Dumb Diesel Turbo question.

Submitted: Sunday, Mar 09, 2008 at 18:36
ThreadID: 55367 Views:2462 Replies:8 FollowUps:11
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We have always had petrol powered vehicles, but for the past six months or so have had a diesel, it is a common rail, 3 litre turbo.
I have read a few posts on this forum about some of these turbo being noisy but we don't seem to have that problem.
NOW THE DUMB QUESTIONS!! What does a turbo do? What sort of noise does a turbo make? What is meant by the turbo spooling? At what RPM does it start doing what it is designed to do. & if you have an inter cooled turbo what does that translate to compared to one that is not inter cooled.
Yep, I'm fair dinkum ( can I quietley sneak back to my kennell?)I do know that inter cooled turbo increases the power of the motor by (I think) sort of force feeding the fuel, but would just like to understand a bit better the principles behind it.
I think I will have another beer now & sort of wait for the flak I maybe deserve. Hopefully SWMBI will call me for my dinner soon & save me from embarrassment. Cheers
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Reply By: Dave B (NSW) - Sunday, Mar 09, 2008 at 18:46

Sunday, Mar 09, 2008 at 18:46
Barry,
you will find a fair bit of info here.

Exploroz

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Reply By: Member - Graham H (QLD) - Sunday, Mar 09, 2008 at 18:51

Sunday, Mar 09, 2008 at 18:51
Well I will put my head in the noose and stand to be corrected
A Turbo forces air (not fuel) in at a set pressure called boost.

It whistles until the bearings let go then it graunches usually signified by huge cloud of white smoke

Spooling is it winding down when u have turned it off too soon and its boiling the oil
Eradicated by buying a turbo timer to allow it to spool down with oil feeding thru it

It comes in at the revs set by the manufacturer about 3000 usually.
The intercooler cools the air so that it is more dense before ramming it back into cylinders.

Waits for the flames LOL
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Follow Up By: stefan P (Penrith NSW) - Sunday, Mar 09, 2008 at 20:23

Sunday, Mar 09, 2008 at 20:23
'Spooling is it winding down when u have turned it off too soon and its boiling the oil
Eradicated by buying a turbo timer to allow it to spool down with oil feeding thru it'

Close....the term 'spooling' means when it starts spining and forcing air into the motor. As a turbo is powered by the exhaust gas, there is a delay before it is working at full speed. Hence the term 'spooling up'.

Most are quite restricted by the standard exhaust. Hence some good power gains and drivability can be gained by fitting a more FREE flow exhaust on your car, as the quicker you get the exhaust gas out, the quicker the turbo will be spinning.

Hope that makes sense

Cheers Stefan
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Follow Up By: stefan P (Penrith NSW) - Sunday, Mar 09, 2008 at 20:26

Sunday, Mar 09, 2008 at 20:26
'Most are quite restricted by the standard exhaust. Hence some good power gains and drivability can be gained by fitting a more FREE flow exhaust on your car, as the quicker you get the exhaust gas out, the quicker the turbo will be spinning.'

Should read 'the quicker and sooner the turbo will be spinning'

Stefan
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Follow Up By: Nomadic Navara - Monday, Mar 10, 2008 at 11:44

Monday, Mar 10, 2008 at 11:44
The turbo comes in at much lower revs than 3,000. When you are idling along in low gear and you floor the throttle, when you feel the big kich in acceleration, that is the turbo starting to work - and that is long before 3,000 RPM.

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Follow Up By: Member - Graham H (QLD) - Monday, Mar 10, 2008 at 18:23

Monday, Mar 10, 2008 at 18:23
Was just taking a stab, everythings different and its probably lower as you say.
I thought spooling down was when u turn it off and spooling up is as you say above just my interpretation!!
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Reply By: Member - Kiwi Kia - Sunday, Mar 09, 2008 at 18:58

Sunday, Mar 09, 2008 at 18:58
With the pistons going up and down very fast and the valves only being open for a very short time only a certain amount of air can actually enter the cylinder during each intake stroke. Put a turbo onto the engine and it will force more air into a cylinder in the same time period. Add a bit more fuel at the same time and you now have more 'charge' in the cylinder and this will give you a bigger 'bang' on each ignition stroke.
AnswerID: 291813

Reply By: Kev & Darkie - Sunday, Mar 09, 2008 at 19:05

Sunday, Mar 09, 2008 at 19:05
Barry......Maaaate

A Turbo on a Diesel motor is like the Queensland footy team (Unbeatable),
Where as a Naturally Aspirated Diesel motor is like the crummy Cockroaches (your Team) sluggish and cant win a game to save themselves.

I hope this clears up your problem ha ha ha ha ha ha ha ha ha ha ha

Cheers Kev
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Follow Up By: blue one - Sunday, Mar 09, 2008 at 20:11

Sunday, Mar 09, 2008 at 20:11
Kev,
Do you know that the Turbo was invented by Ron Turbo from Newtown.

It's gotta be a first for NSW.

Cheers
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Follow Up By: Kev & Darkie - Sunday, Mar 09, 2008 at 20:22

Sunday, Mar 09, 2008 at 20:22
To bad their football teams aren't so inventive, Queenslanders have no problems in reading their plays LOL

Cheers Kev
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Follow Up By: Kiwi & "Mahindra" - Sunday, Mar 09, 2008 at 23:50

Sunday, Mar 09, 2008 at 23:50
Obviously you are hanging for nrl to come back!!! Go you mighty cowboys!!....but Im a blues girl and country girl all the way....just go those cowboys....and i aint talking about you either kev!!
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Follow Up By: Member - Norm C (QLD) - Monday, Mar 10, 2008 at 19:22

Monday, Mar 10, 2008 at 19:22
Blue One, your Ron Turbo from Newtown story is a bit off the mark. Thought I should straighten that out and state the true history of the turbo.

A Queensland bushy named Al (know as Al the Bushy) from Tambo first came up with the idea in about 1903. Al was a big 2 Up player and called his invention a Spinner, to honour his favourite game of chance. Already back then, nobody was interested in Australian inventions, so he moved to Sweden. When he introduced himself as Al the Bushy with his invention from Tambo, they thought he said 'Alfred Bushi with his invention, a Turbo'. Al didn't speak much Swedish back then you see.

Anyway, his invention was a great success and was patented in 1905.

Don't believe me? Google it and you will find that the Swiss now claim Alfred Bushi and his turbo invention as their own.

Typical of the Swiss and a New South Welshman to try to claim a great Queenslander as your own.

Norm (trust me, I'm a Queenslander) C
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Follow Up By: Member - Norm C (QLD) - Monday, Mar 10, 2008 at 19:28

Monday, Mar 10, 2008 at 19:28
The Sweds also claim him of course, as well as the Swiss and NSW.
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Follow Up By: blue one - Monday, Mar 10, 2008 at 20:06

Monday, Mar 10, 2008 at 20:06
Norm,
I know his grandson and Norm patented it in 1902. Therefore Al must be a show pony riding on the back of a New South Welshman.

NSW continues to carry QLD, must be something to do with the geography. (See the GST)

Or maybe this Bushi fella is a Swiss plant, they are everywhere.

Cheers
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Reply By: Member - Axle - Sunday, Mar 09, 2008 at 19:47

Sunday, Mar 09, 2008 at 19:47
Hi Barry, I think Kiwi Kia has explained it exactley right, the problem seems to be performance gain against reliability issues, Eg ZD30 nissan motor, If you look at all the old engines 4&6 cyl non turbo, i doubt if there was a major issue with any of them no matter what brand!!, Turbos are great but things can be vunerable IMHO.


Cheers Axle.
AnswerID: 291822

Reply By: Member - Paul C (NSW) - Sunday, Mar 09, 2008 at 21:25

Sunday, Mar 09, 2008 at 21:25
Gday Barry

I'd expect to see the turbo cut in around 200RPM.
Try this link.
Site Link

Cheers
Paul
AnswerID: 291840

Reply By: robak (QLD) - Monday, Mar 10, 2008 at 11:07

Monday, Mar 10, 2008 at 11:07
I'm no mechanic so I only know in very simple terms about turbos. A turbo is essentially a fan (that spins ridiculously fast). Any engine will perform better when it has more air going into it. The turbo squeezes more air into the engine. The problem with squeezing air is, like with any another gas, is that it produces heat, which is counter-productive as hot gases want to expand. An intercooler is a sort of a radiator for this compressed hot air. And as the name suggests, it cools the air that goes into the engine which again allows more air to be pushed into the cylinders.

After the air (and fuel) is used by the engine, it is expelled through the exhaust. In the exhaust tubes is another little "fan" that the exhaust fumes rotate as they pass through. The exhaust "fan" and the intake air "fan" are connected so that the exhaust one propels the intake "fan". These two connected fans are the turbo.
AnswerID: 291891

Follow Up By: Member - barry F (NSW) - Monday, Mar 10, 2008 at 17:30

Monday, Mar 10, 2008 at 17:30
Thanks everyone for you input & info, much appreciated, I now know a little more than I did before which is what I wanted. Cheers.
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Reply By: Member - JohnR (Vic)&Kath - Monday, Mar 10, 2008 at 18:59

Monday, Mar 10, 2008 at 18:59
Barry, you have had several comments about the rev range that people expect to have the turbo kick in at.

Really though that will vary according to the design of the turbo and the free flow through the exhaust. Some have big fans and some have small. The bigger the fan and the better the flow, the better the potential. The hotted up Nissan 4.2 has a bigger capacity fan and actually Lucy posted a pic last week of a competition 4.2 and a huge turbo in comparison to standard.

Likewise with intercoolers too. The Nissan intercooler on a 4.2 needs to be bigger capacity to improve performance. It does a bit more on improving the emissions but I thought it made our 4.2 more breathless than improve it against non-intercooled 4.2s. On a Yota 4.2 diesel, the intercooler is bigger capacity, but could be bigger again with more turbo boost.
Cheers,
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