View Poll Results: What kind of vacuum (as measured by the PFC Commander) are you guys seeing at idle?

>475 mmHg, stock motor

11.66%

450-475 mmHg, stock motor

19.63%

425-449 mmHg, stock motor

13.50%

400-424 mmHg, stock motor

14.11%

<400 mmHg, stock motor

4.29%

>475 mmHg, streetported motor

1.84%

450-475 mmHg, streetported motor

4.29%

425-449 mmHg, streetported motor

5.52%

400-424 mmHg, streetported motor

10.43%

<400 mmHg, streetported motor

14.72%

Voters: 163. You may not vote on this poll

Power FC What kind of vacuum (as measured by the PFC Commander) are you guys seeing at idle?

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Jul 31, 2002 | 01:15 PM

#26

1point3liter

Twin Turbo LSX

Joined: Mar 2001

Posts: 787

Likes: 1

From: Jacksonville, Fl

I see about 395 - 405 at 760rpm

Streetported, 3mm hurley seals, less than 3k on the motor.

Sep 27, 2002 | 12:00 AM

#27

evot23

Classy

iTrader: (17)

Joined: Feb 2001

Posts: 6,900

Likes: 2

From: Gainesville, FL

When are you coming to the track with that thing?

Sep 30, 2002 | 01:48 PM

#28

TailHappy

Addicted to Track

Joined: Jan 2002

Posts: 903

Likes: 0

From: NC

For the record, I just got my new streetported engine installed and broken in (~800 miles), and I'm showing 450 at idle. It has new rotor housings and also upgraded apex springs. Outside temps were from 70-85F (didn't seem to matter). Other mods are below...

Sep 30, 2002 | 04:28 PM

#29

ech

Senior Member

Joined: Apr 2001

Posts: 334

Likes: 0

From: Boston, MA, USA

Just out of curriosity, won't you get nice HIGH vacuum settings with a clogged Intake Filter?

Or if you took off the air filter altoghether wouldn't your vacuum readings go down? Anyone willing to try ;-)

Oct 2, 2002 | 07:10 AM

#30

The DJ

Senior Member

Joined: Mar 2001

Posts: 344

Likes: 0

From: Connecticut

vacuum

Warmed up I'm at 350 at 800 rpms.....idle became rough after I switched to Mobil 1 Super Syn 10w30. But it's a mild streetport so it was always alittle roughish......still worried though. 30K on new motor.

Oct 2, 2002 | 10:46 AM

#31

Turborl7

Full Member

Joined: Mar 2001

Posts: 136

Likes: 0

From: NYC/NJ

Just a question,

my fan is rigged to come on all the time when the car is running. Is this bad? I get really good water temps (83 -85 even on hot *** days) and air temps (38-48 even on hot *** days).

?

Apr 11, 2003 | 02:03 PM

#32

redrotorR1

LS6 Convert

Joined: Jan 2002

Posts: 1,827

Likes: 0

From: Austin, TX

Oops. Old thread. Oh well, ~490 mmHg at ~800rpm idle. Stock reman engine with about 30,000 miles on it. Most of my mods are recent (within the last year).

Jun 22, 2003 | 02:04 PM

#33

bploz RX7

Full Member

Joined: Apr 2001

Posts: 242

Likes: 0

From: marietta, ga (soon 2B san diego)

only about 380 mmHg on a fresh rebuild, streetported, with only 500 miles... kind of worried its so low even though it should get a little better as it breaks in.

Jul 8, 2003 | 08:12 PM

#34

cavellm

Eats, Sleeps, Dreams Rotary

Joined: Aug 2002

Posts: 3,118

Likes: 0

From: Dallas, TX

Between 400 and 415 with a big *** street port, 1500 miles on it.

Jul 8, 2003 | 11:28 PM

#35

Wargasm

Weird Cat Man

Joined: Aug 2001

Posts: 2,868

Likes: 3

From: A pale blue dot

Since this thread has been resurrected... Here is some input.

The vacuum at idle is affected by porting (as already mentioned) but also by other factors.

On my car if I have my idle Air/Fuel Ratio at around 14.5:1 I get around 13 inches Hg vacuum at 1000 RPM. If I richen up my AFR to 12.5:1, I get about 16 inches Hg at 1000 RPM. That's a pretty big difference!

Timing changes can also tweak it one way or the other a tiny bit I think.

And this still doesn't cover the WIDE range of street ports people run! My car has a port job that I did myself on it, but I still pull as much vacuum at idle as some stock ports do I bet

This is because I didn't enlarge the primary ports that much.

Anyhow, just saying that you can get as much variation in idle vacuum from an AFR change as you can from some port jobs.

Brian

Jul 12, 2003 | 10:08 PM

#36

turbogarrett

0 lbs of boost

iTrader: (1)

Joined: May 2002

Posts: 1,261

Likes: 1

From: wisconsin

13-15 in on the boost gauge, ~420 mm w/ 900 rpm idle. streetport and not using an idle speed controller right now.

Jul 14, 2003 | 01:48 AM

#37

radkins

Rotary Enthusiast

Joined: Aug 2001

Posts: 1,236

Likes: 1

From: Waiting for Indykid to catch up

I get about 11in on my boost guage with my Pineapple large race port (I think this is about 350 or so on the Camander), but my car idles at 1000rpm.

Jul 29, 2003 | 02:46 AM

#38

damian

DDH Motorsports

iTrader: (2)

Joined: May 2002

Posts: 4,256

Likes: 21

From: Minnesota

stock motor - 47K miles
-460 at 800 rpm

Feb 12, 2004 | 01:31 AM

#39

cloud9

The bomb is in the toy!1!

iTrader: (6)

Joined: Oct 2003

Posts: 2,229

Likes: 292

From: Dallas Tx.

how consistant should these numbers be? because sometimes I see 450 at idle and sometime I see up to 500 at idle. stock motor 24K mods in sig

Feb 25, 2004 | 11:59 AM

#40

jpandes

Rotary Freak

Joined: Mar 2001

Posts: 2,236

Likes: 1

From: San Francisco, CA

Pineapple street ported motor w/ 7k miles
370+/- mmHg @ 720 rpm
380+/- mmHg @ 900 rpm

I'm glad to see that my vacuum numbers are in the majority according to the poll.

Apr 28, 2004 | 10:02 PM

#41

rotoboy661

Eats, Sleeps, Dreams Rotary

Joined: Nov 2003

Posts: 3,082

Likes: 0

From: kali

just check mine

im at 770 rpm @ 482mmHg (pfc commander)

stock reman w/airpump

mike

May 11, 2004 | 04:08 PM

#42

TracyRX7

FD = Mr. Toad's Wild Ride

Joined: Mar 2004

Posts: 405

Likes: 0

From: San Antonio, TX

I have a HKS EVC IV that shows vacuum readings when the car isn't on boost. Should these readings be the same as on the PFC? If so I'll add my numbers to the poll. I'm asking since I've heard the PFC reports boost lower than most boost gauges/controllers so I wasn't sure how it handles vacuum readings.

Nov 30, 2009 | 02:58 PM

#43

kensin

Put it in the microwave!

iTrader: (22)

Joined: Jul 2009

Posts: 1,568

Likes: 35

From: CA

hmm

can that pulling vacuum number be brought down cause of a boost leak ?

i think i have a boost leak

but the car pulls -460-490 mmhg

Dec 3, 2009 | 04:33 PM

#44

siguy2k

SLEEPER

iTrader: (3)

Joined: Nov 2005

Posts: 1,145

Likes: 11

From: nebraska

Mine has only pulled around -300-350 for a yr and a half now. A/f 11-11.2. This is with a small streetport? Runs strong but according to the majority of these posts im pulling low vacuum?

Dec 3, 2009 | 11:09 PM

#45

arghx

rotorhead

iTrader: (3)

Joined: Aug 2004

Posts: 16,205

Likes: 461

From: cold

it depends a lot on porting. I get 300-350 mmHg on my car idling around 900-950 rpm, but I have a large streetport. 3mm seals may affect sealing at idle as well

Dec 4, 2009 | 05:12 PM

#46

Traumatic

Full Member

Joined: Mar 2007

Posts: 66

Likes: 0

From: Norway

I got 450mmhg at 850rpm.
Medium streetport, 3mm apex seals

Dec 5, 2009 | 03:31 PM

#47

thewird

Lives on the Forum

iTrader: (8)

Joined: Oct 2006

Posts: 6,603

Likes: 15

From: Toronto, Canada

340-410 @ 1,000-1,100 RPM depending on car temp and weather conditions. Fairly large street port with 3mm one-piece NRS ceramic apex seals, excessive LIM, ported UIM, FEED larger throttle body. 32,000 km on the motor and it has remained fairly consistent to when it was rebuilt.

thewird