Sluggish disco.........not any more!

I certainly agree with DaveK about the double size intercooler taking double the time to fill.

It's probably a trade off between a big cooler taking longer to fill but flowing more all the time, vs a restrictive small cooler filling quick but holding back the system.

I've said it before and I'll say it again, challenge truck guys run a pipe direct from turbo to manifold. This gives zero lag, punchy response, plenty of power - ideal for off road. The cooler is unnecessary cos it doesn't get any flow off road anyway.

Anyone who wants an on/off roader has to fit a cooler because otherwise your pistons would melt on the way home from your amazing punchy powerful pay and play.

The argument about bigger turbo/bigger cooler is of course valid for upping your power output, but that is DEFINITELY a shout for increased turbo lag.

MAYBE the disco turbo is oversize for the standard cooler which undoubtedly has been engineered for cost and size constraints. Thus adding a larger cooler provides a nicely balanced system with appropriate increases, as sible88 has noticed...

Basically, I dunno

davek0974 said:

no it does not.

If say the volume of a standard cooler is 2ltrs and an oversize cooler is 4ltrs you have an extra 2ltrs of air to compress using the turbo, compressing this extra volume uses energy, that loss of energy is turbo lag i.e the effect of the turbo will be slower than with the smaller cooler. It will still reach the same boost but will take longer.

These figures are all just illustrations of course but physics is physics and you can't feck with that. What you need to do is fit the bigger cooler allied with a bigger turbo, or buy a sports car.

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the idea with the bigger intercooler is it cools the air reducing thermal stress which in turn allows the boost to be increased and that forces the air through the cooler quicker so reducing turbo lag and increasing power, also a larger intercooler and more boost can help reduce exhaust smoke because it leans the mix, compensating for the adjustment to the fuel pump

Johnlad has got it in one!!

johnlad said:

the idea with the bigger intercooler is it cools the air reducing thermal stress

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or maybe in real life it cools the air and increases it's density thereby allowing more air to be forced into the cylinder.

You won't thermal shock a disco engine, it belongs in a tractor! They are designed for a reasonable amount of abuse in a Landrover, F1 engine maybe. At the end of the day it's all a tradeoff, more fuel needs more air, to get more air you fit a bigger turbo and cooler, this gives more power but shortens the engine life and to some extent the drivetrain life. It will be running hotter so the cooling needs to be A1 condition.

I think I'll save me money and leave mine as stock

davek0974 said:

or maybe in real life it cools the air and increases it's density thereby allowing more air to be forced into the cylinder.

You won't thermal shock a disco engine, it belongs in a tractor! They are designed for a reasonable amount of abuse in a Landrover, F1 engine maybe. At the end of the day it's all a tradeoff, more fuel needs more air, to get more air you fit a bigger turbo and cooler, this gives more power but shortens the engine life and to some extent the drivetrain life. It will be running hotter so the cooling needs to be A1 condition.

I think I'll save me money and leave mine as stock

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well said

davek0974 said:

or maybe in real life it cools the air and increases it's density thereby allowing more air to be forced into the cylinder.

You won't thermal shock a disco engine, it belongs in a tractor! They are designed for a reasonable amount of abuse in a Landrover, F1 engine maybe. At the end of the day it's all a tradeoff, more fuel needs more air, to get more air you fit a bigger turbo and cooler, this gives more power but shortens the engine life and to some extent the drivetrain life. It will be running hotter so the cooling needs to be A1 condition.

I think I'll save me money and leave mine as stock

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I am talking from experience!!
You are talking out your arse!!

bigger cooler does give bigger lag

Intercoolers increase the efficiency of the induction system by reducing induction air heat created by the turbocharger and promoting more thorough combustion, which removes the heat of compression (i.e., the temperature rise) that occurs in any gas when its pressure is raised or its unit mass per unit volume (density) is increased. A decrease in intake air charge temperature sustains use of a more dense intake charge into the engine, as a result of supercharging. The lowering of the intake charge air temperature also eliminates the danger of pre-detonation (knock) of the fuel air charge prior to timed spark ignition on petrol engines. Thus preserving the benefits of more fuel/air burn per engine cycle, increasing the output of the engine.

It has less restriction!! Because it has a bigger cooling surface it can flow quicker and still be the same or bit lower temp.
More air more fuel= more power

If you are looking for a reason not to buy one because you have short arms and deep pockets, then yeah they are rubbish!!
You dont get more low down grunt or better pulling power,
All you get is big turbo lag!!

it s more the fact that hot air is less dense on a tdi,cooler is a easier cheaper way of increasing air without fitting bigger turbo and , tdi is not high performance engine google is not allways your friend

If I wanted a high performance motor I would of brough one. But pushing a 1600kg shed through the air, it needs a bit more power!!

I am gonna let your argue on your own because you are the man who knows everything and won't be told.

sible88 said:

If I wanted a high performance motor I would of brough one. But pushing a 1600kg shed through the air, it needs a bit more power!!

I am gonna let your argue on your own because you are the man who knows everything and won't be told.

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if you where talking to me that goes both ways ,you put your ideas or side of argument down others agree or counter others decide later,whole point of forum,

Of course most people would fit a bigger turbo with a bigger cooler, and that definitely gives more lag because the turbo spools up at higher engine rpms.

However just fitting a bigger cooler may indeed not make that much difference, because if you think about it realistically, the volume of the intercooler is small either way round, and if you've ever taken a boost hose off you'll know that a turbo makes for a very powerful air pump.

Undoubtedly adding a larger cooler has more benefits in the ways of charge cooling, flow rate increase and thus greater power potential, vs. perhaps a small increase in lag and loss of throttle response.

It is obvious that the best route for response and punchy boost characteristics is the highest flowing lowest resistance lowest volume inlet system possible (only on a turbo motor of course)

The trade off with no cooler is increased charge temps which limit high boost potential, but for off road where most of the time the engine runs off boost or low boost, a cooler simply is not worthwhile, or indeed, necessary.

Cheers

So true!! ^^

What happens if you put an inline elecy pump in just before inlet??
Would this work?

sible88 said:

I am talking from experience!!
You are talking out your arse!!

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You pays your money, you takes your choice, I know im right, where you think it's coming from is irrelevant.

jamesmartin said:

bigger cooler does give bigger lag

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Those that know, know.

sible88 said:

If I wanted a high performance motor I would of brough one. But pushing a 1600kg shed through the air, it needs a bit more power!!

I am gonna let your argue on your own because you are the man who knows everything and won't be told.

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1600kg how much have you chopped off? Discovery weighs in at around 2200kg.

I'm not arguing with anyone, it's a forum and this is what they are for

sible88 said:

What happens if you put an inline elecy pump in just before inlet??
Would this work?

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An electric pump capable of the same performance of a turbo would consume a massive amount of power albeit electrical power. You would be better off looking at supercharging, this is the way forward and is better than a turbo but far more expensive.

davek0974 said:

Those that know, know.

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i disagree, if the air travels through the cooler quicker than in standard form then it can have less lag, but its a balancing act between boost and intercooler size, but im not talking about fitting bigger turbos im using standard turbo with boost increase and in real life situation i have less lag than before after fitting larger cooler, next move will be vvt