Nice intake manifold... - The ITB thread

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Just a question, I need to run a vaccum line for my brake booster, also some other bits and pieces like crankcase breather. The manifold has no provision int he runners at present. Should I drill and tap them say 1/8" on the underside of the cast runner. And then fit a hose tail, and run all 8 back to a manifold block, with then the booster line going to it?
I have read about vacuum assist having problems with big cams, would it be a better idea to have a second vacuum tank and plumb to that?
Or could i get by with only tapping into one of the runners, not all 8?
Just a question, I need to run a vaccum line for my brake booster, also some other bits and pieces like crankcase breather. The manifold has no provision int he runners at present. Should I drill and tap them say 1/8" on the underside of the cast runner. And then fit a hose tail, and run all 8 back to a manifold block, with then the booster line going to it?
I have read about vacuum assist having problems with big cams, would it be a better idea to have a second vacuum tank and plumb to that?
Or could i get by with only tapping into one of the runners, not all 8?
Drill and tap 1/8" npt underneath just past the TB blades. Tie them all to a common vacuum block. You won't know if you'll have enough vacuum consistently to boost your brakes until you have it running and test it. I don't run a brake booster on my SLC so it's a non-issue in my build. I run a vacuum block for MAP reference. You should try to make all of the lines close to the same length, and as short as possible to get a stable map reading at idle.
On my c6 I had enough vacuum for my power brakes when I ran my Harrop with a 255/263 112lsa cam. Every setup and combo is different though.
On my c6 I had enough vacuum for my power brakes when I ran my Harrop with a 255/263 112lsa cam. Every setup and combo is different though.
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