Weber DCOE vacuum requirements?? Need Advice

[tr7project]

I have a Sprint engine which uses Weber DCOE carburetors (with a TT fast road cam). I had the engine built but have been sorting it myself. The engine is running fairly well now and I am down to the little details. <br>
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1) Is the vacuum take off sufficient to run the brake booster since it only feeds off one intake runner (1 cylinder)?<br>
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2) Were do I hook up the vacuum advance on the distributor?<br>
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I hooked up a vacuum meter to the intake (where the take off is for the brake booster) and I can watch the needle oscillate from some about of suction to 0 very rapidly. I am wondering if I need to add a vacuum take off to each cylinder and tie them together in order to get the vacuum I need for the distributor and brake booster. <br>
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Thanks in advance for your help!<br>
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Will Norton

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[gmsclassics]

The vacuum for the brake booster seems to be sufficient to run the brake booster. Works adequately on my car with that manifold.<br>
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Simply disconnect the vacuum advance completely - Webers and Dellorto twin chokes don't need it. You don't need to block the hole on the distributor or anything like that.<br>
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Suggest you check the timimg carefully and ensure that the mechanical advance is working correctly. I'm not sure exactly what your cam is or if it has any specific tming requirements. My STR139 race cam needs max total advance to be 32 degrees, which is more thn standard.<br>
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Geoff

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[MaddMart]

Geoff is correct. Just take off the vacuum advance. The vacuum for the brake booster (servo, to us pomms) should be sufficient.

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[Dave]

IIRC the arguement for getting rid of the advance is that as racers are always at full throttle and high rpm as the cam doesn't work below 3,000 rpm anyway it isn't needed. OF course if its on the road its still always on full throttle and 6,000 rpm (if its smifter.....)<br>
For us mortals with less agressive cams and properly set up carbs you will find more economy and smoother low rpm pickup with it attached IMHO. <br>
Ps I'm a wimp and don't exceed 4000 all that often ,unless theres a GTI in the area..........<br>
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