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Flowmasters

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by skyblazer, Dec 9, 2001.

  1. skyblazer

    skyblazer 1/2 ton status

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    Im heading to the exhaust shop this week to fab up some duals for my 72 k5. Im running a 383 with Thorley tri-Y headers. My question is, what are the best series mufflers to run? The 40 series may be too loud based on the info at Flowmasters web sight. Im leaning toward the 40 Delta flows and the 50 series mufflers.
     
  2. Ryan B.

    Ryan B. 3/4 ton status GMOTM Winner

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    All I could tell you is with those 40 series 2 chambers they sound mean and loud! That sounds like it may not be what you are after.
    I have the three chamber flowmasters I think the 50 series and 2 1/4" pipe, with tailpipes out behind the rear wheels. I really like the sound of the 3 chambers. sounds good but not really loud at idle, and when you stomp on it it gets pretty loud. If you don't have carpet in the back of your truck the 50 series should be almost too much for you with the hard top on. Those 40 series seem like you'd have a headache or ear ring after driving for a couple of hours.
    my 2 cents
     
  3. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    I agree with Ryan.....unless you are really "hard core"....the 40-series are miserable! They have a mean sound, but it really gets tiring on a long trip.....and with the top ON it's even worse.

    I just paid to have my 40-series swapped OUT, and to have the 70-series installed. Much better noise level....and more tolerable on longer trips. I've got a pretty lumpy cam, so it's still loud.....but a more "polite" loudness and not so "barky" if that makes sense....[​IMG]



    -Greg72

    '72 K5 Blazer - 427BB/TH350/NP205/6" Lift/35x12.50's
    <font color=blue>See it here: </font color=blue><a target="_blank" href=http://coloradok5.com/gallery/albun38>http://coloradok5.com/gallery/albun38</a>
     
  4. Steve_Chin

    Steve_Chin 1/2 ton status

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    The Delta Flows aren't really a lot quieter than the regular series, but the sound is a lot more mellow in quality (which makes the sound more civilized and less likely to get you in trouble). If you haven't gotten mufflers yet, I might suggest the Dynomax Welded Ultra-Flo mufflers as a point of consideration as well. They are a little quieter at idle than the Flowmaster 50-series Deltas, but flow a bit more in raw gas terms. If you want to obtain a CD that compares a LOT of different mufflers to each other using the exact same test engine and exhaust system setup, check out the "Silent Power" CD that was put together by Tom Hand. It is available at <a target="_blank" href=http://"http://www.classicalpontiac.com">Classical Pontiac</a>.
     
  5. DesertDueler

    DesertDueler 1/2 ton status

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    Put a set of magnaflows on. You will be happy. They sound just like borlas (Same exact design) but half the cost, sometimes you can find them cheaper than flowmasters.

    86Jimmy 4"&35"MTRs,87 burb 4"&33"MT,69Firebird w/525 hp,and 70GTO live in PHX,AZ<a target="_blank" href=http://www.geocities.com/modifierperformance>My vehicles</a>
     
  6. Burt4x4

    Burt4x4 3/4 ton status

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    I am running 2chamber 40sieres Flowmasters w/Hedmens.
    My rig sets off car alarms and I can compete with most Harleys on rapping noises[​IMG]!!
    They are alot of fun especially with a 4spd. They are loud but sound is beasty and deep. I do like them alot and have had them for hmmmmm 6 or 7 yrs now and my whole exahaust system needs to be replaced (leaks and dents and coathangers) someday. When I replace my stuff I will go with a 3chamber 50sires. The 2chambers are fun but you sure can't be quite at 4am firein up to go hunting,fishing whatever.....

    72K5[​IMG]Led Zeppelin[​IMG]Rock ON![​IMG]
    <a target="_blank" href=http://coloradok5.com/gallery/Burt4x4>http://coloradok5.com/gallery/Burt4x4</a>
     
  7. skyblazer

    skyblazer 1/2 ton status

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    Thanks guys, I think Ill try to hear some dyno max mufflers, but it sounds like the 70 series flowmasters might be the hot ticket. I checked on price in Jeg's, and of course they are $99 compared to $59 for the 40 series!! At least I'm consistent. Every step of this resto costs twice as much as planned and takes twice as long. I plan to get twice the pleasure driving this beast when it is finished!!!!!
     
  8. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    SkyBlazer,

    The other thing to note on the 70-series (if you haven't already noticed) is that they are almost TWICE as long as a 40-Series muffler!!! The guy at the muffler shop was really scratching his head as he looked at my K5 and was trying to figure out how to get them in there, and plumb the exhaust pipes to not hit everything......

    It can be done.....just make sure the muffler shop guy is patient. It will take more effort than a "normal" installation.



    -Greg72

    '72 K5 Blazer - 427BB/TH350/NP205/6" Lift/35x12.50's
    <font color=blue>See it here: </font color=blue><a target="_blank" href=http://coloradok5.com/gallery/albun38>http://coloradok5.com/gallery/albun38</a>
     
  9. ShinnyHelmet

    ShinnyHelmet Registered Member

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    Last month I had a shop install dual 2 1/4" pipes w/ a H-pipe w/ Flowmaster 50 series mufflers, comming out to the side behind each tire w/ chrome pencil tips. At this time I dont have carpet...and when I got them I was worried that it would be too loud, however....it sounds pretty quiet inside and has a nice low throaty sound outside.They did a great job and it sounds awsome.
     
  10. skyblazer

    skyblazer 1/2 ton status

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    Thanks again, I didn't realize the size of the 70 series. Did you use the center outlet or the ofset? One more question, where did you run the balance pipe?
     
  11. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    The exact model I used was the #52571. That has an offset inlet (2.5") and a centered outlet (also 2.5")

    I think that the offsets were positioned closer to the framerails, and the balance tube (H-pipe) is after the transfer case....not much room under there to put it anywhere else!!!! [​IMG]



    -Greg72

    '72 K5 Blazer - 427BB/TH350/NP205/6" Lift/35x12.50's
    <font color=blue>See it here: </font color=blue><a target="_blank" href=http://coloradok5.com/gallery/albun38>http://coloradok5.com/gallery/albun38</a>
     
  12. Crushergmc

    Crushergmc 1/2 ton status

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    Desert Dualler, Which magnaflow did you use? I don't like the sound of the Flowmasters at all, sounds like a 5.0 and too much pinging like a tin can. But to each his own. As long as you like it, do it.



    "KEEP IT DOWN"
    70 Jimmy, 454, 2wd
    56 GMC, Big Window
     
  13. Ryan B.

    Ryan B. 3/4 ton status GMOTM Winner

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    Where did you run the balance pipe?
    Here is a picture of where mine is located:
    <a target="_blank" href=http://communities.msn.com/Ryans1972Blazer/picsofryansblazer.msnw?action=ShowPhoto&amp;PhotoID=247>http://communities.msn.com/Ryans1972Blazer/picsofryansblazer.msnw?action=ShowPhoto&amp;PhotoID=247</a>

    [REAL MEN DON"T CARE ABOUT GAS MILEAGE!]
    Ryan B.
     
  14. Burt4x4

    Burt4x4 3/4 ton status

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    Hey guys tell me agin why you are using the balance pipe or H-pipe. Does it make that much difference or better yet what is the differnece or gain??

    72K5[​IMG]Led Zeppelin[​IMG]Rock ON![​IMG]
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  15. skyblazer

    skyblazer 1/2 ton status

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    Sweet pic Ryan! Im bringing it in with me to the exhaust shop. Burt, my understanding of the balance pipe is that it increases exhaust scavenging between cylinder banks and therefore increases torque. The chevy firing order doesn't have equal spacing between cylinder banks (1,8,4,3,6,5,7,2). For example, the 270 degrees between 1 and 3 results in this reduced exhaust scavenge effect on the left cyl bank. The balance pipe theoretically creates a balanced low pressure to increase exhaust velocity. Did I just write all that? Where did I leave my pocket protector and slide rule?
     
  16. Burt4x4

    Burt4x4 3/4 ton status

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    ahhh OK, the part I like is increased torque!!
    hmmmm, might have to add that to my next exahust system....!!

    72K5[​IMG]Led Zeppelin[​IMG]Rock ON![​IMG]
    <a target="_blank" href=http://coloradok5.com/gallery/Burt4x4>http://coloradok5.com/gallery/Burt4x4</a>
     
  17. k5blazerus

    k5blazerus 1/2 ton status

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    well I run headmans and 2 chamber 40 mufflers on my blazer and right after the mufflers I have trun downs and let me tell you when I it 6200 rpms in the mudd I cant explain how much noise is there.
    colin

    Save the whales Harpoon a fat chick.
     
  18. Ryan B.

    Ryan B. 3/4 ton status GMOTM Winner

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    Wow man. Good explination on the balance pipe.
    On top of what skyblazer said,
    The balance pipe makes the exhaust noise a little quieter and not as raspy or crackly i guess.
    my 1.5 cents

    [REAL MEN DON"T CARE ABOUT GAS MILEAGE!]
    Ryan B.
     
  19. Steve_Chin

    Steve_Chin 1/2 ton status

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    Actually, the real purpose of the crossover (whether it's an X or H configuration) is to share reversion signals from one side of the exhaust system to the other. It will change the tone and quality of the sound of the system slightly (an X type will change it pretty radically). The crossover will help with torque in an RPM band that is sympathetic to the downstream placement of the crossover, and how much it helps is a function of crossover length and cross-sectional area (and partially to its interface into the two main pipes). The ideal placement of the crossover should be a distance that would reinforce the third order harmonic of the RPM in question.

    For those asking about the sounds of mufflers, I can't say how much the Silent Power CD is worth there. You get to hear many different Flowmasters, Dynomaxes, Allied, Walter, etc. mufflers with and without crossovers.
     
  20. Burt4x4

    Burt4x4 3/4 ton status

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    English[​IMG]??
    How about a preshcool edition?[​IMG]
    So is a xover pipe gonna give any REAL torque gaines? or just one or two points? I always thought it was lame to see the stock Hpipe hanging down to clear the front driveshaft on newer K5s. Never did know why GM did that.....

    72K5[​IMG]Led Zeppelin[​IMG]Rock ON![​IMG]
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