Exhaust routing at crossmembers?

Discussion in '1976-1983 Pickup Discussion' started by Perkolator, Oct 19, 2020.

  1. Perkolator

    Perkolator Toyotaholic

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    Do any of you have pics of how your exhaust pipe is routed under your truck? Specifically in regards to the crossmembers.

    I've been meaning to tinker with my exhaust for a while - want to change the muffler and need to add clearance over the rear axle so I can lower the truck. Was looking at the rest of the setup and I think I want to redo all after the header so it's more tucked up and not a belly dragger eyesore. My setup: Hedman header, 2.25" pipe, chambered muffler.

    This section where it is routed underneath the front trans crossmember is what's really bothering me. Just not sure if there's enough room if I go above it and not roast myself with heat transfer to the cab space. Does your pipe go above this crossmember or below? I don't have a CAT or heat shields from one, perhaps I'd have to add one - would it make that much difference having one?
    https://imgur.com/J0hOVxN
    https://imgur.com/jt8IYX0
    [​IMG]
    [​IMG]

    Goes above the 2nd crossmember to the muffler and generally stays nicely tucked up
    https://imgur.com/J0hOVxN
    https://imgur.com/ZVvmbc1

    Routed too close to the axle to lower the truck, I've already made it contact just loading my truck with stuff
    https://imgur.com/6KdY7sN



    The existing muffler I'm guessing is a chambered style based on the welds I see on the casing. It's just too damn loud and "ricey" sounding, and the drone sucks. Considered adding glasspacks to the system, sorta like a CAT and resonator. Might end up just going with a super turbo muffler. Put Dynomax Super Turbos on my Oldsmobile and they sound pretty great on that car. My 22re truck is significantly quieter than my Hilux - that truck has a fairly free flowing setup with a hi-flow CAT and Magnaflow round muffler, 2" piping after the Y on stock exhaust manifold (where they cut it when stole my CAT). Guessing it's the carburetor/header/no CAT/larger piping combo that's causing it.
    https://imgur.com/E9YFthD

    Also considering going the 'cool' route and doing a side exit exhaust if I could keep it quieter than what I have now. Figure I'd use one of those mufflers with the in/out on the same side and add some mandrel bends
     
    Last edited: Oct 19, 2020
  2. jetas

    jetas Grand Toyotaholic

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    I routed mine over the trans crossmember but i had to flatten the exhaust a little and clearance the floor for the stupidly placed flange i added. Then up an over the second xmember and dumped it towards the driver side before the back tire. Only part that hung low was the turndown. 2.25" tube and a turbo muffler is what i had
     
  3. Pearce

    Pearce Toyotaholic

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    You can pretty much run a straight tube to the front of the axle. I just had to do 2 pie cuts. Used a flange between the cross supports. The muffler is hanging low because I don't have hangers on it yet but it will go up 4 to 6 inches. Before I added the cutout that added an exhaust leak it was really quiet. Heard induction noise mostly. I would only hear the exhaust if I was beside a building or a car to echo off of. 1603132334705_6438425699_3b56b037.jpg 1603132334673_3530492335_3b56b037.jpg
     
  4. Perkolator

    Perkolator Toyotaholic

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    Dang, underside of your truck is MUCH cleaner than mine, lol. I like to think of the oil under mine as rust proofing, lol.

    Yes, essentially a straight pipe is what I'm going for. I'm assuming you went above the 1st crossmember? Got a pic of how tight it is in there for you? How's the heat transfer?
     
  5. Perkolator

    Perkolator Toyotaholic

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    That's what I was thinking I'd have to do - flatten it/dent it to keep away from the cab. How's the heat?
     
  6. Pearce

    Pearce Toyotaholic

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    It can get the cab kind of warm but not to bad for me being in Washington. As you can see I could of dropped it lower. Thats 2" pipe. 1603138366546_1412780540_3b56b037.jpg
     
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  7. Perkolator

    Perkolator Toyotaholic

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    Hmm, maybe the crossmember on the 75+ trucks are different? Yours looks like it has a ton of space; mine also doesn't look as flat as yours https://imgur.com/jt8IYX0 I'm going to try and measure how much space there is later tonight - visually it looks like a soup can (3.25" diameter?) would be touching
     
  8. Pearce

    Pearce Toyotaholic

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    Oh yeah definitely different. 1603139214432_2898824755_3b56b037.jpg
     
  9. Perkolator

    Perkolator Toyotaholic

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    Well dang. Hopefully someone with a 75+ chimes in with their clever routing

    BTW - how the heck are you easily posting pics here? I couldn't figure it out, but I'm also not great with computers
     
  10. Pearce

    Pearce Toyotaholic

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    I mostly do it on my phone and resize the pictures with a messenger app by sending them to myself and saving them. I always make the images appear in the post by clicking full image because of problems loading pictures on this site through the photo albums.
     
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  11. Pearce

    Pearce Toyotaholic

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  12. Perkolator

    Perkolator Toyotaholic

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    Ah thanks - I think the image sizing is my issue - which is why I used imgur....but I always thought those would show up as pics like photobucket used to do, not just a link. Oh well. "Get off my lawn" lol.
     
  13. jetas

    jetas Grand Toyotaholic

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    Pretty sure the early trucks had a much different xmember than the 75+ trucks
     
  14. Pearce

    Pearce Toyotaholic

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    You might need to do v bands to be able to fit. Those could be pricey for a good set. I'm measuring a 3 hole flange for a 2 inch pipe at 4 inches.
     
  15. jetas

    jetas Grand Toyotaholic

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    Yea those 3 hole flanges take up too much space. The 2 hole ones are nice and wont take up too much more space than the tube itself when positioned right
     
  16. TRUCK ACTION

    TRUCK ACTION Grand Toyotaholic

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    My 88 is bagged & lays frame so all must be up inside the frame Exhaust work - 3.JPG 1.jpg 17.jpg .
    Just recently added the flex piece into the mix to prevent movement at the side body exhaust exits.
     
  17. Perkolator

    Perkolator Toyotaholic

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    Well I got a better look last night. Looks like it's going to be a lot more work than I was wanting to invest at this time. I don't think the space above the crossmember quite enough room like I'd hoped.

    I measured the gap to be less than 2.5" directly above where the exhaust is now, I couldn't get an aluminum can to fit there and that is 2.5" diameter, it's wedged there in the pic. Also there's the brake cable system in the way right there. I could maybe squeeze it in closer to the transmission, but even there it is so tight that my 2.25" pipe would be basically touching everything. I doubt I'd really be able to fit an exhaust flange through that spot either, even a compact v-band style......and to do any of those options I'd have to relocate and modify the parking brake cable system to work elsewhere :confused: I could see it maybe happening if I changed that crossmember and modified the brake cable, but I dunno about that investment right now.

    I think what I'm going to do for now is hug that crossmember as tight as I can, perhaps using a bent piece of pipe so it's only a small section sitting that low. I've got 1.5" gap there currently, so figure I'd go up as close as I can without it rattling from contact.

    Figured out how to add the pics :headbang:
    IMG_9531[1].jpg IMG_9534[1].jpg IMG_9537[1].jpg IMG_9538[1].jpg IMG_9539[1].jpg
     
  18. jetas

    jetas Grand Toyotaholic

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    See that little section above the xmember that bumps down? Take a BFH to it and theres your clearance. You'll barely feel it in the floorboard and eventually you'll forget about it. OR buy some oval pipe and a couple of transition pieces to go back to round before and after it
     
  19. Perkolator

    Perkolator Toyotaholic

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    I see what you're saying. I'm not worried about bashing in the floor a little bit, but it looks like quite a bit to move so I have enough room to not melt my carpet. Guessing I'd have to pull the crossmember to even do it. Also need to brainstorm over moving or modifying that brake lever assembly, I wasn't really thinking about that when I got under the truck.

    Thinking about all this reminds me of how not fun it is to work on vehicles without a garage or even concrete pad.
    This was last weekend's brake caliper replacement on my other truck, fun times
    IMG_9505.jpg
     
  20. David Woods

    David Woods Newbie

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    Perkolator hi. I am having the same sort of obstruction issues with the crossmember in my '75 long-wheelbase. But I think my situation is worse than yours. You see in your photo that there is a slight upward curve in your crossmember from left to right before it drops down some? (it corresponds to where the exhaust pipe is to be routed for clearance).
    My crossmember does not even have that curved/raised bit, it is straight across the bottom. I have had to make custom exhausts such that the pipe has to bend down to clear the crossmember and then back up again to route rearward from there. I don't want bends in the pipes there.

    Why does your truck have the relief in the design and mine doesn't? I suppose it could be because my frame is designed for heavier (camper vehicle) duty. But I wonder if there could possibly be a difference based on what market or EPA/CAFE standards it had to meet i.e., were there CA destined cars that had emission exhaust components (like cats) that needed more clearance.
    In the photo provided by Pearce a few posts from yours there is something very different going on there. The crossmember pictured has either been flipped over from side to side, or it is from another truck. If you look to the far right of that pic you can see the frame rail and a shadow in the spot where the crossmember should occupy. With the crossmember hanging down below the truck there will be zero exhaust issues with a pipe between it and the cab. But structurally it is compromised and not as engineered/built. If it had a box section added to the crossmember the way it is now it might be fine and I might do that to mine since I do not plan on lowering it at all.
    I bought a piece of rectangular heavy gauge steel to section into the crossmember as a "window or tunnel" for my pipe to go through but I'd rather get it done more efficiently than that plan.

    Do you know if your truck was sold in Canada, US CA emissions, or Federal emissions?
    If this has been discussed I apologize but I got here by searching....
    Thanks in advance.
     

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