alex_00s

iTrader: (18)

I've got an adjustable actuator on my TD05 18G and to cut a long story short the turbo has been clocked and the actuator welded in a new position. I've had to use washers to help re-position the actuator and that made it a bit loose so I tightened the adjuster a tiny bit til it just held closed.

What would happen if I tightened the actuator in one more turn to hold the wastegate shut that tiny bit tighter??

I have a boost problem at high boost in 4th and 5th where the boost had to be turned down coz the wastegate was opening a tiny bit and therefore creating a turbo stall effect.

Would tightening the actuator (and holding the wastegate closed tighter) stop that problem?

Big 'D'

Can you describe the turbo stalling effect that you are on about, ie can you hear it or see it on the boost gause etc.

Cheers Iain

saiklon

Not sure what a turbo stall problem is and how it could be caused by an opening wastegate.

There shouldn't be a problem with tightening the actuator a bit, Actuators are usually tight enough that you need a bit of force to open the wastegate, just make sure that the actuator arm still has enough travel to open the wastegate fully.

alex_00s

iTrader: (18)

When its boosting its like you're taking your foot off the accelerator a touch so the boost drops and then planting it again... the only way to get round it was to reduce the boost on 4th and 5th to around 1bar until each gear goes above 4k rpm then the boost could be increased up to 1.5bar.

But I want to be able to have the boost cranked the whole way and not held back coz of this problem

Glowplug

iTrader: (8)

Sounds more like a boost spike than wastegate creep Worth giving the BCS and associated plumbing a clean out.

Big 'D'

I think you have compressor surge, do you have any turbo intake mods ie a silicone intake duct etc.

Cheers Iain

alex_00s

iTrader: (18)

I have a silicone inlet tract, but its from Lateral Performance and has a steel coil within its construction so is specially designed not to compress under pressure

If it is compressor surge can that be cured Iain?

alex_00s

iTrader: (18)

I cleaned out everything...

'Wastegate creep'... that term will just add to my boost problem hypacondria, lol

alex_00s

iTrader: (18)

So if it is compressor surge, can that be cured??

Glowplug

iTrader: (8)

What is the boost gauge reading at this point??

Big 'D'

Absolutely, all you need to do is fit an alloy pipe joiner into the silicone intake pipe to reduce the size of the internal bore, I have found that depending on setup and turbo used the optimum size seems to range between 57mm and 60mm. 57mm would almost certainly prevent the compressor surge if that is what it is.

Cheers Iain

alex_00s

iTrader: (18)

It was reading 1.3 iirc, but it was all dealt with at the time of mapping and therefore had the boost turned down.

alex_00s

iTrader: (18)

So by reducing the internal diameter of the turbo inlet tract it could stop the compressor surge if thats whats happening... I'll look in to this thanks Iain

Big 'D'

Exactly mate

It does work but only if it is compressor surge.

Cheers Iain

Glowplug

iTrader: (8)

So your hitting the boost target then?

I'm gonna leave it to you. I don't think it is compressor surge, but that is the route you seem to be heading down. I don't see the point of chucking more into the mix until you have modified the inlet and got a result either way.

Watching with interest .

alex_00s

iTrader: (18)

Well the target boost was 1.5 (or even a squeeze to 1.6) and Bob was mapping it and even he said it was strange that the turbo was cutting out...

...I'll try what Iain said and then have it mapped. I've recently changed the exhaust system and air filter so its due a map anyway

I'll post up the results of this

Big 'D'

Will you be getting Bob to map it again? If so I could look it over for you prior to the map if you want.

Cheers Iain

Big 'D'

I have to agree that it may well not be compressor surge as it is more of a rapid continual cycle of backing off and picking up again not just a one off, it does sound like it could be your wastegate is opening a touch at the point of the backing off effect you are getting.

Out of interest what is your wasetgate base pressure and what boost solenoid are you running? (this will help with the diag)

Cheers Iain

alex_00s

iTrader: (18)

Hi Iain,

I'll definately be getting Bob to map it, if you want to wire up and check it out prior then be my guest

I have a funny feeling its the wastegate also... the actuator was re-welded in a different position and I did space one bolt out a touch with thin washers to get a central position on the actuator arm. BUT this was all after the mapping and I also tightened the actuator up so the wastegate was tigh against the turbo.

It was loose and was resonating on tick over and I was loosing boost until tightening it in. But that was my fault for using the spacer washers and not adjusting the arm in, durrr...

Altho I think I could get it 1 turn tighter and maybe thats all thats needed to ensure the wastegate stays shut that fraction more and not open and cause the problem I'm having.

Its 1 of those silly little things that is probably easily solved, but trouble is its all trial and error and with mapping each time costing a few hundred quid, its an expensive silly problem to fix