How much can 88 turbocharger handle psi and how much 89??
Is 89 direct bolt in for 88 and which one is better and why??

 

There is no difference in either one of the turbos themselves. The difference is in the wastegate system used in each.

The 87-88 uses a single wastegate which is less than adequate for venting excess pressure once you start upping the boost.

The 89+ on the other hand, utilizes TWO wastegates, which will allow MUCH better boost control.

 

well than from what year is this turbocharger taken off ?

 

can't tell from this picture, if you look into the exhaust end of the turbo you can see the wastegate, if its one disk the you have the earlier turbo, if there is a pair of disks, side by side, then you have the later one

 

The A/R on both sides is different on the 89+ turbos.

 

Both about 14psi max before they start puking oil...

No, you cannot swap them unless you've got the appropriate year turbo exhaust manifold.



-Ted

 

That's a Zenki 1986-1988 turbo - the tip-off is that it doesn't have the bleed-off "T" that goes to the boost solenoid for the Kouki 1989-1991 turbos do.&nbsp If I had a better paint proggie, you could probably read the "HT18-2S" that is scrolled down the side of the compressor housing...



-Ted

 

By the way do not be fooled by these TII turbos, they might look small BUT they actually are TO3's...

 

The 89&up turbos are WAY better then the 88 turbos. Not only does it build boost sooner (2500rpm) but it has way more torque midrange. It maintains boost very well, doesn't spike as much too. I noticed a huge difference going from my 87 turbo to a 90 turbo. Here is the full story on it from the 2nd Generation RX7 resource page:

"The makeover in 1989 saw The Turbo II get a new turbocharger. Mazda called it the "Completely Independent Twin Scroll". The impeller was fed directly at the exhaust port. Per Mazda: " This permits the powerful exhaust pulse generated by the opening of the exhaust port to directly hit the turbine blades without interference from the exhaust from the other rotor." This newer design resulted in reduced turbo lag and increased torque. The Turbo II's wastegate was now electronically controlled, rather than the old mechanical design allowing higher boost pressures."