Stock top mount, beefed up...

[sen2two]

No, im going to replace just the actuator. From my own personal experience, i believe the wastegate is the enemy when refering to our stock turbos not holding boost up top. (along with the restrictive exhaust housing on the turbo. I also believe this is why S4 turbos do not have such a problem with holding boost with there larger less restrictive exhaust housing. all in theory of course) I could explain it my way, but below is from BNR, the turbo specialist refering to the stock Rx7 turbo.

quoted from BNR's website:

"Upgraded wastegate actuators are the best way to keep the boost level from falling off up in the top RPM. There are a few things that can contribute to this issue. The issue is backpressure between the turbine wheel and engine causing the pressure to push against the wastegate valve assembly. This opens the wastegate premature and causes you to lose boost pressure. The more you port the wastegate port, the worse the problem will be. The solution is a higher spring tension wastegate actuator upgrade. This is a quick and cheap way to generate a noticible power and torque gain in mid range RPM while holding boost up in the top of the RPM band. There are a few actuators to choose from and it depends on what boost level you are trying to run. From there we will help you decide which actuator is best for your application."

The one im using is very similar if not, one of the very ones they use. So hopefully it will work. If not lesson learned... Not that any of this has to do with the intercooler though.