Setting Your Internal Wastegate
Ok so you've got yourself a new external wastegate, mounting brackets etc. How tight do you do up the wastegate? Is it just a matter of guesstimation?
It is a bit of a guess, but it is worth taking a little extra time and care here as the last thing you want is your wastegate set too loose and therefore never reach max boost psi! If the wastegate isn't done up tight enough then you'll loose boost pressure when the gate opens up when you didn't want it hence never reach your max boost.
1. - Wastegate Actuator mounting bracket
2. - Wastegate Actuator shaft that opens and shuts the wastegate
3. - Wastegate hinge (closes the wastegate)
4. - End of rod that connects to the wastegate hinge
5. - Pin to attach your wastegate actuator shaft (yes I know you knew all of this).
Now this isn't very technical but it's a method that has worked for me none the less. Screw the wastegate actuator shaft (2 ini the image above) until the eye (4 in image) is lined up with the wastegate hinge (5 in image). Once you've got this starting point, check that there are no obstructions for the wastegate shaft. Nothing should be hindering its movement at all.
Depending on what external wastegate you've chosen, you should be able to relatively easily pull on the wastegate shaft and get some movement. So wind your shaft down 2 full rotations and connect parts 4 & 5 from the image. Don't put the C-clip on just yet. Try opening and closing the wastegate with your hands. If you can pull it wide open with ease, give the shaft another full rotation.
The wastegate needs to be firmly shut, it doesn't need to be so damn tight that it can't be opened. Also note there is only a certain amount of movement in the wastegate actuator itself so over do it and the wastegate won't be able to open to release excess boost!
Once you're happy with the shaft - ie the wastegate is closed firmly, you have NOT over tightened the shaft and therefore taken all the wastegates movement - put the C-clip on and you're ready to go.
NOTE : If you're noticing extreme boost spikes back the shaft off as this means the wastegate isn't opening correctly and vice versa. If you're not reaching desired boost, it's more than likely the wastegate is opening up too soon - so tighten the shaft.
cheers,
AJ
ps - if anyone has anything to add or doesn't agree - please feel free to reply...