Compressor surge? Options

[BudmannG]

What would case compressor surge?

I have gotten many answers. I was told it was because my bov is to tight? I have a rfl bov. I did not recieve said spring adjusting washers. So what would I use in place of these washers?

I am at wits end with this thing. I try to pull a wot and when I hit 12psi it burps out the turbo and then I get boost spikes up to 20 psi.

[BudmannG]

I have had to make my own washers to put in this BOV. I will be testing it today to see if it helps. I have two in it right now and have a third if I need it.

[BudmannG]

Bud, I cant recall what turbo you have. I know that I had an issue with compressor surge on my gt35 when I had the bov cranked all the way down (more pressure prior to release) once I backed off the tension, I had great part throttle control, at ot below 10psi.. If I allowed it (throttle modulation) to increase past that, she would buck and kick like a one legged man.

So either I run, nice and easy, making<10pis part throttle, or Im balls out.

One my ask what a one legged man kicks like... Well, its a hard initial pop, then it falls on its face... flops around like a fish out of water, chokes, pukes and sputters... Compressor surge on a dsm is somewhat bothersome

EXACTLY!!!

I was thinking that one of the two homedepot couplers were burping under pressure. I am going to run a boost leak test on it tonight or tomorrow.
I can only drive easy with part throttle. Even if I hit 70-75 it wants to flutter, and it doesn't matter where your pedal is.
I am running, supposed to be a 50 trim garrett, that is what the guy told me when I bought it.

[BudmannG]

I think that I found my problem.

I went out to take some pics of the turbo and did a shaft play test. HUH, OMG!

I got sold a bad turbo! This does not make a person very happy. I was told no shaft play when sold. I got it through my favorite brown carrier. When I opened it that was the first thing I checked. And yes there was shaft play then also.
So I went to my sources and asked what to do? They said it will go away once there is oil in it. NOT!

I bet that is why I have compressor surge! FRAUCK!

[turbohcar]

Compressor surge is not caused by a turbo with too much shaft play. Yes, a turbo that has been sitting with no oil in it will have a bit of shaft play in it. A little, but not much. More than likely, your RFL is set too hard. I know when I was playing with the setting on mine, you cannot get it to go soft enough for anything less than about 24psi. I cut the spring 1-2 coils back and it helped greatly. Running 18psi with no compressor surge it was not a problem. The adjustment washers should only increase the pressure, not lower it. The BOV runs off of vaccum. The vaccum in the intake manifold has to over come the spring pressure in the BOV in order to actuate the valve. The RFL comes with an already too stiff spring so you have to soften it a bit. Better to run too soft and stiffen it up than to run too hard and get compressor surge.

[AWD DSM 1]

Compressor surge is not caused by a turbo with too much shaft play. Yes, a turbo that has been sitting with no oil in it will have a bit of shaft play in it. A little, but not much. More than likely, your RFL is set too hard. I know when I was playing with the setting on mine, you cannot get it to go soft enough for anything less than about 24psi. I cut the spring 1-2 coils back and it helped greatly. Running 18psi with no compressor surge it was not a problem. The adjustment washers should only increase the pressure, not lower it. The BOV runs off of vaccum. The vaccum in the intake manifold has to over come the spring pressure in the BOV in order to actuate the valve. The RFL comes with an already too stiff spring so you have to soften it a bit. Better to run too soft and stiffen it up than to run too hard and get compressor surge.

agreed

[BudmannG]

I will go hack them up right now!!! So you are saying that it is ok to cut the spring? I also made the washers to set where the top screws down to them. Around the spring and cylinder. This way it gives it a little more space inside the bov. Is this right? I do know it didn't help at all!!!!!

I am in a PM conference with the guy that sold me the turbo.

[99Spyder]

I am not an expert on either shaft play (I know some you are) or compressor surge. In just thinking about the two however it would seem that compressor surge, boost escaping back past the compressor wheel, could make shaft play worse but sloppy shaft movement would not keep boost from leaving through the BOV. That is just my assessment. I would say keep working on the BOV.

If someone has another thought on this throw it on the table.

[BudmannG]

Alright!! I cut off three rings. Now I can pull hard in 1st and 2nd without surge. But, My boost gauge goes up to 22-24psi . Just bouncing like a jumping bean. When I hit third and start to pull hard it does it's dance on me again.

But wow what a difference those three rings made. I have no control over my mbc. It is turned all the way out, which is less boost, right? I will have to look again. But it don't boost over 24 psi right now.

Just so you know my vacuume line from the intake is hooked to the bottom. And the outlet to the wastegate is hooked to the side.
Is this correct? It is a hallman boost controller.

[99Spyder]

Yep, just checked the Hallman site and the boost source should come through the bottom and the side should head to the WG actuator.

[BudmannG]

OK, That problem is solved, I have it hooked up right.

Now why can I not get my boost to go down? I really don't want to run 22-24psi all the time. I did check the valve on the mbc and it says out to lower boost and in to up the boost. It is turned all the way out for the lower boost. I have it turned out so far that you can here the ball and spring when you shake it.

[99Spyder]

Well let's see... the Hallman has an internal spring that keeps the signal line closed until the pressure on the source side overcomes the spring pressure. If the spring had little tension the source signal should pass through to the actuator and open it up.

On the contrary, if the spring pressure is never overcome, the actuator will not receive a signal and you would run full boost. Using that logic I would have to guess that the MBC is not opening until really late or maybe not at all. Maybe your turbo loses efficiency around 24psi and can't build anymore boost.

I would pull the MBC off, dial it to the lowest boost setting, and see if you can blow through it. An air compressor with a pressure regulator set to about 15psi would work pretty well if you have it.

[turbohcar]

If you've got really sloppy shaft play that my have something to do with your boost pressure doing the dance it does.

Hook the WG directly up to the intake manifold vaccum boss. That way you bypass the boost controller all together and eliminate it as a possibility. If that changes anything then you've found where your problem is.