Omega Owners Forum

Chat Area => General Car Chat => Topic started by: Andy B on 26 November 2011, 20:28:38

Title: intercoolers
Post by: Andy B on 26 November 2011, 20:28:38
Numpty question time .....
The air - air intercooler on my diseasal Astra has the hot air that's been compressed by the turbo cooled by sending it through the inside of a radiator (intercooler) which in turn is cooled by an air flow across the fins ie air flow as you drive along.  :y :y

On a  'go-faster' Brabus Roadster there's a water filled intercooler.
Question ....... where's the water relative to charge air or cooling air?  :-\ :-\ :-\
Title: Re: intercoolers
Post by: Brikhead on 26 November 2011, 21:01:06
Same as in a normal radiator... running through the vanes?
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:07:30
Same as in a normal radiator... running through the vanes?

Where's the charge air then?  :-\
Title: Re: intercoolers
Post by: hotel21 on 26 November 2011, 21:08:16
Engine air is seperated from external cooling (air/water/whatever) medium by metalwork/fins etc. :)
Title: Re: intercoolers
Post by: hotel21 on 26 November 2011, 21:10:11
Charge air is the external air thats gone through the turbo/supercharger and is compressed.  Charge air cooler cools this mass of air, reducing its relative volume, allowing more of that volume into the cylinder thus, more fuel to mix and so, bigger bang per cycle = more power....

Edit to add that external air goes through air filter into charger, then cooler, then engine.  Use of a dump valve expells excess charge air to atmosphere so as to prevent overpressure or back pressure issues into the charger when the engine goes off load/gearchange...  :y
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:13:04
Engine air is seperated from external cooling (air/water/whatever) medium by metalwork/fins etc. :)

Still not getting it ......  :-\ :-\ :-\ As said with an air - air intercooler, combustion air that's being cooled goes where coolant would be in your 'normal' rad ie inside it & is cooled with an air flow across it.
So, if as Brikhead says, the water is in the same place in a water cooler intercooler ............. your car is going to drown  ;D ;D
Title: Re: intercoolers
Post by: hotel21 on 26 November 2011, 21:17:28
Engine air is seperated from external cooling (air/water/whatever) medium by metalwork/fins etc. :)

Still not getting it ......  :-\ :-\ :-\ As said with an air - air intercooler, combustion air that's being cooled goes where coolant would be in your 'normal' rad ie inside it & is cooled with an air flow across it.
So, if as Brikhead says, the water is in the same place in a water cooler intercooler ............. your car is going to drown  ;D ;D

Imagine being back on a marine diesel engine.

Air goes through filter, compressed by turbo, then cooled by a fresh water recirc system before entry to engine.

Fresh water recirc then cooled by a seawater heat exchanger and thus, the three mediums remain mechanically and physically seperate.  Water cooling on your car will be similar whereby the cooling water cools the air?

Clear as mud...... ;D ;D ;D

Water passing through charge air cooler will thereafter be cooled by engine rad and then through engine etc afterwards as required.
Title: Re: intercoolers
Post by: tidla on 26 November 2011, 21:18:36
(http://i1114.photobucket.com/albums/k536/tidla1/s-road-v6-2.jpg)

thingy on the left?
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:21:49
...
Fresh water recirc then cooled by a seawater heat exchanger and thus, the three mediums remain mechanically and physically seperate.  Water cooling on your car will be similar whereby the cooling water cools the air?

Clear as mud...... ;D ;D ;D

OK, got you now, not sure how the water actually helps any though.  ;) ;) ;)
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:22:55
(http://i1114.photobucket.com/albums/k536/tidla1/s-road-v6-2.jpg)

thingy on the left?

I think you've managed to find the V6 Brabus Smart!  ;) ;) ;) ;)
Title: Re: intercoolers
Post by: hotel21 on 26 November 2011, 21:23:16
Same as in a normal radiator... running through the vanes?

Where's the charge air then?  :-\

Picture a 'normal' radiator encased in an air/watertight shroud.

Air passes through internals wher water would normally be.

Water passes through fins etc where air would normally be.

Casing keeps the water in place rather than being lost as air would normally be on a 'normal' car.
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:25:05
(http://www.fq101.co.uk/images/stories/452/engine/icpipes9.jpg)

intercooler is here with its own fan

off to find a Brabus's  :y
Title: Re: intercoolers
Post by: hotel21 on 26 November 2011, 21:25:22
...
Fresh water recirc then cooled by a seawater heat exchanger and thus, the three mediums remain mechanically and physically seperate.  Water cooling on your car will be similar whereby the cooling water cools the air?

Clear as mud...... ;D ;D ;D

OK, got you now, not sure how the water actually helps any though.  ;) ;) ;)

Depends on the relative difference in temperatures.

If air has a greater cooling effect then air will be used whilst on tighter engine space fitments, probably easier to cool water below ambient and thus have greater cooling effect.
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:27:29
.....

thingy on the left?

I think it is  :y
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:28:52
Same as in a normal radiator... running through the vanes?

Where's the charge air then?  :-\

Picture a 'normal' radiator encased in an air/watertight shroud.

Air passes through internals wher water would normally be.

Water passes through fins etc where air would normally be.

Casing keeps the water in place rather than being lost as air would normally be on a 'normal' car.

Completely understand now!  :y :y :y :y
Ta!

I knew I'd get a proper answer here!
Title: Re: intercoolers
Post by: tunnie on 26 November 2011, 21:34:32
(http://www.fq101.co.uk/images/stories/452/engine/icpipes9.jpg)

intercooler is here with its own fan

off to find a Brabus's  :y

and I thought the V6 engine bay was tight  :o :o
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:38:33
...
and I thought the V6 engine bay was tight  :o :o

Have you seen what you need to do to change all 6 plugs?  ??? ??? ???   (it's only 3 cylinder)

(http://www.fq101.co.uk/images/stories/452/panels/coupe14.jpg)
Title: Re: intercoolers
Post by: hotel21 on 26 November 2011, 21:38:54
Same as in a normal radiator... running through the vanes?

Where's the charge air then?  :-\

Picture a 'normal' radiator encased in an air/watertight shroud.

Air passes through internals wher water would normally be.

Water passes through fins etc where air would normally be.

Casing keeps the water in place rather than being lost as air would normally be on a 'normal' car.

Completely understand now!  :y :y :y :y
Ta!

I knew I'd get a proper answer here!

Only took 15 replies!   ;D ;D ;D :y :y
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:39:46
Same as in a normal radiator... running through the vanes?

Where's the charge air then?  :-\

Picture a 'normal' radiator encased in an air/watertight shroud.

Air passes through internals wher water would normally be.

Water passes through fins etc where air would normally be.

Casing keeps the water in place rather than being lost as air would normally be on a 'normal' car.

Completely understand now!  :y :y :y :y
Ta!

I knew I'd get a proper answer here!

Only took 15 replies!   ;D ;D ;D :y :y

I knew the air - air ........... just couldn't see where the water would be  ;D ;D ;D ;D ;D
Title: Re: intercoolers
Post by: hotel21 on 26 November 2011, 21:40:25
...
and I thought the V6 engine bay was tight  :o :o

Have you seen what you need to do to change all 6 plugs?  ??? ??? ???   (it's only 3 cylinder)

(http://www.fq101.co.uk/images/stories/452/panels/coupe14.jpg)

Changing a turbo on a Disco4 means splitting body from chassis to get access....   ::)
Title: Re: intercoolers
Post by: tunnie on 26 November 2011, 21:40:30
...
and I thought the V6 engine bay was tight  :o :o

Have you seen what you need to do to change all 6 plugs?  ??? ??? ???   (it's only 3 cylinder)

(http://www.fq101.co.uk/images/stories/452/panels/coupe14.jpg)

 :o :o :o :o :o :o :o

and I complain about a loom over one bank  ;D
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:44:22
...
and I thought the V6 engine bay was tight  :o :o

Have you seen what you need to do to change all 6 plugs?  ??? ??? ???   (it's only 3 cylinder)

(http://www.fq101.co.uk/images/stories/452/panels/coupe14.jpg)

 :o :o :o :o :o :o :o

and I complain about a loom over one bank  ;D

It's not as bad to do as it looks  ;)
Title: Re: intercoolers
Post by: tunnie on 26 November 2011, 21:45:13
Think I would rather have the M5 in the background  :)
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 21:46:34
.....
Changing a turbo on a Disco4 means splitting body from chassis to get access....   ::)

Sounds like a job for a (http://www.buyonsaletools.com/images_products/Off_Hand_Grinder.jpg) and weld it back in again afterwards  ;D ;D ;D
Title: Re: intercoolers
Post by: hotel21 on 26 November 2011, 21:51:00
In reality, raising a Disco4 body from the chassis is only a dozen or two bolts and a number of wiring connectors . 

Reassembly is the reverse of removal, according to the haynes book of best guesses.   ;D

Next time ones being done in the workshop, must take a piccy.....   :y
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 22:00:42
...
 is only a dozen or two bolts and  .....

And how long does it take to remove a bolt?  ::) ::) ::)

It could be real fun a few years later after a X thousand miles of salt covered roads later.  ;) ;)
Title: Re: intercoolers
Post by: Vamps on 26 November 2011, 22:14:52
Thanks for asking that question Andy as, I think I also learned something, I have never owned a car with a 'Turbo' or Intercooler on it, until now, must lift the bonnet one day and take a look...... :y :y :y
Title: Re: intercoolers
Post by: hotel21 on 26 November 2011, 22:18:30
...
 is only a dozen or two bolts and  .....

And how long does it take to remove a bolt?  ::) ::) ::)

It could be real fun a few years later after a X thousand miles of salt covered roads later.  ;) ;)

No argument from me on that point!    ;D ;D ;D ;D
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 22:20:49
Thanks for asking that question Andy as, I think I also learned something, I have never owned a car with a 'Turbo' or Intercooler on it, must lift the bonnet one day and take a look...... :y :y :y

I've had a TD Astra for a few years, SWMBO got the Smart a couple of years ago but even though I kinda knew the different bits, I'd never really thought of them all as a whole. My Dad was asking about turbos, intercoolers etc & I realised I didn't actually know properly myself especially when I thought of the water bit on the Brabus Roadsters. It all makes sense now.  :y :y :y
Title: Re: intercoolers
Post by: Kevin Wood on 26 November 2011, 22:24:31
The advantages with a charge cooler are that water has a much higher heat capacity than air as a cooling medium so a cooler cooled by water can be much smaller to shift a given amount of heat from the charge. In addition, you can locate it on the engine rather than where you have cooling airflow. It'll be more free-flowing and tie up a smaller volume of air in the cooler than an intercooler, hence reducing turbo lag.
Title: Re: intercoolers
Post by: Brikhead on 26 November 2011, 23:10:33
I knew I'd get a proper answer here!...
Only took 15 replies!   ;D ;D ;D :y :y

I thought I explained it perfectly in the first reply!?
 :D
Title: Re: intercoolers
Post by: Andy B on 26 November 2011, 23:47:59
I knew I'd get a proper answer here!...
Only took 15 replies!   ;D ;D ;D :y :y

I thought I explained it perfectly in the first reply!?
 :D

 ;D ;D ;D I suppose you did.  ;) ;) ;)
Title: Re: intercoolers
Post by: aaronjb on 27 November 2011, 12:03:59
The advantages with a charge cooler are that water has a much higher heat capacity than air as a cooling medium so a cooler cooled by water can be much smaller to shift a given amount of heat from the charge. In addition, you can locate it on the engine rather than where you have cooling airflow. It'll be more free-flowing and tie up a smaller volume of air in the cooler than an intercooler, hence reducing turbo lag.

 :y

I ran an air-water system on the MR2 for those reasons; better packaging (it's hard to locate an air-air cooler effectively on a rear engine car) and better charge temperatures during extended boost periods (i.e. on track) thanks to the large volume of water in the system (as the water rad was at the front of the car, in front of the regular engine radiator).

Worked well, though a good chargecooler is rather expensive (I think I paid ~£500 for my PWR barrel - I was never that convinced that the cheap 'square' ones on eBay were all that good, flow wise)