Diesel P38 - Which Chip to go for?

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Datatek said:
Can use the same bell housing and torque converter by all accounts, the only difference I can find is the extension piece between the end of the box and the transfer box is shorter for the ZF4HP24 to accomodate the extra length of the gearbox. I don't have the cash to buy a 24 or I would try to do it. As far as I can see the 24 is a straight swap for the 22 as long as it's from a P38:)
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you might check that again, i know the bell housing is different and the box is longer. im told that if you change the bell housing and tourqe converter you the box its self will work.
 
I don't think so no, but also, it's not advisable because the ECU is different, and mix'n'match is not a good idea.

Also, having just read back over this thread; improving engine efficiency can oth increase power and fuel economy, if it simply increases the percentage of the injected fuel doing useful work. My old 3.9 Disco converted petrol into noise, but very little power was produced along the way. If that wasted energy went into kinetic energy, the performance would increase, and the car would have moved from the fuel burn, hence mpg would increase. Having said that, I have no idea what the DSE chips do, so in the P38 case it may be different.
 
TCubed said:
I don't think so no, but also, it's not advisable because the ECU is different, and mix'n'match is not a good idea.

Also, having just read back over this thread; improving engine efficiency can oth increase power and fuel economy, if it simply increases the percentage of the injected fuel doing useful work. My old 3.9 Disco converted petrol into noise, but very little power was produced along the way. If that wasted energy went into kinetic energy, the performance would increase, and the car would have moved from the fuel burn, hence mpg would increase. Having said that, I have no idea what the DSE chips do, so in the P38 case it may be different.
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By simply chipping a diesel it is IMPOSSIBLE to get more power and torque unless more fuel is injected. Anybody who claims they can is talking through his arse.
 
wammers said:
By simply chipping a diesel it is IMPOSSIBLE to get more power and torque unless more fuel is injected. Anybody who claims they can is talking through his arse.
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I accept that perhaps the simple addition of a chip may not affect the engine's injection management sufficiently to make a difference. However, although maybe not in the case of the M51, but certainly diesel engines, particularly those developed during the early eras of ECU technology, are not controlled by the most intelligent processors. Modern ones monitor all aspects of driving and conditions to ensure that only the precise amount of fuel is injected into the cylinders, thus minimising as I said the percentage of that fuel's energy that is degraded. Reprogramming of the ECU, be it through a chip or just simple upgrading, can if done correctly maximise the ratio of kinetic energy:chemical energy. I do not profess any knowledge of whether this is the case with the BMW P38 engine, but simple physics dictates that changing the engine's electronics can improve both the torque and mpg figures. Simply consider the fact that an idealised diesel engine is only just above 50% efficient.
 
TCubed said:
I accept that perhaps the simple addition of a chip may not affect the engine's injection management sufficiently to make a difference. However, although maybe not in the case of the M51, but certainly diesel engines, particularly those developed during the early eras of ECU technology, are not controlled by the most intelligent processors. Modern ones monitor all aspects of driving and conditions to ensure that only the precise amount of fuel is injected into the cylinders, thus minimising as I said the percentage of that fuel's energy that is degraded. Reprogramming of the ECU, be it through a chip or just simple upgrading, can if done correctly maximise the ratio of kinetic energy:chemical energy. I do not profess any knowledge of whether this is the case with the BMW P38 engine, but simple physics dictates that changing the engine's electronics can improve both the torque and mpg figures. Simply consider the fact that an idealised diesel engine is only just above 50% efficient.
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Changing the engine mapping to a more linear map can improve MPG and engine response that is true. But you cannot get more power without increasing the amount of fuel injected it is not possible.
 
wammers said:
Changing the engine mapping to a more linear map can improve MPG and engine response that is true. But you cannot get more power without increasing the amount of fuel injected it is not possible.
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I still disagree: if an engine were 30% efficient and one wanted to 10% more power from it, either an additional 3% diesel could be injected as you say - of course decreasing mpg. Or the efficiency could be increased by 3%. That would not require additional fuel, just an improved use of the already injected fuel. If you look at those little VW Blue Motion cars' exhaust pipes they are immaculate, because very little of the diesel is wasted. By contrast an old 200tdi's pipe is black with the fuel not fully burnt, ie wasted.
What I am saying is that if a chip/remap can up the efficiency of the engine (which granted will only be possible if the original ECU is already substandard) and thus increase both the power and the mpg.
 
TCubed said:
I still disagree: if an engine were 30% efficient and one wanted to 10% more power from it, either an additional 3% diesel could be injected as you say - of course decreasing mpg. Or the efficiency could be increased by 3%. That would not require additional fuel, just an improved use of the already injected fuel. If you look at those little VW Blue Motion cars' exhaust pipes they are immaculate, because very little of the diesel is wasted. By contrast an old 200tdi's pipe is black with the fuel not fully burnt, ie wasted.
What I am saying is that if a chip/remap can up the efficiency of the engine (which granted will only be possible if the original ECU is already substandard) and thus increase both the power and the mpg.
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I will say again you CANNOT increase the power and torque of a diesel engine unless you inject more fuel. It is not possible. I have already said that a more linear map may give slightly better fuel figures but you CANNOT have 30 bhp and more torque without more fuel. It is simply not possible. Common rail engines are a totally different proposition, they get there increase in power and torque from a simular sized engine by having much higher injection pressures and much better atomisation of the fuel. They are tuned for low emissions as standard and are pretty easy to get a big power up on. You cannot do that with the M51 EDC engine. Even on the common rail engines you are still introducing more fuel to get the increase.
 
wammers said:
I will say again you CANNOT increase the power and torque of a diesel engine unless you inject more fuel. It is not possible. I have already said that a more linear map may give slightly better fuel figures but you CANNOT have 30 bhp and more torque without more fuel. It is simply not possible. Common rail engines are a totally different proposition, they get there increase in power and torque from a simular sized engine by having much higher injection pressures and much better atomisation of the fuel. They are tuned for low emissions as standard and are pretty easy to get a big power up on. You cannot do that with the M51 EDC engine. Even on the common rail engines you are still introducing more fuel to get the increase.
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But if you're developing 30hp's worth of noise and other degraded energies, and that is changed into useful work, that has increased the power without requiring any more fuel. I have a highly limited knowledge of diesel engine mechanics, but anyone can look at the M51's power torque and mpg figures, and then compare them to Land Rover's latest diesel engine, and notice that all 3 figures are much higher. I know that is due to improved mechanics, but electronics are also a key aspect of that improvement.
 
TCubed said:
But if you're developing 30hp's worth of noise and other degraded energies, and that is changed into useful work, that has increased the power without requiring any more fuel. I have a highly limited knowledge of diesel engine mechanics, but anyone can look at the M51's power torque and mpg figures, and then compare them to Land Rover's latest diesel engine, and notice that all 3 figures are much higher. I know that is due to improved mechanics, but electronics are also a key aspect of that improvement.
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The newer engines are common rail units, that is the big difference. As already explained.
 
Hello,

I bought a psi power chip and fitted it myself. Easy to fit.
Quite expensive but noticed the difference in power when revs hit 2220 ish. Car runs smooth.
I also changed to coil springs, took out the suspension pump and the chip fitted inside the pump box nicely. Out of site out of mind as the saying goes.

Mike.
 
TCubed said:
Ah ok, so how do they differ mechanically and electronically?
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Vastly, there is no mechanical injection pump. All is done electronically much easier to control and a much higher injection pressure. Much finer adjustments of fuel/injection timing. Like the 200 TDI you mentioned mechanical pump, mechanical diesel metering and control. EDC as fitted to M51 much better control but still has mechanical pump. Common rail, no mechanical pump, fully electronically controlled injection, a quantum leap better than the other two.
 
wammers said:
Vastly, there is no mechanical injection pump. All is done electronically much easier to control and a much higher injection pressure. Much finer adjustments of fuel/injection timing. Like the 200 TDI you mentioned mechanical pump, mechanical diesel metering and control. EDC as fitted to M51 much better control but still has mechanical pump. Common rail, no mechanical pump, fully electronically controlled injection, a quantum leap better than the other two.
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Why when people replace engines don't they favour the common rail then? Or is it not that simple to cross them between cars?
 
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