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Blow off valve for boost control

Blow off valve for boost control

Blow off valve for boost control

(OP)
I the case of a defective wastegate,can a blow off valve be used for boost control?

RE: Blow off valve for boost control

It would act as a safety valve , I suppose.  You would need one that could handle very high cfm . REALLY noisy and ---WHY THE HECK WOULD YOU WANT TO DO THAT ANYWAY???


Rod

RE: Blow off valve for boost control

(OP)
Someone has been tampering with the wastegate controls,and some are in the bin,never to return.I have no information on the vehicle,and parts supply is nonexistant.Just looking for an easy way out.

I would set it up like a friend of mine did - a seperate exhaust system complete with muffler,that should control the noise.Anyway,it has to be noisy so I can hear over the boom box!

The vehicle in question is a 1987 Daihatsu Charade GT ti,DOHC,3cyl.Not totaly rare,but thin on the ground in my market.

RE: Blow off valve for boost control

Your fuel/spark system will probably hate you. You will also wear out your BOV quickly (using it alot more than you normally would) and if its not adjustable you will probably need a smaller one anyway (unless you are planning on upping the boost to where it blows off anyway).


-=Whittey=-

RE: Blow off valve for boost control

If the wastegate is still intact, and just not hooked up, then you can rig up a manual controller that will work very well.

A bov can regulate boost to some extent, but it doesn't do a good job of it. With an inactive wastegate (closed) the turbo will generate as much boost as possible. The engine will most likely not be able to handle the boost pressure. If you have the BOV vacuum port connected to the intake manifold, it will maintain compressor pressure x psi above manifold pressure. It will bleed off the extra boost, but if you floor it, you'll still get full boost. Using the throttle to control boost like this is a bad idea, you'll end up wiping out the thrust bearing in the turbo because of the large pressure differential across the turbo. (happened to me a few times until i figured it out)

So... if the wastegate can is still there, and you can move the arm, then i can help set up a boost controller for you.

RE: Blow off valve for boost control

(OP)
Thanks for the help,the wastegate is opperating,but I am concerned about missing electical valves,I don't know what they were or what they did.I will drive it with a guage on today and see what it's doing.

RE: Blow off valve for boost control

(OP)
10psi boost,this motor outs 100hp from 1000cc.It's getting up there,but not tooo high a boost.

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