korance

Hey ,
Recently i finish my Mazda RX8 2JZGTE VVTI swap . i got the stock J3 5 speed automatic transmission with engine from lexus GS300/Aristo .
My Mazda had electronic throttle pedal so my mechanic did convert it to mechanical pedal and he replaced the stock e-throttle body by mechanical one from older 2jz engine. Now the issue that i am facing is that when i press full throttle i don't feel that much power & difference on half throttle vs full throttle. also i don't have any downshifting unless by pressing break which decrease the gears. Totally i got 4 functional gear modes (P,R,N,D,3) and manual shifting gears is not working at all.
Other issue is that when i put the gear on D or R mode i feel very hard kick which pushing car to forward or backward and i am not sure is from transmission or differential. i want to know since my mazda had 4speed auto transmission , possible that toyota 5speed transmission could not work directly and properly with mazda differential. i know each transmission gearbox or diff has different ratios but i don't have any good knowledge about how they work together in different cars .