I need to replace my turboed 1.6 L engine, and am looking at a 1992 MX5 JDM unit. I have not been able to find out the compression ratio of the JDM, or if there is any difference in the head. Is it the same as the US model, at 9.4:1 CR? Searching turns up piles of info, but I have not found this simple fact, maybe there is just too much info out there. Anyhow, given the J14/11 IHI turbo, running at 10 psi, I would like to know what the JDM gives.

 

I thought it was supposed to be the same. I went with the 1.8 swap considering the price.

 

they are the same jdm and usdm.

 

Hey, thanks both for the input.