Catalytic converter delete

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    • SlingRider wrote:

      @Trooper you need the header. Stock is very restrictive
      That's interesting, I thought I read some posts from @Dave@DDMWorks talking about the stock exhaust manifold not being very restrictive, from way back in their ECOTECH DAYS prior to the Slingshot . Did I get that right Dave or are we now of the opinion stock is restrictive enough to warrant a header when staying normally aspirated with just a tune and a cat delete ?
    • kev wrote:

      SlingRider wrote:

      @Trooper you need the header. Stock is very restrictive
      That's interesting, I thought I read some posts from @Dave@DDMWorks talking about the stock exhaust manifold not being very restrictive, from way back in their ECOTECH DAYS prior to the Slingshot . Did I get that right Dave or are we now of the opinion stock is restrictive enough to warrant a header when staying normally aspirated with just a tune and a cat delete ?
      The stock exhaust manifold is not that restrictive and actually works pretty decent. After Maggie Valley this year, Bob came back here and we were on the dyno for a couple days solid, testing all kinds of combinations of header, intake, exhaust and tune and by far the 2 things that consistently gained significant power were - Tune and exhaust without the catalytic converter. All the intakes we tested (Stock, SLR, DDMWorks, HAHN and Alpha) had very minimal gains and the same with the headers. If you have a naturally aspirated Slingshot and just want power gains, install any exhaust without the catalytic converter and get a tune, the rest is just going to be for appearance. We only recommend the header when going to the 300hp setups on our supercharger kit to help keep the exhaust flowing out of the engine a little better at that point, but the stock manifold is not needed on our base supercharger kits.

      Hope that helps,
      Dave
    • Dave, thank you for that answer. I appreciate how many people are willing to help on this forum.
      I especially enjoyed your explanation on the performance differences of a belt driven supercharger vs a turbocharged engine.
      I will be modifying my sling slowly, and doing my best to keep it reliable, and fun! :P
    • Dave@DDMWorks wrote:

      kev wrote:

      SlingRider wrote:

      @Trooper you need the header. Stock is very restrictive
      That's interesting, I thought I read some posts from @Dave@DDMWorks talking about the stock exhaust manifold not being very restrictive, from way back in their ECOTECH DAYS prior to the Slingshot . Did I get that right Dave or are we now of the opinion stock is restrictive enough to warrant a header when staying normally aspirated with just a tune and a cat delete ?
      The stock exhaust manifold is not that restrictive and actually works pretty decent. After Maggie Valley this year, Bob came back here and we were on the dyno for a couple days solid, testing all kinds of combinations of header, intake, exhaust and tune and by far the 2 things that consistently gained significant power were - Tune and exhaust without the catalytic converter. All the intakes we tested (Stock, SLR, DDMWorks, HAHN and Alpha) had very minimal gains and the same with the headers. If you have a naturally aspirated Slingshot and just want power gains, install any exhaust without the catalytic converter and get a tune, the rest is just going to be for appearance. We only recommend the header when going to the 300hp setups on our supercharger kit to help keep the exhaust flowing out of the engine a little better at that point, but the stock manifold is not needed on our base supercharger kits.
      Hope that helps,
      Dave
      thank you Sir for your honesty and much respected professional advice, always appreciated !
    • I'm going from an exhaust back to the factory muffler with a cat delete pipe.
      Trying to quiet it back down and keep the heat down.
      Already have a manifold shield and got a factory muffler heat shield.
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    • 0DDJ0B wrote:

      I'm going from an exhaust back to the factory muffler with a cat delete pipe.
      Trying to quiet it back down and keep the heat down.
      Already have a manifold shield and got a factory muffler heat shield.
      Yep, that will quiet it down and bring it back to a more mellow tone....

      But, a pot belly stove glowing red in the windstream before you is not gonna be cooler...

      Just my 2 cents...
      And now I am mod money short.
      Let me stop everything and Work on Your Problem!
    • MiM wrote:

      What are you doing with the 1320? :whistling:
      If my new setup works as planned, I'll probably sell it.

      airoutlaw wrote:

      0DDJ0B wrote:

      I'm going from an exhaust back to the factory muffler with a cat delete pipe.
      Trying to quiet it back down and keep the heat down.
      Already have a manifold shield and got a factory muffler heat shield.
      Yep, that will quiet it down and bring it back to a more mellow tone....
      But, a pot belly stove glowing red in the windstream before you is not gonna be cooler...

      Just my 2 cents...
      And now I am mod money short.
      I'm hoping that by removing the cat a lot of the heat will be lessened.
      Adding the heat shields should help like the newer models have.
    • 0DDJ0B wrote:

      I'm going from an exhaust back to the factory muffler with a cat delete pipe.
      Trying to quiet it back down and keep the heat down.
      Already have a manifold shield and got a factory muffler heat shield.
      Besides having the best sounding exhaust out there. IMHO I never had the problem with the heat after I got rid of the Cat.
    • 0DDJ0B wrote:

      MiM wrote:

      What are you doing with the 1320? :whistling:
      If my new setup works as planned, I'll probably sell it.

      airoutlaw wrote:

      0DDJ0B wrote:

      I'm going from an exhaust back to the factory muffler with a cat delete pipe.
      Trying to quiet it back down and keep the heat down.
      Already have a manifold shield and got a factory muffler heat shield.
      Yep, that will quiet it down and bring it back to a more mellow tone....But, a pot belly stove glowing red in the windstream before you is not gonna be cooler...

      Just my 2 cents...
      And now I am mod money short.
      I'm hoping that by removing the cat a lot of the heat will be lessened.Adding the heat shields should help like the newer models have.
      the reason the stock muffler heats up is because it also has a second CAT inside. This adds additional heat.
      The only way to bypass this 2nd Ca
      CAT is to cut open the muffler, drill bypass holes then weld it all make together. I have both the delete pipe and a modified stock muffler and the 1320 header. I'm happy enough to not need anything else.
    • Ruptured Duck wrote:

      The only way to bypass this 2nd Ca
      CAT is to cut open the muffler, drill bypass holes then weld it all make together. I have both the delete pipe and a modified stock muffler and the 1320 header. I'm happy enough to not need anything else.
      Well I'm out of luck there. I don't have the tools or want to spend the money on that.
      I'll just have to put it on there and hope it works.
    • Goats_Hogs wrote:

      M82mike wrote:

      Is removing the catalytic converter worth doing for a non turbo power increase? I'm going with a cai and welter exhaust.
      I just noticed you are from Milton, In. I'm just up the road from you in Lynn. We stop in Cambridge City quite often to eat at Number 9 Grill or Cole's. We pass thru Milton really often when the weather is nice, as the roads start getting fun not far south of you. We'll have to hook up went the weather breaks....
      I’m over on that side of the state quite often. We own a place down @ Brookville, but I worked at the Ford Plant in Connersville until it closed. I grew up by Muncie a little town called Cowan. It would be awesome to meet up with you guys sometime.

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