I know I can get a new one from Mazda for ~$2,000 and some change, but I was wondering what to get that may be an upgrade without spending big $$$ on a dog box or sequential. These transmissions are great, but only last a short time for a dedicated track car, and I've just converted it over for rallycross, and I'm concerned I'll be replacing this transmission every season with that level of abuse.

Does Mazda, or any third party vendor, make a stronger transmission that will mount to the RX8? I was looking at Tremec, but they say they don't approve of the 9,000+ rpm redline.

 

What year transmissions are you working with? The Series 2 (2009+) should be more durable than the S1 Aisin. Buying new seems like overkill, 2nd hand good conditions ones should be accessible.
Other than that I'm not aware of affordable upgrades. Also dog boxes aren't exactly maintenance-free.

 

I got the original in there from my 2006. I can look into the S2 version. If I could find a used Turbo II from an RX7, is that worth the effort? Do they last a good deal of time?

 

There are lots of options... there is a CD009 option... that ends up close to RX8 gear ratios.. it isn't cheap though... bellhousing and mounting brackets for tranny and diff... and new drive shaft

Lots of different sequential boxes as well...

Easiest option is the RX8 5 speed.. its basically plug and play. It's basically a FD gearbox with a push clutch bellhousing

 

The rx7 transmissions won’t line up properly; additionally the T2 trans would also not work with the PPF.

Are you in the UK?

 

I'm in the US. I'm spending a lot of money to get a proper roll cage installed so I can't op for a sequential. Plus, I want my son to drive this car during competitions and properly learn manual transmissions. Which sequentials aren't completely.

The CD009 is about $100 cheaper than what I was looking at over the S2, but with any extras that's obviously gonna be more. So far it looks like the S2 option is what I'm going to do.

 

The 5 spd imported from Japan that Dan mentioned is often found pretty cheap at a JDM import shop, much less than you’ll pay for a good 6-spd. The gearing is a bit wider due to it only being a 5-spd, but it will be more durable for sure and is a direct bolt-in. It has improvements from when it was offered in the FD3 RX7 twin turbo back in the day; multi-pc synchro rings like the 6-spd has, upgraded bearings, etc. Couple of threads on the forum about it; it’s the go-to transmission for upgrading an RX8 to a turbocharger.