turbo question

[JonnySlick]

can anyone explain in simple terms what turbo trim and a/r ratios are all about? what's the difference in a 40 trim vs 50 trim vs super 60 trim? what the difference in a .48 A/R and a .63 A/R?

thanks.

[dreamdrivedrift]

bumpity bump, anyone?

[TokyoDrifterxo7]

not 100% sure but as far as my knowledge trim is the actually turbo housing size and A/R ratio is the tube size in the turbo. The scroll is measured by the cross-sectional area of the scroll's "tube" (A) and the distance from the center of the "tube" to the turbine shaft (R). It basically determines how restrictive the housing will be, versus how quickly the turbine will spin up. smaller A/R ratio, quicker spool up.