wastegate actuators

[jimnielsen]

I have tested the standard Q4 wastegate actuator with a compressor and a pressure gauge. It seems to me that the one i have commences opening at 7 PSI. This is all well and fine, of course - but I think it is a problem for making 1.45 bar boost (my target) right out to 7000 RPM. I have never been able to sustain anything over 1.25 bar to these revs. I often see 1.35 bar or so, but it drops off quickly. I have now installed a 15 psi actuator to see if I can cure the problem.

I have already proven that the problem is *NOT* the boost controller, and I still don't believe that its the (fiendish) Chinese turbo.

Has anyone else tried using a significantly different actuator for the purpose of increasing boost at higher revs.

jim~

[arjunior45]

If I'm not making a mistake the oem wastegate actuator can be registered to open at 0,6 bar instead of the 0,45 preset by the factory.
I do not know how this can be done but I do know that people with Integrale Evo2 have done it. I could ask but this can take a while before {and if I'll have} an answer.

[Juan AR155Q4]

Surely your WG is being opened by exhaust pressure.
you should get one with larger diaphram diameter and more stiffener spring.

[na15575]

Surely your WG is being opened by exhaust pressure.
you should get one with larger diaphram diameter and more stiffener spring.

this is very possible to have happened
especially to old WG

[SteveNZ]

I messed around with a higher pressure actuator for the same reason. It didn't fix the problem. I wish I went straight for an external wastegate.

[jimnielsen]

I wish I has as well Steve... but if an external wastegate could be used to fix 'the problem' assuming that the problem is the wastegate opening at too low a pressure, and not being able to be closed again once it has been opened - why can you not address this issue with a stronger actuator?

jim ~

[SteveNZ]

It sounds logical but it does not seem to work or work as well as an external upgrade does. I don't really know why but I can give you my opinion.

You can pick a spring pressure and easily change it as required.

Externals have huge diaphrams. This gives a lot more force on the valve with small adjustments of air pressure. Basically more control over the valve, makes it easier for the boost controller

External valves are larger so only need to move a smaller distance (lift) to control the boost. I suspect internal valves need to open quite a distance at mid RPM to limit boost

Externals don't have flimsy brackets that like to flex with a stronger spring.

Here is Pauls car with 38mm Tial wastegate
http://www.fccuk.org/forum/imagepopup.php?image=http://i32.photobucket.com/albums/d40/coupenz/Boostfuelfleav191623.jpg

[jimnielsen]

I see what you mean, Steve - the bracket on mine is FAR too flimsy - I will give this setup a go, however as I have already installed it. but it would not surprise me if I have to go to an external one too.

jim~

[SteveNZ]

I hope it works out for you. It is a lot cheaper!

For me, I tried everything before moving to an external gate which was a mistake. I spent more money on turbo modifications, boost controllers, actuators etc etc than a wastegate ever would.

[jimnielsen]

Steve, do you think that the 'EBAY' manifold that I am using could still be used - modified - with an external WG - and also a turbo to suit?

jim ~

[SteveNZ]

Definitely, welding a flange on the manifold should be easy enough. Then just weld the internal gate shut. I've seen it done many times, even on OE manifolds.


http://i139.photobucket.com/albums/q310/mannytheman1257/IM001550.jpg