Hello
2.5l turbo miata nc here!
Planning to turn up the boost and wide sticky tire.
Should produce 350-400ft lbs. Car is used for trackday and amateur drift event.
Gearbox won't hold it, also rx8 rear hub conversion is recommended (stock can fail :/). Do you think I should go with whole rx8 subframe and diff (8")? Or stock 7" is fine?
Gs6 37dz is enough or better go with the heavier gs6 53dz? (Adamat performance offer both options)
Already blew a gearbox, now monitoring gearbox and diff temp to increase life of component
Thanks for your help

 

@vteckiller2000

 

Which NC gearbox have you blown up?

 

Nc1 gearbox 6 speed. Noisy then third gear blow.
Now running nc2 6 speed, with extra heag shielding and lower boost pressure

 

What extra heat shielding? What turbo you running?

I am about to drop a 2.5 and NC2 6speed in my NC. Will be shooting for between 300-400whp with a Garrett of some sort.

 

Subframe swap not required:

https://www.anthonylleras.com/post/d...-rx8-to-an-mx5

 

Thanks for the article.
Rx8 diff bracket is said to be thicker and less prone to failure.
The subframe and control arms might be a bit more robust as well, not sure if the upgrade is worth.

Turbo is garrett gt2871r ar 0.86, custom manifold low mount
I made a custom exhaust and took extra care to protect the gearbox from the heat

 

Was gonna post what jpreston did. Cheers

 

I also just realized today that the RX8 rear subframe has rubber bushings for mounting to the chassis and the MX5 subframe is solid mounted.

 

Correct. I believe the NC subframe is also slightly thinner gauge steel as well.