Actuator preloading?

[gt_addict]

Hi guys,

I was looking at videos on YouTube the other day and a suggested video was one about preloading the actuator to get more power from the turbo. I googled it as its on various forums of jap cars and vauxhalls. They use two methods from what I've read. One is actually adjusting the arm (if there's an adjustable nut on the actuator arm), the other is putting shims under the actuator, between the actuator body and the bracket it sits on.

I was just wondering if anyone had done this to there van or a car they've had and what the outcome was? Any noticeable difference?

Thanks,

Peter.

[paul2012]

it's the cheap way to get a small extra boost from the turbo

Turbo basics

The Actuator(commonly know as a wastegate) acts as a pressure relief valve the controls the turbo's boost output.

Actuator flap is initially close to allow turbo to spool up, once the predetermined boost pressure has been reached the actuator flap will open to slow the turbo down.
It is operated by a single boost pressure control pipe connected to the compressor housing.

Unfortunately in Ford OEM turbo's the actuator can't be adjusted. Turbo tye on the connect 75 & 90ps TDDI 2003-2006 is the Garret GT1544Z. For the 90ps TDCI models from 2006 onwards were fitted the the Garret GT15 turbo.
Except for the 110ps model that was fitted with the electronic VNT (Variable vane) turbo's

I have know people to weld the actuator flap permently closed But I would not do this as once turbo has spooled up it will keep going & going until something blows.
Theere is another way & that was fit a bleed valve into the actuator boost pressure control pipe to give it leak off, which in turn required an increase the boot pressure before actuator flap would open.

Safest way is to fit a external boost controller or replace the actuator with an uprated one.

[andycaca]

relief valve is the best way to control the internal actuator on a non-VNT turbo. youll need a decent boost gauge so you dont "accidentally" run it at 2bar tho

[gt_addict]

Paul, that is exactly what I read earlier today after having some spare time between coats of plaster at work lol.

I tried fitting a boost controller (ball bearing type off eBay) but the van didn't like it :/

I was just curious about this method as although I've been into cars for years I've never heard of it lol.

[jonconnected]

when i was doing the cylinder head on my van i noticed that my actuator has been welded, the arm is not even connected to the part on the manafold so im not sure what going on there, who ever had the van before me must have done this but never said nothing about it when i bought the van, since doing the cylinder head tho my vans well down on power and takes an age to go up hills even when iv nothing in the back, but i think the small pipe that gose to the block under the turbo is losing some sort ov boost due to being loose, need to get a good clip to secure it tight..

[paul2012]

Paul, that is exactly what I read earlier today after having some spare time between coats of plaster at work lol.

I tried fitting a boost controller (ball bearing type off eBay) but the van didn't like it :/

I was just curious about this method as although I've been into cars for years I've never heard of it lol.

By adjusting the actuator arm or by adding shims, techniclally all its doing is giving the actuator a little ajustment so it opens the flap slightly later at a slightly higher boost pressure

It has been around for a while, must people just upgrade their turbo's & get a remap done. Fitting a bigger turbo, engine needs more fuel and better cooling ie bigger intercooler etc as engine run alot hotter.

First thing is to remember the differences in compressor A/R do not affect performance very much, but a large turbine A/R will allow big power gains at high engine rpm, but this will cause turbo lag at low speeds.
Hence why the Diesel turbos are small This allows them to spool up at lower rpm.

With boost controllers on connects they decrease the boost pressure to the actuator so it allows the turbo to produce extra boost. The actuator comprises of a spring & diaphragm, The spring is there to keep the actuator flap closed. BUT as the exhaust gas pressure builds up. It gets to a point where the exhaust gas pressure forces the flap open. Althought the boost controller is doing it's job by reducing the boost pressure to the actuator, but the problem is the spring in the actuator isn't strong enough to keep the flap closed.

Due to this boost controllers would be useless, the best solution would beto fit a uprated actuator that has a stronger spring which operates at a higher boost pressure allowing the turbo to produce more higher boost pressure.
Another thing to check is make sure the actuator flap has a good seal. if it's full of carbon this can cause reduction in engine performance, due to exhaust gases will leaking around it.

The actuator works on air pressure instead of a vacuum line

when i was doing the cylinder head on my van i noticed that my actuator has been welded, the arm is not even connected to the part on the manafold so im not sure what going on there, who ever had the van before me must have done this but never said nothing about it when i bought the van, since doing the cylinder head tho my vans well down on power and takes an age to go up hills even when iv nothing in the back, but i think the small pipe that gose to the block under the turbo is losing some sort ov boost due to being loose, need to get a good clip to secure it tight..

Firstly double check to see it it has been welded shut (in some cases it could be jammed open !) . If not welded shut, then exhaust gases are forcing the flap open & turbo will not spool up (exhaust gases are bypassing the turbine & going through the actuator flap !) Due to the actuator arm being disconnected (theres nothing keeping the flap shut !)

secondly if actuator flap has been welded closed or jammed open the entire manifold will need to be replaced (yes turbo can be seperated form the manifold but check for obvious signs for damage & wear, if required replace it)

Lastly check the operation of the actuator - diconnnect the boost control pipe from the the compressor housing & connect to a airline from a compressor or air pump. Graudually increase air pressure until you see the actuator rod being pushed out. If actuator works fine & flap is operating as it should, re-connect actuator arm to flap & boost control pipe to compressor housing.

[jonconnected]

think il need a new manafold then, although the arm is loose, where its been welded on theres still weld on the part that the arm connects too, if that makes sense lol, i cant move that part with my fingers, its welded solid,. cheers for the info....

[liteace]

think il need a new manafold then, although the arm is loose, where its been welded on theres still weld on the part that the arm connects too, if that makes sense lol, i cant move that part with my fingers, its welded solid,. cheers for the info....

The arm is welded to the spindle shaft BUT the spindle shaft should not be welded to the manifold, the blue dot should have weld, underneath there (red arrow) there should be no weld

[jonconnected]

where you have the red arrow, its been welded there too on mine, so think its a new manifold i think i can here the turbo tho when im out driving or what i think sounds like the turbo dont know whats going on with the actuator, but il need to get it sorted one way or another asap..

[belly]

We used to adjust the actuator pre load on Renault 5's Another trick for just off the line stuff was to make the actuator vac hose about 3m long and coil it up, that would give a delay in the actuator operation allowing a short period of over boost to get ahead The guys racing in the super gt turbo cup used to put water in there actuator pipes and freeze them then after a couple of laps the water would've evaporated

As mentioned pushing your oe baby snails will decrease the lifespan of the turbo but more importantly raise the egt temps, obviously there's always room for a small amount of fiddling but go carefully, I also thought the ecu has a wobbly with raised boost pressure on these ? Hybrid turbos can run more pressure safely and cooler than oe turbos but you do have to get the a/r balance right

[belly]

when i was doing the cylinder head on my van i noticed that my actuator has been welded, the arm is not even connected to the part on the manafold so im not sure what going on there, who ever had the van before me must have done this but never said nothing about it when i bought the van, since doing the cylinder head tho my vans well down on power and takes an age to go up hills even when iv nothing in the back, but i think the small pipe that gose to the block under the turbo is losing some sort ov boost due to being loose, need to get a good clip to secure it tight..

Sounds like yours has been welded open Turbo spinning but no performance, does it use oil at all ? Could've had turbo issues but a Bodge fix

[jonconnected]

no iv not noticed it use alot of oil, iv redone all the turbo pipes and there all tight now, got a small bit more power back but still strugling to go up hills lol
before i done the head it was going up hills no problem but i have noticed that only one of the intercooler pipes is expanding when i give it some revs, the one nearest the gear box..

[gt_addict]

Blocked intercooler? Have you flushed it through? When I got my van I sprayed a can of intake/carb cleaner into it to get rid of any oil that's made it's way in there from the turbo.

[jonconnected]

il try doing that tomorrow, could a blocked intercooler effect the power on my engine that much?

[g-man]

would do if its blocked