Turbo Whistle on DSE (NON EGR)

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aerofabrique

Active Member
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Hi all,

Having examined 2 other DSE's they make a pronounced whistle under load...mine doesn't... Which is correct? I can't tell if these have silencer rings fitted.

If it is supposed to make a subtle whistle like the other two is it possible mines not boosting correctly? DOn't really want to fit a tacky boost guage and look like the P38 owner who crashed into halforrds.

All the plumbings checked and no splits or delamination. Vacuum pipe clear and free of oil from the manifold to boost controller. K&N panel filter and powerflow exhaust.
 
That's what I thought.

Turbos generally tend to whistle at higher RPM 100 000+, so either mine was underboosting and the others were over boosting. I think the the fact the compressed air outlet goes straight into a 180° bend rather than a straight pipe also supresses turbo noise. Hmmm...any methods to check a full and free wg actuator?
 
aerofabrique said:
That's what I thought.

Turbos generally tend to whistle at higher RPM 100 000+, so either mine was underboosting and the others were over boosting. I think the the fact the compressed air outlet goes straight into a 180° bend rather than a straight pipe also supresses turbo noise. Hmmm...any methods to check a full and free wg actuator?
Click to expand...

Put a temporary boost gauge in, you can take it back out, you will then be able to see what pressure your getting , mine has a slight whistle, but as said need Windows open,
 
If you can get it onto diagnostics (Nanocom, faultmate etc.) then you can find out what the boost level is.

Trouble is, I am not sure what 'good' is, other than boost and atmos pressure values should read almost the same when engine stopped or at idle, which is a useful basic check of the sensors. Hopefully somebody on here will know what a sensible max boost value is. I would check mine for you but it is still in bits waiting for parts....



HTH

Cheers

Jerry
 
Boost pressure I believe is around 1atm (14.7psi)

Also the Turbo isn't fitted with a waste gate, but it does have a Pressure Actuator that reduces the exhaust gas pressure acting on the Compressor face, rather than dumping charge air pressure (which is why you don't get the woosh when the Turbo discharges during an unload phase)

The Pressure Actutator works in relation to charge air pressure, as the charge air increases this opens the bypass valve and the exhaust gas pressure is reduced slowing the turbine down, thus reducing charge air pressure.
 
Saint.V8 said:
Boost pressure I believe is around 1atm (14.7psi)

Also the Turbo isn't fitted with a waste gate, but it does have a Pressure Actuator that reduces the exhaust gas pressure acting on the Compressor face, rather than dumping charge air pressure (which is why you don't get the woosh when the Turbo discharges during an unload phase)

The Pressure Actutator works in relation to charge air pressure, as the charge air increases this opens the bypass valve and the exhaust gas pressure is reduced slowing the turbine down, thus reducing charge air pressure.
Click to expand...

That's what I would call a waste gate:confused:
 
Datatek said:
That's what I would call a waste gate:confused:
Click to expand...


Yeah it has a waste gate but not a dump valve. Which is operated by the depression in the manifold when throttle is shut to stop the turbo from stalling. Unfortunatly as there is no throttle valve on the P38 a dump valve is as useful as tits on a Mars bar.
 
Hi there we have 2 diesels dse auto and a manuel the manuel whistles and the auto don't they both drive work fine some whistle some don't
 
Mine whistles quite a bit, you can hear it faintly even with closed windows. I have another sound though. Under load, when i press the accelerator it produces a hairdryer-like sound with constant pitch but variating intensity, from 1200 RPM on... suppose i have a leak somewhere on the exhaust side ;)
 
Interesting thread.

I am thinking of adding a dump valve to my 2.5DT, partly to make it faster (I can have more boost more of the time) but also to make it sound better when changing gear.

Thinking about it, although there is no throttle as such, I could either use the throttle pot % reading (to detect closed throttle) or the clutch microswitch (mine is a manual) to activate the dump valve during gearchanges.

I am also thinking of routing the dumped gas from the inlet manifold through a second exhaust system, which could exit the car on the LHS and give it a cool 'twin tailpipe' look. Hopefullly this will add a few extra bhp too. I will fit the silencer backwards so it makes the dump valve noise louder rather than quieter.



















.....ooops, a day late :)
 
jerrytlr said:
Interesting thread.

I am thinking of adding a dump valve to my 2.5DT, partly to make it faster (I can have more boost more of the time) but also to make it sound better when changing gear.

Thinking about it, although there is no throttle as such, I could either use the throttle pot % reading (to detect closed throttle) or the clutch microswitch (mine is a manual) to activate the dump valve during gearchanges.

I am also thinking of routing the dumped gas from the inlet manifold through a second exhaust system, which could exit the car on the LHS and give it a cool 'twin tailpipe' look. Hopefullly this will add a few extra bhp too. I will fit the silencer backwards so it makes the dump valve noise louder rather than quieter.

















.....ooops, a day late :)
Click to expand...

Waste of time on slow throttle response diesel. Dump valve is to dump air from turbo pipes when throttle is closed, in high revving petrol engines, to prevent the spinning turbo from stalling under back pressure built up against throttle valve. Basically this stops turbo and when throttle is put down the turbo has to get back up to speed before any turbo effect is felt. This gives turbo lag. Not desirable in a racing car. Your P38 is not and never will be a racing car. As there is no throttle body to restrict the flow a dump valve will never be needed. Unless you are a boy racer type, who likes to hear the sound of air being exhausted that is. How much good it would do can be summed up in one word. ZERO.
 
wammers said:
Waste of time on slow throttle response diesel. Dump valve is to dump air from turbo pipes when throttle is closed, in high revving petrol engines, to prevent the spinning turbo from stalling under back pressure built up against throttle valve. Basically this stops turbo and when throttle is put down the turbo has to get back up to speed before any turbo effect is felt. This gives turbo lag. Not desirable in a racing car. Your P38 is not and never will be a racing car. As there is no throttle body to restrict the flow a dump valve will never be needed. Unless you are a boy racer type, who likes to hear the sound of air being exhausted that is. How much good it would do can be summed up in one word. ZERO.
Click to expand...

With the above in mind could a jake brake or exhaust brake be easily fitted to the P38 (e.g. for use when towing)?
 
aerofabrique said:
With the above in mind could a jake brake or exhaust brake be easily fitted to the P38 (e.g. for use when towing)?
Click to expand...


I doult the torque converter/gearbox would like it every much, even if it was possible to fit a jake and a 2.5 litre engine would be to small imo.

Plus it would probably feck a DMF...
 
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