so im going to be doing a non-rotary engine swap. i know that the Turbo driveshafts and the N/A drive shafts are different length. now what makes it a different length? is it the turbo trans or the the diff that determines the length? Im going to be swaping in a non-rx-7 trans and im going to use my my N/A diff untill it breaks. im asking this because im going to need a custom drive shaft for this new trans anyway. And if the turbo/NA diffs need different length driveshafts, i dont want to have to buy 2 custom driveshafts. Im going to be putting out 240hp.

 

Your best bet is get everything done except for the shaft and then tow the car to a shaft shop. Its best for you and them if they measure.

I forgot the name of the place I used last but its in Crestwood.

 

The overall length of the NA driveshaft is only 1mm longer than that of the TII driveshaft. I'm not sure what that means in terms of transmission and differential lengths, but that's not your issue with this project. The problem is that the NA and TII differentials have different driveshaft flanges. Therefore, if your new custom driveshaft is made to fit an NA differential, it will NOT bolt up to a TII differential. Unless you want to buy a new driveshaft (or flange) when your NA differential breaks, you would probably want to have the driveshaft made for a TII differential.



My suggestion: Go to your local salvage yard and pull the entire rear suspension sub-assembly from a TII (with or without shocks, your choice). This will only cost you $150-300, and will get you the TII differential and larger TII halfshafts. Install it in your car along with your transmission, and then tow it to the shaft shop ala Mr. Gadget's suggestion.

 

just how strong is a N/A diff? i know arron cake was running his turbo n/a on it...

i can measure the length and just call quarter master or some place that makes custom driveshafts.

 

im wondering if i should just go with a TII rearend in the first place. I sure it would be the thing to do. iv been looking for one for some time, they seem pertty rare in my area. I have found very few, and they where asking to much for them. if anyone comes across a TII rear end, let me know!

 

hey will my tII tranny fit on my n/a shaft?

 

Tip to tip it is only 1mm shorter

But U-joint to U-joint is closer to 10MM, and diameter the Turbo shaft is almost 3/4 inch wider.

 

so is the TII trans longer then the NA trans?

 

No.
http://www.16paws.com/rx7/index.html

For those who don't know, all of this information is in the factory service manual. (Mazda calls it a "propeller shaft").

 

Well that stinks I wanted to kill my diff, hehe!

 

Evil Aviator:
that link is most helpful.

i wish the measured the trans lengths though.
maybe diff length, too.