Jeremy Fearn Power Upgrade

"Tom Woods" <[email protected]> wrote in message
news:[email protected]...
> On Tue, 27 Sep 2005 19:00:45 +0100, "Huw"
> <hedydd[nospam]@tiscali.co.uk> wrote:
>
>>You are living in a fantasy world of impracticality.
>>In the real world of engine performance, air to air intercoolers are used
>>by
>>very slow moving and even stationary engines which regularly pull full
>>power
>>at full revs while stationary for hours on end.
>>The intercooled discovery would pull its full power at whatever ground
>>speed.
>
> Do turbo diesel engines differ significantly from turbo'd petrol ones?
> All my experience is with petrol ones (does the difference in the
> amount of air flow in/out of diesel/petrol engines make the effects of
> an IC different?).
> .
> The intercooler simply tries to cool the interior air down towards the
> temperature of the exterior air. It will be more effective when the
> exterior air is cooler.

Yes but the difference between a hot day, say 25C and a cold one, Say 5C is
only a difference of 20C which is only a small difference compared to
between the hot and cool side of the intercooler. I think I am right in
saying that the cool side is usually around 50C in an engine running maximum
boost. And remember that maximum boost could well occur at less than
1500erpm under load.

>
> The exterior air is obviously going to be hotter if the car is
> stationary.

It is certainly not obvious to me. The cooling fan moves a large volume of
cooling air even when stationary.



As soon as it warms up (which it will if there is no air
> movement), the intercooler will become less efficient.

But there is always air movement when it is needed even with electric fan
equipped vehicles like my TD6.



> If the car is moving then the intercooler should have a constant
> supply of cooler air and thus be more effective as the temperature
> difference between externally and internally will be greater.

There will never be a constant supply, it varies with speed and particularly
where the fan switches on and off. The intercooler is effectively a radiator
and will cool by heat soak for a while even without significant air flow. In
any case, many [most] modern electronically controlled engines will have an
intake air temperature sensor which will control the fan indirectly along
other systems.



>
> I've got a saab turbo. Adding an IC meant the engine could take more
> boost before it got knock.
> My IC is not front mounted.. When I drove around with my headlight
> removed to give the IC some proper air flow, I could get even more
> boost before knock happened.
> I know people who have adding Front mounted intercoolers, IC misting
> kits to enable them to get even more boost pressure - so I was under
> the impression that if the intercooler stays cooler (which a moving
> one will more so than a stationary one - just use the coolant radiator
> as an example) it will work better and give you more performance.

That depends on whether the intercooler was at its limit to start with. Most
diesel intercoolers are not fitted to enhance performance as much as to
lower emissions. This usually leaves a fair degree of scope for tuning
without increasing the intercooler size. Apart from which, since we are
talking Land Rover here, these vehicles are designed to work hard and to tow
hard in adverse conditions and in low gear range with hardly any natural air
flow and in high ambient temperatures.

>
> There is a post here that mentions how an intercooler gets hot when
> its in use without any additional cooling -
> (http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=12).
>
>

Of course it will get hot. It is a heat exchanger for goodness' sake and it
needs air. That is why it is situated in the air flow and usually in the
area where air is pulled by the cooling fan. There are exceptions, such as
the old Isuzu Trooper 3.1 which had a top mounted intercooler which had no
fan. Now this, you would think would be quite ineffective in the adverse
conditions I describe above. However I have run this machine for 14 years
and towed improbable loads in very hilly conditions and have never seen the
power decline. This may be due to the heat soak effect combined with the
possibility that the intercooler is there primarily to reduce emissions
rather than to allow greater fuel injection leading to more power per-se.

Huw

On 2005-09-27, Huw <hedydd> wrote:

> I maintain that the Land Rover engine can maintain sustained high
> power output with no detriment at lower ground speeds.

Certainly, they're not designed for high speed after all ;-)

I don't reckon it'll generate full power while stationary (which
doesn't contradict what you say), but without figures to back us up I
don't think we'll ever get the truth, and personally I'm not bothered
enough to go and get the figures, I suspect we've got better things to
do ;-) (like sleeping for example)

> To illustrate that ambient is not the aim, I should say that it is generally
> accepted that water to air intercoolers are efficient and commonly fitted.
> The liquid coolant never gets anywhere near ambient. The air temperature
> after the turbo we are concerned with is very hot and is still fairly hot
> after the intercooler. I have figures somewhere, though lord knows where.

Digging figures out of my failing memory, my plastic rocket charge air
temp goes from about 150 centigrade down to about 60, and that gives a
boost of about 80BHP over the non-chargecooled version of the same
engine (charge cooler is Lotus's name for their air-to-water
intercooler), however it reaches heat saturation quickly if the car's
not moving, different design limits to the landy, which has different
design limits to an engine in a non-moving vehicle.

--
For every expert, there is an equal but opposite expert

Huw wrote:
-snip-
> Of course it will get hot. It is a heat exchanger for goodness' sake and it
> needs air. That is why it is situated in the air flow and usually in the
> area where air is pulled by the cooling fan. There are exceptions, such as
> the old Isuzu Trooper 3.1 which had a top mounted intercooler which had no
> fan. Now this, you would think would be quite ineffective in the adverse
> conditions I describe above. However I have run this machine for 14 years
> and towed improbable loads in very hilly conditions and have never seen the
> power decline. This may be due to the heat soak effect combined with the
> possibility that the intercooler is there primarily to reduce emissions
> rather than to allow greater fuel injection leading to more power per-se.
>

Huw, I'm seriously considering one of the '94-'96 3.1 Trooper Bighorn
imports since I hate the Jeep Cherokee for towing and I can't afford
another 110. I regularly see them go for £2-£3k with reasonably low
miles - would this be a good tow vehicle for my 2000kg espresso
trailer? Is the Auto box OK? (I don't see many manuals anyway). Most
that I see are around 50-70k miles, so would need a new cambelt - are
there other things I should be doing to a vehicle with this mileage?
Sorry for all the questions...


--
Regards,
Danny

http://www.gaggia-espresso.com (a purely hobby site)
http://www.dannyscoffee.com (UK advert for my mobile espresso service)
http://www.malabargold.co.uk (UK/European online ordering for Malabar
Gold blend)
swap Z for above characters in email address to reply

@Andrew Cooke i must admit ive not read all the replys you have here there is just to many.

But if you want a chip/reflash and a intercooler and to have it done by someone who WONT thrash the living daylights from your car give me a ring.

www.bellautoservices.co.uk

I use the SAME Serial download spi equipment that superchip and as far as i no jeremy uses to do my landrover tuning.
And infact most of my diesel tuning is done with the same kit as most of the top tuners out there.