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Discussion Starter · #1 ·
So I'm running The CP320 map ...and I've noticed my actuator appears to possibly be getting a little lazy ..as in boost takes a little longer to come on compared to a couple I've driven with Turbosmart ones which seems to be instant.
I'm planning to go CP340 later in the year..but for now want to upgrade ..any suggestions?
 

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So I'm running The CP320 map ...and I've noticed my actuator appears to possibly be getting a little lazy ..as in boost takes a little longer to come on compared to a couple I've driven with Turbosmart ones which seems to be instant.
I'm planning to go CP340 later in the year..but for now want to upgrade ..any suggestions?
When mine started to fail, the boost would drop off at top end. Ie it couldn't hold high pressure, it was fine getting there though. Maybe a boost leak somewhere?. I think collins recommends the standard actuator for there maps, but I may be wrong there buddy.
 

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Discussion Starter · #4 ·
@Robbo I was reading a thread where you mentioned about using a Colin's actuator because it was a standard replacement if I'm correct ?
 

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No, certainly not standard replacement, it has a progressive spring but is firmer than stock.

Only way to get close to a stock like response is a linear spring that is soft enough.

I don't think there are spring options for the Collins but Turbosmart have different springs.

You could try a 3 psi TS and adjust it to approximately 4 psi preload.
 

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As CP320 runs a standard actuator then that's what you should fit. That is what the map is expecting. If you are planning to go CP340 which uses a custom actuator (it is the core to the difference between the two) then wait and change together.

I cannot advise that you start fitting different springs as you are playing Russian roulette with your car and could easily over boost it and cause serious damage. ECU compensation only goes so far to protect an engine. The stiffer spring will be tricking your car's ECU into giving more boost than it thinks it is. CP340 map is expecting this and is written accordingly, CP320 is not. This is important!

Remember that CP320 does not need full boost if you go full throttle over 3.5k revs. Power is not just about turbo boost. It's not the 80's anymore. Cars are more sophisticated.
 

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Graham - mk2 stage 3
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As CP320 runs a standard actuator then that's what you should fit. That is what the map is expecting. If you are planning to go CP340 which uses a custom actuator (it is the core to the difference between the two) then wait and change together.
Problem there is unless things have changed you can't buy a standard actuator unless you buy a turbo! That is why the third party ones are popular - it is Hobson's choice. You might find someone who has changed their actuator and kept the old one, but it was changed for a reason.

I'm running the stage 3 JWR/Autotech map with a Collins actuator and have no complaints. IIRC it has a progressive spring as Robbo says. Interesting to see that the CP320 does not use full boost - neither does my map. Maybe once or twice but it usually peaks around 1.1 bar.
 

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First up I'll say, there was absolutely nothing wrong with my stock RS actuator, but considering how **** they are I wanted a serviceable aftermarket one that I could buy a spring for. The spring is the most common fail. They rust

I run a Turbosmart on my RS engine. The stock actuator has a 6 psi spring and the TS came with a 7 psi spring which was too stiff so I got a 5 psi spring in the TS as it's shorter than the stock one. The response curve works pretty well.

At some point the stock one on my son's ST will need replacing so probably get a TS and 3 psi spring and test it.
 

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Problem there is unless things have changed you can't buy a standard actuator unless you buy a turbo! That is why the third party ones are popular - it is Hobson's choice. You might find someone who has changed their actuator and kept the old one, but it was changed for a reason.

I'm running the stage 3 JWR/Autotech map with a Collins actuator and have no complaints. IIRC it has a progressive spring as Robbo says. Interesting to see that the CP320 does not use full boost - neither does my map. Maybe once or twice but it usually peaks around 1.1 bar.
In that case make sure it has the same rating as a standard actuator. Too many people see the actuator as a way of getting free boost and cause calamity.
 

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Graham - mk2 stage 3
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In that case make sure it has the same rating as a standard actuator. Too many people see the actuator as a way of getting free boost and cause calamity.
Agreed! However with mine I have only seen 1.2 bar on a couple of occasions in around 4/5 years where with my old map it regularly hit the end stop with the stock actuator I'd say that the Collins one is not giving more boost. I changed the actuator thinking it was that which was causing the lower boost with the new map but it is behaving exactly the same as with the stock actuator.
 

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So I'm running The CP320 map ...and I've noticed my actuator appears to possibly be getting a little lazy ..as in boost takes a little longer to come on compared to a couple I've driven with Turbosmart ones which seems to be instant.
I'm planning to go CP340 later in the year..but for now want to upgrade ..any suggestions?
Aside from anything else, if you will go CP340 then it is the Collins actuator you need as the map was written with that on there.

But do at least have block mod if you haven't already as it's going to stress the engine and drive the turbo as hard as it can go.
 

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In that case make sure it has the same rating as a standard actuator. Too many people see the actuator as a way of getting free boost and cause calamity.
The ECU sees boost ramping harder than intended and pulls back the throttle so whilst it hits boost, it's with less throttle in the end and it can pulse the throttle on and off. The engine ends up with quite wonky control and unreliable performance. It will self learn to behave badly. Been there, done that. Decided I wanted the RS engine instead and not hard tune it. Keep it in a safe range and not push boost level.
 

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The ECU sees boost ramping harder than intended and pulls back the throttle so whilst it hits boost, it's with less throttle in the end and it can pulse the throttle on and off. The engine ends up with quite wonky control and unreliable performance. It will self learn to behave badly. Been there, done that. Decided I wanted the RS engine instead and not hard tune it. Keep it in a safe range and not push boost level.
This is why I am happy with 300bhp from my ST engine. In reality 300 is enough for my daily drive and keeps the engine within a safer range.
 

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Discussion Starter · #14 ·
Aside from anything else, if you will go CP340 then it is the Collins actuator you need as the map was written with that on there.
But do at least have block mod if you haven't already as it's going to stress the engine and drive the turbo as hard as it can go.
Yeah i run The block mod already but yes that was generally what I was gonna do anyway regarding Colin's .
 

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At some point the stock one on my son's ST will need replacing so probably get a TS and 3 psi spring and test it.
Just wondering if you ended up trying this Robbo? Or anyone else? I've just ordered the 3 PSI spring for my IWG-75 (came with the 7 psi), hoping it will help with the 'wonky' behaviour I'm experiencing, almost exactly like you've described above.
 

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Graham - mk2 stage 3
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FWIW - when I replaced my actuator I got the mk2 Collins one as they had an Xmas offer on and it has been fine with my stage 3 JWR/Autotech map. This was ages ago so I doubt that the mk1 is still around, but the mk2 was suppsed to be better.
 
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