Okay, I have a CA18DET with t-28 and internal wastegate. This is prolly a stupid question but here goes...

The wastegate is controled by a vacuum/pressure line right?

1) What would happen if I took the line completely off the wastegate and plugged the line so the wastegate is open to the air in my engine bay?

2) What SOULD happen if the motor was running and that vacume line was unplugged and I didnt plug it up, and just left it open?

The reason im asking is that I think either the wastegate is welded so it dosnt move or that vacuum line is clogged. Because my old t-25 ran around 9psi and my new t-28 only runs 6psi.

What can I look for or do to test my theory?

thanks guys, remember im a turbo n00b. lol

-Shane

 

do not unplug this line... esp on a bigger turbo like a t28... 6 psi is what the actuator is set to.. if you unplug this line, it will send it to infinity boost... most likely leading to detonation and utter motor catastrophy. technically.. what happens is that the hose sends x psi from your intake plenum, when you are in boost, throught the line and into the wastegate actuator (round shiny can) this in turns opens a specified amount set by the factory when they built the actuator. The little arm moves and opens the wastegate door... and you hit 6 psi in your case. You will not see the actuator do shit by just free reving your motor hard.. it physically needs to be at least 6 psi for that arm to move.

martin
xat

 

Cool, thanks, yeah I wasnt planning on running it with no line to the wastegate, but what I guess im realy asking is, say my car was idleing and i unplugged the wategate, would the rpms change or do nothing because of the open vacume line?, what should the car start to do upon removal of that specific line? Also, how hard would or should the arm on my wastegate be to move by hand if the car is off or even if it should not move at all by hand?

Thanks again

-Shane

 

unplug the line and the idle goes up... the arm is hard to move no matter what.. almost unmovable unless you are a strongman or something.

martin
xat

 

I thought I'd just share my favorite CA18DET story, that is completely related. Guy buys CA18DET swapped car that he know nothing about. First mod is to put red hoses and accents all over the engine bay. He doesn't reconnect the wastegate line all the way. It comes off. Guy has no boost gauge. Guy is excited because his car suddenly hauls major ass. What he doesn't know is that the turbo is now boosting infinity psi because the wastegate line came off. Turbo snaps the shaft from spinning several hundred thousand rpm. Headgasket blows from too much pressure, and being a CA. Bottom end dies from severe detonation.

Moral of the story: ricing is bad.... I mean, don't disconnect your wastegate line!

 

arg, yall are missing the point of my question, good story but, again say my car is jsut idling, should the rpms drop or idle rough if i were to jsut disconect the line from the wastegate? im not gonna drive it like that, i jsut want to see if the wastegate is geting the pressure/vacuum it needs from the vacuum line or if ther is something worng with my wastegate, im not that big of a turbo n00b lol

thanks again

-shane

 

totaly missed ur post lol, thanks you answerd my quiestion!