I also want to know how much boost...

[Csx254]

I have a '87 CSX with the stock .42 garret turbo. I was told that I can only get about 18 psi out of it. Is this true, or can I get a few more pounds out of it???

[TurboMinivan]

The problem with that turbo is the smaller wastegate actuator spring--it is weak enough that it can't hold the wastgate shut much beyond 14 psi. Once the spring can't hold the 'gate shut, you stop building any more boost. The exact amount you get may vary slightly; on my CSX I only get about 15-16 psi with the can unplugged. Good news: simply upgrade to the 1989 actuator with its larger, stronger spring. Now you can easily get 25-30 psi out of the same turbo.

Your stock 1987 CSX connecting rods will not like this one bit, and they'll try to evacuate your engine by burrowing through the block in a grand, catastrophic fashion. Therefore I suggest leaving your stock actuator alone until you install beefy forged rods. Think of the weak actuator as a safety device.

[Csx254]

So all I would have to do is change that actuator to see more boost? Cool. Yeah I know, I am on the hunt for a set of rods and a common block, but I will have to use what I have for now. Can I use the actuator off any '89, or does it have to be a Garret? What about from a mitsu turbo?