vacuum gauge on an air cooled vw.?

[yostumpy]

Hi again. Apart from Wallace (land rover) I've also got a '76 vw bay window camper, 2000cc air cooled with twin solex carbs. local runs, about 22-23 mpg (imp) longer 26-28 mpg, and a couple of times on motorway tailing truck with a tailwind, I got 33mpg. Now all these figs are above avg (excl last one!!) more like 17-18 local and 23-24 on a run, so I must be doing something right. Now can I run a vacuum gauge on an air cooled bus, and will it do me any favours? I haven't driven it for about 3 months, as its winter, so not tried the eco thing, but vw engines like to be revved freely, and not lugged at ALL, so would a VG encourage me to drive the bus wrongly.

[bestclimb]

nothing different between aircooled and waserboxers, in regards to what is happening between the throttle plates and the intake valves.

[gone-ot]

...a vacuum guage would definitely encourage you to drive CORRECTLY, not wrongly, because you'd still be "aiming" for highest vacuum value at whatever speed you're driving.

[mort]

Hi yostumpy,
A vacuum gauge probably won't help you, especially in a VW van.
Imagine that every driver can be described on a spectrum from aggressive to economical. Aggressive: jack rabbit starts, goes as fast as road conditions allow, short stops, no coasting. Economical: follows the advice given here.
It turns out that the average driver is aggressive most of the time. What a vacuum gauge does is shows those aggresive-ish drivers how to drive more economically. Moderate accelerations, low power cruising, coasting between stops.
But if you are reading ecomodder.com you are likely beyond using a vacuum gauge. You will know about bsfc maps, pulse and glide and more. Things that a vacuum gauge probably is more misleading than helpful.
The VW is under powered so you'd be frustrated trying to not get rear-ended while keeping the gauge in the economy range.
-mort

[kingsway]

I've used a vacuum gauge in the distant past. I don't think it helped much, because it didn't really give me the positive feedback I really needed.

With my new Ultragauge I can see my instantaneous consumption and am much more positively influenced to 'tread lightly'!

However, I am in the process of buying a vacuum gauge for my wifes car. I'm hoping it might help her to drive more economically - but only time will tell!!

[yostumpy]

Originally Posted by mort

Hi yostumpy,
A vacuum gauge probably won't help you, especially in a VW van.
Imagine that every driver can be described on a spectrum from aggressive to economical. Aggressive: jack rabbit starts, goes as fast as road conditions allow, short stops, no coasting. Economical: follows the advice given here.
It turns out that the average driver is aggressive most of the time. What a vacuum gauge does is shows those aggresive-ish drivers how to drive more economically. Moderate accelerations, low power cruising, coasting between stops.
But if you are reading ecomodder.com you are likely beyond using a vacuum gauge. You will know about bsfc maps, pulse and glide and more. Things that a vacuum gauge probably is more misleading than helpful.
The VW is under powered so you'd be frustrated trying to not get rear-ended while keeping the gauge in the economy range.
-mort

Thanks Mort! thats kinda what I was thinking, but being a novice wasn't sure. The bus ,even the 2000cc, is underpowered, but when tuned right has a very nice and definate 'sweet spot' and because of its mahoosive flywheel, once rolling you can feather off the throttle quite a lot for no loss of momentum. It also, from memory, rolls quite freely, compared the the landrover anyway,so coasting should be good, can't wait to try the eco thing with 'Pamplemousse', got a few trips planned for the better weather.

[yostumpy]

Resurecting this old chestnut, the heavy unseasonal rains have finally abated, and 'good ol' pamps' is back on thr road. First tank was old gas (8 months old) so didn't worry and got 22.5mpg, next tank of fresh, getting used to the way the bus rolls etc, its 26.5mpg, I know I can do better aiming for 30mpg. The engine has tinw Solex carbs, its well in emmisions etc and runs sweet, but the carbs have an accelertor pump on each carb, so when you pump down it squirts more in. Now my question is one of acceleration, With my landrover the Bspc thing said to accel, hard up to 18oo-2000rpm because of the deisel turbo, but is this the same for a twin carb aircooled,coz thats a lot of gas being sqirted in each time. Or am I better with moderate accel. Anyone know of a Bspc graph thing for a carb 2000cc VW aircooled.

[RobbMeeX]

Don't really know, but jake raby knows VW TIV motors. What size solexes?