Stg1 Vacuume line diagram - Page 9 - SRT Forums

SilverBullet · 10-22-2003, 04:50 PM

Quote:

Originally posted by cali
Hey man thats all fine an dandy. If I didnt give a fuck I wouldnt be posting on the boards....but that doesnt negate the fact that :

The answer is in this thread. Read it, Print it, take it to the shitter with you. Read again.
Why would you want to loose boost at ANY time?

I think I need to attend Dale Seeley's school of assholes.:p

And I thought you were a graduate of that institution. Man! How wrong can I be.

Nway, I'm going to try few trick I learned on this thread tonight. I have the S1, HKS, BOP, and TXDSBC.

mike_coleman_srt · 10-22-2003, 05:41 PM

tested out the airbox vac line plug didn't notice too much of a difference on my break driving back to work 2 (blocks) did seem to notice some on my second break will drive around tonight and see if I can get the results cali is talking about.

needasrt4 · 10-22-2003, 09:56 PM

i just hooked mine up this way big difference

Pit Viper · 10-23-2003, 06:27 AM

Cali, after following your posts I think you have earned your
BoD degree (Bachelor of Dale-ism). We'll mail it off shortly.
(Can I call you "shortly"?)

cali · 10-23-2003, 06:36 AM

Quote:

Originally posted by Pit Viper
Cali, after following your posts I think you have earned your
BoD degree (Bachelor of Dale-ism). We'll mail it off shortly.
(Can I call you "shortly"?)

Please tell the president not to forget my Block Off Plates

Pit Viper · 10-23-2003, 07:20 AM

You still waiting on that? How many?
El Presidente has been slacking.

cali · 10-23-2003, 08:00 AM

nah, dont need it....I love being loud and intimidating.

Pit Viper · 10-23-2003, 08:17 AM

It's nice when your car is that way, too

ripcuda · 10-23-2003, 08:30 PM

I've noticed nobody explained why the BOV hooked directly to the intake manifold (vac/boost source) leaks or hisses or flutters... whatever when cruising. It's simple.

With a BOV hooked directly to a source off the intake manifold, anytime that there is a vacuum in the intake manifold there will be equal vacuum on top of the BOV (above the diaphram). This is what helps boost overcome the spring in the BOV (vacuum sucking on the diaphram) which allows it to "blow off".

There are times when you are cruising (not accelerating - constant speed) where the engine is turning some RPM above idle (depends on which gear you're in) and you're light enough on the throttle to maintain the same speed, the same RPMs and still be creating a vacuum in intake manifold (and registering a vacuum on your vacuum/boost gauge). This happens all the time when your cruising.

Well when your engine is turning however many RPMs for the above mentioned cruising... it is moving enough air through it to actually cause the turbo to have a slight amount of boost. You won't see it on your boost gauge cause your gauge is connected to the intake manifold where it is reading the vacuum in the intake manifold... but there are a few psi being created... just not getting through the slightly opened throttle plate.

When this happens: vacuum in the intake manifold + a few psi in the intake tract... the BOV WILL VENT... it will hiss/vent/leak... whatever you call it... it will release the pressure and probably make a noise you can hear. It will do this as long as you keep cruising at the constant speed/throttle position.

The BOV(BPV) on my WRX was directly connected to a source off the intake manifold (stock). When I put an intake on my WRX... I could hear the BOV alot louder. Anytime I held the RPMs constant like over 3k with the throttle light enough to have the intake manifold in a vacuum... my BOV would hiss. It would hiss all day long. I would do this all the time while I'm cruising around... ie not accelerating (not WOT)... so much so I put the stock intake back on so I didn't have to listen to it hiss so much!

This is perfectly normal and actually a good thing. I allows the turbo to freewheel creating whatever boost it will at said RPMs so when you do dip into the throttle...it's already got some for ya! If the BOV didn't vent during cruising at RPMs where a freewheeling turbo would normally be making a pound or two... it would cause the boost to stack-up in the intake tract and it would mildly stall out the compressor of the turbo... causing that extra split second of delay for the turbo to start pumping after you dip into the throttle. Would you notice it? Probably not... but it's happening!

I'm not sure how the stock BOV vac line setup works... obviously the ECU is in more control of when it vents and when it doesn't... which also could act as a form of backup boost control. This could be why Cali (stock vac line hookup) doesn't get the hiss while PSI (vac hooked to intake manifold) does get the hiss like I described above.

This was a great topic of debate/discussion a few years ago amongst the old TD crew. Gus Mahon (RIP) had a wonder way of describing the whole idea. Sorry for the long post.

cheers,

needasrt4 · 10-23-2003, 08:38 PM

hey, for those of you who have been pulling codes 234 and 1188, we reran our vacuum lines to match the diagram and we no longer pull these codes even if we try

Pit Viper · 10-24-2003, 05:12 AM

One more question answered:

This will NOT work with just the aGP wastegate. You need a boost controlller. Unless you like maxing out at 9 lbs.

turbobozz · 10-24-2003, 05:56 AM

Quote:

Originally posted by Pit Viper
One more question answered:

This will NOT work with just the aGP wastegate. You need a boost controlller. Unless you like maxing out at 9 lbs.

You mean this setup? (edit: refering to the psifi setup)

I'm running the AGP WGA alone directly to the turbo.... running 17psi boost.

Pit Viper · 10-24-2003, 06:25 AM

Are you running the setup from page 1?
I've got it like Cali suggested, since I've got the Mopar BOV and don't want the constant leak. I turned my WGA all the way up and only could push 9.
Hooked up like stock I was pushing 18 no problem. Next step: add a manual boost controller to the mix to get the desired boost.

turbobozz · 10-24-2003, 07:24 AM

nope... I'm running the stock surge valve with the stock setup through the solenoid... and boosting to 17psi with just the AGP WGA connected directly to the green line (turbo housing).

Pit Viper · 10-24-2003, 07:50 AM

I removed the green line and just ran a line from the housing directly to the WGA. Couldn't build more than 9 psi.
Hmmmm.