Vacuum Gauge Connection ?Signal quality?

[Peternell]

This question and answers will be applied to my 74 260 406/th400 street/strip car but for now apply to my 67 Chevelle 454/th400 with a Holley 780 VS. I'm Installing a vacuum for carb tuning purposes among other benefits.

 

Route separately or tie into existing vacuum line? That is the question.

 

A clean and easy install would be tapping into the steel brake vacuum line adjacent to the firewall and prior to the vacuum canister.

 

Would the vacuum signal be a little slow/lazy or moderated by the larger [1/2†vs. 1/8†or 1/4â€] diameter line?

 

As proposed would applying the brake affect the vacuum signal to the gauge? Don’t want that.

 

I want to monitor engine/manifold vacuum not brake line vacuum.

Is the vacuum signal to a gauge unaffected by other connections along the same line?

 

THANKS in advance.

[Guest VietVet]

You referred to tapping into the vacuum line going to the Brake Vacuum Canister.

Most cars have a one way valve in that line. Do not - Do not tap the line between the check valve and the canister.

 

Better to have a little longer line and tap closest to the intake manifold.

 

Hope this helps.

 

Newbie on this site. Old School Z-Car pilot.

 

Cheers VietVet -

AKA VietVet68 AKA AmyCroft on www.my350z.com see my totaled 350Z

 

http://www.my350z.com/forum/showthread.php?s=&threadid=86865

 

The Vanity Plates have been moved to the 1988 300ZXT Shiro Special.

But it's not the same as on the 350Z Puz Z

( I thought I'd get a G35 Coupe and use the plates - but the G35 guy's

have little or no sense of humor. )

 

 

 

This question and answers will be applied to my 74 260 406/th400 street/strip car but for now apply to my 67 Chevelle 454/th400 with a Holley 780 VS. I'm Installing a vacuum for carb tuning purposes among other benefits.

 

Route separately or tie into existing vacuum line? That is the question.

 

A clean and easy install would be tapping into the steel brake vacuum line adjacent to the firewall and prior to the vacuum canister.

 

Would the vacuum signal be a little slow/lazy or moderated by the larger [1/2†vs. 1/8†or 1/4â€] diameter line?

 

As proposed would applying the brake affect the vacuum signal to the gauge? Don’t want that.

 

I want to monitor engine/manifold vacuum not brake line vacuum.

Is the vacuum signal to a gauge unaffected by other connections along the same line?

 

THANKS in advance.