ilcbbjf

need some help guys a few weeks ago i had a lot of boost problems with my99 uk spec i took it to pts in luton the problem turned out to be the boost solenoid which they replaced withe a bleed valve with 1 bar of boost the car pulls steam train right up to red line im just thinking after reading about the dawes unit would it inprove things further or should i leave the bleed valve one????

dhorwich

Replaced it with a bleed valve....??

First off it is an essential parts of the car the boost soloniod.... if there are any problems with the engine... e.g high intake temps.... high water temp...e.t.c the ecu sends a signal the the boost solonoid to reduce the amount of boost to the engine to prevent damage.... also the solonoid stops you from having high boost pressure in the lower gears i.e 1st and 2nd.....to protect the drive train...

So you definitly need one... also a bleed valve is not as good as a dawes or relief valve.. as it still enables the wastgate to creep... with a dawes the bosst will hit max lower in the rev range and be held for longer.....

I know of a bloke who sells a dawes or relief valve for £25 inc delivery.... they are nearly identical to the dawes but cheaper....

His web site is: www.k1ano.co.uk go to the modifications section and look at relief valve boost contoller..

HTH

Dan

ilcbbjf

thanks for the reply but when you fit a dawes dont you remove the factory boost solenoid anyway thats the point in fitting it!!!!!!!!

UkLegacyT

no mate, as above, solenoid stays. you just plumb in the dawes or bleed valve in the hose going from the solenoid to the actuator. all your doing is interupting the pressure and fooling the actuator into holding more boost

dhorwich

Thought it was like that..!!

Dan

ilcbbjf

i under stand what you are saying but if you read the link on this site which is harryboy`s scooby web site it say the dawes unit goes across the turbo nipple and the wast gate which takes out the boost solenoid there is even a photo of it?????????????

john banks

Most Dawes installations leave the solenoid electrically connected pneumatically disconnected - but if you do not have one you need a resistor across the terminals to fool the ECU into thinking there is one.

A bleed valve should not be a fix for bad boost control - they should make the original system work properly. Bleed valves are more susceptible to environmental conditions than Dawes, and probably result in slightly slower spool up. But the part throttle smoothness is better. The best of all the MBCs is a hybrid = Dawes + bleed hole.

You are losing safety features with any boost control method apart from the ECU.

ilcbbjf

sorry the solenoid is still connected electrically and is disconnected pneumatically what would you recommend do i leave the bleed valve in do i buy a dawes or do i buy a new solenoid at the cost of £115 +vat from subaru and lose the big improvment in power iv`e just got from the bleed valve or is there a way to mix and match all these parts.

john banks

Get a new solenoid from a breakers for about £30-40 if this really is what has failed, but it sounds like you've had a botch job done to be honest. If you then want to use a bleed valve to increase the boost, then you are best doing it with a WORKING duty solenoid.

BruceWarne

Are you sure they fitted a bleed valve?
They didn't perhaps fit a turbosmart boost controller, or something similar?