if you werent so lazy and actually RTFA that was linked in the OP you would have seen:

Transmission
It was determined that using the stock transmission with this engine would not be a very good choice. Some parties claim that the stock transmission was very reliable and well built, others have told us about transmissions that they ripped in half with 250 and 300 horsepower. Plus, it only makes sense to get a stronger transmission when you're increasing the stock engine's horsepower by over 230 percent! For this reason, we bought a Porsche 6-speed manual transmission with Limited Slip Differential. It came out of a 1995 Porsche 911 Carrera 2.


hate board members who need to be spoon fed.

 

back to the future part 4!

 

I hate board members who act like an *** to newer members. You are better than noone.

 

it says it is a twin turbo 20B but only makes 300hp?


Yes, as installed in the Cosmo 4 door, it makes about that - if it was perfectly stock and had the original ECU, that would be the output.

S

 

But at least he can read and not ask questions which are answered in the article