What is your vacuum reading at idle ?

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05-23-09, 06:56 PM

#26

FutileLover

Project FD

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oooo another vacuum thread

16inches @ warm idle, 600-700rpm, stock port

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05-23-09, 07:35 PM

#27

ImraanK

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hehehe... I think my gauge could be acting up but it reads boost perfectly, just low vacuum... Thats what scares me..

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05-23-09, 08:18 PM

#28

Red95FD

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450ish at 730 rpm

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05-24-09, 07:07 PM

#29

93RedDragonFD

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Quote:

Originally Posted by 93RedDragonFD

Mine sits at 12 in. @ 950-1000rpms... Streetport with non. seq. stock twins.

Had a problem, fixed it. Now sits at 14in - 1000rmp idle.

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05-24-09, 07:23 PM

#30

rotarymaz

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19-20inch @ 1100rpm, street port w/ stock twin

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05-25-09, 02:38 AM

#31

Ol-Skool

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stock motor and twins, power fc on base map, -500-600mmhg

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05-25-09, 08:32 AM

#32

moehler

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Both FDs I've owned had lower vacuum... it's tough to tell your engines health from vacuum alone. My current car has -320/-330 at 950 rpms with a large street port. Engine just had a compression test and made 110 and 114 psi on front and rear rotors.

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05-25-09, 12:27 PM

#33

Oliv

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around 500 mmhg at 800rpm. Stock ports.

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05-25-09, 12:37 PM

#34

Sgtblue

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If you've removed the double throttle, ported your throttle body or reduced restriction in some other way in that area...wouldn't that tend to affect vacuum readings, making them lower?

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05-25-09, 03:49 PM

#35

hal0gical

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18-21 in. @ ~800 stock port

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06-03-09, 01:32 PM

#36

jhaywood

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Pineapple mild street port, 850 - 900rpm idle

Vac ~500 mbar/375 torr(mmHg)/14.8 inHg

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06-15-09, 11:02 AM

#37

kash

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Quote:

Originally Posted by Sgtblue

If you've removed the double throttle, ported your throttle body or reduced restriction in some other way in that area...wouldn't that tend to affect vacuum readings, making them lower?

Anyone know the answer to this? My vacuum used to read 380-390 with my old turbo t60-1 and now reads 340-350 with the double throttle removal and new turbo T51

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06-24-09, 03:26 PM

#38

sinned2545

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i have 430mmhg
stock port, single turbo, Power FC.

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06-24-09, 05:27 PM

#39

GoodfellaFD3S

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Dennis, you need to list your idle rpm when you talk about vacuum readings

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06-24-09, 11:40 PM

#40

sinned2545

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^ oops sorry..
its at around 800...900 rpm

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06-24-09, 11:54 PM

#41

Integrals

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18-20in/hg at 840-880rpm
Stock Twins, Engine has 2k on my own rebuild with old housings, stock ported

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06-25-09, 12:19 AM

#42

sinned2545

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What are good numbers from Bad ones???
when should u worry???

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06-25-09, 01:11 AM

#43

TIF_FD

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Question

I recently rebuilt half my motor..chipped seal in the rear. front was making 100+ compression so I left it alone. I put 20 miles on the rebuild and im pulling 420mmHg at 1000k which is only a little less then before I blew it. However my compression test is showing only 80 psi in the front and rear..how is the possible?

Is vacuum a good indication of compression? Maybe my compression test is not right or something is causing my vac to be high?