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View Full Version : HELP: S14 SR Vacuum Config - Have Pic


bK_S14
11-10-2009, 11:28 AM
Car currently runs perfectly fine. No idling issues. Only issue is that it stalls when i clutch in or when i'm in neutral at higher speeds.

So the only things I need to hook up to a vacuum source are:

a. BOV (NOT RECIRC)
b. Wastegate
c. FPR
d. Coldpipe (small bung)

Currently:
a. BOV vacuum is running to the side of the throttle body, looks like 'after' throttle. The one on the side.
b. Wastegate is running to a source under the throttle body.
c. FRP is running to under the throttle body.
d. Coldpipe (small bung) is running to under the throttle body as well.

Questions: Am I supposed to put a nipple on the hotpipe for the wastegate vacuum? maybe even the BOV? some ppl say i should put a nipple on the hotpipe and have both wastegate and bov running to the nipple and T it off.

Can someone please explain what vacuums should run where according to the attached pic? Thank you in advance!

http://sites.google.com/site/barrykong/DSC03073.jpg

jspaeth
11-10-2009, 11:45 AM
FPR should see manifold pressure....you have this right.

IACV shoud be a thicker rubber hose that comes off the cold pipe and goes to the IACV under the manifold.....I THINK you have this right.


Wastegate should see boost.....as near the turbo as possible.....probably should have a nipple on the hotpipe close to the turbo outlet.


BOV should see manifold pressure....so, connected to one of the manifold nipples.....so that when you close the throttle plate, the manifold pressure goes down very fast, but there is still pressure in the hot/cold pipes, which gets "blown off".


Ususally, people need to "tee" off of the manifold, since the OEM setup only gives you 2 vacuum ports under there.

sr20drifter
11-10-2009, 11:46 AM
If I am understanding you correctly this is very common when running an open atmosphere BOV. The MAF meters the air recieved from the BOV so when you let off the gas, the car sputters or dies occasionally, or atleast mine does. Its due to you running an open atmosphere BOV though. My vacuum lines are ran just like yours except my wastegate is hooked up to a nipple on the hotpipe.

jspaeth
11-10-2009, 11:58 AM
This is correct. Yes, with MAF sensor and open-atmosphere BOV, you will run rich in between shifts (flames!) and it may die or bog on decel.

Try tightening up your BOV.

You want it to blow off if you build more than a few psi of boost and then abruptly let off the throttle.

However, a little bit of chatter (surge) is okay ONLY if you had only built a very tiny amount of boost.

You should be able to find the "sweet spot" where it is tight enough that it's fully closed on partial throttle let off and decel, but loose enough that it is preventing compressor surge.

bK_S14
11-11-2009, 08:21 PM
Cool. Thanks guys.

I will change the wastegate vacuum line to connect to a hotpipe nipple.

Do you guys think that by doing a coolant bypass on the throttle body will cause the stalling at all? Right now I am bypassing the coolant that goes through the bottom of the throttle body... any ideas?

Thanks again.

cactus
11-11-2009, 09:36 PM
sorry to hijack the thread, but its kind of related.
with the line from the boost source to wastegate actuator, i notice in the workshop manual that this tee's off to the boost solenoid pipe, is this right??