dump valve
Turbo Mini Forums

Driving my car specially in high revs the dump valve seems to be open and piss air out is it meant to be? and its how avonbar said to have it got the return to the inlet and the dump valve in a T near as pos to the plenium chamber, but it's got to be lossing power piss air out all the time!! would a stronger dump valve be better e.g. piston type

http://www.Zeemax.com

how much boost are you running? have you plugged up the old valve in the plenum? what dump valve are you using at the minute?

where abouts you talking about? cos everything taken up at the mo! the only thing that i've heard thats different to some others is a pipe on the carb just above the one you block off and the fuel in. people block that off as well instead of joining it to the one the top which is just in front the plate that holds the accelerator cable like i've done! I'm only running about 5 psi lol sounds like it leaking though i'm running diafram i'm not sure if i'd be better with a A series one though but there masive

http://www.Zeemax.com

surely its not ment to be like that it sound not very good

http://www.Zeemax.com

Any ideas

http://www.Zeemax.com

The standard blow off (dump) valve located in the plenum chamber is probably the cause of your problem if it still has the standard spring.

this help?

i think your right but do i have to do to fix it??

http://www.Zeemax.com

dont want to barge in tom & gav but i thought a disassembled pic may be better?

you can see the spring and the valve seat hole etc

some chaps fit a stronger spring or blank this off with running a 3/8" BSP tap straight down as the hole is the right size to except the tap

then use a taperd hex plug with a little tape ptfe tape on

some pack the spring to give a higher pre load

but the best is just to blank this off permanentley


hope this ones a little better ?? best i can do with my
steam powerd camera

Edited by BENROSS on 28th Jun, 2005.

I welded over the hole in mine

Team Racing

Ben,
Can I borrow this pic off you for referencing in another post?

is the other post about wheely bins?

Team Racing

its yours dave next time i place a pic its got to be a better background

lol..... at jimster

having said that if you wait i will take another tomorrow
better laid out and a better background

and replace the one above

i just packed mine full of 5p's

Is there anyway of doing this on the car cause i don't really want to take it off cause i seem to get problems and it works at the mo

http://www.Zeemax.com

Not really... You could drive slower, or wind the boost down. That will solve it.

do you block both holes i cant remember?

there's only one

you have to split the plenum zeemax like in the pics

no big deal!

On 27/06/2005 23:05:23 bud666 said:

i just packed mine full of 5p's

Team Racing

I drilled through the solid half, and threaded it M6. I then put a bolt in, and a flat plate underneath the spring, to allow me to adjust the pre-load on the spring, thus allowing me to still have a degree of overboost protection, but making it easier to set up.

good idea tom

i've thought of idea!! would this work! since the return is pulling the dump valve open to much to stop that i could put a bleed valve in the line on the return

would it work?

http://www.Zeemax.com

But from what people are thinking its not the dump valve hissing.

but yeah a lot of people find a bleed valve in the vacuum line prevents the diapraghm from being pulled open on idle but still leaves enough pressure for it to work, its commonly seen. THIS IS IF ITS LEAKING ON IDLE ONLY!!

Ive just re-read your original post and you say its higher up the rev range. This will be either a split diaphragm in your DV (they dont last that long!) or it could be as everyone has suggested and its the overboost valve in the plenum thats leaking due to running more boost than it was either handle OR the spring having gone weak over the years.

Edited by iain on 7th Jul, 2005.