not boosting proply
not boosting proply
Author
Discussion

jdearden

Original Poster:

1,746 posts

206 months

Saturday 19th February 2011
quotequote all
hi guys finsih the car today at last just been for a blast and the actuators are realeasing at .5 bar. it just keeps releasing as im pushing throttle wooshwoosh woosh if i keep my foot planted it goes through it and boost proply.
i have replaced the front turbo with a refurbed one and replace the boost pipe that goes from the actuator to the top of turbo i was told to make this a longer pipe so can fit a boost regulator when its remapped nxt month
1. a weak actuator
2. this new pipe has come off.
3. this pipe being longer is effecting it.

any other ideas. its dark and car is hot so will have a look again in the morning.
any ideas would be great.

cheers

Gadgeroonie

5,362 posts

265 months

Saturday 19th February 2011
quotequote all
is it a 2.5 or a 3.0 ?

i suspect your actuator has seized - i had one in a few months ago and it needed a new set fitted

you might be able to get the boost back again with some simple tweaks - where r you based ?


jdearden

Original Poster:

1,746 posts

206 months

Saturday 19th February 2011
quotequote all
It's a 2.5. I'm in Hampshire. I'm gonna have a play with it tomorro but have a feeling it needs a new actuator. Can the front one be changed whilst still on the car. As only just put it back on and it's a biatch of a job. My arms have the scares to prove it.

R0162

2,435 posts

193 months

Sunday 20th February 2011
quotequote all
Just been messing with the actuators on mine, they are very easy to get access, i think i have the same problem, I have the Gt28Rs ready to be fitted but i want to fit them at the same time as the engine rebuild, so in the mean time to put me on i am going to change the actuators.

Can i put the actuators from the Gt28rs? I think they are 0.6 bar actuators and if i remember correctly the car is supposed to be running at 0.9 bar, is there any problem with fitting these actuators?

jdearden

Original Poster:

1,746 posts

206 months

Monday 21st February 2011
quotequote all
can the front turbo actuator be changed without removing the turbo. also does any1 have any actuators or know where i can get them.

andygtt

8,345 posts

293 months

Monday 21st February 2011
quotequote all
can be but its a bd job!

Gadgeroonie

5,362 posts

265 months

Monday 21st February 2011
quotequote all
the front one is a PITA !

there is an alternative, you can fit a mechanical boost valve set to std pressure that makes the turbo's spool up as if you have stronger actuators

once it opens the standard boost control can take over

The devil

2,152 posts

212 months

Monday 21st February 2011
quotequote all
I changed both my actuators and quite honestly although it is a bit of a pig, I would rather change that one than the rear, at least you get to lay down for a while. Its not that bad but I found if you get the turbo shield off, there is a little bit of up down work but its OK if you are patient.
Mike Tuckwood has normally got the actuators or universal turbos

jdearden

Original Poster:

1,746 posts

206 months

Monday 21st February 2011
quotequote all
Gadgeroonie said:
the front one is a PITA !

there is an alternative, you can fit a mechanical boost valve set to std pressure that makes the turbo's spool up as if you have stronger actuators

once it opens the standard boost control can take over
i was going to have a boost regulator fitted at end march anyway.
will i do any damge driving it like it is as long as i take it easy.

Gadgeroonie

5,362 posts

265 months

Monday 21st February 2011
quotequote all
Best to get it on the rolling road and give it a health check

R0162

2,435 posts

193 months

Friday 25th February 2011
quotequote all
Advice needed on actuators.

Are my actuators too strong?

I put the actuators from mt GT28RS onto my standard turbos which are running at 0.9 bar boost, i believe this equate to about 12 psi, the actuators i got from universal are suppsoed to be 0.7 bar about 10 psi.

Are they too strong? How do i know if they are really 10 psi actuators, what if universal turbos sent em the wrong ones by mistake?

If an actuator is 10 psi then i assume it will start to release boost at 10 psi, but seen as though the car hax 12 psi max boost should i have put an actuator that allows the wastegate to open sooner?

Gadgeroonie

5,362 posts

265 months

Friday 25th February 2011
quotequote all
unplug the boost solenoid and see what boost you get

how did you set the preload on them ?

R0162

2,435 posts

193 months

Friday 25th February 2011
quotequote all
Gadgeroonie said:
unplug the boost solenoid and see what boost you get

how did you set the preload on them ?
What is a boost solenoid and how do you set the preload?

R0162

2,435 posts

193 months

Friday 25th February 2011
quotequote all
Ok the actuators got fitted last night, took the car out to test today and no boost, put me fioot down and nothing, its goes to 0.0 bar, then if i keep pushing it to higher revs, it struggles to reach 0.5 bar for an instant and then runs out of puff.

The funny thing is i was going to fit them myself, but then some friends advsied me to get them fitted by somebody who knows what their doing, lol, that turned out well didnt it, i have been reading up on actuators, it seems to me that they could possibly of fitted the actuator so the waste gate is in an open position?

GC1

908 posts

209 months

Friday 25th February 2011
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mike where abouts are you based ?,could do with getting together if possible with the view to twinking my car.....thanks.

Gadgeroonie

5,362 posts

265 months

Friday 25th February 2011
quotequote all
pm sent

R0162

2,435 posts

193 months

Friday 25th February 2011
quotequote all
I'm pretty sure i have found and fixed the problem, they had set the actuator arms so that the wastgates were permanently open!
The rear was approx 1cm too long, so i shortened it to the correct length and then shortened by approx another 3mm to pretension the spring,s o as to make sure it has power to snap the wastegate shut again.
The front was not as bad only about 2mm too long, but still was in the wrong direction and was not pretensioned.

I have not been able to test the car yet due to bad weather but i feel i must have fixed the problem.

I am still trying to understand actuators, i understand how they work in principle, but if i have a 10psi actuator does that mean it will only start to open at 10psi? and once boost drops below 10psi it will snap shut again?
How accurate are these things? I had a tug at the arms and one actuator felt like it had a stronger spring to the other.
If a wastegate remained shut then would the car overboost?
My actuators are 10 psi my car runs at 12psi boost, so does that mean because my wastegates are opening quite late that they may not be able to relaese anough pressure in time, and that may cause overboost?
I cant understand how the old actuators which were really weak, if they were cracking at 2psi and letting the wastegate open, how did the boost manage to keep on increasing to 12psi?

If you get overboost, what exactly would that do to your engine?

I always remember my friend who had a Sx200, he put some sort of valve on a vaccuum pipe and got his turbos to run at silly boost, i was a bit suprised by how fast it was actually, he ran the car like that for months until eventually he got a crack in one of his turbos.
Was he just lucky his car lasted this long with that amount of boost? I would have thought fuel pumps and injectors etc.. would have needed upgrading to provide the extra fuel required and how come he did not blwo the engine? The car was an old piece of junk.

andygtt

8,345 posts

293 months

Friday 25th February 2011
quotequote all
The problem you have is that the noble runs an electronic boost valve.... this bleeds pressure away from the wastegate and allows the ecu to control the boost above the actuators spring valve.

What this means is that your ecu will be set up for a specific spring value, if you used to run the std 0.3bar actuators and stick 0.7 bar ones in your ecu will be confused it may produce way too much boost but what exactly will happen I don't know all I know is if you change the actuators to stronger ones you must remap it.

Its actually arguable if a stiffer actuator is better than a softer one... softer ones give you a wider range of control via the ecu, however stiffer ones bleed off less at high boost... tuners opinions seem divided on which is best.


R0162

2,435 posts

193 months

Friday 25th February 2011
quotequote all
cheers Andy, if it is stll not running correct tommorrow i will stick some new 0.3 bar actuators on, i think the old ones were allowing the wastegate to open too early as boost was low, rarely going above 0.5 bar.