I have already worn out the search button and have learned a lot, but odviously not enough. My setup is basic...306 blow-thhru, s400 head unit w/the stock 71mm wheel, 1.32 a/r, 3in crossover pipe, bbk shorties flipped and cut w/flanges threw all the plumbing..air to air cooler,and a pretty short 4in. downpipe, xo2 50mm bov, and tial 60mm wastegate. I have tried (2) xo2 60mm wastegates and figured I was making to much power for a knockoff so I bought a new tial 60mm wastegate and have had similiar boost creep problems....The tial has the big blue spring ( .637 bar, 9.77 psi ) and it allows the boost to creep to 19 or 20 psi. Its even a fats creep at that.. I took it off the car and applied pressure and a boost gauge to it and it doesnt even begin to open up until 17psi....I know doing it off the car isnt 100% accurate, but it is very close to how it acts on the car...For the reference to activate the wastegate I tapped the compressor housing and it goes straight to the lower fitting on the wastegate, about 18 inches of some thick vaccum hose....No boost controler right now, 1 thing at a time... I'M STUMPED ....WHAT ELSE causes boost creep or what am I missing...

 

If you´re applying that kind of pressure and it just begins to open there it wouldn´t open in the car either. Obviously the spring is off spec. If it begins to open at 17 psi it starts to flow enough gas to control boost at 1-3 psi later that matches your creep measurements. Change the spring. Did you do the same tests with the knock off valves?

 

I had one of those knock offs advertised as a 8 psi spring and it was actually 17psi. The gate should be fully open at the rated pressure of the spring, so if its not, the spring isnt what its meant to be.

 

take the spring out and make a hit to see what it makes!

 

Do you have the small inner spring and the large outer spring in the X02's? They seem to ship them that way. If you run just the outer spring, the wastegate valve should start to open at 8psi and be fully open at 12psi. If you run it with both springs installed, it won't open til about 15 and is fully open at about 18psi. The X02 is not a bad gate, especially for the money. I've run them before. We had to pull them apart and seal all the holes for the adjusters and the lockdown, and also retap the lock down insert. But all in all, they work extremely well.

 

I have not tried with the knockoffs, but I will give it a try for the hell of it. Also I will eventually try it out on the street when traffic dies down....I was just at the track on thurs. so I know the spring that came in it goes to 19psi (lrg. blue 9.77psi rated). When I ordered it I specifically said 15psi and they told me it would come with a lrg. blue and sml. blue spring to make 15.25psi. O well, thats just my luck this season. Thanks for the info guys..

 

ShaneH: With the xo2 w/g they did come with double springs so I have about 6 or 7 springs laying around...I'm gonna try different spring combos. In july I totally wrecked my shit into the wall so I am very adiment on figuring this out. I blew my load to get a new car togther for this year. What sent me into the wall was the w/g very quickly spiked the boost to over 20 psi and the tires broke violently loose about 200 ft out. I have used the xo2 products on mid 10 sec. cars with great success, but I wouldnt recommend going to much faster.....A simple w/g cost me $10,000..

 

Those X02 60mm gates come with 3 springs. They have the largest diameter and the smallest diameter installed in the wastegate together, with the middle diameter spring in the box usually. The largest diameter and smallest dia together give about 18-19psi. the largest by itself will give about 10psi. I haven't tried any other combos on the bench.

FWIW.....I've had turbonetics and Turbosmart gates stick oipen and closed on me. So knowing that, I wouldn't hesitate to use the X02s.

 

I just tried the largest and smallest together and it was at that level (18-19 psi). I also tried the largest by itself and it looks like the valve starts to open at about 6 psi and is full open at about 10psi. BUT the kicker is if I dont stop sending pressure, the boost gauge will go clean to 40 psi....Does that sound normal????? How would it react on the car...

 

That's because you're deadheading pressure inside the wastegate. It has nowhere to go so it keeps building pressure. On the car, it'll go to about 3psi above where it starts to open.

 

It is normal. If the source of pressure you are using has say 100 psi and you don´t close the valve it will rise up to that pressure in the best case, the worst case you will blow the diaphragm.

Remember the waste gate reliefs pressure from the section in between the engine exhaust ports and the turbine housing but the pressure that opens the WG doesn´t go anywhere it´s a dead end at the WG diaphragm chamber it just rises and falls as the system operates normally.

 

awesome. I'm just using a cheap air pump that you plug into the cigeratte lighter with a plastic fitting from a hand pump kit.. It only goes to about 60 psi and has a limited amount of uses, but I like it...Thanks, a rode test is in order.....cool this is some good info. more info " I heard that a tial and xo2 60mm w/g's are interchangable because they have the same flange. Wrong, I had to cut off the xo2 and install the supplied tial flange"..

 

Something also on the ones with adjusters, they sometimes prevent the valve from opening all the way compared to a Tial. We noticed that on the 44mm xo2 vs the tial. The tial would have double the valve lift but when we took the adjuster out and let the spring sit on the top of the WG it opened the same amount. That was what caused our boost creep issue on the twin MPT70 12:1 355 SBC we built.

 

Does the gate have a top hose/fitting on it? Do you have it plugged?

 

The top is vented to the athmosphere. I just used 1 spring and it stays at 10psi... I wanted 15psi, but I'll figure out a spring combo next season or do a boost controller.