well im in the market of putting together a turbo kit for my 2008 Civic Si....ive been in the market looking at a lot of turbos and trying to compare them but it seems like soo much numbers and i dont know what they really mean...

my plans are to pick a turbo that spools decently quick, but doesnt put too much stress on the motor (more power wit less boost)

first off a/r numbers....i realize that most compressor side a/r are the same on most turbos...its either a .60 a/r or a .70 a/r compressor housing
same thing i realized on the exhaust side, the a/r numbers for most turbos are a choice of .48, .63, and .84 a/r....but what do these actually mean and which would be better for my setup.

next is the trims i dont understand...50,56,57,60...just all numbers to me, i know its the relationship between the inducer and the exducer, but i dont know what numbers are for what im looking for...

these are some turbo options im looking into now....keep in mind im looking to make decent daily driven power on not too much boost (350-400whp) with a decent spool time

garrett t3/t04e 57 trim (non BB)
garrett 60-1 60 trim (non BB)
Precision SC6152S 56 trim (BB)
Garrett 35R 56 trim (BB)

 

This isn't going to be easy, and you'll NEVER know all that you need to know from a webforum, only from experiences and speculation from people that have a similar setup or similar engine design. Remember, no one knows what you want MORE than you do.

Don't worry about "trim" so much. It is simply a calculated distance between the inducer and exducer. A larger "trim" does NOT necessarily mean a larger turbo, w/ the exception of the "Standard" 50-60 "trims". You need to know a power goal that you're looking for, whether or not you plan to keep the engine stock or to build, the type of fuel being used, and your budget.

"Spool" time is relative, and first and foremost, you need to understand the actual definition of "spool", which is the "moment of inertia created by the exhaust gas pulse of the engine". What you're referring to is when a turbocharger will reach maximum surge pressure based upon a specific boost pressure.

PM me, we can solve this together, and get what you need.

 

TheShodan is the man, always has the right answer