Why So Boosted?

[tektic]

I thought this was originally a bad WGA but I swapped in another and well... It didn't change much if at all.
My car is spiking at 25psi and settling back down at 23psi as measured from a t in the fpr line.
There is no mbc. It's vacuum line is shared via t with a 1g uncrushed dodge garage modded bov and then connected directly to the manifold nipple.
The only other vacuum lines I have are for the cyclone which activates nicely at around 4100 rpm. All lines have clamps. Turbo specifics are: mhi 7cm evo 3 turbine housing with wg ported smooth and a small 16g compressor with a modified 14b cover.

Is it this high because the manifold turbine and 02 housings are highly ported with no cat and 3" turbo to tip exhaust?
I just need a bigger waste gate don't I?

 

[prove_it]

I'm running a small 16G too. I have it on a 2.5in exhaust otherwise same as you. I can control the boost down to 12psi. With that said, I'd check to make sure your wastegate is opening properly. I'm fairly sure you should be able to dial down the boost even with the 3in exhaust.

 

[transparentdsm]

dont connect it to the BOV line. it needs to go from the actuator to the turbo outlet or hot side intercooler piping.

like this without the MBC

 

[tektic]

Thanks for the conformation. That's what I figured... Haven't been able to so far.
I have to get a new regulator for my compressor. I'll see whats up after that.


Edit:
@transparent ETS wasn't kind enough to provide said port.


This is my vacuum system:

Not currently using the evap though.

 

[prove_it]

Technically, the BOV should have it's own dedicated line, however the line sees vacuum and boost and can be used for a boost source for the WGA. You should still see lower boost.

Again, did you actually check to make sure the wastegate flapper is able to move?

 

[tektic]

It was a good working unit 200 miles ago when I put it in. The arm still moved freely when I swapped out the WGA 4 days ago. I guess it's possible that I have 2 bad wgas.

 

[Spyke169]

If you have a hand pump I would test it with that, you will be able to both verify the WGA is working properly as well as see that the internal wastegate is moving and opening far enough.

Long vac lines could contribute to a spike, but overall shouldn't lead to overboosting.

 

[tektic]

I have a fuel siphon that can be used as a pump... no gauge on it though.
/ubbthreads/images/graemlins/smirk.gif Ahh..... Need more tools.

 

[minneSNOWta]

My ETS j-pipe didn't come with a vacuum nipple, so I just tapped a brass barbed fitting on for my EBC.

 

[Kibby]

My 16g runs wg pressure until it gets up to 5500 and higher. by redline it was hitting almost 25psi. That was from a stock exhaust broken flex pipe, though a 3" open downpipe only lowered the boost to 21 by redline lol. Didnt help much but sounded better than it did before. Ill be installing a hks hi power 2 1/2" catback once I get the time to mock it up.

 

[CutlassJim]

I'd get that boost gauge off the fuel pressure regulator line ASAP. Would suck to see you run lean and pop your motor because of a leak in the line going to the gauge.

 

[tektic]

I'd hate to see that too Jim. I had the boost gauge on the bottom tb port and it was not reading vac. Under advice from another board I moved it to the fpr line.

 

[ade]

what happened to the extra port you drilled and tapped for it?

 

[tektic]

That was the usdm manifold. I swaped to the cyclone and didn't modify it.

 

[CutlassJim]

Quoting tektic:
I'd hate to see that too Jim. I had the boost gauge on the bottom tb port and it was not reading vac. Under advice from another board I moved it to the fpr line.



The board is a liar! The "P" port on the throttle body gives you vacuum and boost.

 

[slugsgomoo]

Yeah, boost gauges can leak, so I would highly recommend getting it off the FPR line... the only thing you could tee into the FPR line that would be worse is an MBC in my opinion.

this is an ancient super elite MSPAINT drawing I did but it should be correct, though Jim is right, the P port is a good choice for pulling a boost/vacuum source. I'm not using it anymore because all those ports on my TB were welded over... but YMMV there /ubbthreads/images/graemlins/wink.gif

 

[tektic]

Quoting CutlassJim:
[quote name=tekticI I'd hate to see that too Jim. I had the boost gauge on the bottom tb port and it was not reading vac. Under advice from another board I moved it to the fpr line.



The board is a liar! The "P" port on the throttle body gives you vacuum and boost.



I did not get more than 5lbs of vac when I hhad it connected to p port. That's why I changed it.

 

[slugsgomoo]

if you're getting very low vacuum (inches of vacuum, pounds of boost /ubbthreads/images/graemlins/wink.gif), it means you probably have a pretty severe boost leak somewhere. Have you boost leak tested? are your readings different off the manifold than they are off of "P"? If they are, that's an indication of a problem as they should match exactly.

For what it's worth I think I'm ~ 17inHG at idle with HKS 272/272 cams, stock should read a bit more vacuum than that, bigger cams a bit less.

 

[tektic]

Since moving to the t in the fpr line I register 16 vac with gsc 268 cams... P port did not work right. Cams probably need to be degreed, but reading is accurate.

 

[CutlassJim]

Your P port is broken. /ubbthreads/images/graemlins/hsugh.gif


Inches of vacuum in a correct term but it's not very widely used. Here in Murica we like inches of mercury.......or Torr.