Okay so I am a newbie to the whole turbo world. I have been doing some searching on how turbos are plumbed and now have a few questions on some fuzzy areas especially the the waist gate.



From what I understand the waist gate has a preset boost limit that once the turbo builds the predetermined boost limit a valve opens and redirects exhaust around the turbo acting much like a turbo break. Which leads me to my question's:



#1 - Hypothetically speaking an engine that has a cr 10.0:1 on 4 psi of boost would have the same dynamic compression as a engine with 8.0:1 with 8 psi of boost. Would both engines run exactly the same? Or would the one with higher compression have more low end torque and spool the turbo up much faster than the other engine, am I correct on assuming this?



#2- How accurate (with out having a boost controller) is a waist gate at regulating boost levels?



Any feed back would be awesome.

 

Well great questions first off, About the engine compression question, I would assume your right just because lower compression less exhaust flow, slower spool.... etc etc.



About the wastegate, wastegate pressure is set but a diaphram that does a good job, more so external than internal. I ternal have a tendecy of being slightly unsteady.



I have ran a 38mm tial external and now on my Miata I have a 15g with ported internal port thats does a good job but not rock steady like my Tial.