View Full Version : All about intercoolers...
How do intercoolers work? Is it..
They either get filled with air from the induction system or the turbo which ciculates through them, cooling via outside air, and then into the inlet manifold?
Student here needing to learn. I'm thinking that things like pressure, flow and so forth are excessively important.
:cheers:
air sucked from air filter into the turbo - then pushed through the intercooler. intercooler should act like a heatsink & get warmed up - and dispersing the heat into the atmosphere. then the air runs to the inlet manifold & into your engine.
but. if you have too big an area you can welcom turbo lag with open arms while it compresses the air even more.
acts like a radiator in laymans terms, except instead of hot water like @ home, you have hot air.
Yup.
Turbo compresses air.
This unfortunately causes it to rise in temperature and therefore expand ~ undoing some of the work your turbo has just done.
Running it through an intercooler allows the "charge" to cool and compress again.
:)
not forgetting that colder air is more dense & is more oxygen rich - produces better bang
Now what you really need is a turbo that isn't fed off the exhaust to get away from all that heat.
I think they call that a sup.....
M
ibizacupra
28-05-2003, 18:56
LOL.... the heat generation form the turbine is'nt exhaust related but compressor related. Superchargers will get just as hot (even hotter in mechanical terms) as they too are compressing a gas which generates heat.
Remember the days when you pumped your bike tyres up and the end nozzle of the pump got really hot? Compressing the gas generates that heat.
Intercoolers and charge coolers are there to dissipate the heat to atmosphere so cooler, denser air can be given to the combustion process.
Intercoolers typically are air to air, but you can also get air to water ones, which are called Charge Coolers (which is what I have) Water to air heat conduction is much better than air to air in efficiency terms. - specific heat capacity, latent heat of evaporation etc....Anyone remember their physics lessons? :p
A good book to read and learn about turbos and superchargers is by Corky Bell, "Maximum Boost"
regards
bill
regards
bill
What do they say about a picture worth a thousand words?
http://static.howstuffworks.com/gif/turbo-plumbing.gif
that makes sense :redface: just wondered how the turbo gets cherry & if that heats up less than (pascals theory??) compressed air
Thanks for the the info guys - sorted now!
Bill - re: charge cooling - care to explain how the move from air to water works? I'm thinking about how i'm going to solve the problem of intercooling on the larger IHI turbo so any of your expert and respected advice would be useful :) Any recommendations?
I've been toying with the idea of using the golf TDI FMIC (it's huge) but i'm worried about compression and flow etc esp. if i'm having the pipework made up. Charge cooling sounds fun but is it expensive? Who does such wonderful toys?
Questions questions..
:cheers:
ibizacupra
29-05-2003, 11:11
Originally posted by dangel
Thanks for the the info guys - sorted now!
Bill - re: charge cooling - care to explain how the move from air to water works? I'm thinking about how i'm going to solve the problem of intercooling on the larger IHI turbo so any of your expert and respected advice would be useful :) Any recommendations?
I've been toying with the idea of using the golf TDI FMIC (it's huge) but i'm worried about compression and flow etc esp. if i'm having the pipework made up. Charge cooling sounds fun but is it expensive? Who does such wonderful toys?
Questions questions..
:cheers:
Chargecooling is very $$$. A large FMIC, air to air is going to be much better on the wallet.
http://www.paceproducts.co.uk/index.shtml for more info on their products.
TDi's run big boost compared to petrol so it would be fine for pressure. If the end tanks and pipework are of decent size then I would think a TDi FMIc would work pretty well. Good value for $$ also.
If you have the space I would go largest FMIC I could.
Chargecooler can be compact and very efficient but is more expensive.
regards
bill
idea of using the golf TDI FMIC (it's huge)
Timbo - IMO - I'd be a little concerned about fitting another radiator in front of your existing ones. Remember you have engine radiator and aircon already there. If you bung another one in front of those two, you will heat up the air before it reaches them. Bear in mind that you are already planning to increase the engine power significantly and therefore increase how much your existing radiator has to dissipate. The only way for it to dissipate more heat (for a given airflow and ambient temp) is for it to run hotter...therefore your engine too potentially. It also depends on your driving style though - maybe not an issue for a quick squirt & road use (but then stock intercooler ok anyway?) - big issue for track use I guess.
You might get away with it - you need to work out how many kW the intercooler has to dissipate, air flow through it and therefore how much hotter the ambiant air will be. (only few degrees @ speed?) :confused:
Personally - I would go for a better SMIC - maybe with a simple water injection mod.
Also - I believe TDI's are more efficient engines, therefore less heat for the radiator to disspate - so FMIC makes more sense(?)
Peter
PS: Bill - have you run your car hard in the warmer weather yet? Do you notice the engine temp go up at all?
It's interesting the FMIC kits are sold by Forge and Star - surely if there was that big an impact on the radiator temp they wouldn't bother? At the end of the day i can't see a SMIC being anywhere near as efficient, due to much smaller surface area than the FMIC and less airflow.
As the air whips through the FMIC can it really heat up that much before it hits the rad? The rad in the leon appears to be damn efficient from what i can tell..
Have a gander of this pic of the star performance conversion...
ibizacupra
29-05-2003, 12:28
Originally posted by PeterS
PS: Bill - have you run your car hard in the warmer weather yet? Do you notice the engine temp go up at all?
No measureable difference in running engine water temps at all. Not expecting them either.. my pre-rad is relatively small and sits forward of the air-con and main rad.
http://www.badger5.demon.co.uk/bin/pre-rad-1.jpg
regards
bill
Cheers Bill & Timbo
As the air whips through the FMIC can it really heat up that much before it hits the rad?
Well, this is the bit I don't know, not having done the calcs:o. For road use, one would guess not; and Bill's answer suggests that the engine rad is coping well with the extra thermals. FMIC clearly would improve the intercooling a lot over a SMIC, but I'm still nervous about heating air/restricting it into engine radiator (hey maybe I'm getting too careful in my old age....:p)
Regs
Peter
max_torque
29-05-2003, 13:42
Don't fall into the trap of assuming that a "chargecooler" (air to water) is better than an intercooler (air to air) because, as discussed before, although water does have a specific heat capacity 4 times that of air, unless you drive into a lake, at some point your gonna have to reject the heat from the hot water back to the ambient air. however the thermal mass of the water will allow the low temp rad to radiate this heat over a longer period than with an intercooler, so for road driving they can be very effective.
Also worth remembering that the advantage of a small unit under the bonnet(due to air to water specific heat ratio's again) that can be packaged easily with short pipe runs, is reversed in the low temp rad that will need to be bigger than an equivilent intercooler. This is compounded by the fact that an intercooler's delta temp between air charge temp of say 130degC and ambient at say 15degC is large, but in a chargecooled system the water exiting the underbonnet exchanger can only be a maximum of your target air charge temp (say 50degC) so the low temp rad will have to reject the same heat flow with only a 50 - 15 = 35 deg C delta.
max_torque
29-05-2003, 13:56
Originally posted by PeterS
not having done the calcs
Peter
i'll save you the trouble
1.8T at 1 bar boost 70% compressor effic, 6500rpm in a 15deg C ambient, doing 50 mph, with an intercooler of 500mm by 250mm with 60% fin density and an 80% efficiency.
plenum air charge temp = 44 degC
engine intake air mass flow = 0.205 kg/s
Heat to air (in compressor) = 19.2kw
heat rejection from intercooler = 12.56 kW
ambient mass flow through intercooler rad = 2.04 kg/s
therefore ambient air temp exiting inetrcooler will be = 21.13degC
(an increase of 6.13 deg C on ambient air):p
Cheers max_torque...ok that's not a lot ;)
ibizacupra
29-05-2003, 14:14
I'm glad we have you on here Paul.... helps with the Maths. :)
Package size under bonnet is as large as can be made, but is as small as will fit.... if you get my drift. Not a lot of space in an Ibiza engine bay!
Small pre-rad and reusing washer bottle helps reduce the overall component count.
Tuesdays the day for my testing and remapping back @ Jabba, so we will have to see how it gets on now. More boost is planned if it can hold onto it Ok...
Need more.. The voices are telling me to do it.:devil:
Gut feel "butt dyno" says its stronger now already, and very consistent with its power delivery.
I am suspecting my current DV is'nt quite working as quickly as I would like, so I will try the old DV006 I have rebuilt (specially) and see if this helps dump faster.
Bill
Wow talk about some expert advice ;) Thanks - that's cleared up a lot for me!
I emailed Forge and they said:
"1. Do you do a FMIC kit for the Leon Cupra (03) yet? Cost? :)
Sorry we do not have a Front mounting intercooler
2. Does having a FMIC in front of the radiator cause the raditor to get significantly hotter - i.e. how much would you expect the air
to heat up as it travels through the FMIC?
This is dependant on the type of intercooler core used and specifically the vehicle in question ie is there a oil cooler or air con radiator already sighted in front of the radiator.
The intercooler will obviously have an effect but to what extent and whether it will take the OEM radiator out of its operational range is never known untill we do the development."
But from what i've read here it confirms my belief that ambient air temp hitting the rad won't be heavily effected by a FMIC.
So.. The question is do i go with a full ready built kit for loadsa-money or get the TDI150 FMIC and attempt to build the pipework myself? Cost difference is something like 5X the cost - the star FMIC is near a grand i think from memory - i can get the TDI FMIC for er.. about 70quid :) Pipework on top of that but i have a mental bending friend (Not Yuri Geller (sp?) before you ask).
Timbo - what do the TDI110 Leon's use? I assume not as big as the Golf TDDI150 - but you know it should fit(?). (unless you know the big Golf one will...)
Peter
Originally posted by PeterS
Timbo - what do the TDI110 Leon's use? I assume not as big as the Golf TDDI150 - but you know it should fit(?). (unless you know the big Golf one will...)
Peter
A very good question - and not a bad idea. Unfortunately i don't know a TDI110 owner off hand.. I wonder if my car dealer will lemme have a look? It may not be as big but prolly will suffice..
max_torque
29-05-2003, 15:57
I've got a couple of air to water chargecooler units sat in my garage, i can't remember how big they are compared to say Bill's. they might only be suitable for use in series with a std intercooler or similar.
I get a couple of pics if anyones interested?
(might even have a few Bosch electric water pumps floating around somewhere as well)
ibizacupra
29-05-2003, 16:21
Originally posted by max_torque
I've got a couple of air to water chargecooler units sat in my garage, i can't remember how big they are compared to say Bill's. they might only be suitable for use in series with a std intercooler or similar.
I get a couple of pics if anyones interested?
(might even have a few Bosch electric water pumps floating around somewhere as well)
Yep
I am interested in seeing them :D
Are they DIY ones or ProDrive ones... (like there's a difference :D)
Bill
Originally posted by PeterS
Timbo - what do the TDI110 Leon's use? I assume not as big as the Golf TDDI150 - but you know it should fit(?). (unless you know the big Golf one will...)
Peter
Not sure but I think it's pretty much the same as (and same place) as the 1.8T.
max_torque
29-05-2003, 16:29
Originally posted by ibizacupra
Yep
I am interested in seeing them :D
Are they DIY ones or ProDrive ones... (like there's a difference :D)
Bill
seem to remember they fell out the back door of Cosworth many years ago now!
(probably pace cores, welded into fabricated ally jackets / end tanks, not sure what the connections for air or water look like, but it would be easy enough to get then chopped around and re welded to suit)
i take a pic this evening
ibizacupra
29-05-2003, 17:13
Originally posted by max_torque
seem to remember they fell out the back door of Cosworth many years ago now!
(probably pace cores, welded into fabricated ally jackets / end tanks, not sure what the connections for air or water look like, but it would be easy enough to get then chopped around and re welded to suit)
i take a pic this evening
:D :p
Cool...
Nice one Paul..
regards
bill
max_torque
29-05-2003, 17:31
think it's a development escort cossie unit, when the car gained an extra chargecooler on top of intercooler
air inlet / outlet on oppposite sides, 2 water inlets, 2 water outlets on bottom, header cap / resevoir on top
ibizacupra
29-05-2003, 18:19
Compact wee beastie... integral cap and everything.
Hmmm.
Bill
put it in line with your current one and share the water feed (by this I mean parallel the water feed)? Might look cack, but sure to work better?
edit: even better...two pumps, two rads!:D
ibizacupra
29-05-2003, 22:09
Originally posted by PeterS
put it in line with your current one and share the water feed (by this I mean parallel the water feed)? Might look cack, but sure to work better?
edit: even better...two pumps, two rads!:D
You talking to me?
:p
You talking to me?
Oh yes.... ;)
So do you reckon there's any good reason why i can't use the TDI150 intercooler (so long as there's space to fit it on the car)?
It's obviously designed for a lot more stress than i'm prolly gonna put on it, so is it just a case of getting good piping made up?
and the obvious lack of cooling that your rad will receive
Originally posted by m0rk
and the obvious lack of cooling that your rad will receive
As dicussed tho, it's pretty small. Remember your not blocking the rad entirely, just adding a few degrees to the airflow...
maybe i'm imagining this intercooler to block the bottom 'scoop' in that case?
looking at the shape of the '03 & R bumpers recently the sealed bottom & air going in @ the front bottom (ooer) and up the face of the rad & out the grill I've been depicting this InterCooler to sit in the whole 'mouth' at the front of the car (not good)
be interesting if you're able to measure your coolant temps before & after while on the move accuratly to ensure that you're not killing the engine & also to have it proven by inlet temps both before & after the intercooler on stock & 'massive' size to ensure that it's not a waste of money
M
Yeah temps would have to be taken but it's pretty much taken as gospel that bigger intercooler results in lower inlet temps - the only question is the influence on the rad. Then again, there's plenty of cars out there with big FMIC on them, so there must be some point to it..
I'd have a careful look at seeing how i could offset the FMIC so that it didn't block the rad if possible, otherwise i'd just measure the temps and see how much the rad was affected. As suggested by figures above this doesn't look too bad..
Originally posted by dangel
Wow talk about some expert advice ;) Thanks - that's cleared up a lot for me!
I emailed Forge and they said:
"1. Do you do a FMIC kit for the Leon Cupra (03) yet? Cost? :)
Sorry we do not have a Front mounting intercooler
2. Does having a FMIC in front of the radiator cause the raditor to get significantly hotter - i.e. how much would you expect the air
to heat up as it travels through the FMIC?
This is dependant on the type of intercooler core used and specifically the vehicle in question ie is there a oil cooler or air con radiator already sighted in front of the radiator.
The intercooler will obviously have an effect but to what extent and whether it will take the OEM radiator out of its operational range is never known untill we do the development."
But from what i've read here it confirms my belief that ambient air temp hitting the rad won't be heavily effected by a FMIC.
So.. The question is do i go with a full ready built kit for loadsa-money or get the TDI150 FMIC and attempt to build the pipework myself? Cost difference is something like 5X the cost - the star FMIC is near a grand i think from memory - i can get the TDI FMIC for er.. about 70quid :) Pipework on top of that but i have a mental bending friend (Not Yuri Geller (sp?) before you ask).
I've spoked with Forge and they told me the same thing, but someone told me that they installed the TT 225 FMIC to their Cupra R, is this possible?
Originally posted by pablovi
I've spoked with Forge and they told me the same thing, but someone told me that they installed the TT 225 FMIC to their Cupra R, is this possible?
Anthing is possible.. it's just a question of
a: space to mount it
b: fixings to do so
c: pipework to plumb it in
Had a good look at the car tonight and I reckon it's no problem to get the FMIC in, just time and effort sorting the design!
Working on it!
:cheers:
Originally posted by m0rk
be interesting if you're able to measure your coolant temps before & after while on the move accuratly to ensure that you're not killing the engine & also to have it proven by inlet temps both before & after the intercooler on stock & 'massive' size to ensure that it's not a waste of money
M
You could do this data logging with VAG-COM.
A guy I know fitted a hefty-sized FMIC to his Corrado G60 and noticed that as well as lower charge temps, his oil and water temps were lower as a result of the lower in-cylinder/head temps.
I guess it's a matter of getting that magic balance right?
max_torque
31-05-2003, 11:02
Originally posted by Glenn
his oil and water temps were lower as a result of the lower in-cylinder/head temps.
EH?
sorry to say but adding better intercooling will atually increase water and oil temps!
although you will loose say 10deg of your charge temp, this is negligable compared to the 2000 odd degrees during combustion!. And because of lower charge temp you will have a denser charge so more fuel will be burned (more heat release), and the ignition will be advanced by the ECU, which means an earlier burn, so there's even more time for heat from the combustion event to soak into head and piston. Typically water temp is load and speed related, as heat comes almost entirely from cylinder head with maybe 10% from liner cooling in block, Oil temp is mosty engine speed related, with engine friction heating oil at high rpm, and piston temp heating the oil hitting the underside.
The biggest advantage of lower charge temps is atually an improvement in Brake specific air & fuel consumption, as the advanced ignition timing releases more work into the piston, and less escapes down exhaust at EVO. the lower exhaust temps then mean you don't have to chuck so much fuel in to stop your turbo melting!
ibizacupra
31-05-2003, 17:51
Originally posted by m0rk
and the obvious lack of cooling that your rad will receive
Why all he concern over the rad not getting airflow?
TDi's run them, running much higher boost (so hotter) and don't have temp issues.
Whether it can flow enough air for an IHI though is unknown.
If in doubt get a big purpose made FMIC
Bill
ibizacupra
31-05-2003, 17:58
Originally posted by max_torque
EH?
sorry to say but adding better intercooling will atually increase water and oil temps!
although you will loose say 10deg of your charge temp, this is negligable compared to the 2000 odd degrees during combustion!. And because of lower charge temp you will have a denser charge so more fuel will be burned (more heat release), and the ignition will be advanced by the ECU, which means an earlier burn, so there's even more time for heat from the combustion event to soak into head and piston. Typically water temp is load and speed related, as heat comes almost entirely from cylinder head with maybe 10% from liner cooling in block, Oil temp is mosty engine speed related, with engine friction heating oil at high rpm, and piston temp heating the oil hitting the underside.
The biggest advantage of lower charge temps is atually an improvement in Brake specific air & fuel consumption, as the advanced ignition timing releases more work into the piston, and less escapes down exhaust at EVO. the lower exhaust temps then mean you don't have to chuck so much fuel in to stop your turbo melting!
Paul.. whats your opinion on http://www.bethcutler.com/~swett/Manifold_Insulator.html this sort of thing?
An insulating gasket of sorts....
I run a phenolic 1/2 thick spacer on my 16v Jetta between the cylinder head and t'bodies, and it did significantly drop conducted heat temps from the inlet manifold (t'bodies on the jetta).
Thinking on my 20VT that a similar product would also have benefits.. heat soak when in traffic and switch off is very high, so I would hope it would help.
What do you think?
Worth me making some?
Bill
I'm with bill on this one... My only REAL concern is having enough cooling for the IHI! The Leon rad is very efficient anyway (hence they can happily put the air con rad in front). I'm going to have the bumper off and see if i can make the TDI150 rad fit with custom made fixings and piperwork. It seems silly to go with a 1000quids worth of kit when it's possible to make it up yourself!
max_torque
31-05-2003, 18:36
Upheat from coolant jacket temp of say 90 odd degrees can be significant , especially on NA engines that run with low intake temps close to ambient. On turbo's you have a higher air temp, so not such a great upheat, but it will still effect in-cylinder charge temeprature. Typically the effect is worse under low load conditions, where the airflow is slow and each fresh charge hangs in runners for longer. On the Bosch ems we insert thermocouples just upstream of the inlet valve to calibrate the cylinder filling model, and this upheat is a function of the delta between engine coolant temp, manifold air temp,and intake mass airflow.
adding an insulating spacer, or doing what the majority of OEMS are doing, and having a moulded plastic inlet manifold and plenum will help things.
you could also consider dropping coolant temp with a lower rated thermostat, worth something, especially on 5V engine which suffers from excessive cylinder heat metal temps due to lack of space for coolant in head. On my rally car i run with a 75deg top hose temp, but i you need careful monitoring of the piston / bore surface, as the production piston barrelling profile will have been optimised for a higher temp and hence larger diameter liners
TDi intercoolers are not usually that thick though. the frontal area may be big but the thickness could well be thin.
Originally posted by max_torque
EH?
sorry to say but adding better intercooling will atually increase water and oil temps!
I must say I thought it was odd but I've seen the evidence for myself as far as the lower temps (-10C coolant) are concerned. Perhaps it's something as simple as his (now) stone-cold inlet manifold acting as a heat-sink thus drawing heat away from the cylinder head and perhaps this is being passed on to the oil temp by a smaller delta temp across the oil-water heat exchanger?
I'm trying to put a viable theory to the effect we've seen. There were no other changes to the car in terms of boost level or timing or in fact anything else.
andycupra
27-04-2004, 18:40
A very good question - and not a bad idea. Unfortunately i don't know a TDI110 owner off hand.. I wonder if my car dealer will lemme have a look? It may not be as big but prolly will suffice..
Hi,
i liek the idea of the diesel fmic, as i have found that the previous owner of my car uprated the smic and it got rid of alot of the problems i am having. (he put standard smic back on before selling)
however im not really wanting to spend that much, the diesel one sounds like a very good compromise as i dont think i really need a flash one...
sure it could be done...
also cheaper maybe if 2 of us worked together on this?
probably see you at next cambridge meet as im only 30 mins away...
andy