I own an 1993 fd twin turbo and have developed an interest into buying an old rx4 or an rx5. I have found and rx5 with disk brakes, 13B engine, 4 barrel carb. but with an auto tranny.

I am thinking about butying it but was wondering how hard it will be to swap the tranny to a manual. Also any recommendation rx4 vs rx5 and what to look for on this mx5.

Ultimately, I may drop in either a 20B if room alows or a 13-brew

Thanks a bunch. please attach a web site if anyone know of someone that has done this swap. Tranny mounts auto vs manual?

Your help on this matter will be greatly appreciated.

Jay

 

I never attempted this project, but I made a web page detailing some of the possible mods required to fit a 20B in a CD Cosmo (RX-5) with the stock automatic. I don't know how much it will help you, but take a look. http://www.geocities.com/cd23c/20b.html

 

I just changed my RX4 from auto to manual. Not as hard as you may think. I did use a RX7 1st gen tranny. It made life simple. If you have plans on running a 20B then you will defiantly need a stronger transmission. I would go with a Turbo II. With that set up you will need to make some custom transmission mounts and you’ll need the Turbo II driveshaft. It’ll need to be cut to fit and possibly it’ll need to have the original driveshaft’s yoke welded on to it to fit the original rearend. But you’ll probably want to change the rearend too if you run the 20B. (note: the RX4 rearend is much stronger and stouter then any 1st gen.)
On mine there’s a plate (as in the PICs) that’s on the driver’s side firewall. That’s where a clutch master cylinder should have gone. You can remove it and put in the master cylinder. All I had to do is use, again, the 1st gen RX7 clutch master cylinder and change the mounting studs, they were to short. I got the brake and clutch pedals from a 1st gen RX7 as well. Since I was using the 1st gen transmission all that was required was that the mount be moved back to the second set on mounting holes. There are three sets of mounting holes on the body. The automatic used the first set. Mount the pedals in was easy. All I had to get was a longer mounting bolt and nut (Home Depot). Make sure you get the sleeves for the pedals too. Once you look at the set up its pretty self-expletory If you have any question please email me SBMotors@***.net .

 

Thanks guys... great setup, pics and ideas. Will e-mail with questions when I get my project car. Still devating betweel the availble RX5 or a potential rx4. SBMotors.... what type of engine will you be dropping in? Is your setup complete. VA Beach... miss that place since I left ODU. Thanks again.

 

You'll also need to jumper the starting inhibitor switch.

Personally, I'd go with the RX4, especially if you can find a '74 or '75 as they got the heavy bumpers and Toyota station-wagon looking grill in '76.

Cosmos are heavier and not the best-looking IMO.

 

Wankelguy... what type of rearend and brake system do 74 or 75 rx4's models have? about how many horses can the rear end handle?

 

They have rear drums, the cosmo has a dual rear break set up, disc brakes and inside the hub a drum break for the parking breaks................
Both are nice cars.

 

I'm putting in a S5 N/A witn an extreme street port. Had to change the front cover and oil pan pan and use an 85-84 GSL-SE front cover and oil pan because of the motor mounts.

I'm glad to hear someone likes Va Bch. I hate it here. The auto laws here are too harsh. I can't wait until we transfer to Texas in a few months.

 

RX5 has a few things to be cautious of: the rear end is a different pumkin than all other Rx3/4/7. Not interchangible. No LSD available, different stud pattern, (sorry dont remember that one) Rear is a 3.7 ratio.

It was built as a luxury coupe sans Porsche 928.

RX5 is pretty heavy also, IMHO it'd make a great restoration project but might not be the best choice for a performance car.

I initially used one with the center welded as my RX3 race diff but soon changed it for a different set up.

 

Cosmo rear is 3.636, the stud pattern is 4x120 (1st gen RX-7 is 4x110), the weight has been described as similar to an REPU. I'm not so sure about that though. The platform, while only available in 2 door, is based on the RX-4 platform and shares some key features; especially under the hood.

I have access to a Cosmo and an RX-4 wagon. I wonder which is heavier.