hi baz its a forge twin piston suppose its a blow off valve ,gonna put some new breather pipes on tomoro then i will post pics and you can tel me if i have it right or not since i put the pipes on like i said it dumps air when changeing gear and the boost gage works now but not running right as we set up the timeing ,carb etc without all these connected and soon as you put these on she pops ,farts and misses if u get me as needs setting up right ....will post pics in the mornig so you can see what i meen .......thank you

gonna go get all new hoses from gsf in the morning will put them on and give you all loads of pics as i need my buggy finished and trust me i am learning as i go ...take bloody pics lol

its a forge universal twin piston dump valve 

If it is a dump valve do not run your engine. You're venting an air fuel mixture to atmosphere every time it activates, that's a fire waiting to happen. As Zebethyal said, in a draw through system, you don't need a dump valve. I'll try to explain again:

On a blow through system, the turbo is before the carb. That means it can spool up and pressurise even though the throttle plates are closed. This can damage the turbo, so to stop this from happening a blow off valve (dump valve) is installed. This actuates when the throttle is closed so that the excess pressure between the carb and the turbo is vented.

On a draw through system (like yours), the turbo is after the carb. That means when the throttle is closed, it is spinning in an almost vacuum, as there is no air being supplied (the throttle is closed and before the turbo). Due to this a blow off valve is not required, as no pressure is being built up to blow off.

Until you get those pictures on here and get some feedback, do NOT start that engine!

I've just looked at some pictures of the engine in the buggy's for sale advert, you have a blow through setup, panic over. You can (and should) run a blow off valve. The blow off valve should have its source signal from the manifold (or beneath the butterflies on your carb). From your description it sounds like you have an extra connection, hopefully the pictures will clarify what is going on.  All you need is manifold to tee piece, the tee should go to your boost gauge on one side and the blow off valve on the other side. Looking at the picture, you have an internal wastegate so no worries about plumbing that up. For the pictures, I'm most interested in the connections at your manifold and on your carb.

thanks baz ...paniced when first read it lol..pictures soon buddy

hope these help you help me ,its defo dumping now etc and turbo spooling just missing and burbling etc ..just red up in my turbo mania book and on a turbo mated to vw aircooled engine the oo9 mechanical should be set at 24 degrees advance btdc so think i may need to do that as its missing as its set at 10 degrees advance btdc as it normally would ,but it says this is fine if its a turbo distributor is this correct baz...cheers chris

From what I've researched, it sounds like you've connected everything right. I assume the hard line in the tee goes to the boost gauge but I can't see in those pictures where your manifold connection is.

Regarding the timing, you're confusing the total advance (24 degrees) and the initial advance (which is 10 degrees according to what you've said). You want the total advance, when the engine is running at 3k rpm, to be 24 degrees btdc. The problem with that is, your timing will be too retarded at lower engine speeds. You can either lock your dizzy to a set timing or limit it, the latter being the better choice of the two. For more explanations about that and more turbo stuff, the best thing for you to do would be to go here:

http://www.shoptalkforums.com/viewforum.php?f=3

And do as much reading on turbo's, 009's, timing etc as possible.

got it all running now ,set it at 20 degrees btdc as trial and error at the moment its dropping air etc ,but not at low revs it seems like you gotta boot it to get boost and i cant do that ,how can i get it to give better boost at low revs etc.....the thing is i overhauld all the engine ,newly refurbed carb ,widend venturi,electronic distributor ,new barrells and pistons ,you name it i did it lol...it also had a standard 009 with points so basically its all totally changed and needs setting up as is ....any advice buddy
thanks chris

Is that 22 degrees total advance? What dizzy are you running now?

electronic one buddy ...accuspark see its running fine now dumping etc ...but boost is only at higher revs think my problem may be it has to be 24 degrees bang on?

Your timing has nothing to do with boost. The boost coming on at higher revs, is this a new symptom or has it always been like that?

used to come in a lot lower....


i am miffed to be honest ,dosent drop the air as early either

Sounds like its not building up the pressure. Could be a leak in the system.