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What cam for JDM 5.4 with a 4.0

Discussion in 'SVT Shelby GT500' started by RI GT500, Dec 3, 2018.

  1. RI GT500

    RI GT500 Member Established Member

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    RI
    I just bought a JDM aluminum 5.4 and a 4.0 Whipple ,long tubes ,fuel system, etc etc. It has a FB 4R70W. How much cam can i go and still pass emissions , (car is an 07)? At the least I'm going 13-14 GT500 cams. The motor is going together soon so now is the time. Thanks for any advice .
     
  2. Catmonkey

    Catmonkey I Void Warranties! Premium Member Established Member

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    I can tell you there are no cams with an EO number for 5.4. I don't know what your state emissions laws are, so I have no idea what they look for, but found this on the internet after search. What they do is going to be pretty tough with much modifications. I think the 13-14 could be a safe bet, but there is no guaranty, because the 5.8 has 25 more cubic inches to "tame" that cam. I'd be pretty reluctant to go beyond that. Any tuner will tell you that the idle a/f ratios jump around quite a bit with any amount of overlap. The more overlap, the worse it becomes.

    You have to ask yourself what your fall back position is if it doesn't pass. Swapping out cams is not a cheap endeavor, unless you're doing it yourself. I hope you're planning on using cats with your long tubes for the emissions test. I'd look for a some high performance shops in your area and speak with them about what their customers have been able to get away with on the emissions angle.
     
  3. RI GT500

    RI GT500 Member Established Member

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    Thanks for the reply , I'm in RI , we got it thru last few years with out cats ( thanks Pete Performance Dyno ). I was hoping someone has experience with a cam that passed. I would think the 13-14 cams will pass no problem and that will be the safe bet .
     
  4. biminiLX

    biminiLX never stock Premium Member Established Member

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    I would start with talking to JDM and then some local shops around you. Good luck.
    -J
     
  5. JB_2010GT500

    JB_2010GT500 Active Member Established Member

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    I’m in CT and I have a KB 3.6 with Comp XER stage 3 blower cams. Not the most aggressive out there but they’re still a 0.475 lift. Passed emissions with cats in the car. Everything but EVAP showed readiness.


    Sent from my iPhone using Tapatalk
     
  6. RI GT500

    RI GT500 Member Established Member

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    That's what i was hoping to see , thanks for the reply
     

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