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-   -   12a Tranny HP rating? (https://www.rx7club.com/1st-generation-specific-1979-1985-18/12a-tranny-hp-rating-433264/)

Fire85GSLSE Jun 12, 2005 08:47 PM

12a Tranny HP rating?
 
Who is running a stock 12a 5 speed in a FB or FC with over 200hp?
Tell me your hp and how the tranny is doing. Looking to bolt it up to about 200-250 flywheel hp and would liek to know if it will hold up.

peejay Jun 12, 2005 11:45 PM

You can break the trannies with stock HP if your clutch is too abrupt in engagement and/or if you have too much traction.

shadylurker Jun 13, 2005 12:07 AM

get a turbo II tranny :)

diabolical1 Jun 13, 2005 12:16 AM


Originally Posted by peejay
You can break the trannies with stock HP if your clutch is too abrupt in engagement and/or if you have too much traction.

exactly what peejay said here ...

my brother is putting down 210 HP at the flywheel and his tranny is the stock 12A fare and has been in the car for over 7 years. the clutch will be an issue and also how you treat the tranny itself. i'm sure you'll get some bickering about this, but you don't NEED a T2 tranny unless you plan to race or you're making ridiculous torque.

PaulFitzwarryne Jun 13, 2005 12:56 AM

The stock 12A tranny will take up to 350hp flywheel. What kills the tranny is shock load like dropping the clutchin too quickly. I get 215 hp at the wheels with no problem.

peejay Jun 13, 2005 01:28 AM

Oh, and shifting hard. That kills trannies in a roundabout way... it adds more "shinies" to the oil, which makes the oil somewhat abrasive, which damages the bearings, which allows the gears to deflect more under load, and eventually you lose 3rd.

That tranny I stuffed in 30-odd thousand miles ago? It's got a reallty strong whine to it. Not as bad as the rearend, but hell. When I'm on the rallycross course, and I need to shift, i *shift* and damn the noises. 2nd gear, every time, GRRRRONK.

You aughta heard it when I got mired in the "swamp" at this year's first event. Trying to rock back and forth wit hthe engine at 4-5k. Trans makes *ugly* noises when you slam it into Reverse when the wheels are still going 15-20mph...

I'll have my dogbox soon enough. :)

Fire85GSLSE Jun 13, 2005 01:24 PM


Originally Posted by shadylurker
get a turbo II tranny :)



Not even close to the gearing I need.



Thanks for the info. Keep it coming.

Hades12 Jun 13, 2005 02:41 PM

My buddie ran a 76 13B with Mikuni and RB headers, He would kill a 12A trans in about a year, and a Rear about every year and a half.

Fire85GSLSE Jun 13, 2005 03:49 PM


Originally Posted by Hades12
My buddie ran a 76 13B with Mikuni and RB headers, He would kill a 12A trans in about a year, and a Rear about every year and a half.


Ouch! Did you get my pm about the 80?

Hades12 Jun 13, 2005 03:54 PM


Originally Posted by Fire85GSLSE
Ouch! Did you get my pm about the 80?

Sure did. been meaning to reply.

I would take it but I am kind of full up right now. Plus you live so far away. I will keep watch for anyone wanting one though.

Fire85GSLSE Jun 13, 2005 04:08 PM


Originally Posted by Hades12
Sure did. been meaning to reply.

I would take it but I am kind of full up right now. Plus you live so far away. I will keep watch for anyone wanting one though.


Put her with my 79 that you bought. Hope she is doing well.
Know anyone with a good 13b 6port motor?

WackyRotary Jun 13, 2005 04:40 PM

I don't like how fragile the 12a tranny can be. I guess it really should be used for n/a use only in the long run. The turbo I was using really adds a lot of torque and I have broke 3 so far, but its still cheaper to just find another used one then buy rebuild parts. :)

Alak Jun 14, 2005 01:37 AM

Buddy with a Supercharged 12A. 175WHP and he blew his FB tranny in about a year. Went through 2 and finnally upgraded to an S5 N/A. He had a 4 Puck Racing Clutch and Pressure Plate. Drives it Very Hard. My Daily driver 225 Flywheel HP 13B powered FB lasted about 6 weeks, but Im an insane driver in my RX-7. Not a bad driver, just insane.

peejay Jun 14, 2005 12:16 PM


Originally Posted by Alak
Buddy with a Supercharged 12A. 175WHP and he blew his FB tranny in about a year. Went through 2 and finnally upgraded to an S5 N/A. He had a 4 Puck Racing Clutch and Pressure Plate.

which is probably why it died... the clutch!

coldy13 Jun 14, 2005 07:23 PM

I'm suprised by how much abuse my tranny's taken. I drove my car for about a year with a 12a turbo and 6 puck ceramic clutch and the tranny still shifts perfect.



And for the guys on here that still remember my project, it will be running again in about a week. I just put a new motor in it today :)

peejay Jun 16, 2005 12:11 AM


Originally Posted by coldy13
I'm suprised by how much abuse my tranny's taken. I drove my car for about a year with a 12a turbo and 6 puck ceramic clutch and the tranny still shifts perfect.



And for the guys on here that still remember my project, it will be running again in about a week. I just put a new motor in it today :)

Hey! You're still around! :)

Better watch out :D

peejay Jun 22, 2005 10:14 PM

I discovered that the SA transmission is stronger than the bodyshell where the rear upper links attach.

85rotarypower Jun 22, 2005 11:56 PM

What about the rear end? How much power will it take? I've heard a lot about how weak these trannies can be, but not much about the rear end.

ponsai03 Mar 9, 2026 04:54 AM

Peejay shop location
 

Originally Posted by peejay (Post 4448106)
You can break the trannies with stock HP if your clutch is too abrupt in engagement and/or if you have too much traction.

Hey Peejay, I live in Englewood OH and will like to see if we can connect to get something done to my RX7
ponsai03@yahoo.com

ponsai03 Mar 9, 2026 04:55 AM

ponsai03@yahoo.com


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