

    Standard OEM 2 Inlet/Outlet 138-152 CFM
    Standard OEM 2 Inlet/Outlet 161-197 CFM


    1. Always use a crossover of one kind or another. Our tests indicate that the X type gives additional improvements over the H type.

    2. Mount the mufflers as far to the rear of the chassis as possible. An important characteristic of the exhaust system (behind the headers) is its ability to dissipate heat energy. Heat loss brings with it, gas volume reduction, enabling smaller mufflers and pipes to be used without penalty.

    3. Always us the largest case muffler that you can fit under the chassis possible. The larger internal volume allows additional acoustical energy to be absorbed ,dissipated and eliminated.

    4. Unless an engine is in the 500+ horsepower level or run at very high RPM, the maximum tailpipe size required for minimal power loss is probably 2.5" diameter. When the exhaust pipes and mufflers drop the temperature significantly, the volume of the exhaust gas is reduced and tailpipe sizes is not as critical.

    5. When you must adapt various pipe sizes, always use long tapered cone reducers, such as, those available from Flowmaster. You can also use a crossover that has reduced pipe sizes built into it."

  6. #6


    Wow, great post!
    2005 Chevrolet Silverado 4.3L V6
    -Dual exhaust
    -K&N Cold Air Intake
    -8000K HID Headlights

  7. #7


    well hopefully it helps there are some decent mufflers out there with good tone and its much better than running straight pipes for low end grunt and fuel mileage..

  8. #8
    Sr. Mechanic raisor87's Avatar
    Join Date
    Jul 2008
    the nasti nati
    Blog Entries


    I have to second nightraven you will hate life if you remove the mufflers completely
    1998 GMC Sierra SLE- Bone stock engine, 4'' in dash dvd 2 10" subs 800watt amp.

    1999 Buick Park avesdf

    1971 Buick Electra 225 built 455 and turbo 400

  9. #9
    Jr. Mechanic catbert's Avatar
    Join Date
    Sep 2008
    Tobacco Road, NC


    GM motors run best with a little back pressure when stock, or nearly stock. Switch mufflers for a better sound, but running without one isn't the answer to anything but hearing loss and harmonic headaches.

  10. #10


    Lol thx Guys, i did try the no muffler just to hear it, it was a beast, and pissed off the neighbors, IT WAS SUPER FUNNY!!!!!!!

    1995 Chevy Silverado
    Fully loaded!!!
    4Wheel Drive
    5.7 Liter
    Best Engine In The World!!!!!
    Once i had a nearly dead battery and was only able to get 1 slow crank per attempt, Once to the fifth crank she fired up! (True Story)
    Do you have a Tahoe,Yukon or a suburban? Join My Group

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