|I am getting ready to purchase new turbos for my Z and after seeing all the information Greg and others have posted about stock turbo cars with full breathers I am wondering if there is really any reason to upgrade to any ball bearing turbo smaller than the sport 700's. As far as my car I am currently planning on buying either MSP's or new Ash manifolds and am going to upgrade to expansion down pipes regardless so the difference in cost for changing to a five bolt isn't really factor for me. I am in the midst of mocking up a dual front mount intercooler setup and modifying a plenum to run the 60mm Stanza throttle bodies and larger suction pipes which I believe will cover the breather mod bases.
I don't have ready access to e85 around here so I plan on sticking to pump gas. I understand from Greg's post comparing multiple dyno pulls of cars with breathers and the many popular turbo options
that the stock turbo cars with full breathers really shine at pump gas boost levels and from what my amateur eyes can see there really isn't that much of a difference between the stock turbo and smaller ball bearing turbo dynos. Only stepping up to the SP700 range seems to make large gains.
The only reason I am even considering moving up is an opportunity to grab a pair of new s15 turbos (I don't mind a little fabrication to get them bolted up) at a really good price locally and am curious as to whether their ability to make similar power at lower boost would be a better, i.e. safer, route. Any input would be great, thank you.