this is getting old, added another spring to the wastegate, i cannot get over 3-4 psi when WOT...here is a 1st 2nd gear to redline. I pressure checked from the intercoller to the TB, no leaks. Cheap ebay wategate being forced open?

 

Maybe it's just me , but it sounds like the bov is open ... turbo seems to be spooling fine............. I dunno , have you checked the bov with air pressure ?

 

check the gate and the BOV... Sounds like it is spooling up fine.

 

i have the BOV set light, at idle its just barely seated, I thought the boost will hold it shut?

 

check vacuum lines to wastegate, i know mine was building more boost than the spring. Once vacuum lines were fixed, it was building the right boost

 

if the line to the wastegate was off then it should build more boost.....

other thing I noticed..I have the wastegate set-screw cranked down, i checked the gate with compressed air and it only opens about 1/2" ...Full open would have about 1.25" of travel to totally open, is that enough to bleed off pressure? If not then I definetly have a leak.

 

BOV should be hooked to vacuum at idle and boost to force it open... I think you just found your problem.

 

well.....i was sitting here bored so i tried one more thing, the wastegate setscrew was 1/2 way turned down, i figured what the hell. i cranked it down and went for a ride, its like night and day, pegs the needle at 6 then settles at 5.

 

Glad you figured it out...

 

i didnt want to take the setscrew in anymore because of the short travel of the valve to open, i didnt want it not to open! Dyno on Saturday.....hopefully ill get 450 rwhp...

 

Just to be clear, did you check to make sure you had the same amount of boost going to the top of the BOV? If not the boost in your charge pipe will blow it open not keep it shut.

 

yes, i ran the line from the BOV right to my gauge, it shows the same psi.
I thought the wastgate had to be fully open to bleed off the pressure, but i guess it doesnt take much?

 

Ok let me clear up my last statement. Your reference line that goes to the top of your BOV should see both vacuum as well as boost. That way when you let off of the throttle very quickly it opens the BOV to release pressure (swoosh sound that you hear).

When in boost that same reference line holds the BOV shut to counter act the pressure coming through the charge pipe going into the engine. If you have the top port of your BOV just going to a gauge and not referenced from your intake (post throttle blade) then boost will blow it open causing your problem.

Assuming we are now on the same page my guess is once that is corrected the way you have your WG done is going to cause your boost rise like crazy . I hope this helps.

 

the line going to my BOV is off the intake, I took that line and attached it to my boost gauge, so I know I have boost and vacuum there. wastegate reference is off the turbocharger outlet.

My whole problem was I didnt crank the set-screw down far enough thinking it wouldnt open far enough to control the boost. How far does the wastegate have to open for you to lose pressure, cant be much because I have less then 1/2" of valve opening.

 

Okay cool. As far as WG on my car I didn't touch that screw at all and my WG works great.

If you have to limit your WG in order to build boost then I think you must be lossing pressure somewhere else. Even your lightest WG spring should be able to keep your WG shut until it reaches the limit of that spring. Are you sure that the valve in your WG is completely seated? If the valve isn't closed all of the way that would explain it.

 

I just think its all in the wastegate, its a cheap ebay unit and the spring seem weak, i went to the loacl hardware store and added a 2nd spring inside and that helped alot....It has to be the spring, because I put a fiberglass sock on the outlet , and as soon as I hit 1-2 psi it blew up, meaning its opening was too soon.

 

Okay I got ya now. Keep us posted.

 

Never fails, get the boost set< now my converter is slipping bad...if I floor it at 2500, it spools up nice, pulls to 5000 rpm easy, but im only going 85 mph.....should be over 110 with 3.42 gears....I figure 25% slippage.