[dhanushs]

Most turbos in India (I guess..) come with an Internal wastegate which can be tweaked for different purposes. The best part is that, you can increase or decrease the boost, and hence increase or decrease the power of your turbocharged vehicle at home, with just a spanner and a plier.

What all you can do:

1. Increase the max boost (at higher rpms).
2. Decrease the max boost.
3. Zero Boost. Bypass the turbocharger.
4. Maximum possible boost.

Given below is an illustration of how you can adjust the preload setting of your turbocharger.


Mine is a 2.6 CRDe turbo.



Usually in a Turbo:



And,







Usually what happens in a turbocharger is:

The boost is built up in the compressor, and the black pipe, which can be called the boost sensor(?) conveys the boost pressures to the actuator, where there is a spring mechanism, which pushes down the rod. More boost, more pushing down the rod. Pushing down the rod means opening the wastegate valve. Opening the waste gate valve creates a bypass way for the exhaust gases to escape, without doing work on the turbine wheel. Hence, the compressor fins doesnt turn, and boost drops.

When boost drops, the rod is pushed up by the spring which again closes the wastegate valve, and hence now, exhaust gases have to escape by doing work on the turbine wheel, which inturn builds up the boost. Hence, by this wastegate mechanism one can decide on what max boost one can run.

Now, the adjustment:

Remove the pin or circlip which holds the rod to the valve.





Loosen the nut shown in the figure below.



Now, you can turn the rod to increase and decrease its length.



What all you can do:

Decrease the maximum boost: By increasing the length of the rod, you can reduce the preload which means, lesser boost is required to open the wastegate valve. And hence, lesser maximum boost.

Increase the maximum boost: By reducing the length of the rod, you increase the preload, which means, more boost is required to open the wastegate valve and hence more maximum boost.

Bypass the turbo: For bypassing the turbo (no-turbo effect), just remove the pin, and uncouple the valve and spring mechanism.

Maximum possible boost: The easiest way to achieve maximum boost is to, just pinch the boost sensor pipe (the black pipe) . So that no boost reaches the spring actuator, and hence the wastegate valve always remains closed. (See Below) And, hence the turob charger keeps on developing boost as the rpm increases.




Watch the video:

http://www.youtube.com/watch?v=S7VCr...re=c4-overview

Disclaimer: I have no idea about what is the max/min boost your turbo or your engine can handle. So, please make sure you gain sufficient knowledge regarding the same before this tweak.

P.S: Please feel free to add/modify inputs.

[GTO]

Thread moved to the Technical Section. Thanks for sharing!

[anupamjain2k]

While this is useful piece of information, IMHO changing the maximum boost is a job that's best left to people who know what they are doing...

If done without adequate knowledge, you risk a blown and (in worst cases, a destroyed!) cylinder block!!

[vikram_d]

Just one question, adjusting boost is easy. But what about proper fueling to go with change in boost?

[jdr]

Originally Posted by vikram_d

Just one question, adjusting boost is easy. But what about proper fueling to go with change in boost?

I believe that is what the dual channel dirseltronic box from race dynamics does. it modifies both turbo boost and rail pressure.
Increased boost + more fuel == more power

jdr

[007]

The turbo theory in short is
Power is directly proportional to amount of fuel burnt successfully.
For more power more fuel to be burned, but within limits of the stoichiometric air / fuel ratio (14.5 : 1 vol - slightly lean for diesel in practice for avoiding unburnt fuel or soot), the upper limit is by cubic capacity of the engine.
So obvious option is to supply more air ( more oxygen) so that more fuel can be burned and hence more power. This achieved by turbocharging. Further to reduce the effect of the air getting hooter ( & thinner) due to compressing inter cooler is incorporated.

Now about the thread.
The location shown is not boost pressure sensor.
Caution has to be taken while tweaking with turbocharger as engine software (maps) have a defined table of expected boost under any given condition of engine operation. This is achieved through interpolation among the set defined limits.
Whenever the engine ( or boost pressure sensor) does not senses the expected boost among set limit tolerance based on operating conditions, you will have check engine lamp ON.

[vikram_d]

Originally Posted by jdr

I believe that is what the dual channel dirseltronic box from race dynamics does. it modifies both turbo boost and rail pressure.
Increased boost + more fuel == more power

jdr

I'm not entirely sure how the RD box can manipulate turbo boost unless the turbo has an ECU controlled waste gate.

Most stock common rail diesel engines run a little lean to meet emission standards. All the RD box does is to bump up the rail pressure to a more stoich/rich mixture based on the setting of the mode selector switch.

The bump in boost may be an indirect result of increased rail pressure. More fuel means more exhaust gases and that in turn means more boost.

[vaisakhr]

Thanks a ton for sharing the info dhanush. Very informative thread. Rated five stars

[jdr]

Originally Posted by vikram_d

I'm not entirely sure how the RD box can manipulate turbo boost unless the turbo has an ECU controlled waste gate.

Most stock common rail diesel engines run a little lean to meet emission standards. All the RD box does is to bump up the rail pressure to a more stoich/rich mixture based on the setting of the mode selector switch.

The bump in boost may be an indirect result of increased rail pressure. More fuel means more exhaust gases and that in turn means more boost.

The dual channel box IS designed for cars whose VGT turbo boost is controlled by the ECU. The single channel box controls only rail pressure. Adding more fuel will increase performance to an extent, and that power increase can be improved by adding more air as well (hence dual channel). I'll not discuss more about the RD box as there's a separate thread dedicated to it.

As for the turbo wastegate, it is there to limit the boost provided by the turbo. Without this mechanism, the turbo boost would keep on increasing and consequently blowing the engine. At low engine speeds, you want the turbo to kick in early so as to reduce lag, and at high engine speeds, you want the turbine to not exceed its rpm capacity, which is achieved by closing and opening the wastegate (respectively).
The wastegate is designed by the manufacturer for safe operation. Playing around with it might not be a very wise idea unless you really know your stuff.

I'd not mess around with this stuff, but I'm a computer engineer...

jdr

[atlantis0965]

hello
just wanted to say that the black rubber hose you have mentioned cannot be called as the boost sensor; it is rather the air pressure from the intake which is acting on the actuator.

for max boost:
the air pressure will increase only when the turbocharger is spinning faster which is only possible when you have more load on the engine producing more exhaust gases which act on the turbine wheel which in turn makes the compressor take in more air.

for min.boost :
i am not sure why someone would want to do this since lesser air always means combustion will never be proper .

[A350XWB]

Originally Posted by dhanushs

Usually what happens in a turbocharger is: Pushing down the rod means opening the wastegate valve. Opening the waste gate valve creates a bypass way for the exhaust gases to escape, without doing work on the turbine wheel. Hence, the compressor fins doesnt turn, and boost drops.

When the waste-gate opens, the turbine do turn and so, the compressor which is coupled to the turbine still turns, but the rpm reduces due to the exhaust gases exerting less force on the turbine blades due to the reduced volume. AFAIK, the bypass valve does not work as ON-OFF, but rather in a linear way which regulates the pressure release smoothly.

Originally Posted by dhanushs

Now, the adjustment:
Bypass the turbo: For bypassing the turbo (no-turbo effect), just remove the pin, and uncouple the valve and spring mechanism.

For totally bypassing the turbo, wouldn't you need to remove the waste-gate valve itself so that the exhaust gases have a free flow route and not just uncouple the mechanism? (Or is it the same thing you meant by the term uncoupling?)

Originally Posted by dhanushs

Maximum possible boost: The easiest way to achieve maximum boost is to, just pinch the boost sensor pipe (the black pipe) . So that no boost reaches the spring actuator, and hence the wastegate valve always remains closed. (See Below) And, hence the turob charger keeps on developing boost as the rpm increases.

If you remove the pressure feedback to the actuator, there is a chance of boost pressure increasing beyond the capabilities of the turbo (under the right circumstances), which can cause damage to the components, as you have mentioned. So, AFAIK its not advisable to do this.

For turbos with mechanical waste-gate, this method will work (but still the question of fueling remains as the boost will increase without a corresponding increase in the input fuel), but for others with an electronically controlled waste-gate, an ECU piggyback or remap are the better ways to control both to get better results.
I think by increasing the boost, there might be a small gain as it will aid better combustion if the engine is not yet running at it's peak efficiency. Am not sure about this though, need some research

[::CMS::]

Most probably you will endup with a blown turbo when it goes beyond its tolerance levels and needs good lubricating and a bigger intercooler to cater the EGR tempreature under control

[sagarpadaki]

Originally Posted by jdr

The dual channel box IS designed for cars whose VGT turbo boost is controlled by the ECU. The single channel box controls only rail pressure. Adding more fuel will increase performance to an extent, and that power increase can be improved by adding more air as well (hence dual channel). I'll not discuss more about the RD box as there's a separate thread dedicated to it.

---------SNIP------------

jdr

Originally Posted by vikram_d

I'm not entirely sure how the RD box can manipulate turbo boost unless the turbo has an ECU controlled waste gate.

Most stock common rail diesel engines run a little lean to meet emission standards. All the RD box does is to bump up the rail pressure to a more stoich/rich mixture based on the setting of the mode selector switch.

The bump in boost may be an indirect result of increased rail pressure.

The dual channel RD Box works with turbos which have ECU controlled waste gate . And it does not limit to just VGT's . i20 CRDi has FGT controlled by ECU and is compatible with the dual channel box

[TurboGuru]

Before going to main agenda, just wanted to correct the remarks made in the second snap, the part you are holding is Compressor outlet & the properly machined cylindrical projection is the inlet for the compressor.
@ Dhanushs, what you have demonstrated here could prove quite expensive as it may blow up the Turbo wheel (because of over speeding), specially if you travel to higher altitude where Turbo try to spin faster.
However you may try moving the nut by fraction of inches which may slightly improve your low end performance while trading off with high end performance, Believe me it is not worth a penny.

[dhanushs]

Originally Posted by TurboGuru

Before going to main agenda, just wanted to correct the remarks made in the second snap, the part you are holding is Compressor outlet & the properly machined cylindrical projection is the inlet for the compressor.

Hi,

I have not mentioned whether its the inlet or outlet. What I have mentioned is: that side (aluminum side) is the compressor (compressed air to the inlet) side and the other side is the turbine side.

@ Dhanushs, what you have demonstrated here could prove quite expensive as it may blow up the Turbo wheel (because of over speeding), specially if you travel to higher altitude where Turbo try to spin faster.
However you may try moving the nut by fraction of inches which may slightly improve your low end performance while trading off with high end performance, Believe me it is not worth a penny.

I'm not sure how my post came out..

However, what I need to confirm is that, this illustration is to adjust your wastegate for different purposes NOT ONLY increase in power. Infact, the main reason why I ventured into this is that I'm turbocharging a NA diesel engine, and needed very minimal boost. So, i have set the wastegate accordingly.

Just thought of sharing the idea, and its different purposes. Also, I guess the disclaimer at the bottom covers for me?