I am amidst a turbo build for a 1986 MR2. I am using a 4AGZE longblock and have been tossing the turbo idea around for a awhile. I did have a T3 50 trim which would have probably been a good choice but I sold it instead. I want something that is going to spool up quicker so I went with a T25 from a 2nd gen Eclipse. I know they are small and they make next to no horsepower but my goals are quite modest. I am looking for 200hp and that is it. I want to do it with minimum lag as this is a daily driver so the T25 should be OK for me.

However I have been looking around and have read about the T28. This is a mid range turbo I am guessing. Designed to give you give decent spool with a good mid range. They are said to be good for around 300hp. I have looked and they are supposed to be a hybrid using a T25 turbine and center housing with a T3 compressor. I have not found any other documentation about this.

What I want to know is how to make one? I know how to make a T3/T4 but I can not find any info about a T28. It seems like the perfect answer for me giving me both spool and mid range yet some room for me to add more hp later. I already have T3 compressor wheel from a 55 trim and that should be an interesting turbo if it is possible.

Any help will be greatly appreciated.