Gas Mileage in the AC Vanagon, 1980

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luftvagon
Old School!
Location: Little Rock, AR
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Re: Gas Mileage in the AC Vanagon, 1980

Post by luftvagon » Fri Aug 28, 2015 4:27 pm

Colin, just megasquirt your bus already.

luft with squirt
1981 Volkswagen Vanagon Westfalia - air-cooled Type4 1970cc CV (hydraulic lifters, 42x36 valves, stock cam, microSquirt FI with wasted spark ignition)
1993 Ford F-250 XL LWB Extended Cab 7.3L IDI

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Amskeptic
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Re: Gas Mileage in the AC Vanagon, 1980

Post by Amskeptic » Sat Aug 29, 2015 7:40 am

luftvagon wrote:Colin, just megasquirt your bus already.

luft with squirt
When its current L-Jet fails, we will talk about it (some time in 2037)
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

luftvagon
Old School!
Location: Little Rock, AR
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Re: Gas Mileage in the AC Vanagon, 1980

Post by luftvagon » Sat Aug 29, 2015 9:00 am

In terms of vacuum, at 3300-3700 RPM, pulling about 65mph, I'm anywhere between 6.23 inHg to 3.57 inHg. I will need to attach GPS to my logging unit to give you exact numbers. Not sure about head temperatures. Probably significantly lower than with the perfectly factory tuned stock unit. I'm recording about 160-190F through the intake runner bolt sticking out of the head on cyl#3.

Anything lower than 3.28 inHg, and my mixture starts to go from 13.5 AFR to 12.6 whilst approaching 0 inHg.

:digital
1981 Volkswagen Vanagon Westfalia - air-cooled Type4 1970cc CV (hydraulic lifters, 42x36 valves, stock cam, microSquirt FI with wasted spark ignition)
1993 Ford F-250 XL LWB Extended Cab 7.3L IDI

72Hardtop
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Location: Seattle, WA./HB. Ca./Shizuoka, Japan
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Re: Gas Mileage in the AC Vanagon, 1980

Post by 72Hardtop » Mon Oct 08, 2018 11:41 pm

With lean tune cruising it's important to remember the (1) area to stay out of when under load WOT....

14:0 - 15.5:1at WOT (Highest EGT/CHT temps.

Anything under 3/4 throttle and you are NOT hot enough to worry about being to lean AFR wise.

16-17 AFR is where you'll make great MPG's. No leaner than 17 (lean miss w/light load) Lean cruise tune only with vacuum advance distributor or mapped EFI. Not with centrifugal only. With a cracked throttle one is NOT on the main circuit (carbs/s). Main circuit is over ~1/4 throttle.

See where CHT's go from peak lean EGT (leaner)...
Attachments
engine.jpg
engine.jpg (36.78 KiB) Viewed 7034 times
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

cegammel
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Location: Thomasville Georgia
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Re: Gas Mileage in the AC Vanagon, 1980

Post by cegammel » Tue Oct 09, 2018 5:31 am

Holy thread resurrection, Batman!

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Amskeptic
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Re: Gas Mileage in the AC Vanagon, 1980

Post by Amskeptic » Sat Oct 13, 2018 10:12 pm

cegammel wrote:
Tue Oct 09, 2018 5:31 am
Holy thread resurrection, Batman!

Always good to blast reminders from the past. To that end, I have never been able to get a Volkswagen to run at 16 AFR and successfully dive down into the 12s under acceleration without having a dreadful mid-throttle hot zone.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

72Hardtop
Old School!
Location: Seattle, WA./HB. Ca./Shizuoka, Japan
Status: Offline

Re: Gas Mileage in the AC Vanagon, 1980

Post by 72Hardtop » Tue Oct 23, 2018 11:36 pm

Amskeptic wrote:
Sat Oct 13, 2018 10:12 pm
cegammel wrote:
Tue Oct 09, 2018 5:31 am
Holy thread resurrection, Batman!

Always good to blast reminders from the past. To that end, I have never been able to get a Volkswagen to run at 16 AFR and successfully dive down into the 12s under acceleration without having a dreadful mid-throttle hot zone.
Colin
The pleasures of an IDF or Dell set up.

Define a mid throttle hot zone.

If your on the main jets (not part/cracked throttle) under load (correct jetting) you should be ~ 13:0 - 13:5 or so. But if you are loafing along on the highway flats or around town there is nothing wrong with a lean tune cruise of 15:5 - 17 AFR.
1972 Westy tintop
2056cc T-4 - 7.8:1 CR
Weber 40mm Duals - 47.5idles, 125mains, F11 tubes, 190 Air corr., 28mm Vents
96mm AA Biral P/C's w/Hastings rings
42x36mm Heads (AMC- Headflow Masters) w/Porsche swivel adjusters
71mm Stroke
Web Cam 73 w/matched Web lifters
S&S 4-1 exhaust w/Walker 17862 quiet-pack
Pertronix SVDA w/Pertronix module & Flamethrower 40K coil (7* initial 28* total @3200+)
NGK BP6ET plugs
002 3 rib trans
Hankook 185R14's

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