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  1. #1
    Might as well be part of the furniture.
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    Where to put vacuum connections

    Spurred on by recently returning from the nationals and a bit fired up I want to get a few bits done to the T (don't worry normal apathy will return soon I'm sure).

    So the engine as we know is a big block Mopar with a tunnel ram and twin holley's, the ignition will be megajolt lite with a MAP take off for advancing the ignition. I have done a fair bit of research on this little set up and the MAP is better for this combination than the TPS system but it is advised to get the vacuum from all the runners not just one so I will make a vac log that I can place where I want it with eight ports, one for each runner, now here is my issue, normally the vac take off is at the base of the carb but in this instance the take off's will be each runner, but where do I drill the runners, top middle or bottom or does it make no difference at all, also is there an optimum size of tubing to use, I was thinking of -3 and using AN fittings, is this too large or am I just over thinking the whole thing and just about anything will work.

  2. #2
    Might as well be part of the furniture.
    Join Date
    Jun 2013
    Location
    Bucks
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    2,766
    Fuel log I made for mine. Takes off are one for each runner and they go in just under the butterfly.



    Uses just normal silicon vac tube with a 3mm bore. No real volume to speak of just draws a vac signal. Oh and the 2 takes offs are one for the EFI and one for the modulator on the transmission.


  3. #3
    Might as well be part of the furniture.
    Join Date
    Jun 2013
    Location
    welwyn
    Posts
    1,313
    So by that reckoning then as high up as possible towards the carb butterfly's even though there is a large plenum underneath the carbs. One thing I don't have to worry about is a vac line for the gearbox as the 727's don't have a vac controlled modulator, all the shifts are done via linkages which will probably be a bugger to set but we are a VERY long way from that time.

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