Just bought and installed a vacuum gauge! - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 10-05-2006, 09:32 AM   #1
Registered Member
 
LincolnW's Avatar
 
Join Date: Sep 2013
Posts: 108
Country: United States
Location: Portland, OR
Just bought and installed a vacuum gauge!

I finally got around to buying and installing a vacuum gauge! Well, it's a boost gauge, but my turbo won't go in for a few more months, so for now I am only using the left side of the gauge. lol

By the way, I bought it from Dax, thanks again!

My goal right now is to go for a whole tank and never go under 10 in/hg. It takes a lot of throttle control and I really have to pay attention to my RPMs, engine load, gear etc. But I believe that staying above 10 in/hg will help me reach my goal of 40mpg.

Any of you experimented with the use of a vacuum gauge? Are you able to keep it above 10 in/hg all the time?
__________________

LincolnW is offline   Reply With Quote
Old 10-05-2006, 08:12 PM   #2
|V3|2D
 
thisisntjared's Avatar
 
Join Date: Mar 2006
Posts: 1,186
Country: United States
Send a message via AIM to thisisntjared
above is better for fuel economy? i thought the motor injects less fuel then the pressure is lower....
__________________

__________________
don't waste your time or time will waste you
thisisntjared is offline   Reply With Quote
Old 10-05-2006, 09:30 PM   #3
Registered Member
 
omgwtfbyobbq's Avatar
 
Join Date: Jul 2006
Posts: 1,516
Country: United States
Yessir, welll.. strictly speaking, the lower the pressure the more efficiently the engine is operating. Now if the driver uses P&G, then shuts off and coasts, minimal pressure while accelerating is good. But I can have efficient engine operation and inefficient/fast driving, which can lead to worse mileage compared to inefficient engine operation and efficient/slow driving. By breaking everything up into an acceleration/deceleration phase, the hope is to combine efficient engine operation with efficient/slow driving.
__________________
Quote:
Originally Posted by FormulaTwo
I think if i could get that type of FE i would have no problem driving a dildo shaped car.
omgwtfbyobbq is offline   Reply With Quote
Old 10-06-2006, 09:21 AM   #4
Registered Member
 
LincolnW's Avatar
 
Join Date: Sep 2013
Posts: 108
Country: United States
Location: Portland, OR
Quote:
Originally Posted by thisisntjared
above is better for fuel economy? i thought the motor injects less fuel then the pressure is lower....
I was speaking in terms of vacuum, measured in inches of mercury, which is how a vacuum gauge reads it.

Basically the higher the vacuum (higher the In/Hg) the better fuel economy. When the throttle plate is all the way open, there is near zero vacuum. When you decelerate the vacuum goes way up because the engine is trying to pull air through the throttle body.

Anyways, I was looking at my fuel maps the other day and they showed that the higher the vacuum, the less fuel that is used.
LincolnW is offline   Reply With Quote
Old 10-06-2006, 07:34 PM   #5
|V3|2D
 
thisisntjared's Avatar
 
Join Date: Mar 2006
Posts: 1,186
Country: United States
Send a message via AIM to thisisntjared
thats what i was thinking when i went to bed after responding...hahaha

for some reason i thought 'under' was left when its definitely right when measuring vacuum.
__________________
don't waste your time or time will waste you
thisisntjared is offline   Reply With Quote
Old 10-15-2006, 03:27 AM   #6
Registered Member
 
GasSavers_irsa's Avatar
 
Join Date: Oct 2006
Posts: 10
Country: United States
I haven't used, or seen, a vacuum gauge in years! My first car, a 1983 Holden Commodore wagon with a 202 ci I6, 2 barrel carb and 3 speed auto, had one. Once I learnt how to use it I always tried to get the most vacuum possible. I'm planning to add a vacuum gauge to the Charade soon.
__________________
Project Charade aim:
Keep it alive to the end of the year .
GasSavers_irsa is offline   Reply With Quote
Old 10-16-2006, 12:56 PM   #7
Registered Member
 
Join Date: Mar 2006
Posts: 675
Country: United States
I've got a vacume gauge I've been running on my 89 Honda Wagon, for the last couple of month's. It would be nice to have a real readout of the mileage, at any point in time, however since cash is a big challenge, the gauge is what I have.

Where I find the gauge seems to help, is I have noticed that their seem to be a number of circumstances where I can back off the throttle, just a little and get the vacume to go to around 15 inch's, without losing much or any speed. Once my speed starts to drop significantly, or if I can see I'm pulling a slight grade, I try to pull just enough throttle to maintain the speed. When I find I am going to go down a slight grade, I try to use that to accelerate.

I generally try to run either 5 inch's, for acceleration, or I try to back off the throttle to pull the 15 inch's. Where it is really helpful is the difference between 12 and 15 inch's is very minute, on the throttle, but it seem's to make a significant contribution to the mileage. It seem's to me like, when I am diligent, that I can make a very noticable, positive effect on my fuel use. However it get's difficult to keep myself focused on what I am doing. This is another place the gauge really help's because as soon as I look at the gauge, I realize I am running at more like 10-12 inch's but as soon as I notice, most of the time, I remember to back off on the throttle.

This is probably just a crude imitation of pulse and glide, but it is where the vacume gauge seems to help me, the most.
Gary Palmer is offline   Reply With Quote
Old 10-16-2006, 08:47 PM   #8
Registered Member
 
Join Date: Aug 2006
Posts: 541
Country: United States
Quote:
Originally Posted by irsa
a 1983 Holden Commodore wagon with a 202 ci I6, 2 barrel carb and 3 speed auto, had one. .
If you remember on that gauge it had those colored sections on the dial , with the red band on the left side.
That red portion (maybe labled accelerate or power) should prety well coincide with the vacuum level required to activate the high load enrichment circuit in the carburettor.
Keeping the needle just on the orange scale border of the red , but not going into the red , should give the most efficient acceleration but with the least amount of fuel used.
I had a 173 VB commodore manual and when driven like this was suprisingly fuel efficient - well , for a big car anyway.
onegammyleg is offline   Reply With Quote
Old 10-16-2006, 11:13 PM   #9
Registered Member
 
Compaq888's Avatar
 
Join Date: Oct 2005
Posts: 1,460
Country: United States
My SG2 has it.

I usually ride around 8.8

When I coast in gear it hits 2.3-2.4
__________________

Compaq888 is offline   Reply With Quote
Old 10-27-2006, 02:25 PM   #10
Registered Member
 
Join Date: Oct 2006
Posts: 1
Country: United States
Quote:
Originally Posted by 90CivicStandard
I finally got around to buying and installing a vacuum gauge! Well, it's a boost gauge, but my turbo won't go in for a few more months, so for now I am only using the left side of the gauge. lol

By the way, I bought it from Dax, thanks again!

My goal right now is to go for a whole tank and never go under 10 in/hg. It takes a lot of throttle control and I really have to pay attention to my RPMs, engine load, gear etc. But I believe that staying above 10 in/hg will help me reach my goal of 40mpg.

Any of you experimented with the use of a vacuum gauge? Are you able to keep it above 10 in/hg all the time?
I have and it's a great way to save gas and spot engine problems. I bought a new one I found at http://ideamaster.com/mm.htm for only $5. Great service, good people.
__________________

George Wilson is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 03:53 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.