Can someone help me? I'm struggling to dump!!!
Turbo Mini Forums

Hi,

I recently bought a diaphragm dumpvalve from avonbar and fitted it to my plenum (one of nic's). I've Tee'd the vacuum hose that goes from my inlet to the megajolt and boost gauge to the other side of the dumpvalve like i believe it should to trigger it.

However it still isn't dumping and i'm getting more "chatter" than when i was running the standard plenum! I'm running about 7psi of boost at the moment, soon to be up'd to 10psi.

I've had a search and tried some of the things suggested in other threads to no avail. I've even tried a friends dump valve (that worked on his mini) to check whether i had a dodgy one.

Cheers,

Guennie

100% BMW Free

whereabout on your inlet does it come from? not through the one way valve on the servo take-off is it?

ive got mine teed off from the pipe that used to go to the brake servo, took out that valve as i dont have a servo, and just used a t piece into that pipe, one for bailey one for guage.

I've got it on the pipe that would normally run to the vacuum advance on the dissy. My boost gauge works with no problem at all off the same one.

100% BMW Free

on my setup it came directly from the manifold, i found that when the throttle was completely closed (well near enough ) the vac advace take off gave no vacuum

Yes i moved to the darkside

Instagram @jdm_brett

With the throtle closed the vac advance pipe sees no vacuum as it is on the plenum side of the throttle disc, not on the manifold side. Idealy drill and tap a conection on the acutal manifold or use a sandwich plate between the carb and manfold with a take off on that.

O right that makes sense. So the boost gauge will work off the vacuum advance take off but the dump valve might not. Is this www.minispares.com/Product.aspx?ty=pb&pid=36947&title=MANIFOLD%20ADAPTOR%201.75 the sandwich plate you're talking about?

Edited by Guennie on 10th Aug, 2009.

100% BMW Free

the boost gauge will work off it but won't show a proper vacuum figure iirc?

TBH the original vac advance is rubbish for most things, as Nick says it's not great for the boost gauge either. I use it for megajolt but on over run with the throttle closed it reads atmosphereic and doesn't give enough advance. That spacer with the vac takeoff should work, mine has a 2-3mm take off which flows enough to trigger the dump valve. I tried using the part throttle lean off pipe conection as a dump valve trigger but that doesn't work.

Edited by Jay#2 on 10th Aug, 2009.

The part throttle lean off pipe will work if you run a 1/8 drill through it first - at least it did on mine.
I now have a direct tapping off the manifold with three outlets -dump valve, boost guage and actuator.

I am moving mine to the Banjo for the break servo. By removing the valve which I believe came from the air filter housing allows you to fit a NPT fitting to tap your dump valve to.

Own the day

Thanks for the info. Hopefully i'll be picking up the spacer with vacuum take off at mitp, so i'll fit it there and dump all the way home!

100% BMW Free

I'm with Mr Joshua on this.

Mine is fitted to the brake servo banjo bolt in the centre of the manifold via an NPT stub take off adapter screwed into the top of the threaded hole in the banjo bolt.

A tee fitted to the outlet of this takes boost to (1) the dump valve, and (2) the boost gauge, megasquirt and boost controller.

Works great.

Richard.

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

i used the sandwich plate thing from minispares and connected my dumpvalve to it, and all i got was a long and delayed shhhhhhhhhhhh sound.

on inspection, the take off was not a straight threw hole, so connected dumpvalve to take off from inlet, and bob was my uncle.

'always keep a spare shot for a stray bird'

100% BMW Free

you may be able to to yeah, ive just used a drilled take off from the manifold.

'always keep a spare shot for a stray bird'

I did the same as mr joshua exept I used a big bleed nipple off a truck or something easy! works a treat