Hi all , I guess like some I may have been guilty of assuming that the T51R BB cartridges were just trim altered versions of the Garrett marketed GT42R bb turbos . I did notice that the HKS marketed T51R KAI and SPL used 76 trim rather than 84 trim turbines like the GT42R's (GT4294R and GT4202R) do .

It was suggested to me recently that the 76 trim turbines are actually TA series like possibly TA45's and TA51's use but in ball bearing shaft size . Can someone say for sure that T51R BB turbos use a TA series turbine and GT42R BB's a UHP (Ultra High Pressure ratio) turbine or what ever the truth of the matter is please .

Cheers Adrian .