Actuator installed....help with setup?

a318t

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Hi everybody,

Please excuse my lack of knowledge before I begin. I'm still very new to 1.8T's and in fact, turbo charged engines in general.

Just had my new actuator fitted, but am worried about overboost. I have scanned through all threads on over-boost, but failed to find anything relevant to my query.

Basically, when I first drove the car it was no better than when it had the knackered, old actuator on it. So, I've gradually tightened the actuator arm up so that it now 'flies down the road'.

However, I am very, very worried that the car is perhaps over-boosting, and causing potential damage to the turbo and/or engine. There are no symptoms of overboost, no 'cutting out' or 'hesitations', in fact it's a dream to drive. However I've set the actuator arm about 3-4mm away from it being as tight as it will go. I have no boost gauge or VAG COM equipment....yet!

What I need to know is, is it possible for the actuator to cause over-boost? Or is the actuator only ever strong enough (no matter how it's adjusted) to work within safe parameters? Or is that just total ******** haha? Or is boost regulated and managed by something else, N75? Or would limp mode cut in if it was beginning to cause damage or work outside safety parameters? (Yes I really am guessing now).

Obviously I've been seriously thinking about getting a boost gauge and adjusting the arm of the actuator so it boosts as required, but then I knew you guys would know whether I need to, or I'm worrying about nothing (I'm pretty sure the latter isn't true however :sadlike:). Also, how do I find out what it should boost too?

Any help would be extremely appreciated. The car drives superbly by the way now I've wound the arm up....mega torquey and smooth!

The car is an A3 1.8T engine code AGU with a stage 1 map if relevant in any way.

Many thanks!
 
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If you've cranked the actuator arm right up, then there's every chance you've increased boost, possibly by a little, possibly by a lot!

Now, there are two potential answers here:

1. This is of course very dangerous if you've cranked it up too far. too much boost can kill your engine if it's not mapped for it.

2. Slightly less responsible answer: the ko3 is so tiny, that with a st1 map, even if you let it run wild, it's unlikely to do any damage, and it certainly can't exceed the limits of the standard fuelling setup, so it'll probably be fine.....

Either way, I'd advise setting the actuator up properly. You don't state what actuator you've fitted, is it a replacement standard one? or a Forge one? You also don't state what st1 map you've got, it matters, because some are great, and some are shyte.

To setup up static actuator pressure, you can either do it on a physically, with a variable pressure source and a guage, and increase line pressure until the actuator springs open, or, you can unplug the N75, and drive and see what boost it's making, then adjust accordingly until you're at your desired actuator pressure, around 6psi for a stock ko3.

As you don't have a boost guage, I'd bet you probably havn't got a way of measuring the crack pressure under the bonnet either.

having an AGU, you also can't log boost and do it that way! so whatever you do, you need some help!

Quickest and easiest way would be to find a mate / member with a spare boost guage lying around, hook it up as a temp with the line in through the window, drive and see what boost you're getting.

Where abouts are you?
 
If you've cranked the actuator arm right up, then there's every chance you've increased boost, possibly by a little, possibly by a lot!

Now, there are two potential answers here:

1. This is of course very dangerous if you've cranked it up too far. too much boost can kill your engine if it's not mapped for it.

2. Slightly less responsible answer: the ko3 is so tiny, that with a st1 map, even if you let it run wild, it's unlikely to do any damage, and it certainly can't exceed the limits of the standard fuelling setup, so it'll probably be fine.....

Either way, I'd advise setting the actuator up properly. You don't state what actuator you've fitted, is it a replacement standard one? or a Forge one? You also don't state what st1 map you've got, it matters, because some are great, and some are shyte.

To setup up static actuator pressure, you can either do it on a physically, with a variable pressure source and a guage, and increase line pressure until the actuator springs open, or, you can unplug the N75, and drive and see what boost it's making, then adjust accordingly until you're at your desired actuator pressure, around 6psi for a stock ko3.

As you don't have a boost guage, I'd bet you probably havn't got a way of measuring the crack pressure under the bonnet either.

having an AGU, you also can't log boost and do it that way! so whatever you do, you need some help!

Quickest and easiest way would be to find a mate / member with a spare boost guage lying around, hook it up as a temp with the line in through the window, drive and see what boost you're getting.

Where abouts are you?

Prawn, thanks for your reply at these early hours of the morning :)

The actuator is a genuine brand new borg warner one, correct for the turbo. The remap was by R-Tech, so very good as I'm sure you know!

I'm situated near Norwich in Norfolk

Thanks again chap!
 
unplug your n75 and keep adjusting till you see actuator pressure of 5-6psi


I don't have a boost gauge (well, I've just ordered one actually), but not at present. If I connect my gauge up when it arrives and set the actuator arm to produce 5-6 psi, I won't need to disconnect the n75 will I?

Thanks
 
I don't have a boost gauge (well, I've just ordered one actually), but not at present. If I connect my gauge up when it arrives and set the actuator arm to produce 5-6 psi, I won't need to disconnect the n75 will I?

Thanks
the standard actuator should be set at 6 psi i think, prawn will confirm.
the map you have is likely to be tailored to this, as with all stage 1 maps.
disconnecting the n75 electronically means the car will run at actuator pressure, so when you have your boost gauge in, id disconnect it and adjust the actuator until you see that 6psi. then reconnect and you should boost to what the map is designed to/requesting.

you dont want to run on 6psi all the time, it will be shiiiite slow. so dont adjust it to that with the n75 plugged in.
 

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