rogezeus2003

Hello Guys:

I have been reading and searching a lot about Miatas in general and there seems to be a general rule regarding transmissions, or more exactly, the 5 speed transmission:

"After 230-250 hp, the tranny life expectancy is uncertain, some last some dont, with the average Joe breaking 5 speeds left and right"

Anyway, there seem 4 options:

1-Reinforcing the stock 5 speed (cryo, micropolishing, shot peening, Carbonizing the gears)
2-Upgrading to a Quaiffe gearbox or complete tranny.
3- Make a 6 speed swap and be safe at least until 400whp
4- Make a 5 speed RX7 transmission swap.

To do a 6 speed swap, and I quote from Solomiata:

"The 99+ Miata 6-speed is made by Aisin and is not related to the Type II 5-speed (it is listed below for reference ony). Will the 6-speed bolt in a 5-speed Miata? Yes, make sure to get the trans plate and shifter from the 6-speed donor since they are unique to it. You will have to use only two of the three 5-speed starter bolts but that shouldn't be an issue, otherwise it bolts in (same PPF mount, etc). Keep in mind the 6-speed is combined with a 3.909:1 rear in the USA (3.636:1 other markets) since the tranny gearing is much steeper so your '90-93 or 99+ 4.30:1 5-speed rear should also be changed to the 3.909 or at least the more common 4.10:1 otherwise you'll have a nice tree stump puller"

My questions:
What about the RX7 tranny swap? What does it envolve?
Anything else needed for the 6 speed swap?
Any personal advice on transmissions for the Miata and BP platform?

My goal is 400 whp.

Thanks, Roger

BTW We should make more stickies!!!

18psi

iTrader: (76)

btw you should search...there are a **** ton of tranny threads here...no pun intended

Savington

iTrader: (31)

Search.

NA6C-Guy

iTrader: (1)

I like bananas

I say do the 6 speed swap, its the easiest. I wouldnt want to undertake an RX7 swap unless it was a track only car and I had plenty of time and money, and skills and tools.

hustler

iTrader: (6)

search, this is beaten to death. Enjoy cryo treating and polishing powdered steel.

rogezeus2003

OK OK I will search more. But it seems like the RX7 swap is difficult, the 6 speed is. Roger

redrumracer

yep

mazda/nissan

iTrader: (2)

if you get 3 more people to agree to it, we can get some dog cut PPG gears for the 5 speed

hustler

iTrader: (6)

details on "ppg gears?"

mazda/nissan

iTrader: (2)

Here is the site

When I inquired about the gears
We are nil-stock on this product and will not be putting it back into production until we receive orders for 5 or more sets which may be mid this year. The cost was approximately $7800aud

https://www.miataturbo.net/forum/t29169-2/

Savington

iTrader: (31)

lol, 1:1 5th. 5000rpm on the highway, anyone? I would also max 5th on three different tracks in California.

mazda/nissan

iTrader: (2)

I noticed that, I guess a different rear end would be needed

hustler

iTrader: (6)

nice, sequential boxes are great because they last a few hundred miles and are so expensive. Also, I had spur gears in the corrado...I do not miss them.


btw, 3rd gear gets louder every time I drive my car...and I've driven in fear since I put it back on the road.

redrumracer

Quaife has the upgraded gear set for the miata for about $1k cheaper than FM, and they also have "universal" 6 speed sequential transmission with helical cut gears or straight cut. Although I'm not too sure how much the shipping is from the UK.