right now i have a 91 coupe with JDM Turbo II. but it still has the NA ECU. https://www.nopistons.com/forums/pub...O_DIR#>/11.gif





can the NA ecu's read boost? how bad is it for my car? oh, and can i use a S4 TII ecu? i cant find a S5 TII ecu yet.



thanks in advance

na ecu might read 2-3psi, not really no it doesnt see boost.



the turbo only see's boost to fuel cut, ~8.5-9psi



timing maps are different though, na is a little aggesssive for a turbo

i found a few s4 TII ecu's on ebay. how much of a difference does it make? i know the s4 TII had 8.5 CR and the s5 are 9.0, should i just baby my car until i find the s5 tII ecu?

The connectors are different , you won't be able to plug it unless you redo your harness, which is a pain... don't go there.