car is now over boosting :/ ????

Hi

I have yet another problem its over boosting and big time of the scale on the standard one and almost 2 bar on aftermarket one :shock: :doh:

the car currently has the pipe going from actuater to t piece then wastegate solonoide then to plenum so basicly standard :/

cant get my head round it

could it be actuator has goosed

thanks

sam
 
solved it its the turbo/wastegate solonoide is playing up i took it off and im getting 0.9 pressure insted of the 2 bar i was getting before so i will leave it like that till i find a replacement.


thanks

sam
 

PobodY

Moderators
Staff member
The factory solenoid? It's probably stuck open and is just bleeding all the boost off; without a restrictor in the line it's pretty easy for that to mean unlimitted boost.

Just use a Dawes device (or similar) instead?
 

PobodY

Moderators
Staff member
No, it's not the same... although it may look like it.

Essentially it's a mechanical boost control device using a spring and ball bearing to keep the boost away from the wastegate actuator until you reach the set point (which is set by adjusting the tension on the spring, thus the pressure required to shift the bearing out of its seat).
There may be a little hole which looks like a bleed port, but that's just to ensure that there is no back-pressure on the mechanism.

A bleed valve works by just letting some of the boost escape (thus the name) so that the actuator only sees a fraction of the real pressure, thus only opens when the pressure it sees reached whatever it's set at (0.5bar as standard).
Interestingly, this is pretty-much how the factory boost control works; when the solenoid is closed all the boost goes to the actuator (thus you get a "low boost" setting), when it's open it bleeds boost back into the induction pipework (thus you get the "high boost" setting).

The dawes-style device acts a little more like the after-market boost control; in theory the actuator sees nothing until you reach the set point, so the boost should build quicker as there is no partial opening of the wastegate until you reach the set point.
In practice I don't know how true that is.
 

stumo

Active Member
how does the dawes device work? isnt it the same as a bleed valve but with 2 nipples insted of 3 on a bleed valve?
a bleed valve bleeds off pressure and a dawes doesn't.

bleed valves belong on Fords only.

if anyone fits a bleed valve to their R and it blows up i will laugh my cock off.
 

PobodY

Moderators
Staff member
bleed valves belong on Fords only.

if anyone fits a bleed valve to their R and it blows up i will laugh my cock off.
I think it's the same with those Bailey single-piston dump valves; they only work on Fords and cause normal cars not to idle right.
 
Top