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!!!

 

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

 

Search.

 

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.

 

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

 

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

 

yep

 

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

 

details on "ppg gears?"

 

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/

 

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

 

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

 

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.

 

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.