has anyone a dyno sheet running with and without dump valve to compare?
Few minutes ago run my rst without d/v and i think my car went much much better! thanks to Rob_DOHC and his d/v outlet cap on his samco's......

 

dump valve should make absolutely no difference to power unless of course it's worn out and not sealing so leaking boost?

 

i don't know... isn't very old! I used a twin piston forge, 4-5 months old..

 

What's the best dump valve to buy I have got a baileys at the mo but I think it's leaking.

Joe

 

Ditto. The Escort RST always drives better without a DV, just the nature of how the injection system works on them. I binned my DV off years ago after trying several different ones. Never looked back and the car won't be running one again.

 

the previous owner on my car has cut into the original pipe and stuck a d/v there lol. its running poorly . Should i just bin the d/v and get a normal pipe or get a fitting kit and see how it goes? its a bailey dump valve dont know if its a twin piston one.

 

RST's run so much better wihtout them. Better throttle response and they seem to pull harder. Took mine of a while back and the car dirves much better, big noticable difference.

 

And without the DV does it do the "Flutter dump effect" like a laughin squirrel noise lol?

 

if your are on mfi, you need to be running 14+ psi for noticable chatter.

 

Not on mfi. If converted to efi it will sound ace!

 

Hiya Tasos, thought i would leave the plug in for you incase!

Mine always ran much better with out a dump valve, plus the noise annoyed me. Not sure it was any faster...... no real need for a dump valve either tbh unless you are running lots of boost

Good luck mate

Rob,

 

Age old discussion! lol
I currently dont run mine, but will try it at some point as I am running 27psi peek boost!
As regards power they make 0% difference as the volume of air and fuel entering the chambers, being compressed, and burnt does not change either way.
There is some debate as to wether response is improved when running big boost... but I have never read or seen anything conclusive.

 

was just told by sitech last week to bin it!

 

Anyone know why its better without?

And can they be set up to dump only at certain boost levels? Like if you peak at 20psi and only want the dump over 15psi?

That way driving with less than full boost would retain good driving feel since working like no DV attatched...

I understand they work via vacuum, but isnt there a spring/adjuster inside which would stop them opening too often?