What is the diff between the turbo's?

 

wastegate size & set-up
mounting flange
I believe the hotside is different but I'm not sure on the specs

 

S4 & S5 also have a slight difference in body style side trimming mirrors tail lights front and rear bumper and i believe the center console is also different

the upper manifold is quite different as well probably bigger ports
but there is also a decent difference in horse power

from the factory..
86-88 NA = 146 HP @ 6500 RPM w/ 138 Ft/lb @ 3500 RPM

86-88 Turbo = 182 @ 6500 RPM w/ 183 Ft/lb @ 3500 RPM

89-91 NA = 160 HP @ 7000 RPM w/ 140 Ft/lb @ 4000 RPM

89-91 Turbo = 200-202 @ 6500 RPM w/ 196 Ft/lb @ 3500 RPM

Infini IV = 215 @ 6500 RPM w/ 206 Ft/lb @ 3500 RPM (JDM only)


hehe well ththis is fom what i read up on
i wish i had an s5

...something ima convert to in the future.

this is just touching on it tho...

hope it helpedd

 

one was made from 86-88, one was from 89-91. i think thats about it.