engine swaps series 4 to series 5
 

do i have to change harness/ECU when swapping Series 5 turbo motor into Series 4 turbo car ?

i tough that i have to change harness/ecu only for NA to turbo swap.....

+ for those questions

what would u do with blown series 5 turbo motor (probably just water seal or something not bad for rotors/housings and good series 4 turbo motor ?

Swap
 

Nope. There is a couple of things you have to do. You need to use 2 cycle oil premix in the gas.....1oz per gallon and if you have the early 87-88 model.....you need to use your injectors off the series 4 motor. Low impedance. If you have the later 88... June of 88 and on...then you dont have to worry about swapping injectors. I have been running this combo for 2 years and had no problems at all. It runs cleaner also because of the 2 cycle oil. It burns cleaner than conventional oil.

what about using series 4 block and series 5 injectors, fuel rails, all intakes, turbo and stuff ?
what about oil metering pump ?

if you run premix like FC3sRacing said, you will have no need for the OMP.

....im not sure if you absolutely HAVE to do this, but you may as well