Depending upon your setup and how much "tension" is already applied to your wastegate actuator another two options are:
If your wastegate actuator is attached to your compressor housing and you have the ability to be able to "clock" the compressor housing in a direction which pulls the actuator further from the point at which it attaches to the wastegate flap this will add a small amount of extra tension. You would be surprised at the small amount that you move it is able to add more tension and gain more boost.
I ported my wastegate which in turn created a larger surface area trying to force the wastegate flap open. With the factory preload on the actuator it could not hold more than 12psi under load (you could bleed off enough for it to start at 20 psi but once loaded up it would drop to 12psi). So after carefully checking that the actuator had enough range of movement to still be able to open the wastegate flap sufficiently I clocked the turbo a little (adding more preload to the actuator spring). This allows me to hold a rock solid +20psi (no spikes, no creep, no drop).
The other method people use gives exactly the same effect as above but they cut the actuator rod and weld on a threaded section so that you increase the tension by shortening the actuator rod with the twist of a nut.
I have also seen the method mentioned above where an additional spring is added.
I would try a bleed valve first and use the above methods to correct any further problems (like I had with boost drop under load). As the above methods can be risky if you get a calculation wrong, ie limiting the wastegate movement, too much spring tension causing too much boost etc.
Think about what you are trying to achieve and then carefully go about doing it.
Mon, 08 November 2004 05:11
