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Old 04-09-2012, 08:54 AM   #118 (permalink)
sinceday1
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Quote:
Originally Posted by blackonorange View Post
I don't get this t4 turbine housing stuff :s
I'll try to elaborate to the extent of knowledge.... (puts flame suit on)

T3, T4, T6... refers to the compressor size. Bigger the number, bigger it is but there are different dimensions entirely. Usually to reduce the lag, T3/T4 hybrid uses T3 hotside and T4 compressor so there can be expansion of some power due to T4 compressor and T3 hotside reduces lag to certain extent. It ultimately becomes limitation of the turbo in some cases...at same turbo rpm, the amount of gas T3 hotside will push will be smaller than that of true T4 thereby becoming the limitation. A/R ratio also works to determine the spool speed. Bigger the A/R later the turbo spools but if compressor size is different, same A/R does not mean same spool speed. So the compressor size and AR numbers work in conjunction to determine the spool speed per se.

It's still all arbitrary nomenclature of the size..... no exact dimension is set up.. what really matters is CFM...
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