Results 1 to 8 of 8

Thread: Jag v12 inlet manifolds and throttle bodies

  1. #1
    Senior Member nicktruman's Avatar
    Join Date
    Aug 2010
    Location
    Iver, Bucks
    Posts
    1,070

    Jag v12 inlet manifolds and throttle bodies

    Hi Guys
    I raised this question in my build thread but somehow it got overlooked.

    My twin turbo 5.3l Jag V12 has its throttle bodies in the middle of the manifold. This works well when he engine is in a front engine jag, but not so well when in a midengines car. I want to move the throttle bodies to the end of the manifolds more like the OEM Zonda, or Ferrari config.

    I realise that this will mean a lot of cutting and welding the aluminium casting but in theory its very doable. My question though is will this affect performance?

    I can open the plenum, which on the Jag is very small and make it larger with a bigger air capacity, but would this make the car run badly?

    I appreciate your help on this please

    Cheers Nick
    Regards
    Nick

    Twin turbo V8 Zonda inspired thingy

  2. #2
    Senior Member AdrianBurton's Avatar
    Join Date
    Jun 2003
    Location
    Tucson, AZ
    Posts
    969

    Re: Jag v12 inlet manifolds and throttle bodies

    Nick you could actually replace the entire plenum with a "rectangle box" and put the TB's at the end like they are on the BMW, Merc, and Viper engines Since you are still planning to turbo you can get away with a bit more and it might be a bit less work.

    Performance wouldnt suffer and the extra volume would be nice too

  3. #3
    Senior Member nicktruman's Avatar
    Join Date
    Aug 2010
    Location
    Iver, Bucks
    Posts
    1,070

    Re: Jag v12 inlet manifolds and throttle bodies

    Quote Originally Posted by AdrianBurton
    Nick you could actually replace the entire plenum with a "rectangle box" and put the TB's at the end like they are on the BMW, Merc, and Viper engines Since you are still planning to turbo you can get away with a bit more and it might be a bit less work.

    Performance wouldnt suffer and the extra volume would be nice too
    Thanks Adrian
    I did read somewhere that if you increase the length of the inlet tracks you can improve torque. But maybe that is on a NA setup. I don't have enough room above the engine for a proper plenum, So I will have to improvise
    Regards
    Nick

    Twin turbo V8 Zonda inspired thingy

  4. #4
    Senior Member AdrianBurton's Avatar
    Join Date
    Jun 2003
    Location
    Tucson, AZ
    Posts
    969

    Re: Jag v12 inlet manifolds and throttle bodies

    The longer intake runners will improve TQ but you are turbo'd so that isnt much of an issue for you, the shorter runners will give you more upper RPM power, that will soften the TQ down low and give the trans a fighting chance behind the 12

  5. #5
    Senior Member nicktruman's Avatar
    Join Date
    Aug 2010
    Location
    Iver, Bucks
    Posts
    1,070

    Re: Jag v12 inlet manifolds and throttle bodies

    Quote Originally Posted by AdrianBurton
    The longer intake runners will improve TQ but you are turbo'd so that isnt much of an issue for you, the shorter runners will give you more upper RPM power, that will soften the TQ down low and give the trans a fighting chance behind the 12
    Thanks Adrian
    Regards
    Nick

    Twin turbo V8 Zonda inspired thingy

  6. #6
    Senior Member AdrianBurton's Avatar
    Join Date
    Jun 2003
    Location
    Tucson, AZ
    Posts
    969

    Re: Jag v12 inlet manifolds and throttle bodies

    NP, I have to live thru your build since mine is about 1000 miles from me :'( :'( :'(

  7. #7
    Senior Member nicktruman's Avatar
    Join Date
    Aug 2010
    Location
    Iver, Bucks
    Posts
    1,070

    Re: Jag v12 inlet manifolds and throttle bodies

    Quote Originally Posted by AdrianBurton
    NP, I have to live thru your build since mine is about 1000 miles from me :'( :'( :'(
    Hi Adrian
    What would you think if I cut off the plenums and in their place bolted 3 1/2" steel or aluminium tube sealed at one end and with the throttle body at the other. I could then flow/open out the intake runners. So using tube, the inner surface will be dead smooth and being 3 1/2" have a much larger inner area.

    Each intake runner is about 1 1/4" iirc

    This is a very crude mock up and the oem

    Then I can clear the V of all the throttle linkages, the only complication would be the TPS (throttle position sensor).
    Attached Images Attached Images   
    Regards
    Nick

    Twin turbo V8 Zonda inspired thingy

  8. #8
    Senior Member AdrianBurton's Avatar
    Join Date
    Jun 2003
    Location
    Tucson, AZ
    Posts
    969

    Re: Jag v12 inlet manifolds and throttle bodies

    That is how the BMW intake is, so I see no problem at all with that. The TPS shoul not be a problem either since most throttle bodies have TPS provisions on them

Similar Threads

  1. Repro Throttle bodies for mucri anybody interested?
    By murcilambo in forum The Mall
    Replies: 5
    Last Post: 10-17-2008, 06:54 AM
  2. Fuel inlet hoses
    By Ferrari Berlinetta in forum Technical Discussion & Question
    Replies: 5
    Last Post: 09-07-2003, 04:11 PM
  3. Throttle body
    By backseatdriver in forum Technical Discussion & Question
    Replies: 1
    Last Post: 12-22-2002, 02:03 PM
  4. Home-made Exhaust Manifolds
    By vortecfiero in forum Technical Discussion & Question
    Replies: 0
    Last Post: 06-28-2002, 02:18 PM
  5. throttle body
    By RJONES in forum Technical Discussion & Question
    Replies: 3
    Last Post: 03-31-2002, 10:55 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •