LS TURBO SELECTION-FULL RESULTS. 2 TURBOS & 2 TEST MOTORS! BIG TURBO vs SMALL TURBO. Check out this comparison test between a cheap GT45 turbo and a larger 80-mm Comp turbo on an LS3 stroker. Also tested, the same GT45 turbo vs S475 from Summit Racing on a smaller 5.3L. In the end, it comes down to response vs power, so choose your turbo wisely (but go a little big).