hey guys,

just a few small pointers plz

basically i'm pullin parts off my S4 US motor.. and sticking them on my S4 JDM block

i've noticed some differences..

for example.. in the thermostat housing... my US spec has 2 sensors... this JDM has only 1...

and the jdm UIM has a **** load of differences vs my US spec.. alot of things are "missing" and it looks cleaner and simpler...


do i HAVE to change the front cover? or can i leave that one sensor off? (it's the one with the 2 wires running off the back of it)

the reason i'm hesitant to swap the front cover/housing.. is i've heard it's easy to screw up the alignment of the bearing sand what not on the front of the Ecc shaft..
i'd rather not take the risk if i don't have to

is it possible for me to use the JDM UIM? or do i have to put my UIM on it?

(i'm still running the stock US wiring.. on a Rtek 1.7)

 

ttt

 

Do you mean the water pump housing or the thermostat cover (where the hose connects)? S4's have a 2-wire ECU thermosensor on the back of the water pump and a 1-wire e-fan thermoswitch on top of the thermostat cover. S5's have both on the back of these on the water pump.

Front cover? There are no 2-wire sensors on the front cover. Are you still talking about the water pump?

The only difference is the J-spec has no nipple on the back for the double-throttle system and nowhere for the AWS solenoid valve. Neither are required.

 

the physical housing it self.. what's left after u take the neck off...

behind it there's 2 sensors.. one has an "injector" like clip.. where it's just a femal like socket/plug

the other has a pair of wires running off of it... that lead to a clip...




yea the back of the housing next to the other sensor
both are tapped right into the water stream




there was more than that missing.. perhaps it was removed...

perhaps i should take a pic of it later to show u..

 

here's the pics: the clean one is the JDM one.. the dirty one is my US spec..

what's with the single vs double vacuume things?













and here's the water pump housings.. US first J second

 

us engine simply has more emission bs

 

On US TII's the double throttle system has two purposes. The first is to prevent idiots romping on a cold engine by holding the upstream secondary throttles closed until the cooalnt gets to ~140degF. This is controlled by the thermovalve (attached to the thermowax) which is connected to the manifold by vac lines and a check valve. The second purpose to slow the opening of the upstream secondary throttles so they don't open too fast, which can cause a stumble at low rpm.

J-spec TB's don't have the first function, only the second, hence the simpler linkage and lack of vac lines and thermovalve. Mazda obviously trusted Japanese drivers more than US ones. Note that someone's pulled the thermowax off the J-spec TB.

I have no idea on that second temp sensor. The green one is the ECU thermosensor.

 

is the DTS system controlled by those 2 "UFO" like things?

i guess it can't be that important then eh? :P


so is it ok for me to use the Jspec manifold then?

 

One is a vacuum actuator to pull the upstream secondary throttles closed and the other is a damper to slow their opening speed.

You won't have anywhere to connect it to so I guess not.

Yep.