boosting too high!!!

[thefisl]

ok here it is, I just installed a boost gauge(splitfire [side note:it came with a t fitting that had a restrictor on it and i dont know if that's normal, installed it ne ways but ne opinions?]) so that i can better tell whats going on.... heres what i got:

Max vacuum ~25
vacuum @ idle ~20
Max boost ~20PSI!!! ( I really dont know since thats where the boost gauge maxes out!!)

Now.....my car is a 98gst with cai, magnecore wires, type s bov(I have both nipples connected, the lower of which is t-ed into the line between the turbo and the BCS, can anyone acknowledge that this a correct setup?) and boost gauge and thats it!!! whats going on. i thought if my vacuum was where its at i shouldn't have any boost leaks....if thats so, then WTF is going on?? Please help....

 

[DSMeclipse4G63]

Are you still on the t25? do you have a mbc or some form of boost control? Do you have the bcs restricter out? If the bcs is out hook that up stock and take the mbc off, I had the same problem I tached out my boost gauge past 20psi and I took my mbc and put the restricter in and was running 13-15 psi depending on gear.

Now your vacuum is normal anything from 17-22in/hg at idle is normal, 23-25 under load(driving with throttle depressed) is normal as well. try that and let me know.
Andrew

 

[Tallen]

Boost controller.

 

[thefisl]

I am stock except for the mods mentioned. No MBC and still on stock T25. I tried to remove the BCS restrictor but gave up b/c I didn't want to break it. This was way before I installed the type s bov and everything was fine. So I dont think its that. Also note on prior post about how I installed the BOV, do you think this might have something to do with it? Please guys, keep 'em coming....... but my situation still :thumbdown I think my hg is going out now can you Donate Some Money (DSM) :laugh:

 

[dmtunc99]

My car's vacuum is at around 15 at idle, is this too low?

 

[Drifter00]

Could have a vacuum leak. Most 2G's will idle around 18-20hg

 

[Tallen]

My car's vacuum is at around 15 at idle, is this too low?

Check your timing marks on the cam gears. You mya have skipped a tooth. If your lucky its just a vac leak, so check the hoses first.

 

[dmtunc99]

Is checking a vac leak the same as a boost leak test? What would be the best way to check

 

[dmtunc99]

Check your timing marks on the cam gears. You mya have skipped a tooth. If your lucky its just a vac leak, so check the hoses first.

Could you be a little more specific with some directions, I don't really know what this means. Thanks

 

[DSMeclipse4G63]

Low but steady = late ignition or valve timing, low compression, stuck open throttle valve, vaccum/boost leak. I figured my problem with my t25 boost out of control to be a faulty wastegate actuator. It would stay closed and just wouldnt open...

 

[95BoostinTalon]

type s bov,I have both nipples connected, the lower of which is t-ed into the line between the turbo and the BCS, can anyone acknowledge that this a correct setup?)

I may be wrong here but i'm just takin a guess, you said you have the BOV vented to the line between the BCS and the the line to the turbo, doesnt this line go to the wastegate? If so then that would mean venting to this line would cause the wastegate to stay open and that would make you max out your boost past 20psi. Try recirculating the BOV somewhere else like back into the intake system and you shouldnt have a problem, because now it seems everytime it recirculates air it keeps your wastegate on your turbo open causing to to run such high boost...Good Luck hope it helped

 

[thefisl]

no, the bov is vented to the intake........there are two nipples on the back of the type s. the top one goes to the intake manifold vacuum line where the stock bov went (i know that much for sure), the lower one, heres where it gets sketchy, goes to a boost source like the line between the turbo and the bcs..(anybody feel free to chime in on this one)

 

[igs]

With the stock bcs my boost spiked to 20psi as well. This is normal.

 

[thefisl]

there are two nipples on the back of the type s. the top one goes to the intake manifold vacuum line where the stock bov went, the lower one goes to a boost source like the line between the turbo and the bcs

so can anyone tell me whether this is wrong or not. or if this could possibly be causing the problem

 

[92awddsm]

Unhook the bottom line to the bov. Leave the top connected as stock and leave the lower nipple unhooked and open. The boost pressure to the lower line is trying to open the valve while the boost pressure to the top is trying to keep the valve closed. With equal pressure to both top and bottom of the diaphram, it is more likely to leak.

 

[igs]

so can anyone tell me whether this is wrong or not. or if this could possibly be causing the problem

What problem? Everything is normal.

 

[igs]

Unhook the bottom line to the bov. Leave the top connected as stock and leave the lower nipple unhooked and open. The boost pressure to the lower line is trying to open the valve while the boost pressure to the top is trying to keep the valve closed. With equal pressure to both top and bottom of the diaphram, it is more likely to leak.

A leaky BOV would lower boost not raise it.

 

[92awddsm]

I didnt say it would cause or fix the problem. I was stating the best way to hook up the type s.

 

[thefisl]

Unhook the bottom line to the bov. Leave the top connected as stock and leave the lower nipple unhooked and open. The boost pressure to the lower line is trying to open the valve while the boost pressure to the top is trying to keep the valve closed. With equal pressure to both top and bottom of the diaphram, it is more likely to leak.

I thought that the top line created a vacuum when the throttle body closes therefore sucking on the diaphragm and causing the bov to open. I also thought that by connecting the bottom to a boost source it would assist the diaphragm by constanly applying pressure so that when the vacuum is created on the the top end the bov flies open in a split second.... again this is just what i thought.....is there a wiseman that can verify or disprove this.......or can we just get 2nd, 3rd, 4th etc...... opinions on this......

 

[thefisl]

Still need to do some further test but I think I found the problem... The problem is that thefisl=jackass!!! Well when I added the second line to the lower part of the bov, I forgot to adjust it to a harder setting!!! I figured it out today when I took my chick to work b/c I jammed on it and I told her to watch the gauge for when it hits 10 psi....it steadily rose to 10 then after that it just shot to 20!!! Meaning, the bov was set for a max of 10 psi, therefore as soon as it hit 10 the bov would start to open causing it to spike to 20 almost right away. Boost gauge is key!!!!

 

[92awddsm]

I thought that the top line created a vacuum when the throttle body closes therefore sucking on the diaphragm and causing the bov to open. I also thought that by connecting the bottom to a boost source it would assist the diaphragm by constanly applying pressure so that when the vacuum is created on the the top end the bov flies open in a split second.... again this is just what i thought.....is there a wiseman that can verify or disprove this.......or can we just get 2nd, 3rd, 4th etc...... opinions on this......

You are correct. This is the quick release method but I have heard of problems with people setting up this way.