what is your vac in hg at idle
08-03-2008, 12:31 PM
#1
TGO Supporter
Thread Starter
iTrader: (12)
Join Date: Jun 2002
Location: AR
Posts: 6,819
Likes: 0
Received 2 Likes
on
2 Posts
Car: 1991 Camaro RS Vert
Engine: 350 S-TPI
Transmission: T5
Axle/Gears: GU5/G80/J65
what is your vac in hg at idle
I know this will vary a bit due to the modifications on every engine. But I am noticing my car idles at 700rpm @ 16hg's. I am trying to get my engine to use a bit less gas and am wondering that since I lowered my rpms from 800 to 700 has actually increased my vac? I have always had this setup idle at 700, so I dunno what my vac would be at 800.
Can some of you chime in and tell me if your auto/manual, warm idle rpms, and your vac in hg's.
Thanks!
Can some of you chime in and tell me if your auto/manual, warm idle rpms, and your vac in hg's.
Thanks!
08-03-2008, 08:07 PM
#2
Senior Member
iTrader: (1)
Join Date: Jul 2007
Location: MA
Posts: 1,141
Likes: 0
Received 2 Likes
on
2 Posts
Car: '87 IROC/'68 SS
Engine: 5.7L/350
Transmission: 700R4/Muncie 4-spd
Axle/Gears: 3.27 9 bolt / 3.31 12 bolt
Re: what is your vac in hg at idle
My '87 5.7 TPI idles at 700 w/ 20". Yours seems low.
08-04-2008, 12:05 AM
#3
Member
Join Date: May 2005
Location: California
Posts: 189
Likes: 0
Received 0 Likes
on
0 Posts
Car: 89 Iroc-Z
Engine: 5.7
Transmission: 4 spd auto
Re: what is your vac in hg at idle
89 5.7 tpi mild cam. intake, as&m runners, base timing at 8d, idle programmed in at 750, vacuum 17 to 18". Lots of folks on this site with mild setups are in the 16 to 18" range-not all that bad.
08-04-2008, 07:32 AM
#5
TGO Supporter
Thread Starter
iTrader: (12)
Join Date: Jun 2002
Location: AR
Posts: 6,819
Likes: 0
Received 2 Likes
on
2 Posts
Car: 1991 Camaro RS Vert
Engine: 350 S-TPI
Transmission: T5
Axle/Gears: GU5/G80/J65
Re: what is your vac in hg at idle
So mine is a bit average to just a hair low. Think its worthy of playing around or just leave it?
Guess I got use to my L67 that is 22@600
Guess I got use to my L67 that is 22@600
08-04-2008, 10:02 AM
#6
Senior Member
iTrader: (3)
Join Date: Dec 2005
Location: Fresno, CA
Posts: 522
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Iroc-Z
Engine: 5.7 350 TPI
Transmission: stage2 700r4
Axle/Gears: 2.73 for now
Re: what is your vac in hg at idle
question....how do U come up with these numbers?? Is there a tool to test vacuum?
08-04-2008, 11:27 AM
#7
TGO Supporter
Thread Starter
iTrader: (12)
Join Date: Jun 2002
Location: AR
Posts: 6,819
Likes: 0
Received 2 Likes
on
2 Posts
Car: 1991 Camaro RS Vert
Engine: 350 S-TPI
Transmission: T5
Axle/Gears: GU5/G80/J65
Re: what is your vac in hg at idle
Yea, I have one mounted in each of my cars 24/7. Plus there is a test tool for temporary use.
Then I am programing my pcm myself, so I know where the car idles +/-25rpm.
Then I am programing my pcm myself, so I know where the car idles +/-25rpm.
Last edited by Dale; 08-04-2008 at 11:37 AM.
Trending Topics
08-04-2008, 12:17 PM
#8
Senior Member
iTrader: (3)
Join Date: Dec 2005
Location: Fresno, CA
Posts: 522
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Iroc-Z
Engine: 5.7 350 TPI
Transmission: stage2 700r4
Axle/Gears: 2.73 for now
Re: what is your vac in hg at idle
all I see is a boost gauge and a air/fuel mixture gauge. What the test tool for vacuum look like?
08-04-2008, 12:21 PM
#9
TGO Supporter
Thread Starter
iTrader: (12)
Join Date: Jun 2002
Location: AR
Posts: 6,819
Likes: 0
Received 2 Likes
on
2 Posts
Car: 1991 Camaro RS Vert
Engine: 350 S-TPI
Transmission: T5
Axle/Gears: GU5/G80/J65
Re: what is your vac in hg at idle
the boost is also a vac. One side of 0 is vac, one side is boost.
Its very hard to find a vac only, and they are not marked as well.
stand alone temp..
http://www.iequus.com/product_info.p...tegory_id=1_30
dash mount..
http://www.iequus.com/product_info.p...ory_id=100_105
Its very hard to find a vac only, and they are not marked as well.
stand alone temp..
http://www.iequus.com/product_info.p...tegory_id=1_30
dash mount..
http://www.iequus.com/product_info.p...ory_id=100_105
Last edited by Dale; 08-04-2008 at 12:26 PM.
08-04-2008, 01:27 PM
#10
Senior Member
iTrader: (3)
Join Date: Dec 2005
Location: Fresno, CA
Posts: 522
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Iroc-Z
Engine: 5.7 350 TPI
Transmission: stage2 700r4
Axle/Gears: 2.73 for now
Re: what is your vac in hg at idle
on that first one, what do I plug it into...just any vacuum hose in the car??...Any particular place?
08-04-2008, 02:40 PM
#11
TGO Supporter
Thread Starter
iTrader: (12)
Join Date: Jun 2002
Location: AR
Posts: 6,819
Likes: 0
Received 2 Likes
on
2 Posts
Car: 1991 Camaro RS Vert
Engine: 350 S-TPI
Transmission: T5
Axle/Gears: GU5/G80/J65
Re: what is your vac in hg at idle
Either one, you have to splice into a hose as there is nothing you can disconnect that wont cause the car to idle differently.
Do not tamper with your MAP one, it needs to be smooth shot.
You can not tap into the one from the purge canister. It will cause twitchy readings.
This leaves
FPR (easiest and correct size)
Brake Booster
PCV
Make your own port.
Anyway, back to original question. Anyone else know the readings of there setup?
Do not tamper with your MAP one, it needs to be smooth shot.
You can not tap into the one from the purge canister. It will cause twitchy readings.
This leaves
FPR (easiest and correct size)
Brake Booster
PCV
Make your own port.
Anyway, back to original question. Anyone else know the readings of there setup?
08-04-2008, 04:13 PM
#12
Supreme Member
Join Date: Aug 1999
Location: sweden
Posts: 2,441
Likes: 0
Received 1 Like
on
1 Post
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
Re: what is your vac in hg at idle
415" 9.0:1 big cam 9" hg (70kPa)
415" 8.7:1 smaller cam 12"Hg (60kPa)
/N.
415" 8.7:1 smaller cam 12"Hg (60kPa)
/N.
08-19-2008, 09:14 AM
#13
Supreme Member
iTrader: (8)
Join Date: Sep 2004
Location: Charles County, Maryland
Posts: 1,896
Likes: 0
Received 0 Likes
on
0 Posts
Car: 2000 BMW M5
Re: what is your vac in hg at idle
I have not checked the 327 since I put the roller cam. But-
327, 0.462/0.482", 219/229@0.05, 10-11" at 850 idle
327, 0.462/0.482", 219/229@0.05, 10-11" at 850 idle
Thread
Thread Starter
Forum
Replies
Last Post
