Boost going crazy over 20 lbs?

[Big Mike]

I have a te 45a turbo hooked up tunner style and when a the track and getting the boost slowiy higher and tuning it with the gas it's fine.I take the dump of the thdp and the boost is up 2-3 lbs and do a pass ,no problem.I get to around 20 -22lbs and go down the track the boost spicks to 30-31lbs?There are no hole in the vac lines (changed them all)The turbo has had the 1 1\8 hole done from John Craig and the puck seats perfectly and the waste gate came with the turbo and I assume it is a high boost acc.Do I add a spring to help the waste gate?Is the exhaust sucking the puck open causing the boost gauge to show 30 or more pounds?Do I go to something else?(Race gate and new thdp)If anyone had the same problem please reply ,season almost over.
thanks
Mike

 

[Big Mike]

Anybody have an idea?

 

[UNGN]

A spring will make it worse.

A high boost actuator should give about 18 psi minimum boost at it's max length.

Is the actuator hose hooked directly to the turbo compressor housing, with no orifice or bleeder?

 

[Big Mike]

yes,tuner style they call this.My friend told me to do this.More accurate boost readings???

 

[azgn]

you just have a piece of vac hose going between the turbo compressor and wastegate, yes?

how tight is the wastegate arm to the puck? With a HD actuator, you don't need it that tight....too tight on a stock actuator could cause the problem you describe

try loosening the wastegate arm and see what happens....on a HD one, you'll see 16- 18 lbs with no tension as UNGN pointed out

on mine, 5 turns from no tension makes 23 lbs boost

 

[Big Mike]

ttt

 

[UNGN]

Use a mityvac or an air compressor and a regulator (set to 16 psi to start) to make sure your actuator doesn't have a hole in the diapham and works properly. It's a long shot, but it may account for the boost raising from the 20's to the 30's.

A sticking puck is also a possiblility, but usually this results in lower, not higher boost.

 

[Big Mike]

Thanks ,I'll try it in the morning.