To correct this uneven drum rotation we've developed the "Center Support Kit". When these elements are unevenly loaded (due to uneven drum rotation) eventually these elements will fail. Each time the trans is shifted into 2nd gear the direct drum applies a load to the sprag elements. The most common hardpart failure in this trans is the "34-element" intermediate sprag. What is the weakest link in the Turbo 400 in Hi-performance applications? To significantly reduce this loss in a Competition TH400, we offer (3) aftermarket Alum. The hp loss would be more noticable with the sb if both engines were accerated at the same rate. The acceleration rate of a small block versus a big block also varies because the bb develops more bottom end torque sooner. In race cars which are asked to accelerate much faster the percentage of hp loss becomes more apparent. So, for ordinary driving the losses are negligible when compared to other transmissions. For instance, the hp loss is greater when accelerating from idle to 4000rpm in 2 secs. The solution lies in how fast the heavier internals of the transmission are forced to accelerate. Many have tried to approximate the answer to this question. What are the hp losses through a Turbo 400? This is typical with stroker motors and big blocks. Generally a Turbo 400 is preferred when the motor is producing more than 500hp and greater bottom end torque. When should a Turbo 400 be considered over using the Turbo 350?