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Exhaust

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by blazer72, Jul 24, 2000.

  1. blazer72

    blazer72 1/2 ton status

    Joined:
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    When I bought my blazer 6 or 7 years back it had duel exhaust, cheap old headers (so old that they had 4 bolt flanges!) 2 inch pipes and glass packs IT WAS VERY VERY LOUD!!!!! In the first week I changed the glass packs out for so walker turbo’s, Still very loud but better and now I could hear the headers leaking. Changed the old cheap headers for new cheap headers leaking stopped for a few months. Still loud. Changed from and holly carb to holly EFI Now the exhaust liked to glow in places from time to time. I changed the pipes all out to 3 inch on both sides with a cross-over. The pipes stopped getting so hot, the sound went up to a roar. Tork dropped! Bigger is not better!
    I got tired of the header flanges warping and the gasket needing to be replaced ever few months. Plus the header collector is right by the rear shackle on the front springs and the lower spring bushing kept on melting out.
    I changed to JBA Shorty headers that can use the stock exhaust for 87 and up. Better tork and the exhaust pipes are up in the frame were there safe plus the sound dropped back to a nice loud! Stared to look at other’s blazer and I was still tired of my ears ring after a road trip or day spent on trails. Saw that the same years that my headers fit used a y-pipe that had 2 and ¼ in to a 3 inch. Depending which years (87 to 91, or 92 and up) I could pike which side I wanted the 3-inch primary pipe to go down! I used the 87 to 91, which runs it down the left side, which is the open side!
    The Y-pipe almost bolted up, would have if had the heat valve! I used the next section after the y which put the 3-inch dead center of the frame and the side of the trany and transfer cases.
    For now the system flows on out the old left side muffler (flowmaster 50 series) and left side tale pipe. Did I get a loss of power not that I can tell! My engine modeling programs say yes above 3500 RPM. But they also say that tork peak has dropped 5 LBS. But were it peaks has also dropped down 300 rpm!
    It still sounds the same just not as loud!!!!
    This fall I plan on flipping the rear shackles which means the old tail pipe and the flowmaster will have to come out, at that time I plan on going to the stock GM diesel muffler with to 2 and ½ outlets or 1 4 inch outlets.

    More usable tork range, same over all power, Less heat loss under the truck so less heat coming in to the truck (bed floor is cool to the touch on a 85 degree day. PLUS MY EARS DON’T RING AFTER DRIVING IT ALL DAY!!!!!!!!!!!!!


    I understand the jeep thing I drive a BLAZER!!

    Ken
     
  2. K5 NUTT

    K5 NUTT 1/2 ton status

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    Location:
    Grand Junction Colorado
    Howdy Ken..this is Doug...the weirdo who brought 2 K5's to the run...lol. BTW...thanx for the ride up the trail that last day :). If i remember right you also had that white header wrap to reduce engine heat on your headers...which correct me if i am wrong were JBA's....leanin in there direction for the 79 as the stock y pipe will bolt right up or so they say. I figure no matter what you do headers will provide hours of entertainment no matter what brand is used ... but the Chalet really hummed up those hills without droppin gears like the 79 so i'm all for tinkerin....goin to be adding a MSD offroad box here shortly as the quest for mileage is still fresh on the brain after the trip...lol. Took just under $600 to power the 2 there and back...never again. Have even gone as far as thinkin this way Ken....85 CUCV....3.08's (stock) EPA estimate 23 in town 31 Highway....to a built 700R4....to doubler to locker filled rearends...however the wife to be squashed that idea in 5 minutes so i'm cleared to FI as soon as i can afford it and find a system out there that will fir the bill for the 79! Chat with ya later!

    AZBLAZER

    1979 K5
    1976 K5 Chalet
    1972 K10 Suburban
     
  3. blazer72

    blazer72 1/2 ton status

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    Yep the headers are JBA's there for the 92 to curent Blazers, which means they dont have air tubes but do have a place for the O2 senser! pluss the A/C fit on with no problems. I put them on with the new copper gaskets that every body is selling now and other than running the bolts ever other month or so I leave them a lone. I used the 88 to 91 y-pipe that way it goes down the left side leaving room on the right for drive shafts shift's for the t-dubler! plus less heat and the rap is no longer needed!
    Lets talk about the FI befor you get one.

    I understand the jeep thing I drive a BLAZER!!

    Ken
     

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