Turbine side: T3.63 VS. T4 .58 on VRT

[B4passatglx]

Got a Turbonetics T3T4E 60 trim, with a .63 A/R turbine housing and a stg3 wheel, on a VR6 running stock compression 13psi boost, Is it benificial to switch to a T4 with a .58A/R hotside? I like the torque and this is in a Passat so I don't want a lot of lag.

My question is:

Will a t3/t4 .63a/r spool a lot faster than a t4 .58? Are they similar?

If I want to convert to a .58 T4 hotside what do I need? Turbine wheel and turbine housing? Anything else?

This is a gem of a turbo, oil and watercooled, and very shiny and I got it for next to nothing so I'd really like to keep it.

[VWTUNING]

bump :)

[boostin20v]

If I want to convert to a .58 T4 hotside what do I need? Turbine wheel and turbine housing? Anything else?

manifold assuming yours isn't dual pattern.

[B4passatglx]

I am switching to the .82 a/r turbine for the T3 side, It will move my power curve more toward where the 262 cams really set in, and it should be easier on the transmission and axles. .63 a/r comes on hard,