How to adjust the turbo?

[Svirre]

I've been study my engine for a little while now, and I see two rubber pipes from the turbo to the actuator. Seems like one of them are for vacuum, and the other one is for pressure. Tried to hose the clamps with a pair of pliers on each of the pipes. The car ran better, but I'm not sure how much the pressure is.

Some hints? Without changing the funny little thing.

Sorry for VERY bad english, but my head isn't good now, and Google Translate to help me it's be like a crappy translation

[cuaz64]

1. Get a boost gauge to know how much boost are you running.
2. If delete both hoses, you will be running 12PSI.

[v8volvo]

Do not try to change the boost pressure setting without first installing a boost gauge inside the car. You need to be able to see the effects of the changes you are making. You can quickly destroy your engine if you mess with the turbo without a gauge to tell you what is going on under the hood.

The upper hose is the boost reference signal to the wastegate, to tell it when to open and limit charge air pressure. The lower hose is just an oil drain from the turbo inlet; fooling with it won't have any effect other than maybe making a mess. If you remove or crimp the upper (boost reference) hose, it will NOT just go to 12 psi like Cuaz said, so do NOT try that..... when I was experimenting with my 760, removing that line from the wastegate resulted in boost spikes of 20+ PSI in second gear, which is enough to do major damage. This is on a car with GTD spec Monark nozzles and an open exhaust which is part of why it went so high so fast. But you don't want to gamble like that. Make sure you have a gauge and a way to carefully control how much you restrict the boost signal to the wastegate. Do not just take the line off unless you want to blow up your motor quickly.

Stock boost level is ~10.5 psi. I am running 14 now and it made it a little faster, but to get real gains you need an intercooler. Just turning up the boost without other modifications (intercooler, airflow, exhaust, fuel) will not get you all that much more power, and will be hard on the engine. You don't really want to go much above the stock level without an intercooler, and an EGT gauge would be a good idea as well.

[Svirre]

Originally Posted by v8volvo

Do not try to change the boost pressure setting without first installing a boost gauge inside the car. You need to be able to see the effects of the changes you are making. You can quickly destroy your engine if you mess with the turbo without a gauge to tell you what is going on under the hood.

The upper hose is the boost reference signal to the wastegate, to tell it when to open and limit charge air pressure. The lower hose is just an oil drain from the turbo inlet; fooling with it won't have any effect other than maybe making a mess. If you remove or crimp the upper (boost reference) hose, it will NOT just go to 12 psi like Cuaz said, so do NOT try that..... when I was experimenting with my 760, removing that line from the wastegate resulted in boost spikes of 20+ PSI in second gear, which is enough to do major damage. This is on a car with GTD spec Monark nozzles and an open exhaust which is part of why it went so high so fast. But you don't want to gamble like that. Make sure you have a gauge and a way to carefully control how much you restrict the boost signal to the wastegate. Do not just take the line off unless you want to blow up your motor quickly.

Stock boost level is ~10.5 psi. I am running 14 now and it made it a little faster, but to get real gains you need an intercooler. Just turning up the boost without other modifications (intercooler, airflow, exhaust, fuel) will not get you all that much more power, and will be hard on the engine. You don't really want to go much above the stock level without an intercooler, and an EGT gauge would be a good idea as well.

Okay. Thanks to good advices I've tried to crimp the upper hose and took a ride for about 1 km. It's was more effekt, but I've thought it'll be too much pressaure than the engine could withstand.

My wiches is to mount a gauge, IC, dissamble the original mufflers and replace one sport muffler (for the sound ).
They say an InterCooler do a lot of the effekt when you mount it, so I look forward to get it mounted!

Offtopic:
Do I've to dissamble the air intake manifold? The pipe for the turbo into this is stuck, and I belive I have to dissamble this to get it removed.

[RedArrow]

Originally Posted by v8volvo

Do not try to change the boost pressure setting without first installing a boost gauge inside the car. You need to be able to see the effects of the changes you are making. You can quickly destroy your engine if you mess with the turbo without a gauge to tell you what is going on under the hood.

The upper hose is the boost reference signal to the wastegate, to tell it when to open and limit charge air pressure. The lower hose is just an oil drain from the turbo inlet; fooling with it won't have any effect other than maybe making a mess. If you remove or crimp the upper (boost reference) hose, it will NOT just go to 12 psi like Cuaz said, so do NOT try that..... when I was experimenting with my 760, removing that line from the wastegate resulted in boost spikes of 20+ PSI in second gear, which is enough to do major damage. This is on a car with GTD spec Monark nozzles and an open exhaust which is part of why it went so high so fast. But you don't want to gamble like that. Make sure you have a gauge and a way to carefully control how much you restrict the boost signal to the wastegate. Do not just take the line off unless you want to blow up your motor quickly.

Stock boost level is ~10.5 psi. I am running 14 now and it made it a little faster, but to get real gains you need an intercooler. Just turning up the boost without other modifications (intercooler, airflow, exhaust, fuel) will not get you all that much more power, and will be hard on the engine. You don't really want to go much above the stock level without an intercooler, and an EGT gauge would be a good idea as well.

Good Info. Are they the two, short, appr 4mm inner diameter hoses that have a red line running on them? On my d24t car those hoses were `loose` and there were no clamps on any of the ends. What kind of material are they made of? I`d like to replace them as they look worn and the ends had to be trimmed due to being expanded too much, so they appear too short now.

[RedArrow]

Originally Posted by v8volvo

Do not try to change the boost pressure setting without first installing a boost gauge inside the car. You need to be able to see the effects of the changes you are making. You can quickly destroy your engine if you mess with the turbo without a gauge to tell you what is going on under the hood.

The upper hose is the boost reference signal to the wastegate, to tell it when to open and limit charge air pressure. The lower hose is just an oil drain from the turbo inlet; fooling with it won't have any effect other than maybe making a mess. If you remove or crimp the upper (boost reference) hose, it will NOT just go to 12 psi like Cuaz said, so do NOT try that..... when I was experimenting with my 760, removing that line from the wastegate resulted in boost spikes of 20+ PSI in second gear, which is enough to do major damage. This is on a car with GTD spec Monark nozzles and an open exhaust which is part of why it went so high so fast. But you don't want to gamble like that. Make sure you have a gauge and a way to carefully control how much you restrict the boost signal to the wastegate. Do not just take the line off unless you want to blow up your motor quickly.

Stock boost level is ~10.5 psi. I am running 14 now and it made it a little faster, but to get real gains you need an intercooler. Just turning up the boost without other modifications (intercooler, airflow, exhaust, fuel) will not get you all that much more power, and will be hard on the engine. You don't really want to go much above the stock level without an intercooler, and an EGT gauge would be a good idea as well.

This is great info here!

I would like to install a boost gauge...not because I want to increase power or performance but because I would like to track what exactly is going on under the hood, approximately. The instrument cluster does have the Volvo boost gauge in it (top right corner) but it is not marked with numbers except some colors (yellow, red).

It would be good info, to know what boost the car is currently using/producing, I always wondered. That would have been my first question but I'm glad I found it here.
So the most ideal boost gauge would probably be one that reads 0-15 (maybe even 20)? --for a car like mine--- with stock/near stock settings/timing/injectors/turbo.
I found a T junction under the steering wheel (one end of the T appears plugged with a screw) and I assume this car had a 2nd boost gauge before (maybe for reference and experimental purposes?)..



EGT gauge.
Where exactly would you place that (I mean the probe/sensor)? What's the most ideal location for most accurate measurements? (Exhaust manifold?)

What are the high temps down there? other forums mention 900-950 Celsius (!) for bricks with a turbo. Seems super high.



Intake pressure control valve at the front of intake--- overboost release valve?
I took it off for cleaning and to check its o-ring (needs a new one I think).
I made a little tool to measure the valve (spring action) opening pressures and measured appr 19-20 there. I turned the thing clockwise (in) with the flat head screwdriver then I measured 22-25, never more than 25. I should read about its purpose and the proper way to set it up/check/keep it stock.

I assume that the two wires are simply just sending an input to cluster that it opened? How does the feedback indicator light look? Is it the red arrow pointing upward? No idea. I thought that was an automatic tranny thingy... I remember seeing it sometimes, sometimes too often, then I pulled the bulb, I think.
The wires to that valve also disintegrated and I thought I should ask you guys about this whole unit.

In the meantime I am locating this in the Greenbook, too. I remember seeing it mentioned somewhere. How to set/check/adjust this thing, and what to set it to (stock specs/values)? In the meantime I found a page in the Greenbook that mentions some numbers. I will connect the wires at the intake front to see if any lights come up on my cluster, then go from there..