PorterzSupra said:
I dont quite understand and it seems that 80% of memebers on here dont full understand either. This is what I have gathered so far correct me if im wrong. A "T4 turbo" is a reference to the COLD side or housing that ranges from about .58 to .70 in size? There is also the exhaust side or HOT side of the turbo that also is measured. Any combination can be mixed of matched for different engine/air needs. The must common exhaust side is around .68 for the supra but can go over 1.00. Is the intake and exhaust side usually suppose to be within a certin percentage of each other? What is the point of having a bigger intake and smaller exhaust or vis versa? A smaller exhaust means it spools up fast but with lower boost levels? a bigger intake side means more overall CFM airflow but does not dictate any overall boost PSI If you had a T66 for example that would be a bigger COLD side and most likely a bigger exhaust side but can be changed based on desired CFM and max boost?? **This is what I have put together in the past few days anyone wanna correct me or go more into depth please feel free because I know u cant always go by what you gather **
hmmm youre way off in most of what you are saying lol....
first off a t4 turbo isnt specified to any certain turbine or compressor wheels....its simply called a t4 turbo because it has a t4 footprint flange which is used to bolt it to the manifold...there are many other flanges.
the "cold" side is the compressor wheel and housing.... the stock ct i believe is around the 40mm ish range..... and they go MUCH higher.... ive even seen a 101mm compressor wheel.
the "hot" side is the turbine wheel and exhaust housing.... ranging from around .50 to about 1.16 etc..... these will basically explain spool characteristics to you...however they SLIGHTLY have to do with max attainable power as well as how well boost is held until redline and throughout the gear.
bigger intake plus smaller exhaust housing= surging... which isnt good. the key is to find the happy medium to get max spool time with max power without damaging anything.
go buy a book called maximum boost by corky bell. its all you could ever want to know and learn about turbos and their applications and then some.
hope that helped
