Ok i did a lot of search and i can't find the answer. What is really bigger on a hotside of 10.5. It can't be the area where the wheels spin because it is a direct swap so what is bigger? I know also about dual and single flapper.

Maybe someone could show me with pics the difference. Thanks.

 

Actually it is bigger where the wheel spins. If im correct the area is called the vollute. Its wider and taller if im not mistaken. Its the part where the exhaust travels around the wheel before exiting. It allows for quicker spool and more sustained higher end. Sorry I don't have pics to compare the two I just put a 10.5 on and im not taking it off to get pics lol. Search around in the threads for one on evo 8, evo 8.5, and 9 turbo differences. There is one with very good descriptions and very detailed pics comparing all three.

 

Ok i'll take a look. thanks!