idle vacuum

[2010Elanore]

In my Sig are my mods, only getting around -6 or -7 pressure at idle. Is this normal with a lope cam? Checked for leaks, nothing I could see.

 

[andyman]

In my Sig are my mods, only getting around -6 or -7 pressure at idle. Is this normal with a lope cam? Checked for leaks, nothing I could see.

That's what it did for me, couldn't stop the car so I got a separate vaccuum pump and put that in and that took care of the problem.
http://www.s197forum.com/forum/showthread.php?t=23187

 

[2010Elanore]

You got a part number for that please?

 

[2010Elanore]

Never mind I got it.

 

[2010Elanore]

What about just a different vacuum can? Just an idea. Anyone know which one would work best?

 

[andyman]

What about just a different vacuum can? Just an idea. Anyone know which one would work best?

If you can wait until mid april i can sell you one already rigged up...

 

[JeremyH]

Thats way low for nsr cams. what compression on the motor?

Do you mean -6 or 7 in/hg vaccum right?

 

[2010Elanore]

Just the stock motor, it is really weird. It has been checked for leaks 3 times with no luck. I wish I knew what the hell was going on. What else could play a role in the vacuum at idle? I am getting -10 or -11 on decel.

Also, yes i meant in/hg. Sorry about that.

 

[stang67gt]

what gauge are you using? sounds more like negative psi rather than in. Hg, as 1 psi is roughly 2.03 in Hg. so your negative 6-7 would be 13-14" vacuum and 22" on decel.

 

[JeremyH]

what gauge are you using? sounds more like negative psi rather than in. Hg, as 1 psi is roughly 2.03 in Hg. so your negative 6-7 would be 13-14" vacuum and 22" on decel.

Exactly my thought as well.

 

[JeremyH]

My car with turbo, cams, and 9:1 compression sees 17-18 in/hg at idle but i still see the full 22-23 in/hg at decel.

 

[2010Elanore]

I am using a glow-shift
http://www.glowshiftdirect.com/Blue-Digital-Boost-Gauge.aspx

 

[2010Elanore]

Can the tune make any more vacuum or is it just a hardware issue?

 

[JeremyH]

Adjusting the idle in the tune can maybe change the vacuum 1-2 at most.

 

[JeremyH]

May be your gauge, im not a fan of digital/electrical boost/vac gauges.

Is it hard to brake?

 

[2010Elanore]

Not really. Never has been low like this

 

[JeremyH]

So it didnt use to read this low, and your brakes are fine?

Then its the gauge or the sender.

 

[bullitt boy]

Want to see an idle vacuum come to my house the wife hasn't touched it for months.

 

[2010Elanore]

That's funny. Once I put on the edelbrock I noticed it. It may have been before but just didn't see it as abnormal

 

[JeremyH]

Yeah with only 6-7 vac your brake booster would be hurting and the brakes would suck.