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seattlejester

Intake manifold vacuum port sources on custom intake

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My intake manifold is going to the welders eventually. Especially now that it is cut up a bit.

 

It is basically a large D tube manifold. Looks to be about 1/4 inch thick.

 

While he has it should I just have him weld on a piece of aluminum bar stock with some holes drilled in it for some vacuum ports?

 

I had 4 ports I used in my last manifold. 

1 x 1/4 for map reference

1 x 1/4 for wastegate

1 x 1/4 for blow off valve

1 x 3/8 for brake booster

 

Or should I just go with fittings like:

http://www.ebay.com/itm/Speed-5183-Low-Profile-Aluminum-3-8-NPT-Vacuum-Fitting-Tee-/400886774503?hash=item5d56b6bae7:g:iC0AAOSw34FVCJ8a&vxp=mtr

http://www.ebay.com/itm/PSS-1042-Stainless-Steel-Two-1-8-NPT-Ports-Low-Profile-Vacuum-Fitting-3-8-NPT-/230364313545?hash=item35a2c877c9:m:meLNZ7UEKw4ID0JyK7DU1DA&vxp=mtr

 

Cost would be about the same really. The latter would be easier to do since i just drill and tap and install a fitting. The block would require me to cut a slot and make the piece and drill and tap those for each individual barb. I think those flat profile distribution fittings could look pretty snazzy.

 

I'm not sure on this. Would love to hear your guys thoughts on one over the other or a third option if you have one.

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Mine has two. One to the bov and another to the map sensor with a T to the fuel pressure regulator. Brake vacuum is done with an electric vacuum pump. Wastegate is connected to the compressor housing. I just drilled and tapped into the thicker areas of the plenum. Do you have a picture of yours?

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Hmm have a link to the electric vacuum pump? That sounds interesting. Is it on all the time?

 

http://www.ebay.com/itm/2JZ-GE-FFIM-SUPRA-TURBO-SC300-IS300-INTAKE-MANIFOLD-/122006738231?hash=item1c682b1537:g:zqMAAOSwyjBW3FZZ&vxp=mtr

 

Same unit as that one.

 

Well after going back and forth I decided the benefit to the NPT would be that it would be self sealing in a way and that the benefit to a vacuum block type arrangement would be that you could use any threaded fitting like a banjo fitting. 

 

I ended up buying the 3 port fitting and found a spot to tap the back of the manifold for an independent brake booster fitting. I think it will end up looking pretty snazzy, if it ends up leaking horridly I'll have to just go with a block.

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The vacuum pump is something I found on eBay. It was a new Ford part. I don't know what it actually fits. I have the pump wired to a relay which is triggered by the brake switch so it only runs while pressing the brake pedal. Since the booster is sealed it always holds a vacuum so no worries about an initial hard pedal. Works great.

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Its not too bad. I use my car for drag racing so when I'm in the staging lanes I use the ebrake instead. My alternator is only 80 amps. Plus I'm using a ati damper with a ridiculous underdrive pulley and a 17" electric fan. Keeping up with demand is tough. I need more alternator.

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