Go Back   EcoModder Forum > EcoModding > Success Stories
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 12-29-2008, 06:42 PM   #1 (permalink)
EcoModding Lurker
 
Join Date: Dec 2008
Location: Canada
Posts: 8

The Beast - '89 Chevrolet G30 (Cube) Cube Van
Thanks: 0
Thanked 0 Times in 0 Posts
Tach & Vacuum Gauge Installed

Well, after reading about how poeple are improving their driving skills by literally installing a piece of instrumentation on their dash, I took it upon myself to try this method and now see why many are opting for this route.

I had absolutely no idea the amount of fuel you could save alone by just installing a vacuum gauge to monitor how heavy your foot is on the pedal.

For the TBI (throttle body injection) GM guys, instead of drilling into your intake and tapping the vacuum gauge in through that route, or running t-fittings into vacuum lines, there is a 9/16" bolt just below the air cleaner directly on the TBI. I used a male compressor coupler and bolted that into this area and hooked my vacuum line directly to that. No drilling, coupler was a direct bolt-in and literally took 5 minutes.

I am noticing that at idle my truck runs at 20 on the vacuum gauge and under load depending on what I am doing and how I am driving it averages about 8-12.

At 60 km/h, I am running at about 2200 rpm and at idel 800-900.

This is a cube van with a 14' box and has a 350 5.7 liter with a 3spd tranny. Before these two installs, I was averaging 27 liters per 100/km or 11MPG. I have just installed these two pieces and switched out the old fuel filter and cleaned the TBI. I will advise on what sort of fuel savings I am getting into within the next couple of fill ups.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 12-29-2008, 07:37 PM   #2 (permalink)
Cause I'm an 80's Baby!!
 
festivaWES's Avatar
 
Join Date: Dec 2008
Location: Strafford, MO
Posts: 37

Festiva hauler - '02 Chevorlet S-10
90 day: 27.98 mpg (US)
Thanks: 0
Thanked 0 Times in 0 Posts
Nice. I too hope to install a vac gauge on my truck to fine-tune my gas saving driving skills.
__________________
In search of the ideal gas mizer.....METRO
  Reply With Quote
Old 12-29-2008, 07:48 PM   #3 (permalink)
Wannabe greenie
 
Join Date: Aug 2008
Location: Yorba Linda, CA
Posts: 1,098

The Clunker (retired) - '90 Honda Accord EX sedan
Team Honda
90 day: 29.49 mpg (US)

Mountain Goat - '96 Ford Ranger XLT 4x4 SuperCab
90 day: 18 mpg (US)

Zippy - '10 Kymco Agility 125
90 day: 65.03 mpg (US)
Thanks: 5
Thanked 53 Times in 40 Posts
Excellent. Let us know how it goes. I was thinking of installing one in my '96 Ranger with the 4-speed auto, but I'd like to see how well it works for somebody else with a large engine and automatic.
__________________

  Reply With Quote
Old 12-29-2008, 08:59 PM   #4 (permalink)
Master EcoModder
 
Join Date: Aug 2008
Location: South Dakota
Posts: 460

WonderWagon - '94 Ford Escort LX
Last 3: 51.52 mpg (US)

DaBluOne - '99 Ford Escort SE
90 day: 48.97 mpg (US)

DaRedOne - '99 Ford Escort ZX2 Hot
Thanks: 0
Thanked 15 Times in 4 Posts
Quote:
Originally Posted by midnight rumbler View Post
I am noticing that at idle my truck runs at 20 on the vacuum gauge and under load depending on what I am doing and how I am driving it averages about 8-12.

At 60 km/h, I am running at about 2200 rpm and at idel 800-900.

This is a cube van with a 14' box and has a 350 5.7 liter with a 3spd tranny. Before these two installs, I was averaging 27 liters per 100/km or 11MPG. I have just installed these two pieces and switched out the old fuel filter and cleaned the TBI. I will advise on what sort of fuel savings I am getting into within the next couple of fill ups.
800-900 idle rpm might be a smidgen high. If you've got AC, check again with heater control set to off. If that reduces idle rpms a bit, it's fine; you're done. If not, double check manufacturer's specifications.

Engines differ, but if traffic allows 55 km/h @ ~2,000 rpm may give significantly better FE. A bsfc map/chart would be ideal for an initial guess at best speed/rpm for FE, but they are harder to find than hen's teeth. If you can find a dyno chart of torque, power & rpm for a stock 1989 GM 3.7L TBI, that would also be useful

Is 800-900 rpm just an approximation for a steady idle at 8xx +-5 rpm or does it lope? Loping idle indicates a vacuum leak or some other problem.

FWIW Reading a vacuum gauge give a pretty good summary of various other things a vacuum gauge can tell you.
__________________
  Reply With Quote
Old 12-30-2008, 06:41 PM   #5 (permalink)
EcoModding Lurker
 
Join Date: Dec 2008
Location: Canada
Posts: 8

The Beast - '89 Chevrolet G30 (Cube) Cube Van
Thanks: 0
Thanked 0 Times in 0 Posts
Couple things I noticed today.....

Today compared to yesterday was lot cooler +11 Yesterday compared to -6 today. My vacuum gauge yesterday was at 20 and today it is at 16. Is cold a factor when it comes to reading vacuum gauges?

Second.

When I am at 60km/h my trucks RPM's are at 2200 and at 100km/h they are at 3000 RPM's. This is a 5.7 TBI 1989 350 with a 3 spd tranny. Seems a little high if you ask me although this truck is a cube van and is meant to haul.

Is there anyway I can lower the RPM's drastically without putting in a 4spd or swapping gears yet maintain driveability and increase fuel mileage?

I am not sure what the factory gears are in the rear-end on this truck. Something I will have to look into
  Reply With Quote
Old 12-30-2008, 07:30 PM   #6 (permalink)
Wannabe greenie
 
Join Date: Aug 2008
Location: Yorba Linda, CA
Posts: 1,098

The Clunker (retired) - '90 Honda Accord EX sedan
Team Honda
90 day: 29.49 mpg (US)

Mountain Goat - '96 Ford Ranger XLT 4x4 SuperCab
90 day: 18 mpg (US)

Zippy - '10 Kymco Agility 125
90 day: 65.03 mpg (US)
Thanks: 5
Thanked 53 Times in 40 Posts
I think cold is a factor because the engine is actually working that much harder. On my Honda, my normal idle is 21-22, but when I start the engine on a cold morning (<32 degrees), it's 16-17, and then when I let the clutch out in neutral, the extra drag of the cold transmission lube drops the idle to 14-15. Also, higher altitudes seem to reduce vacuum as well, probably because the engine needs to work harder to get the same amount of oxygen in.
__________________

  Reply With Quote
Old 12-30-2008, 09:12 PM   #7 (permalink)
Master EcoModder
 
Join Date: Jul 2008
Location: Russellville, KY
Posts: 540
Thanks: 8
Thanked 33 Times in 27 Posts
Quote:
Originally Posted by midnight rumbler View Post
Couple things I noticed today.....

Today compared to yesterday was lot cooler +11 Yesterday compared to -6 today. My vacuum gauge yesterday was at 20 and today it is at 16. Is cold a factor when it comes to reading vacuum gauges?

Second.

When I am at 60km/h my trucks RPM's are at 2200 and at 100km/h they are at 3000 RPM's. This is a 5.7 TBI 1989 350 with a 3 spd tranny. Seems a little high if you ask me although this truck is a cube van and is meant to haul.

Is there anyway I can lower the RPM's drastically without putting in a 4spd or swapping gears yet maintain driveability and increase fuel mileage?

I am not sure what the factory gears are in the rear-end on this truck. Something I will have to look into
The reason you're seeing the difference in vacuum in colder weather is because it is putting more load on the engine therefore lowering vacuum.

One thing that can be done to change the gearing and is very simple is go to a larger wheel and tire.
__________________



  Reply With Quote
Old 12-30-2008, 10:58 PM   #8 (permalink)
Disco Machine Gun
 
Join Date: Dec 2008
Location: Central Arkansas
Posts: 16

The Hawg - '08 Tazou Chunl LB150T
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Ford Man View Post
One thing that can be done to change the gearing and is very simple is go to a larger wheel and tire.
Haha, I can hear it now
"Cube van sitting on 23's,
I'll be getting 17 mpg's.
Drivin' all over picking up homies.
Deliverin' packages for mad money!"
  Reply With Quote
Old 01-01-2009, 01:33 PM   #9 (permalink)
Cause I'm an 80's Baby!!
 
festivaWES's Avatar
 
Join Date: Dec 2008
Location: Strafford, MO
Posts: 37

Festiva hauler - '02 Chevorlet S-10
90 day: 27.98 mpg (US)
Thanks: 0
Thanked 0 Times in 0 Posts
Your lyrics are tyte yo!

Switching to a bigger tire wheel is going to add rotatioal weight thus decreasing FE and lowering mpg.

There should be an RPO code in the glove box that tells you the gearing.

I know s-10 are these numbers:

GU4=3.08
GU5=3.23
GU6=3.42
GT4=3.73
GT5=4.10
HC4=4.56

G80 - locking differential

__________________
In search of the ideal gas mizer.....METRO
  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Econometer/Vacuum Gauge Installation Guide Johnny Mullet Instrumentation 80 02-18-2015 12:58 PM
If you don't have a vacuum gauge, you're missing out! Clev Success Stories 60 10-29-2010 02:10 PM
10-minute Accord vacuum gauge "install" Clev DIY / How-to 7 09-10-2010 03:53 AM
no vacuum for vacuum gauge? modmonster Instrumentation 2 11-07-2008 07:40 PM
Vacuum gauge problems :( DifferentPointofView Instrumentation 3 05-14-2008 11:04 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com