Car will not make boost. Need some help

[Sprayer84]

I measured it in the front o2 port on the passenger side. My exhaust back pressure gauges pegged out at 15psi. Could have been twice that, who knows. I have almost zero back pressure on the downpipe side. That measurement was at load. But even with no long a quick throttle snap at idle made 9psi of back pressure pre turbo and 0 post turbo.

 

[JeremyH]

Based on that sounds like the gate is closed to me and forcing the exhaust through the turbo.

 

[Sprayer84]

What do you mean? I had a brand new tial WG on and now a brand new TurboSmart WG and this symptom didn't change.

 

[muztangman93]

Could you try venting it to atmosphere to see if that makes a difference

 

[Sprayer84]

I wouldn't think there would be any back pressure post turbo with no cats and straight through mufflers

 

[Sprayer84]

Based on that sounds like the gate is closed to me and forcing the exhaust through the turbo.

Isn't the gate suppose to be closed except when forced open by the boost pressure over coming the spring?

 

[JeremyH]

Based on that sounds like the gate is closed to me and forcing the exhaust through the turbo.

What do you mean? I had a brand new tial WG on and now a brand new TurboSmart WG and this symptom didn't change.

In other words sounds like the gate is good and working and is shut which is driving up the pressure pre turbo to spin it like it should. I would give Comp a shout about the turbo slowing down like that and your boost issues.

Isn't the gate suppose to be closed except when forced open by the boost pressure over coming the spring?

Correct.

 

[Sprayer84]

In other words sounds like the gate is good and working and is shut which is driving up the pressure pre turbo to spin it like it should. I would give Comp a shout about the turbo slowing down like that and your boost issues.




Correct.

That's what I thought you meant. I am mentally exhausted lol. Any guess on turn around time if it is a turbo issue?

 

[JeremyH]

That's what I thought you meant. I am mentally exhausted lol. Any guess on turn around time if it is a turbo issue?

I hear ya man! Call them and see what they think first. Also it varies they can give you an estimate though on the phone. 909-599-5757

 

[Sprayer84]

The idea of tearing this back apart makes me consider removing the whole thing.

 

[weather man]

The idea of tearing this back apart makes me consider removing the whole thing.

Well.....fuck.

 

[Sprayer84]

How much pre turbo pressure is acceptable? Is there a ratio? What would make it abnormally high?

 

[07Bossman]

The claim to some fame is how those turbos are supposed be so friction free and spin like crazy even after shutoff. I think you damaged something internal when it got overboosted. Who knows, maybe you exposed a design flaw. Just throwing that out there.

2:1 backpressure seems to be where people draw the line, then start looking at various places for restrictions to reduce.

 

[Sprayer84]

The claim to some fame is how those turbos are supposed be so friction free and spin like crazy even after shutoff. I think you damaged something internal when it got overboosted. Who knows, maybe you exposed a design flaw. Just throwing that out there.

2:1 backpressure seems to be where people draw the line, then start looking at various places for restrictions to reduce.

I understand what you are saying but I don't know how a turbo could be damaged by creating too much boost.

 

[07Bossman]

I understand what you are saying but I don't know how a turbo could be damaged by creating too much boost.

I understand, but you are running a design that only very recently has been on the market, right? It's one of the oil-less, grease packed, water cooled/warmed billet CHRA? I'm not sure how many people here have access to how that center section is designed. You would think it might have a different bearing configuration and all those other internal pieces. Your inadvertant overboost might have somehow, someway caused a bearing failure or spacer failure or who knows what. But that wheel not moving is NOT what those things are supposed to act like.

 

[Sprayer84]

I feel the same way. I keep trying to tell myself that maybe it isn't broken in yet and that's what is causing issues.

 

[michael.konor]

The claim to some fame is how those turbos are supposed be so friction free and spin like crazy even after shutoff.

Some do. I've never timed my Precision Turbo BB, but I can hear it spinning for quite awhile after turning the engine off.

 

[JeremyH]

If you exceed max shaft rpm and go into surge you can definetly damage a turbo specificly the bearings from harmonics/vibration/heat etc, also the stall/surge can damage the impeller blades as well. But that's not what happened here you would have seen 30-40psi before hitting that range. Your couplers would give way long before and you would have had to stay in it for a good while after. Which orginaly is likely why you had the 6 large leaks after you overboosted and why you had no boost immediately following.

What did comp say?

Fresh after install my turbo still spooled up and made full boost and never slowed down like that. The difference I noticed after full break in is increase in transient/off boost response(basicly zero lag while the car is moving under load as soon as I touch the throttle I see boost) and full boost comes in a little sooner. Also when shutting the car off the impeller would spin for around 10-20 seconds originaly, after break in it spins for a minute or longer when shutting the car off.

This was first start after install on my car, you can see it spins a bit slower than it does now but it never slowed down or wanted to stall like yours was doing.

 

[Sprayer84]

I haven't had a chance to call them. Figured they were not there on Saturday and closed today. I'm going to call them in the morning.

 

[Sprayer84]

After speaking with comp they told me to put a second boost gauge on the compressor housing and compare the two. 1 being intake pressure and 1 compressor housing pressure. The gauge on the compressor housing is reading almost 17psi, but the gauge on the intake is only seeing 5.4 psi.