Turbo Actuator(s)

[sri_130]

Just been thinking...

My new turbo does not have an actuator.
The old turbo does.

The old turbo ran at 8psi the new one, may need to run a lot more.
The old turbo is a smaller item than the new.

So how do you scope an actuator for what you actually need? If you buy a stock actuator to match the turbo, isn't the spring set at low/efficient levels?
How will I know this, until Mr Chipwizards has it on the rollers and may say, come back with a better actuator as we can't make X pressure!?

Not sure what to buy and my understanding is weak.
Help.

[sri_130]

Oh hang on...
In the old days... didn't people used to put a manual boost controller inline to the actuator? Thus being able to influence/over-ride the spring rate/setting and in turn, a dirty way of increasing boost. They look massively flimsy/Chinese though...

I don't have a boost controller... So maybe I should get one and an OEM actuator?

[Synister]

Nout wrong with manual boost controllers. If you get a decent one (turbosmart etc) it won't creep/leak. They just aren't as easy to adjust (no cabin access) and aren't as accurate.

You'll still need a wastegate actuator though!

[axsaxoman]

If you waste actuator is 8psi --then that is the boost you will get if you have no other control system -- but be ware unless you have an actuator with pressure take offs on both sides of the diaphragm --then no matter what controller you use you will never be able to have less than its value once you get to its spooling up RPM
you want proper control across a bigger boost range --then you need more complex actuator and boost controller
actuator spring value is lowest boost you can control down to
which is why up todate OEM turbo,s use a waste gate that is naturally open --not shut and can then control boost properly ,which is why modern turbo,s you don,t have big lag and the units are small so they spin up even at low engine rpm and can give boost from 1000rpm under total ECU control

bottom line is you don,t need a turbo the size of a dustbin on a 1.6 engine to get good boost --al that does is mean its high up engine rpm before it is fully spooled up because of the volume of EX gas needed to drive it .also large turbines respond slower both to speed increase +decrease
you have to remember that the reason people picked the gt 28 unit years ago was it was cheap + looked "cool"
take a look, at modern turbo

[sri_130]

Originally Posted by axsaxoman

If you waste actuator is 8psi --then that is the boost you will get if you have no other control system -- but be ware unless you have an actuator with pressure take offs on both sides of the diaphragm --then no matter what controller you use you will never be able to have less than its value once you get to its spooling up RPM
you want proper control across a bigger boost range --then you need more complex actuator and boost controller
actuator spring value is lowest boost you can control down to
which is why up todate OEM turbo,s use a waste gate that is naturally open --not shut and can then control boost properly ,which is why modern turbo,s you don,t have big lag and the units are small so they spin up even at low engine rpm and can give boost from 1000rpm under total ECU control

bottom line is you don,t need a turbo the size of a dustbin on a 1.6 engine to get good boost --al that does is mean its high up engine rpm before it is fully spooled up because of the volume of EX gas needed to drive it .also large turbines respond slower both to speed increase +decrease
you have to remember that the reason people picked the gt 28 unit years ago was it was cheap + looked "cool"
take a look, at modern turbo

I think, although not confirmed, but I'm claiming it.....a world first.

I'll be the first to run a GT22 (variant) on the J4. Maybe go as far to say on the JP4 as well.

I'd like a certificate from an official body, but there isn't one. So if you could mock me one up John...

The disco potato is too late in the range for my liking. Youtube confirms it, like you say and the GT25 wasn't attainable when I was searching, the 2259 fits the bill, I hope. Lets see.