im getting an engine swap to a nissan 3.5 or ls1 would i need to completely change the tranny. or is there an alternative cuz i really dont want to buy a new tranny lol

 

Not sure if serious .................. ????

But :

Stock tranny will support 270ish lb/ft of torque for a reasonable length of time so long as you don't do stupid stuff .
If you are over 300 torque you should change it .

 

you need to make sure the transmission can be bolted to the new engine. its not you can or can not keep the tranny thing.
also the 3.5V6 is called VQ35DE.

 

A rotary transmission will only "bolt to" a rotary engine. There are ways to adapt a given transmission/bellhousing to bolt to a different engine.

However I should point out that the stock 6sp trans is neither geared to suit, or strong enough internally to suit, a more torquey V6 or V8 engine. The stock rotary makes about 160 ground thumping ft-lb of torque and even with that the stock trans seems to struggle to hold up without failing in some manner or another.

I'd strongly recommend against trying to reuse the rx8 trans in any engine swap.

Also bear in mind that the position of the stock trans, determines the position of the back of the engine. The rotary is small and compact, and has a specially designed stepped intake manifold to clear the firewall, which it technically sits under. Piston V engines have a set of heads sticking out in the wrong direction and would almost certainly have major clearance issues unless you plan to cut or beat the hell out of the firewall to clearance...and so you may wind up moving the trans and engine forward as a whole...in which case you'd have to fabricate a new way to mount the trans, a new driveshaft, etc. anyway...making the attempt of keeping the stock rx8 trans foolish.

 

Ok thanks for the help dudes

 

one more question does any one kno if the 3 rotor 20b directly bolt on to the 6 speed tranny

 

yes. You'll need an aftermarket lightweight flywheel for the 20b (buy one for an rx8/turbo rx7), and you can use an rx8 clutch.

That ignores the fact that it would be kind of like bolting a hayabusa 1300 engine to a riding lawnmower transmission and expecting it to hold up, though.

 

You will need one of thse :

http://www.richmondgear.com/01transmissions.html

and you will need to do a little bit of cutting and welding.