12a motor with FC turbo II box

Gearboxes, clutches, diffs, wheels & tyres....
Post Reply
Dan Dillinger
Posts: 120
Joined: Fri May 25, 2012 11:14 pm
Location: Edinburgh

12a motor with FC turbo II box

Post by Dan Dillinger » Tue Sep 29, 2015 10:35 pm

Got a series 5 turbo II gearbox I want to use on my FB.

I've also got a racing beat paddle clutch for a 12 with turbo II spline.

I know the gearbox will bolt upto the 12a ok.

My questions are. What flywheel can I use? Standard 12a wheel ok to use?

What starter motor can I use?

Last question, the tail housing. I guess this is a straight swap over? So I can keep my gearbox mount and speedo drive etc?

I think I've read somewhere that I need to remove some damper thing that the series 5 box has?

0-0
1982 - Mazda SA22c import

User avatar
ian65
Posts: 5660
Joined: Wed Mar 30, 2011 12:11 am

Re: 12a motor with FC turbo II box

Post by ian65 » Tue Sep 29, 2015 10:53 pm

1986 Series 3 13B Turbo II
http://rx7fb.com/viewtopic.php?f=2&t=2400
1992 Peugeot 205 1.9 GTI
1975 Honda SL125 Street Scrambler

TOOL
Posts: 2514
Joined: Thu Sep 01, 2011 10:30 am
Location: Var, France (ex NZ, ex UK)

Re: 12a motor with FC turbo II box

Post by TOOL » Wed Sep 30, 2015 4:16 am

If you want to run a turbo box you need to fit the matching flywheel for the bellhousing.

You can't fit a standard turbo 2 as you will unbalance the rotating assembly. So you have to fit a turbo light flywheel and fit the matching 12A rear counterweight. If you have a S3 rotating assembly you will struggle to find a counterweight now. Try Oz.
You then need to fit a turbo clutch.
You also need a turbo 2 starter motor as the bolt holes are different on the boxes.

You will need to fit a turbo yoke to the propshaft as well.

A turbo box is about 10mmlonger than a S2/3 box. I believe you can fit the tail from a S2/3 box to the turbo box. I haven't done it myself yet.
You may need to slot the box mount.
Speedo will attach to same speedo drive as it's in the tail section iirc.
Back in sunny France

Dan Dillinger
Posts: 120
Joined: Fri May 25, 2012 11:14 pm
Location: Edinburgh

Re: 12a motor with FC turbo II box

Post by Dan Dillinger » Tue Oct 06, 2015 6:46 pm

Thanks for the help!

I'll maybe drop Racing Beat an email too before I start taking these boxes apart ;)
1982 - Mazda SA22c import

User avatar
ian65
Posts: 5660
Joined: Wed Mar 30, 2011 12:11 am

Re: 12a motor with FC turbo II box

Post by ian65 » Wed Oct 07, 2015 7:02 pm

you'll probably need to change the speedo gear on the output shaft as well if you intend to use a s2 or s3 speedo drive.
1986 Series 3 13B Turbo II
http://rx7fb.com/viewtopic.php?f=2&t=2400
1992 Peugeot 205 1.9 GTI
1975 Honda SL125 Street Scrambler

Post Reply