AJ-RST1

iTrader: (2)

as above people.

orion_crazy_carl

iTrader: (3)

primitive boost controller,wind it out for boost wind it in for less!!!u take out the amal valve,it goes between the turbo and actuator

Turbocabbie

A Bleed Valve does what the name suggests as it bleeds off boost pressure before the actuator, it fools the actuator into believing that its running lower boost than it really is. The problem with bleed valves is that although cheap they raise the boost pressure without ensuring that the ECU is making correct adjustments to the fuelling, which can cause the engine to detonate leading to premature wear and engine damage. They also remove the boost limit, rendering the ECU unable to shutdown the engine if a problem should arise.

Its a pikey cheap way to increase boost and although many people will tell you there is nothing wrong with them reputable tuners in general use a different approach to raising boost. I would not use one

Stu @ M Developments

iTrader: (12)

What you have said is mainly correct, however:

This isnt true. Turbocharged cars boot levels are monitored via the map sensor and the limits are NOT altered in any way by correct fitment of bleed valves.

Also, all Ford Rs Cars of the 80s and 90s came with an electronic bleed valve fitted. You know it as the amal valve. It just has a solenoid to open and close it instead of a screw.

Bleed valves are fine when used correctly. They are also deadly in the wrong hands, as are amal valves when idiots mess with the jets. (Same effect as messing with the screw on bleed valve )

Turbocabbie

Thanks for the correction, better to be an idiot once than for life always happy to learn something

The biggest reason I hate bleed valves is that by nature of being cheep they are usually installed by people who do not wish to pay the price to have the car set-up properly.
Its people like this which often give the impression to others that the RS is unreliable or use the issues created by DIY tuning and tampering to damage tuners reputations (as they only take the car to a tuner when its really messed up).

If you want to change you car get it set-up right for the fuelling, its the only way imho.. it will not only save your engine but it will pay for itself long term with better fuel consumption and reliability

AJ-RST1

iTrader: (2)

well good job my series 2 is in jamsport for a engine set up on rollers aint it? i dont have a bleed valve anyway. always wondered what they were

SWITCHBLADE

iTrader: (5)

jamie at jamsport uses bleed valves, he fitted one to mine when he fitted my gotech ecu etc. its perfectly fine when its setup by someone who knows what theyre doing, the problems come from people who either fit them themselves and just wind the boost up or people who play with them once a tuner has set the car up.

yes there are better ways of controlling boost but for the amount they cost and also how easy it is for a decent tuner to fit one and then setup CORRECTLY they can save us alot of money compared to buying say an electronic controller and then paying somebody to fit it and set it up.........most important thing i suppose is if you get one fitted by a tuner, leave it alone !!!!.

dave

Karlos G

iTrader: (4)

For the price of an good ajustable -31 actuator (collins, forge etc..) about £70 why bother with a bleed valve? They are cheap, but i agree they are a pikey way of ajusting your boost, i've even seen one work it way open through vibrations sending the boost level way beyong what the fuelling was set for!! If you cant even afford a decent actuator that then you cant afford to run/maintain a RS in the first place!!

SWITCHBLADE

iTrader: (5)

ask a tuner why they fit them then, ive got a -31 actuator on my stage 3 turbo but the bleed valve was still fitted by jamie at jamsport, i think its fair to say jamie knows a little more about rs turbos than most of us, no ????.

as stated before, bleed valves are fine if fitted by someone who knows whats theyre doing and then left alone.

if worried i think some people fit some locking wire so they cant be adjusted or come loose on their own.

dave.

Karlos G

iTrader: (4)

Fair play switchblade but i dont see why you would need two forms of adjusting boost (actuator and bleed valve) unless you cant be arsed to spend all of 20 mins it takes to adjust the actuator and so use a bleed valve instead, but then you may as well not have the -31!!
All it will do is facilitate rapid boost adjustment, great if your a tuner in a rush to get the next job on the rollers and this one out the door!
But like everyone says if its set correctly and left alone there is nothing wrong with it. I dont have anything against them they do there job perfectly, but if it were me i'd just take the time to set the boost using the actuator.

Stu @ M Developments

iTrader: (12)

Actuators are VERY RARELY fitted on their own. There is normally some form of boost controller fitted as well.

Stu @ M Developments

iTrader: (12)

Decenty bleed valves have huge locknuts and O'ring seals. They dont adjust or leak pal.

http://cgi.ebay.co.uk/ws/eBayISAPI.d...e=STRK:MESE:IT

Karlos G

iTrader: (4)

Stu, why are actuators rarely fitted on there own? Surely once you've set the desired boost level and the fuelling to match you leave it alone? I know some people like to be able to run less boost for daily driving and then open it up as and when they feel like it, but that is just personal preference.

"Decenty bleed valves have huge locknuts and O'ring seals" yeah the one i was talking about was a cheapy ebay item not one of yours mate!!

sm

nothing wrong with bleed valves, just the idiots who play around with them, totd fitted mine when they set the car up and its been fine since (lockable one)

one reason not to just use the actuator for boost control is have u ever drove a car hard then needed to up the boost and had to get it on a set of ramps and disconnect the actuator right next to a bloody hot turbo? a garage hasnt got the time to let the engine cool properly so no one gets burnt when adjusting the actuator so having a bleed valve which is easy to get to makes sense

Stu @ M Developments

iTrader: (12)

Because pretty much every production car in the world uses a wastegate control solenoid of some form which allows the ECU to keep control of teh gate and overcome rising turbine hosuing pressures. This is what allows you to keep the boost flat through the range and not tail off massively as revs climb. In a nutshell, the turbine hosuying pressure "Assists" the boost pressure in overcoming the actuator spring, hence the more power you make, the more the actuator actually opens, and thus the slower the turbine spins.

Karlos G

iTrader: (4)

So if i get this right what your saying is the bleed valve will release some of the turbine housing presure to help maintain a constant boost pressure through out the rev range, by stoping the gate from opening to early or by too much?
Is this what the Amal valve is designed to do but only up to stock boost pressures, in additon to being a fail safe and cutting boost if the ECU detects high ACTS or Knocking?
Or does RS Turbo ECU's not keep control of the gate to overcome rising turbine housing pressures, which is why the bleed valve is a useful tool?

Always good to learn more Stu!

Turbocabbie

This statement suggests that although rare, they can be fitted on their own. Under what circumstances would you do this and why ?

Out of curiosity Stu do YOU fit bleed valves to cars, if so why do you choose this method and if not what method do you use and why ?

Also bleed valves from my own perspective vary greatly in quality with a large number of them leaking air themselves, which is also something that I find concerning.
Im yet to be informed of a reason to use Bleed Valves as I am off the opinion that there are more reliable methods to obtain the same results

im not being argumentative Stu, however if I do not question things my knowledge remains the same