ok i have sets of twins, and im trying to make one good set. the 2 primary turbos have more shaft play then the secondaries (which is to expected). the original set that was in my car seemed to blow smoke every once in awhile but im only assuming that it could be the turbo seeing as it would only occur over 4.5K. sometimes the secondary did not come online at all.

anyway, ive pulled the original set out to port the wastegate. i figured since they are out (and taken apart) i should try get all the turbo issue sorted out. so my options are to :
A) put them in how they currently are (but w/ a ported WG)
B) rebuild them but the engine has 84K on it and may go any time...possibly killing the turbos that are in there)
C) try to figure out which ones are the best out of the 4 rotating assemblies i have and use the 2 best.

im leaning toward option C, (and possibly doing a little porting of the turbos to enhace flow/ reduce turbulance within the turbos).
so my question is: is there any way for me to test the turbos outside of the car (besides measuring shaft play) in order to choose the best 2?


i have one last question to pose regarding a white buildup that ive noticed on the original set that i pulled out of the car. im worried that it is residue from coolant getting into the combustion chamber... last time i pulled the turbos off they were NOT this color! ill attach a picture of what im seeing. thanks -heath

primary last year :


primary this year:

 

ill give this a bump because i need to get this thing back on the road soon

 

I have heard the same thing about the "white" markings. All FD 13B-REW engines from 92+ have a susceptability to leak coolant into the rotor housings & then out the exhaust. Happens when they get to around the 100k km area mostly.

Go for option-C as thats the most cost effective from what you describe. Gotta remember back to 1992, Mazda wernt expecting these cars to be still going hard 12 years later