jsut by looking at the engines, what are the differences? i think the jspec has a different logo on the intercooler right??. Yea, i prob should try "search" function, but what tha hell, anyone

~ut

 

One of the differences is that the J-Spec's don't have an EGR valve. There is no performance difference between the 2 though.

 

Also I cant remember why but the US TB didnt fit on my j spec upper manifold. I think it was that the throttle cable bracket was different, also the rod for the omp mounting spot.

 

A few of the differences I've noticed:
Intercooler logo
throttle bracket
upper and lower intake manifolds
rotor housings (different text on top of housings, trailing plugs are in a slightly different location)
throttle body
BAC valve (look identical to U.S., but non-adjustable)

I'm sure there are more differences, but that's all I can think of right now.

 

for the 86-88's
they have the different logo in the ic
i think the twin scroll actuator goes the other way??
they use the 89+ us rotor housings (no egr)
they have no egr in the intake
different bac (n318a instead of n318)
the pulsation damper and the fpr are reversed
the fpr has no solenoid
the acv is different
and so is the airpump
they have no aws valves

for 89-91
its the same except the egr, the pulsation damper fpr is like ours, and there is no twin scroll

mike

 

so the S4 j-spec engines do have high compression rotors in them, that's good to know. I do have a question though.

If i have a long block J-spec engine from a S4 and i want to drop it into a '87 TII would it be pretty much a straight swap? By, long block i mean all mainifolds, IC, turbo, and complete wiring harnest to the firewall.

I have searched and didn't find an answer to my specific question.