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Mysterious vacuum unit

Posted: Tue Jul 03, 2012 1:38 pm
by Titan1995
I am currently at a centre having a custom made stainless steel exhaust for my 2.5WLT Auto Bongo. There a vacuum unit fitted close to the first flexy pipe.

I hope that this does nothing special as I it is now not going to be part of the exhaust system.

Cannot post a picture as in the exhaust centre right now.

Hope someone can identify .

Re: Mysterious vacuum unit

Posted: Tue Jul 03, 2012 1:44 pm
by g8dhe

Re: Mysterious vacuum unit

Posted: Tue Jul 03, 2012 1:49 pm
by Tomo 53
You can remove it and blank of the vacuum hose with a 6mm screw, it is not needed in the UK . but when in ice and snow it is closed and so causes faster engine temperature climb.
lots of info on this site about it Ady (northern bongalow) is working on an idea that it could save fuel.
most folk just bin it .

Re: Mysterious vacuum unit

Posted: Wed Jul 04, 2012 11:34 am
by steveyd
Hi,

I've just fitted a 4 part system to mine - or attempted to: if you have the vacuum unit the extra "elbow" joint between the vac unit and the flexi-pipe/silencer is very hard to get right. I ordered 2 off the web and both had a badly made flange which meant it would'nt sit on the warm up valve correctly. The supplier was very helpful and said they could not source any more of these bits as they were so hard to fabricate and couldnt get any more.

I ended up using the elbow from the old system but I'm going to have to get some thermosteel and a bandage on it to seal the split on the weld. My advice is to do exactly what you've done:

Buy a stainless replacement and lose the warmup valve- I would have done but fundage is tight. However - I'm very interested about the fuel saving idea!

cheers,

Steve

Re: Mysterious vacuum unit

Posted: Wed Jul 04, 2012 1:12 pm
by Northern Bongolow
tommo has made it sound like a wonderful invention 8) .
my theory is that that if you use the warm up valve (as i do everyday) the motor warms up quicker whilst on tick over, giving you more efficient driving earlier, and enables top gear lock up earlier. if you do several cold starts a day this potential fuel saving could be considerable over the year.

Re: Mysterious vacuum unit

Posted: Wed Jul 04, 2012 1:19 pm
by Driver+Passengers
Northern Bongolow wrote:tommo has made it sound like a wonderful invention 8) .
my theory is that that if you use the warm up valve (as i do everyday) the motor warms up quicker whilst on tick over, giving you more efficient driving earlier, and enables top gear lock up earlier. if you do several cold starts a day this potential fuel saving could be considerable over the year.
If you've blanked off your EGR, can you still use this 'baffle'?

Re: Mysterious vacuum unit

Posted: Thu Jul 05, 2012 2:49 am
by Northern Bongolow
yep.

Re: Mysterious vacuum unit

Posted: Thu Jul 05, 2012 3:10 am
by Northern Bongolow
steveyd wrote:Hi,

I've just fitted a 4 part system to mine - or attempted to: if you have the vacuum unit the extra "elbow" joint between the vac unit and the flexi-pipe/silencer is very hard to get right. I ordered 2 off the web and both had a badly made flange which meant it would'nt sit on the warm up valve correctly. The supplier was very helpful and said they could not source any more of these bits as they were so hard to fabricate and couldnt get any more.

I ended up using the elbow from the old system but I'm going to have to get some thermosteel and a bandage on it to seal the split on the weld. My advice is to do exactly what you've done:

Buy a stainless replacement and lose the warmup valve- I would have done but fundage is tight. However - I'm very interested about the fuel saving idea!

cheers,

Steve
check the end of this thread. ive posted a bit more.
http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=54168