Manual gearbox conversion? for Eunos Cosmo 20B

[20B Rotary]

I was looking around in DMRH home page, and I found that there are some Cosmo that says that they have a manual gearbox conversion, with FD rx7 transmission and bell housing.

I was wondering do they speedometer keep working with the manual transmission? If they do, how its keep working? does it use the same speedometer sensor as the FD? or what they do to make it work? And the reverse sensor? and all the sensor that it use it is possible to use them with the FD transmission?

I was thinking on making mine manual with an FD manual transmission, but I want to keep the stock speedometer working.

If there's any way to make it, please show me the way because I am about to be a new Eunos Cosmo owner (burnout)

Thanks for your time

 

[Berty]

Most people use the FC gearbox as the speed sensor is the same as the Cosmo's (FD wont work without conversion)

You'll need to dog-leg the gear lever to make it fit through the hole where the auto lever was.

The other reason for using the FD box is that you have to do a push / pull conversion where the FC box is already a push type.

Clutch master and clutch slave can be taken from a few different Mazda's but you might need to be creative in the mounting process as the ABS stuff gets in the way.

 

[20B Rotary]

(bowdown) So in other words with the FC transmission it should be like bolt in and done? (Without the problem of the Clutch Master and slave position)
Is the same with the revers sensor? All my Rx7s are manual so I don't really know how a automatic Rx7 transmission work (dunno)

Sorry if I ask lot of questions, lol, but on this page is where I have found that people know what they are doing and saying (bowdown)

Thanks for your time and opinions (thumb)

 

[kiwiJC]

hey guys my cosmo has had the manual swap done as well.
fc box and clutch master and slave cylinder.
I had to fit a plate on the fire wall to spread the load of the master cylinder as it had started to crack from the stress, as it wasnt designed to have a clutch mounted on it.
i fitted a pedal box from a MX5, as the clutch pedal is separate from the brake pedal, and is the same length as the rx7's, the only thing i am not happy with is the pedal sits a little lower than the others but thats a easy fix that ill do in the next week or two.
for the ABS unit all i had to there was shift the pump to the other side which freed up lots of room and stopped the master cylinder hitting the inlet manifold.
hope this is of any use. i can post pics if people wont to see.

 

[20B Rotary]

Thanks for the info, it helped me very much and I will love to see those pics to be sure of it before spending some money

But I'm sure that I will do my conversion as soon as I can.

Thanks

 

[Antoine]

(bump) for (pics)

 

[kiwiJC]

heres somes pics, sorry for the delay guys ive been helping my mate put a new clutch in his rx7.

the plate on the inside goes right across the brake master cylinder mounting area aswell.

to mount the pump i had to move the radiator over flow tank. but i was able to shift the pump with out having to cut any wires or make new brake lines.

yes thats a 13b but its just temporary, the 20b is not too far away from being finished.

 

[kiwiJC]

bit off topic but thought i would post a pic of the rx7. its now bridge port turbo and 500hp at the tires. the skyline is my other car.

 

[20B Rotary]

heres somes pics, sorry for the delay guys ive been helping my mate put a new clutch in his rx7.

the plate on the inside goes right across the brake master cylinder mounting area aswell.

to mount the pump i had to move the radiator over flow tank. but i was able to shift the pump with out having to cut any wires or make new brake lines.

yes thats a 13b but its just temporary, the 20b is not too far away from being finished.

Nice pics man, it looks just how I think it will look its good to know the info about making it std before buying it,

Thanks for the pics, but do you use fc3s full transmission and flywheel?

 

[kiwiJC]

the gear box is stock FC,
the drive shaft will have to be made up, so you will need the yoke (front end ) off the FC drive shaft and cut the front end off the cosmo one to suit and get it all balanced. for the cross member i had to make up some spacers to drop the cross member about 25 mm and then a plate was welded on to it to meet the FC box mounts.
ill try get a under car pic.

the cosmo motor will of course be a auto motor and have a counter balance on the crank shaft so you will need a flywheel that doesnt have that built in and bolts to the weight, i thought most manuals came with the counter balance weight built into the flywheel, but i could be wrong.

you could just take the balance weight off and fit a weighted fly wheel but i thought they crank, rotors and weights were a blananced set and kept it as is.

 

[kiwiJC]

the drive shaft is a two piece unit still, i couldnt fit it all in the photo.

 

[20B Rotary]

(cool) Nice pics you got there, the last question so far, do you use the stock 20b bell housing? or the fc one?

I know that they can fit both them on the engine but im not sure which one is better.

Thanks and sorry to ask a lot of question but I have never upgrade an 20b, I feel noob lol

 

[kiwiJC]

bell housing is fc still. i think the end plates are the same on all the motors 13b, 20b, cosmo and rx7. only thing is cosmo motors have bigger ports than rx7 motors.

 

[20B Rotary]

Thanks for all the information and yes the end plates are the same, here in puerto rico are a lot of 20b m/t but there arent cosmos around here so the engines are in rx-7s, mustang, miata, etc.

Thanks for all the info you helped me a lot (drinks)

 

[Austerror]

Nice info. When my auto dies, I'll look into a manual conversion.

 

[Rotorzilla]

I just finished converting my Cosmo from Auto to 5 speed.

FC transmission
FC flywheel aftermarket with the 20B counterweight
FC clutch and pressure plate
FD clutch peddle
FD clutch master
FC clutch slave
Cosmo Speed sensor take the top half off and fits right into the FC transmission.
FC starter