Gt 40 Intake

Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by kcard, Mar 8, 2014.


  1. kcard

    kcard Member

    Joined:
    Dec 29, 2013
    Messages:
    48
    Likes Received:
    1
    Trophy Points:
    19
    I have a gt 40 intake going to bore it out to 70mm someone said that will be safe.
    1. do you think i can bore it out to a 75mm
    2. how far in to you go to be safe in boring it out like the depth.
    thanks for the help guys you have been great in my other posts.
    #1
  2. 7991LXnSHO

    7991LXnSHO Active Member

    Joined:
    Sep 1, 2010
    Messages:
    1,086
    Showcase:
    5
    Albums:
    1
    Likes Received:
    86
    Trophy Points:
    49
    Is it a real GT40 or is it an Explorer? Also, if it is an exploder, what year, as the EGR may make a difference too. Any way, the bolts through the neck will decide how wide you can go in as you widen the throat. Tmoss has a site that answers how to measure and do it right. It is one of his many porting documents.
    #2
  3. kcard

    kcard Member

    Joined:
    Dec 29, 2013
    Messages:
    48
    Likes Received:
    1
    Trophy Points:
    19
    Sorry it is a explorer intake, year don't know it is on my 1991 mustang
    #3
  4. kcard

    kcard Member

    Joined:
    Dec 29, 2013
    Messages:
    48
    Likes Received:
    1
    Trophy Points:
    19
    Whatbis the site name
    #4
  5. kcard

    kcard Member

    Joined:
    Dec 29, 2013
    Messages:
    48
    Likes Received:
    1
    Trophy Points:
    19
    can anyone else help out I can't find info on the tmoss site, he talks a lot about porting the lower, I just want to know how much I can bore out the top intake to fit a 75mm tb can I go 75mm or just go 70mm
    #5
  6. 89oem

    89oem Active Member

    Joined:
    Dec 19, 2013
    Messages:
    469
    Likes Received:
    75
    Trophy Points:
    39
    #6
  7. 7991LXnSHO

    7991LXnSHO Active Member

    Joined:
    Sep 1, 2010
    Messages:
    1,086
    Showcase:
    5
    Albums:
    1
    Likes Received:
    86
    Trophy Points:
    49
    #7
  8. 7991LXnSHO

    7991LXnSHO Active Member

    Joined:
    Sep 1, 2010
    Messages:
    1,086
    Showcase:
    5
    Albums:
    1
    Likes Received:
    86
    Trophy Points:
    49
    Here is another site with the same info, maybe more. I spent a lot of reading time here. I wish all of jrichker's regular help posts were all in one spot too. Between my print outs from the two gurus, my Chilton's manual seems generic!
    http://tmoss.efidynotuning.com/
    #8
  9. 2000xp8

    2000xp8 Mustang Master

    Joined:
    Aug 9, 2003
    Messages:
    5,409
    Likes Received:
    227
    Trophy Points:
    104
    Sounds like you don't have a TB already, just buy a 65mm.
    In a combination consisting of an explorer gt40 intake, there probably isn't any power to be had going larger anyway.
    If Kenne bells site is to be trusted, even when they added a 70 over a 65 drawing through it with a supercharger it only added 2hp.

    I think you can even convert the 65 from an explorer to work. Making it extremely cheap.
    Last edited: Mar 9, 2014
    #9
  10. kcard

    kcard Member

    Joined:
    Dec 29, 2013
    Messages:
    48
    Likes Received:
    1
    Trophy Points:
    19
    i have a 75mm throttle body that was free and all the machine will be free.
    #10
  11. mikestang63

    mikestang63 Mustang Master

    Joined:
    Aug 28, 2012
    Messages:
    3,676
    Showcase:
    20
    Albums:
    1
    Likes Received:
    998
    Trophy Points:
    144
    what's this going on? You can slap a 90mm Tb on a stockish engine and it won't go any faster than one with a 65nn.
    #11
  12. kcard

    kcard Member

    Joined:
    Dec 29, 2013
    Messages:
    48
    Likes Received:
    1
    Trophy Points:
    19
    331 stroker supercharged, I have the 75 and when I put it on the stock one it is a lot bigger just seeing if you could bore it out. or maybe it doesn't matter if it is that much bigger. Does it matter? wasn't looking for hp just making sure it would work either way
    #12
  13. kcard

    kcard Member

    Joined:
    Dec 29, 2013
    Messages:
    48
    Likes Received:
    1
    Trophy Points:
    19
    and I have no money to buy any other parts and these are free and it is almost spring and I want to drive it
    #13
  14. 2000xp8

    2000xp8 Mustang Master

    Joined:
    Aug 9, 2003
    Messages:
    5,409
    Likes Received:
    227
    Trophy Points:
    104
    Well, no matter what you can't have the TB bigger than the opening, would cause all kinds of turbulence which is obviously bad.

    Probably not many people out there trying to port the inlet on an explorer intake to 75mm. You may get an answer to if it's safe or you may not.

    I'd just sell or trade the 75 for a 65.
    #14
  15. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

    Joined:
    Feb 19, 2001
    Messages:
    21,619
    Likes Received:
    304
    Trophy Points:
    124
    If you are running the lower intake on that setup unported...just run the parts as is. Your bottleneck will be the lower.

    To answer your question, you can enlarge the opening. basically take the gasket with a 75mm opening and trace it on the explorer intake. Then use a dremel to round the transition into the intake over so the mating area is all seamless. Don't go crazy, just blend it in.

    As for what size TB, it's tough to say. You didn't give enough details on the combo.
    #15

Share This Page