4.2L Twin Turbo 370Z (AUSTRALIA)

Mike@GTM

First off, congrats on getting your build done!

Those turbos are sound asleep though, especially with your low compression engine.

We've installed a large number of systems making well over 450whp on the stock transmission and stock flex plate and never had any issues. Something isn't right for you to have two flex plate failures at this power level especially just after the engine was installed.

The only reason for the flex plate to be failing like that is due to a misalignment between the transmission and the engine. In fact, a misalignment is a very common cause for flex plate failure.

You know, since your engine was removed for this build, I'm wondering if they reinstalled the dowel pins for aligning the transmission to the engine. Also, it is very likely that when the transmission was being installed, the dowel pins may have been pushed into their bores. Sometimes, people will not have the transmission lined up on the dowel pins and simply force the transmission onto the engine and end up pushing those alignment pins in. That is the only reason you would have flex plate failure so quickly like that and in such quick succession. A slight misalignment will overstress the flex plate and cause it to fail extremely quickly.

Keep in mind that our flex plate is treated to have better fatigue strength than the stock flex plate. Even still, it is vulnerable to improper installation. Not even a billet unit will stand up to improper alignment.