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my vacuum at idle is only 12 In.Hg, is it ok?

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Old 06-07-09, 11:43 PM
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my vacuum at idle is only 12 In.Hg, is it ok?

i haven't run my Rx7 for 7-8 months, just started driving it these few days and i notice the vacuum at idle is kinda low, only 12 In.Hg, i couldn't remember wat it's like b4, but it's been low always, comparing to my turbo miata and WRX, is it normal for rotary?

it's a 13B running twins.
Old 06-08-09, 03:01 PM
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only if it is a ported motor
Old 06-08-09, 04:15 PM
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what idle rpm?
Old 06-08-09, 04:35 PM
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hmm I have stock ports and mine pulls 18inch at 500rpms and 20 at 975rpm
Old 06-08-09, 06:13 PM
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Im getting about the same on my stock port fd.. Last compression check I was borderline on the front rotor..
Old 06-08-09, 06:14 PM
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16" at 1000 with a McHuge streetport
Old 06-08-09, 08:59 PM
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I'm running about 10-12 at 500 on stock port twins as well... I don't think that's a good thing though. I'm around 16-18 if i up the idle to 1000...
Old 06-09-09, 12:44 AM
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my idle is set to 750-800 rpm, mild street-port, my vacuum is kinda low i think, but the engine was rebuilt 15k km ago, and it's been sitting for over 8 months.

i think i needa do a compression test, wat is a good compression reading for stock rotary?
Old 06-10-09, 08:50 AM
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Sounds like the compression is a little low but it could run like that for years without any real issue.
Old 03-12-13, 12:08 PM
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21 @ 1000
Old 03-16-13, 08:42 PM
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Half BP 12A supercharged low boost pully 7in, hi boost pully 3in both at 1400 rpms.
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