Ok. I'm v confused about dump valves
Turbo Mini Forums

I've searched the forum and have come across the following facts:

* Diaphragm DVs are better than piston DVs as there's no seal to be perished by fuel vapour
* Diaphragm DVs are best if the diaphragm is replaced by a Kevlar one
* There is no factory fit DV (recirculating or otherwise). So fitting one is a 100% DIY job.

Are these 3 points correct? If so what DV is loudest on a Metro Turbo lump at standard boost? Furthermore I have seen the Avonbar carb' spacer that has an integral vacuum adaptor for fitting a DV - is this recommended?

Oh yeah - and can anyone tell me what diameter the pipe is that I need to cut to insert a T piece into so as to fit the DV? i.e. what diameter T-pieece should I get? Ta!

Methinks I need a kindly soul to give me verbal walkthrough from A-to-B-to-C on the selection & fitting of a DV...

Jim

Edited by Jim on 4th Mar, 2004.

Right here goes:

All 3 facts are correct, its the o-rings that swell and cause the piston to stick apparently but mine was fine all the time i had it (lemans group A).

There isnt a std DV as such, more a over boost valve located in the plenum set to go off if boost goes aver the set limit. 10psi i think on a std metty turbo.

The best place to mount is as close to the carb as possible so most people put a piece of 25mm tube onto the plenum. on the flat sloping side near the bonnet. A rad top hose will do for a pipe to connect this to the DV.

If an intercooler is fitted then you may be able to fit a T-piece into the intercooler plumbing, see my turbo van pics in the "show us yours" section.

An vacuum take-off from anywhere is good. Try give it its own take-off so it gets a good signal. The inlet can be tapped and fitted with a nipple if you like. I used the servo take-off as it was redundant on my car.

Sure ill/others will think of more.

Iain :)

i was going to ask something here but ive decided to put it in a new thread

Edited by Carl on 5th Mar, 2004.

no longer a series, but still 1.3 turbo.

i fitted a dump valve on my metro turbo engine but found it didnt make much noise so i capped the standard overboost valve on the plenum it now works 100%

mini williams sells plenums with the dv take off but not sure on price

always looking for them bigger bunches of bannanas

does that stupid little popet valve on teh buterfly not interfere with the vacuum?

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

you shouln't really see any vacuum in the plenum - other than the restriction induced by a blocked/restrictive air filter...

sorry, i ment the vacuum in teh manifold caused by the shutting of the throttle plate which actuates teh dv

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.