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Bridge Port vacuum readings

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Old Mar 16, 2008 | 07:07 PM
  #1  
mazgtr's Avatar
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Bridge Port vacuum readings

I just started up my half-bridge REW Motor this weekend. My vacuum readings
are 4-5HG. I'll double check where my map sensor is hooked up and make sure its a good source, but what readings are you other folks with bridge port getting at Idle?
Motor has a VERY large port job with pretty decent half-bridge port. No starting issues and drives good and smooth on here 1st outing around the block...

Just wondering if 5 HG is normal for a agrressive c16 race motor.
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Old Mar 17, 2008 | 04:36 AM
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my full bridge pulls ~12mmhg @ 1900rpm... I would think with less overlap a half bridge would pull more than 12mmhg and definately more then 5mmhg.. i'd say uve got a vac leak somewhere..
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Old Mar 17, 2008 | 05:03 PM
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Originally Posted by butcheryboy
my full bridge pulls ~12mmhg @ 1900rpm... I would think with less overlap a half bridge would pull more than 12mmhg and definately more then 5mmhg.. i'd say uve got a vac leak somewhere..
I think he means inches of mercury... inHg.

5" would be 84 kPa, which would be ~127mmHg. Not the highest vacuum readings, but certainly acceptable.

My most recent high overlap BP pulls around 8 inHg.

12mmHg is essential zero vacuum, equal to approximately 0.5 inHg.
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Old Mar 18, 2008 | 04:40 PM
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haha yea my bad, was late.. inches indeed. (inhg)
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Old Mar 22, 2008 | 06:44 PM
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RPM is needed here -- Mine does about 8-10" at 1200-1400rpm.

B
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Old Mar 22, 2008 | 08:02 PM
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yep I had it idling too low, I adjusted it to close to 1500 rpm and now its much better
reading 10-11" now...Hopefully the new Tial Bov with a 9psi spring will work with the
bridge motor.
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