how much should the car boost if the wastegate actuator is not connected?

A

ahmedsalem89

Member +
Hi guys, I was just wondering the above question because I recently disconnected my wastegate actuator as it seemed to be always open, and now the car barely boost beyond 0.6 par on first,second and third, couldint try fourth road wasn't long enough.
But IT reaches 0.5 pretty quick.
P.S. everything is stock except for a FMIC and a Blow off valve
Thanx in advance.
 
WallaceGlanza

WallaceGlanza

Member +
Theoretically you wouldn't make any boost if the wastegate was big enough - that's the whole point in it. You need the actuator connected and wastegate closed to make boost properly.
 
A

ahmedsalem89

Member +
Sorry I don't get it. I thought that disconnecting the actuator hose will prevent the wastegate from opening, isn't that right?
 
spuddy

spuddy

Ulster Area Rep.
IS the hose of the actuator or the bar off the turbo?

Pipe off = tons
Bar = None or very very little and tons of lag
 
WallaceGlanza

WallaceGlanza

Member +
spuddy said:
IS the hose of the actuator or the bar off the turbo?

Pipe off = tons
Bar = None or very very little and tons of lag
Click to expand...

Ya as above you weren't completely clear, saying you've the disconnected the actuator makes it sound like you've removed it!
 
A

ahmedsalem89

Member +
Sry I wasn't clear, I meant I disconnected the hose from the compressor side to the atuator.
I thought the car should be boosting nuts but it doesn't go past 0.7 par if it even could reach it, but it boosts pretty quick until 0.5~0.6 par.
 
dark_knight

dark_knight

Member +
technically, what you refer to as 'free-boosting' should still limit you to somewhere near the spring pressure of your actuator -- reason being that even with the actuator hose disconnected, exhaust is still pushing against the WG itself, and indirectly acting upon the spring.. so all this depends on what actuator (spring) you have in there..
 
A

ahmedsalem89

Member +
dark_knight said:
technically, what you refer to as 'free-boosting' should still limit you to somewhere near the spring pressure of your actuator -- reason being that even with the actuator hose disconnected, exhaust is still pushing against the WG itself, and indirectly acting upon the spring.. so all this depends on what actuator (spring) you have in there..
Click to expand...

Exactly this is what I've been thinking of, Thanks a ton.
at some point the exhaust pressure will push the wastegate and escape. can anyone confirm that?
BTW I'm using a stock actuator.
so is there anyway to prevent the wastegate from opening? I want to make sure that it's only the actuators' fault just to be sure when replacing it.
 
A

ahmedsalem89

Member +
so why doesn't it boost like this for my engine??
a weak actuator spring? a leaky blow off valve maybe? any Ideas?
is there a way to force the wastegate not to move? so I can test further?
 
350ep70gr

350ep70gr

Member +
If you have disconect the pipe to the actuator and it is boost faster till 0.5-0.7 than with the pipe on the actuator...then just this test is a sign that the actuator is weak enough and need to be replaced. you need to block this pipe so boost can not escape from turbo housing...not just diconect it and leave it open.
If you want you can lock the actuator closed by a metal wire or something.
And if you want real unlimited boost you can try remove the efi pipe from the turbo intake so it can breath right.
All the above is a recipe for dissaster and if you dont know what you are doing you can damage your turbo realy fast or blow your engine.

Chris
 
A

ahmedsalem89

Member +
350ep70gr said:
If you have disconect the pipe to the actuator and it is boost faster till 0.5-0.7 than with the pipe on the actuator...then just this test is a sign that the actuator is weak enough and need to be replaced. you need to block this pipe so boost can not escape from turbo housing...not just diconect it and leave it open.
If you want you can lock the actuator closed by a metal wire or something.
And if you want real unlimited boost you can try remove the efi pipe from the turbo intake so it can breath right.
All the above is a recipe for dissaster and if you dont know what you are doing you can damage your turbo realy fast or blow your engine.

Chris
Click to expand...

I really suspected that blocking the actuator pipe would make a huge difference I mean it's tiny :D
and now I'm in the process of searching for an actuator but these things are hard to find around here, would an actuator from another turbo work even with slight modding (anything except for CT9's)?
and how to lock the actuator with a metal wire? you mean tie one end to the rod, pull it the other way and tie the other end to anything?
I already removed my efi pipe long ago and I have a short pipe with a filter just behind the headlight.
and I'm doing all this for testing purpose, I just want to make sure that nothing needs to be fixed or replaced except for the actuator

Thanks man for your detailed reply
 
350ep70gr

350ep70gr

Member +
yes blocking the actuator pipe will make boost climp way faster and higher.Most people use hks adjustable actuator to those turbos but yes if you have some basic skils you can fit one from an other turbo.Just make a bracket to fit on the turbo housing and adjust the length to the boost pressure you wish.

If you disconect the actuator rod from the gate arm then you can easily turn by hand gate arm to open or to close position.For testing you want to hold this gate closed .. so you can keep it close by a metal zip or a metal wire at the end of the gate arm and tight to something around.

Your actuator seems to be weak because you say it boost faster without the pipe connection..other possible faults on those turbos are worn seals if it is smoking and cracks around wastegate flap.

With no actuator connected and no efi pipe on second gear i was hitting boost limit on my megasquirt around 1.3 bar as fast i was putting my foot down.
 
A

ahmedsalem89

Member +
I might be able to get my hands on a CT9 actuator but I don't feel like it cause I know they are weak, so I might use one from a Hitachi HT18s of an RX7 I have lying around although it's a bit big I'll also try to convert the arm to an adjustable one so it could be easier to adjust it. what do you think?

and yes I'm pretty sure the actuator is bad, but thank god I have no smoke and I might inspect the wastegate to check for cracks and I hope it's fine :D

I have standard ECU and It's pretty quick boosting to around 0.6 bar and sometimes it might as well boost quickly till it reaches 0.7 or even 0.8 bar but it happens in very rare occasions.
 
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