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Turbo efficiency question

G

Guest

Guest
Greetings everyone,
Do any of you good folks know enough about turbocharging to help my
befuddled thinking? I would like to know if there is any advantage to
efficiency in raising boost pressure and intercooling for normal everyday
driving?
Our everyday transport here is the 80 series Landcruiser but I also have a
4runner with 3-litre 1KZ-T engine plus aftermarket intercooler which gets
only occasional use at present. Its a good motor and returns almost 30mpg on
70mph motorway drives and also performs 'quite briskly' when I sometimes
regress to my youth and really put the boot in! When the intercooler was
fitted the boost remained unchanged although fuelling was adjusted to take
advantage of the cooler air. I am wondering if there would be any
significant extra mpg to be had from more boost assuming the vehicle is
driven in the same way? In other words if I only ask for the same power from
the engine will the increased efficiency give me this from less fuel?
I'm not expecting anything miraculous but as the intercooler is already in
place the cost of the modifications would be virtually nothing - and I quite
like the sound of that..... You're probably thinking why don't I just try
it and see what happens - well I would, but I do like to understand the
implications of any fiddling before I do it - just in case I have it all
wrong!
If there are any useful benefits I would probably convince myself that
intercooling the 80 was a good thing, although it would probably take 20
years to recover the cost of a good cooler!
(Using very approximate maths a 1mpg improvement from say 25mpg would save
about ?6 over 40 gallons. At that rate a ?600 invesment in intercooling etc
would take around 100,000 miles! Inflation would help a little but its
difficult to make the case on financial grounds. So I'll justify it in some
other way I guess.....)
Have I missed something or just plainly misunderstood the fundamentals? Your
views will be gratefully received.
Have fun,
John
 
John
| Greetings everyone,
|
| Do any of you good folks know enough about turbocharging to help my
| befuddled thinking? I would like to know if there is any advantage to
| efficiency in raising boost pressure and intercooling for normal everyday
| driving?
I've often pondered these questions, and if Jon Wildsmith is reading this he might chime in since (according to my email archive) he had his turbo boost raised from 6psi to 9psi back in 2004 - what was the effect on economy Jon?
Another interesting page is
http://www.allardturbosport.co.uk/pages/turbo_diesel_special_tuning_manual.shtml
Although it costs =A315 to obtain. Look elsewhere on his website and he claims that tuning for economy can obtain up to 15% improvement.
My guess is that increasing boost will only improve economy if it allows you to make more efficient use of the engine, meaning developing power at lower revs. So it might let you change up earlier (is it a manual?), or use a lower gear, but is unlikely to make much difference to motorway cruising.
In my (very limited) experience tuning requires optimisation of the whole power pack and transmission, not just one component - for instance you might need to change the final drive ratio in order to exploit a different torque curve.
Sorry, not a very knowledgeable answer!
Christopher Bell
(Who put =A3100.57 worth of diesel (75.67l) into his tank this am, which took him 481.9 miles @ 28.9 mpg)
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Hi John
Yes you can increase the boost and yes you will get more power
BUT you will reduce the life expectancy of the engine. There is no such
thing as a free lunch! If you increase the power you should increase the
efficiency of the engine and by only using the power that you had before you
should improve your fuel usage but was that a pig I saw flying by! The
chances of you controlling the urge to use the extra power are remote, you
know it and so do I. If the intercooler set-up is working ok I suggest you
stop there.
Roger
Ps If you go onto Diff-Lock you will get a wider response to your questions.
 
Roger wrote....
Ps If you go onto Diff-Lock you will get a wider response to your questions.
SNIP
Roger, with respect can I suggest you sit in a corner and have a talk
with your conscience and ask if it is polite to this list that you
advise others to look elsewhere for answers?
Those of us who are founder members and who have supported Julian
from the beginning, would strongly dispute that better information on
the Land Cruiser range as supplied in European markets can be
obtained elsewhere.
Yes, we all know where there are other forums that can give
information on our favourite vehicles; but we know where to go
without advising others in such a public manner. We can all
correspond to each other off-list using the addresses at the head of
each posting.
Well, that's my opinion anyway, you may disagree
Jon
Linslade, Beds
with experience of 70/80/90 series
 
Morning John,
Out of interest where did the intercooler come from and who fitted it?
The whole point of intercooling a turbo diesel is that as the turbo pumps the air into the engine it also heats it up and it expands. The principle behind it is to cool the air before it gets into the engine, enabling you to get more air into the engine.
So when you install an intercooler you increase the turbo boost to compensate for the extra pipe work and because you can get more of it in to the engine without putting too much extra strain on the turbo. You then increase the fuelling to maintain the same fuel/air mixture.
Only increasing the fuelling will lead to a richer mixture and a less efficient burn.
I would recommend increasing the boost to compensate for the intercooler and the increased fuelling, but to what level, I'm not sure. I would chat to Andrew Graham at Allisport and ask him what he does when installing intercoolers on that engine.
Regards
Julian
Email: [Email address removed]
Tel:=A0+44 (0)845 508 6863
 
Hi,
I was reading about boost pressure on LCOOL Aus. a few months ago. From
memory the boost pressure can be 10 or 11 but check the forum.
Regards,
Clive Marks
Home: +44 1293 514600
Mobile: +44 7821 491897
Crawley, West Sussex, UK.
 
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Jon
| > what was the effect on economy Jon?
|
| I don't think there was any but I didn't keep records then and I don't
now
| ... All the extra weight mine carries and my driving tendencies don't
make
| it a good reference vehicle when discussing fuel ecconomy ;-)
Probably best neither to speculate nor to calculate!
1900kg is a heavy old caravan - that's more than my personal quantum of
a horse trailer and two horses.
CB
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Well thanks everyone for your replies to my question about extra boost after
fitting an intercooler. Some interesting discussions followed. All your
inputs were appreciated, particularly Andy's experiences and Lionel's in
depth appraisal. I should caution that I am now in the extremely dangerous
process of thinking about the subject and will return shortly with my new
understanding and some further questions! I might order a copy of Allard's
book first.
My original comment "When the intercooler was fitted the boost remained
unchanged although fuelling was adjusted to take advantage of the cooler
air" should perhaps have been "fuelling was adjusted to its optimum
setting". At the time I understood this to be making more fuel available to
utilise the cooler and therefore denser charge resulting from the effect of
the intercooler. My apologies if this created some misunderstanding. It can
be surprising difficult to pose a question in such a way that everyone who
reads it makes the same interpretation and answers the question you thought
you had asked!
Julian - the original 4runner intercooler was supplied and fitted by Allards
in Monmouth about 4 years ago.
More to come shortly - sorry folks (haha)
Have fun,
John
 
Hello the guys,
Well I am increase my power by much with kit intercooler and bigger
turbo. I have 1,6 bar pressure now maximum and the IP manipulated for
more fuel delivered. You can not believe the diference! So may be 250
hp instead of 180, I do not know for sur. But almost no other cars
are so fast from 80kph and up after the convertiseur of torque closes
up.
I must had to adjust the automatic box control cable because she
slided in between shifting gears and made death noise one time. Now
she shift hard but no more slipping and no more death noise.
Then we know there is only so many horspower hours in a new motor, so
how will you use it up? Allways tickling that little mushroom under
your right foot? Or mostly drive like the pope but sometimes have a
little fun. I am that later case.
If I tow something heavy like my Ranger then I only use about 1 bar
pressure, that is when the orange turbo light starts to vibrate on a
little bit.
Benoit
2008/7/13 Roger Fairclough <[Email address removed]>:
 
Hello the guys,
Well I am increase my power by much with kit intercooler and bigger
turbo. I have 1,6 bar pressure now maximum and the IP manipulated for
more fuel delivered. You can not believe the diference! So may be 250
hp instead of 180, I do not know for sur. But almost no other cars
are so fast from 80kph and up after the convertiseur of torque closes
up.
I must had to adjust the automatic box control cable because she
slided in between shifting gears and made death noise one time. Now
she shift hard but no more slipping and no more death noise.
Then we know there is only so many horspower hours in a new motor, so
how will you use it up? Allways tickling that little mushroom under
your right foot? Or mostly drive like the pope but sometimes have a
little fun. I am that later case.
If I tow something heavy like my Ranger then I only use about 1 bar
pressure, that is when the orange turbo light starts to vibrate on a
little bit.
Benoit
 
Morning Benoit,
Are you still using the factory turbo, or do you have one of the upgraded versions? I would be very nervous of running the boost on a factory turbo over 1 bar for prolonged periods - they have been known to spit blades into the engine.
The engines are used by Yanmar in marine applications with up to (and I think over) 400bhp so the they can take it, but there are a few things you will need to keep an eye on.
If you are able to adjust the boost in the cab, you need to think about the fuelling side - I guess this will be set for a certain boost - increasing or decreasing the boost from that point will affect the efficiency of the engine - you really need to fit an Exhaust Gas Temperature probe in the exhaust outlet manifold to make sure that the temperatures in the cylinder head don't rise too high.
You should also consider doing some work on the automatic gearbox so that it can handle the extra power. Start off by fitting an extra oil cooler to make sure that you don't cook the oil whilst towing, then consider contacting Rodney at http://www.automatictransmission.com.au/ - they do an Extreme Valve body kit that improves the flow of oil in the gearbox enabling it to run a little cooler, provide better gear changes as well as be able to handle the power better. You should also consider getting one of their up rated Torque Convertors - take a look at http://www.automatictransmission.com.au/extreme_a442f.asp to get a better idea of what they do with their 'Extreme' gearboxes.
Regards
Julian
Email: [Email address removed]
Tel:=A0+44 (0)845 508 6863
 
Thank you for the informations Julien,
Yes I have the bigger turbo from AllAmericanImports. I don't have a
exhaust pyrometre yet but that is in my list to do. Meanwhile I do not
go over 1 bar whist towing and I put in a new temperiture gage for the
transmission oil. So far there is never more than 55=B0 C.
A experienced guy from Equipe Raid in Mulhouse did modify my IP for
more fuel dilivery, and boy she smokes much if I go fast.
Now, that better convertisseur torque you speak of is interesting me.
Can I also have manual lockup button with it? Is there risk of damage
if a shift occurs while the converter is locked up? I will take a
look at http://www.automatictransmission.com.au/extreme_a442f.asp
Benoit
2008/8/1 Julian A.R. Voelcker <[Email address removed]>:
versions? I would be very nervous of running the boost on a factory turbo over 1 bar for prolonged periods - they have been known to spit blades into the engine.
hink over) 400bhp so the they can take it, but there are a few things you will need to keep an eye on.
the fuelling side - I guess this will be set for a certain boost - increasing or decreasing the boost from that point will affect the efficiency of the engine - you really need to fit an Exhaust Gas Temperature probe in the exhaust outlet manifold to make sure that the temperatures in the cylinder head don't rise too high.
it can handle the extra power. Start off by fitting an extra oil cooler to make sure that you don't cook the oil whilst towing, then consider contacting Rodney at http://www.automatictransmission.com.au/ - they do an Extreme Valve body kit that improves the flow of oil in the gearbox enabling it to run a little cooler, provide better gear changes as well as be able to handle the power better. You should also consider getting one of their up rated Torque Convertors - take a look at http://www.automatictransmission.com.au/extreme_a442f.asp to get a better idea of what they do with their 'Extreme' gearboxes.
 
Benoit,
I have investigated the TC lockup with Rodney of WA in Oz when I was
refurbishing my gearbox. It turned out I couldn't become the boxes
supplied between 1990-1992 for turbo diesel Landcruisers are the
hydraulic version of the A442F.
These were the years where the A440F transmission was changed to the
new A442F design and the old A440F valve body was redesigned but still
remained a hydraulic valve body in the new A442F transmission. In
other words it's still hydraulic and not electronic ( NO TPS ), hence
it cannot be locked up manually. The full electronic version was
released about the 10/1992.
Rgds,
Roman (London, UK)
'92 HDJ80 (auto)
On Fri, Aug 1, 2008 at 11:29 AM, Benoit Bernard
<[Email address removed]> wrote:
 
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