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Larger CAT and/or Exhaust

Discussion in 'Performance' started by taco_runner, Sep 7, 2020.

  1. Sep 7, 2020 at 6:15 PM
    #1
    taco_runner

    taco_runner [OP] New Member

    Joined:
    Jun 25, 2020
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    First Name:
    Kev
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    4Runner TRD OR Premium
    Just a thought, has anyone ever changed their 4Runner CAT converter and Exhaust to a larger one?

    I know from experience when you change to a smaller one, that power is reduced.. yeah ask me how :D :D :D
     
  2. Oct 1, 2020 at 2:52 PM
    #2
    atgparker

    atgparker Cal Poly, ETME 1988

    Joined:
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    First Name:
    Andrew
    Mission Viejo, CA
    Vehicle:
    1991 White 4Runner 3.0 L
    Rebuilt Engine MLS and ARP on the heads, DT Header, 2-1/2" CARB compliant Flow-Master CAT with 2.0" Bosal CAT back Dayco 1-1/4" Spacers, SkyJacker M-Series Monotube Shocks, Ball Joint Spacers. 95-9006 K&N Air Cleaner, G-Plus Alum Radiator, ZIrgo 16" Fan, Derale Temp switch/relay
    Sure I did this to my 91 3.0L by replacing the CAT with a nice big 2-1/2" Magnaflow CARB compliant replacement followed up with a 2-1/2" Flowmaster FX muffler all connected with 2-1/2" pipe using the Toyota OEM hangers throughout. CAT's in general are restrictive so I run a Flowmaster HP-2 in its place as it helps quiet things down a bunch. The sound is great but I only have seat of the pants hp-gains to report and I'm sure they are swayed more by the sound than my backside getting thrust into the seat when I accelerate. But the 2-1/2" exhaust is a decent increase over the 1-3/4" stuff that is OEM. The cross sectional area is exactly double when going from 1-3/4" to 2-1/2" so the DT long tube headers really breath well with this set up and the poky 3VZ-E has satisfactory performance when pushed from 3,500 to 5,500 RPM. It will hold 70-80 MPH in 5th gear all day long and will do so at 1/4 throttle.
     
    taco_runner[OP] likes this.
  3. Oct 1, 2020 at 6:47 PM
    #3
    aroyalsfan

    aroyalsfan The Owner

    Joined:
    Feb 12, 2019
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    859
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    Male
    Kansas City
    Vehicle:
    2018 4Runner SR5 Premium - Midnight Black Metallic(218) - 4WD
    Westin Pro Traxx 5 Hood and side window deflectors Black exhaust tip Tinted front windows Billet grill overlay Badge Overlays painted Cavalry Blue Powder coated stock Trail Wheels gloss black 12 Volt Solutions plug and play remote start To do list: led swap Speaker upgrades Sound deadening doors Maybe list: rear backup sensors
    20200803_123958.jpg

    19 lbs. Is that a large enough cat?
     
  4. Oct 1, 2020 at 7:47 PM
    #4
    PVT Pablo

    PVT Pablo

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    Paul
    Kitsap County, WA
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    2016 4Runner TRD Pro
    I'm assuming this is for a 5th gen? The stock piping is already 2.5". High flow or cat deletes aren't gonna do anything on a stock engine or stock tune 4.0L
     
    taco_runner[OP] likes this.
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