Exhaust maintenance (Y) and back pressure effect

Discussion in 'V8 Discussion' started by GEN 3 SHO FAN, Aug 1, 2018.

  1. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    Hi,

    Now 22 years old, my SHO needs a new Y pipe.

    If you have replaced your Y and purchase an aftermarket part, fell free to put your comment here.

    My concerns :
    1) These part don't have the shape when we observe them. I'm wondering is the back pressure will change (some have less curve than original). Ron Porter reports recently that less back pressure can affect medium range torque...
    2) One of my fears is the aftermarket part is cheaper with thiner metal and broke sooner.
    3) Another is some said the cats on them can throw a emission code sometime (49 states Y on a CA emissions car ? Computers seems to see this.)

    I will put more infos and photos here in the next days.

    V8 SHO Y (Motorcraft)

    V8 SHO Y (Magnaflow)
    Y magnaflow 23533.jpeg
    V8 SHO Y (Bosal)
    Y Bosal.jpeg
    V8 SHO Y (Eastern catalytic, not the exact model shown)
    SHO Y Eastern catalytic.jpeg
    V8 SHO Y (Davico)
    Y Davico.jpeg
    V8 SHO Y (Walker)
    Y walker.jpeg

    V8 SHO Y (Unknown canadian brand)
    Y Unknown brand.jpeg

    Thanks for your help,
     

    Attached Files:

    Last edited: Aug 9, 2018
    98SF19 likes this.
  2. 99sho-time

    99sho-time SHO Member

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    In my experience if you put in Federal standard cats you may have a hard time with upstream sai system like I'm having. If you do go with Federal cats don't get a walker. I wouldnt worry to much about back pressure just leave the third cat. All the cars were made with CA standards. So they correct cat is a ton of money. I've also heard that all aftermarket cats even if they are CA cats may still get you a code
     
  3. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    For the 3rd cat, with time it can be a problem. Mine was broken in many parts inside and was blocking around 85% of the flow. When you say leave the 3rd cat, you saying replace it but don't delete it, right ? (I read your posts often.)

    I know in creating this post, I will have to speak about back pressure sooner or later. You felt a difference in the torque with and without the 3rd cat ? The feeling can be affected by others factors like change in ambiant temp and weight in the car for exemple.

    The best thing to understand this possible torque loss will be dyno sheets. I remembered seeing some and never saw a loss in torque (at any low or medium point) with change on exhaust... but I'm not a mechanic. I will have to check these sheets on V8SHO, Gen 1 and 2 owners can help too maybe.
     
    Last edited: Aug 1, 2018
  4. stephen newberg

    stephen newberg Moderator Staff Member

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    When my Y pipe went I put on a Magnaflow replacement along with their 99000 series cats. All fit perfectly and has worked just fine ever since.

    pax, smn
     
  5. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    I'm also wandering if rippled areas on curved parts of Y can have negative effect like in the intake (Bosal and Eastern catalytic). The more is porterized, better it is, logicaly.

    Some Y have a flow entering the cats with an angle like 45 degree which cannot be optimal for a good flow (Motorcraft, Davico, Magnaflow). Any though on that ?

    Some Y eliminate some curves from the original part (Bosal, Eastern catalytic and Walker).

    Davico seems to respect the exact same shape of Motorcraft.

    Speaking only about the shape, Walker seems the best (no rippled areas and no curve in flow entering cats). Cats quality is another aspect too.

    Is bigger cats will result in a less restricted flow ?
     
    Last edited: Aug 1, 2018
  6. 99sho-time

    99sho-time SHO Member

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    the walkers look like garbage compared to oem imo
     
  7. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    Why Walker is garbage, for is material or the cats aren't good ?

    Ok, I think I understand. I just re-read your first post. You're wrong on one thing : All Gen 3 SHO weren't made for CA emissions. We can see the code directly on your ECM. I don't made researches for all four years but 1996 SHO have differents codes on them. For exemple in this year, if they are made for 49 states/Canada, they have "JJK2" and for CA/NY states is "KKX2". Saddly, codes had changed all over the four years.
    https://shoforum.com/index.php?thre...s-a-study-and-an-history.131439/#post-1444309

    Another trick to know if your car is a CA emissions (without unbolting something) is to check on Ford Etis database.

    SHO source on their page for V8 SHO exhaust is selling 2 versions including one for CA and NY, it's Magnaflow IIRC.

    99sho-time, you're in NY IIRC, right ?
     
    Last edited: Aug 1, 2018
  8. 99sho-time

    99sho-time SHO Member

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    yes new york. my walker y-pipe looks like its put together sloppy and seems to be rusting worse in a year than my old y-pipe
     
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  9. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    Ok thanks for the info.
     
  10. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    After some searches, I found a good price for two of them (including the heavy shipping fee because I'm far enough...)

    Magnaflow seems of good quality but I don't know Bosal... They made quality or scrap ? They offert the cheapest part on rockauto.

    Found this interesting link. The old Bosal beside the Magnaflow only had 3 years in VA climate...
    https://forum.ih8mud.com/threads/bosal-vs-magnaflow-you-decide.808315/

    Any though will be welcome, thanks,
     
    Last edited: Aug 9, 2018
  11. 98SF19

    98SF19 AlphaKennyBuddy

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    I'm interested in user feedback as well since my whole exhaust system is original and therefore very much in need of replacement. I'm sure clogged cats are contributing to issues I've been having.
     
  12. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    Mine has developped a third hole on it. Always around cats because of the mesh that was put there from factory, it keep humididy on the hot steel...

    Bosal is interesting because it has less curves on the lines probably give better flow overall. But I finally ended with a Magnaflow, steel quality seems better according to that link above.

    But Magnaflow cats are a way smaller than on factory lines. I'm wondering how much time they will work correctly...

    Bosal offerts a warranty of 5 years on the line and 2 for the cats however, it was the same for Magnaflow.

    I found a place that selling Y pipes without shipping, cannot resist. :)

    My other motivation was time, with the Trump protectionist politics, prices of many good from US are going up here in Canada... (and some are going down when we sell, like my SLO going to scrap for the metal). :(
     
    Last edited: Aug 10, 2018
  13. luigisho

    luigisho SHO Member

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    Exhaust parts are usually get what you pay for in my experience. If the magnaflow steel holds up you can always cut and splice other converters in if they fail. Affordable aftermarket cats are usually anywhere from meh to horrible quality.
     
  14. stephen newberg

    stephen newberg Moderator Staff Member

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    I have had my exhaust system in for 7-8 years or so now and zero problems, no real rust.

    pax, smn
     
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  15. GEN 3 SHO FAN

    GEN 3 SHO FAN SHO Member

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    Thanks for your advice. I think I will also put a ceramic coat on it to protect my investment... (some guys do this when they work on that).
     
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