Hey guys
Was thinking today whilst figuring out my intercooler and rad setup, what is it with RXs and V mounts, is V mount config more efficient ?
Mark
Light touch paper and run for the hills!!
I will say no, and there will be plenty of people that disagree :)
I think there are quite a few threads on the pro\'s and con\'s of v-mount rather than front mount. Personally the latter works best in my eyes.
Its a matter of preference sometimes and depends on what turbo you want to run, my topmounted intercooler has no lag, v mount would be slightly more laggy, front mount would be way more laggy, but if plumbed into a different turbo the airflow would be cooled better on a v mount and front mount, its best to check around, I don\'t really want an intercooler jammed up against my hot radiator and oil cooler blocking airflow lol
The main issue is around ensuring that the water temps are kept low, the FMIC sits in front of the rad and so you are getting hot (well warm) air onto the rad. A V-mount, in theory, ensures that both the rad and the IC get cool air from the front of the car. You could then argue that the angle that the IC sits in some V Mounts means that it doesn\'t get as much cool air as an FMIC so swings and roundabouts. Mine is a bit of an offset V-Mount with the rad laying almost flat on the underside of the engine and the IC at a similar angle to the original rad mounting, I do have two mig electric fans on the underside of the rad drawing air through the rad from the "V"
Hot air rises.....so the warm air from the rad will in theory just rise up and through the intercooler.
If you are worried about heat soak with the FMIC then make sure the ducting is done and put fans on the back of the radiator. When at stand still the fans will draw the air away and not into the intercooler. Having said that when you are stationary...what difference does it make?
I\'ve got a Feed FMIC and I\'ve not noticed any increase in lag over the SMIC. If anything I\'d say it spools the twins faster.
Theoretically you\'d expect more lag (longer and larger piping) but it doesn\'t seem to necessarily be the case in practice.
Quote from: AtomicRex;715379Hot air rises.....so the warm air from the rad will in theory just rise up and through the intercooler.
Again, this is only a factor when stationary, whereas in an FMIC setup (granted, done properly with ducting, fans etc this should be less of an issue) the warmed air through the IC is pushed onto the rad when moving. Again, it is a personal preference really there are pros and cons to either solution (IMHO the V-Mount is a better option from a cooling point of view), but there are probably more tuners out there who favour the V-Mount over the FMIC
My FMIC doesn\'t seem to have any real lag either, in fact it\'s a bit tricky keeping the damn thing off-boost (I\'m allegedly running it in :D). Surely the turbo and porting will have more of an effect on lag than a few extra cms of piperun?
The most important consideration hasn\'t even been discussed here yet....FMICs look double hard and are therefore clearly far superior to V-mounts :p
One of the reasons you only see them in Rx\'s is that they seem to have an abundant amount of space in front of the engine to make one fit. You certainly don\'t have that sort of space in an Evo or Scooby.
Quote from: m1tch;715310Its a matter of preference sometimes and depends on what turbo you want to run, my topmounted intercooler has no lag, v mount would be slightly more laggy, front mount would be way more laggy,
In the real worl I suspect you\'d notice very litle difference at all. Someone much, much cleverer than I once wrote some calculations based on the extra volume of air needed to fill the pipework, and the effect it would have on lag. The difference between something like an extra metre of pipework was microscopic. It\'s a common fallacy.
Have you tried all 3 setups on your car to be able to say?
Far, far more important is the design and size of the core.
Quote from: AtomicRex;715379Hot air rises.....so the warm air from the rad will in theory just rise up and through the intercooler.
Heat also radiates ;) So a rad close to an IC will heat the IC as well. Both of these facts of thermal movement are sort of irrelevant when the car is moving though.
Loads of diffeernt cars use V mounts - I\'ve seen them on S bodies, R boies, Supras, Corollas etc.
Like a alot of things, if done well they can be used to great effect. Ducting is key. If you don\'t duct it, you may as well not bother.
I had a V mounted generiec cheap eBay core that was SMIC size. When properly ducted, it was brilliantly effective. The only time I got heat soak was when sat queing for a track day. Same would have occured with an FMIC in close proximity to the rad.
Both are great methods (FMIC and V) - main advantage of the V mount is that, with an additional divider, you get the opportunity to tune how much flow goes to each component.
I decided to go V with my engine bay re-jig, but with a larger core, simply because I founf the packaging a little easier.
Quote from: Nik da Greek;715383The most important consideration hasn\'t even been discussed here yet....FMICs look double hard and are therefore clearly far superior to V-mounts :p
Case closed!
LOL.... when it comes to V-mount and hot air rising from the rad up in to the IC... simple solution... hit the AC button & the cooling fans go in to warp drive and pull the air down & under the car away from the IC ;) The other thing you can do (which I am going to be doing with new engine setup) is put a devider plate to split the V in to 2 sections... one designated for the rad & one for the IC.... all problems solved ;) also using polished pipe work helps with heat soak slightly as it reflects the heat slightly, and using something other than alloy helps again as alloy pipe soaks up heat like a sponge does water :)
Jono
Whats AC ?!:Giggle
Never really got my head around the lag thing, im sure there is a difference but would imagine you would have to be a driving god to notice the effects between v, front and top mount set ups.
I am afraid for me and my limited tech ability a v mount makes more sense as you have cold air flowing to both rad and intercooler in equal quantities or there abouts.
but surely the amount of air coming in from the opening in the nose is the same, so with a vmount you get 50% or the air at ambient temp to the intercooler, and then 50% of the air to rad at ambient temp to the rad. With a front mount you get 100% or the air to the intercooler at ambient temp and then 100% of the air at an elevated temp to the rad (assuming good ducting for both setups). whilst you want the intercooler to be as cold as possible at all times to maximise charge temp, the radiator has to ensure that the engine doesnt get too hot, so if the elevated air passing over the rad gives sufficent cooling then the higher temp caused by the front mount isnt really an issue. there will be a presure drop across both the rad and the intercooler affecting the cooling air, and in the case of the front mount this will have a greater effect as all the air has to go through both, (similar to resistors in series (front mount) and parrallel (vmount)). If the pressure drop across the intercooler is too great, then it will negatively affect the airflow through to the rad in an FMIC which may well affect engine temps. if this is the case then re-arranging to a vmount will help loads, as it will give more airflow to the rad- bt surely it isnt really a case of \'vmic being better than fmic\' as the root cause is a rubbish IC design?
So much \'hot air\' talked about intercoolers ! :Laugh
Front mounts can work well - provided the ducting is good, the airflow through the intercooler is good (this is important, as you want a good rate of airflow through the radiator, and as some have found with meshing in front of the intercooler, it\'s easy to upset the airflow and reduce the effectiveness of follow on components). There will be some heating effect when the car is stationary - but this can be helped with fans (electric or otherwise).
V Mount setups can also work well - again ducting is important. Heatsoak at idle must be less than with front mount setup, but will still happen. Turbo pipework can be kept short with potentially less bends and hence lower pressure drops than with a front mount
Then top mounts - not an option for the FD guys, but they were standard on the FC. I know everyone calls them \'interwarmers\' - and they certainly do suffer from massive heatsoak problems in stationary or slow moving traffic - but at speed, with ducting (bit of a theme this ducting) they perform suprising well. A lot of well paid engineers came up with these designs - so they won\'t be rubbish until you start pushing things beyond stock.
I\'ve got real figures from my ARC intercooler replacement verses the stock intercooler - and the improvements are marked - but I would not consider a top mount for drifting or any activity where the car is sat idling for any length of time and then expected to perform as the heatsoak will cost you valuable horsepower.
As for pipework lengths, bends and stuff - there is an effect, and I\'ve seen some of the calculations - they are often done assuming static air in the pipes - which is far from the real world. It has to take some finite time to repressurize the pipework - anyone with a comination boiler with a filling loop can see this for themselves -it\'s exactly the same principle.
One other thing that\'s worth considering - protection for the intercooler / radiator from incoming stones and debris - a front mount setup will expose most of the intercooler to oncoming crap - by definition the V mount setup will present less frontal area to oncoming crap, and also because the surfaces are at an angle - they will tend to deflect debris.
Quote from: marco;716840but surely the amount of air coming in from the opening in the nose is the same, so with a vmount you get 50% or the air at ambient temp to the intercooler, and then 50% of the air to rad at ambient temp to the rad. With a front mount you get 100% or the air to the intercooler at ambient temp and then 100% of the air at an elevated temp to the rad (assuming good ducting for both setups). whilst you want the intercooler to be as cold as possible at all times to maximise charge temp, the radiator has to ensure that the engine doesnt get too hot, so if the elevated air passing over the rad gives sufficent cooling then the higher temp caused by the front mount isnt really an issue. there will be a presure drop across both the rad and the intercooler affecting the cooling air, and in the case of the front mount this will have a greater effect as all the air has to go through both, (similar to resistors in series (front mount) and parrallel (vmount)). If the pressure drop across the intercooler is too great, then it will negatively affect the airflow through to the rad in an FMIC which may well affect engine temps. if this is the case then re-arranging to a vmount will help loads, as it will give more airflow to the rad- bt surely it isnt really a case of \'vmic being better than fmic\' as the root cause is a rubbish IC design?
Why would 100% of the air through the front suddenly divide itself to 50% for the intercooler and 50% to the rad? The volume of air is still the same surely, just now passing through two things rather than one?
Quote from: jetpilot;716881Why would 100% of the air through the front suddenly divide itself to 50% for the intercooler and 50% to the rad? The volume of air is still the same surely, just now passing through two things rather than one?
I think Marco\'s referring to the fact that in a vmount the air coming in through the front can only go through either the intercooler or rad - not both, so there will be a division of the air - arbitarily 50% going to each device.
Quote from: Prof;716894I think Marco\'s referring to the fact that in a vmount the air coming in through the front can only go through either the intercooler or rad - not both, so there will be a division of the air - arbitarily 50% going to each device.
Sorry, my tiny brain cant accommodate that! :Giggle
What difference does it make if there are two things in the path of air flow, its still the same airflow, but going through both? Its not dividing but both will get the same force?
P.S Not being obtuse or argumentative, but just cant my head around that!
yeah, sorry i should have made it clearer- with a front mount all the air goes through the intercooler and then all goes through the rad, with a vmount some goes through the rad and some goes through the intercooler, but it will be roughly the same total amount of air between the two varients. if anything the vmount will flow slightly more air due to less of a pressure drop, but i couldnt say how much this will affect it. if you have the same amount of cooling air then you have roughly the same cooling capacity. I think...
Well, this has cleared that up then :flamed
Well i had a vmount, but i also guess a lot comes down to budget too! You will need a rad with a v mount, a front mount needs just the intercooler and personally i would say the average user (track work/road) would notice little to compare between the two.
Quote from: marco;716909if anything the vmount will flow slightly more air due to less of a pressure drop,
Sorry to be pedantic, but if there\'s less of a pressure drop, it\'ll flow
less air :3Confused Air moves from high pressure to low, so what you want is the air to hit a wall and build up massive pressure against it that then forces itself through the holes in that wall.....rather like the upright face of a front mount, in fact :rolleyes:. What you
don\'t want is the pressure wave building up so far back from the initial interruption of the IC face that it starts spilling out through other routes and lessening the pressure against the core. Hence the ducting.
I think for about 98.9% of us it\'s down to fashion, either a decent FMIC or V-mount will be perfectly adequate for all your needs in anything less than outright competition circumstances. Fit the one you like the look of best :Giggle
Quote from: Nik da Greek;716927I think for about 98.9% of us it\'s down to fashion, either a decent FMIC or V-mount will be perfectly adequate for all your needs in anything less than outright competition circumstances. Fit the one you like the look of best :Giggle
that\'s why i chose v-mount :Giggle
looks better imo and also sounds fancier :p
i didnt have much of a plan for the car just fast road car but now, seeing as it drinks so much, highly thinking of making it more of a track toy, just need to add bigger tub then away we go... oh need to add working car 1st lol
Quote from: Nik da Greek;716927Sorry to be pedantic, but if there\'s less of a pressure drop, it\'ll flow less air :3Confused Air moves from high pressure to low, so what you want is the air to hit a wall and build up massive pressure against it that then forces itself through the holes in that wall.....rather like the upright face of a front mount, in fact :rolleyes:. What you don\'t want is the pressure wave building up so far back from the initial interruption of the IC face that it starts spilling out through other routes and lessening the pressure against the core. Hence the ducting.
ok. lets take away the rad and intercooler, and instead repalce the them with solid plates. all the air flows through the opening in the bumper, hits the plates and then, goes nowhere. but if you measure the pressure difference between upstream and downstream of the plates, the difference will be big. big pressure difference across the plates= little flow.
now lets take the plates away and replace them with chicken wire. the air comes into the bumper, flows straight through the mesh, and then goes where ever (under the car, out of bonnet vents etc) there will be pretty much no restriction to flow, but measure the pressure upstream and downstream and there would be virtually nothing. small pressure difference across the mesh= good flow. pressure drop basicly gives an value to the amount of restriction.
the restriction is caused by the geometry of the intercooler/ rad, so in the case of a fmic, you have the pressure drop caused by the intercooler + pressure drop caused by the rad (you have to add them together, similar to resistors in series) in a vmic the air can go through either IC or rad (so similar to resistors in parallel) continuing with the electrical stuff, the freestream (jsut ahead of the car) energy/head/staganation pressure is basicly a function of the car speed and equates to voltage and the amount of air flowing through the system is current. V=IR, re arranged gives I (flow through the system)= V (freestream energy) / R (pressure drop across the system). so by reducing the pressure drop you get greater flow through the system for a given amount of freestream energy.
i hope that makes sense, the beer is starting to take effect. :guinness:Hammer
In fact the cooling has less to do with the pressure and more to do with the temperature differential between the incoming cold air and the hot air/water inside the intercooler/ radiator. The difference allows heat transfer between the 2 - the greater the difference the more transfer occurs. Keeping the air flowing keeps the differential high and ducts away the warmed air to keep the system performing well.
It\'s why blowing on something cools it down much more quickly - it\'s not the fact that your breath is cold - often it isn\'t, but it\'s the fact that your blowing causes a flow and draws in the cold air with it to provide better cooling.
Quote from: marco;716934i hope that makes sense, the beer is starting to take effect. :guinness:Hammer
Nope, sounds suspiciously like boIIocks to me :rollin
Quote from: Prof;716937It\'s why blowing on something cools it down much more quickly - it\'s not the fact that your breath is cold - often it isn\'t, but it\'s the fact that your blowing causes a flow and draws in the cold air with it to provide better cooling.
Really? I thought it was because the escaping heat energy from whatever you\'re blowing on has reached a point approaching saturation of its thermal efficiency in the surrounding air (which really isn\'t a good conductor) and your blowing imparts enough energy locally to remove the point of saturation and allow more energy to escape from the object?
Quote from: Nik da Greek;716955Nope, sounds suspiciously like boIIocks to me :rollin
if you could point out where i am going wrong then i would be grateful....:p
Quote from: Prof;716937In fact the cooling has less to do with the pressure and more to do with the temperature differential between the incoming cold air and the hot air/water inside the intercooler/ radiator. The difference allows heat transfer between the 2 - the greater the difference the more transfer occurs. Keeping the air flowing keeps the differential high and ducts away the warmed air to keep the system performing well.
It\'s why blowing on something cools it down much more quickly - it\'s not the fact that your breath is cold - often it isn\'t, but it\'s the fact that your blowing causes a flow and draws in the cold air with it to provide better cooling.
It does work...but only on something that emits water. So when we sweat the wind causes the evaporation. Likewise we blow the coffee because the molecules that are bouncing up and down at the top of the surface are blown away.
Doesnt work on metal though. But would do if you used an intercooler spray
Quote from: AtomicRex;716970It does work...but only on something that emits water. So when we sweat the wind causes the evaporation. Likewise we blow the coffee because the molecules that are bouncing up and down at the top of the surface are blown away.
Doesnt work on metal though. But would do if you used an intercooler spray
Actually blowing on hot metal objects does cool them (that\'s what CPU fans are for in your PC), because as someone has twigged - you are replacing the heated air in contact with the metal with cooler air that will more readily accept the heat. What you\'re thinking is heat lost by evaporation, rather than heat lost through convection/conduction (radiant heat loss will not be significant in comparison)
Quote from: AtomicRex;716970Doesnt work on metal though. But would do if you used an intercooler spray
So air passing over metal does not cool it!? :rolleyes:
Quote from: DRAGON;716977So air passing over metal does not cool it!? :rolleyes:
Nope...not in my world!
Quote from: AtomicRex;716978Nope...not in my world!
How do ICs work then?
Quote from: DRAGON;716979How do ICs work then?
Magic ;)
I was being sarcastic!!
I didnt quite mean what I was saying...of course the metal radiate heat...otherwise our houses would be a tad cold....All I was meaning is that blowing cold air over it wasnt the most effective way of cooling them down.
Anyway...we spend all of this time and energy debating the best way of putting the coolers....and forget about the LIMs....had a car in the other day that the LIM was too hot to touch! kind of makes the IC a bit pointless!!
I dont think you were being sarcastic, just stupid.
Quote from: DRAGON;716981I dont think you were being sarcastic, just stupid.
Thanks... :)
Quote from: Prof;716849I\'ve got real figures from my ARC intercooler replacement verses the stock intercooler - and the improvements are marked - but I would not consider a top mount for drifting or any activity where the car is sat idling for any length of time and then expected to perform as the heatsoak will cost you valuable horsepower.
Can I ask to see the figures you\'re talking about? Not Disputing what you\'re saying but I\'d love to see some evidence of the improvement an ARC top-mount might make.
Quote from: Prof;716972Actually blowing on hot metal objects does cool them (that\'s what CPU fans are for in your PC), because as someone has twigged - you are replacing the heated air in contact with the metal with cooler air that will more readily accept the heat. What you\'re thinking is heat lost by evaporation, rather than heat lost through convection/conduction (radiant heat loss will not be significant in comparison)
As previously mentioned, its the differential temperature which is the driving force for heat transfer. So a greater dT between objects will permit a greater heat flow from one to t\'other.
The other factors in heat transfer (in no particular order) are:
1) Area
2) Heat capacity of the transfer fluid
3) Thermal conductivity of the object
4) Thickness of the object
5) Various fouling co-efficients
Intercooler are actually (in relative terms) very poor heat exchangers - the reason being that air is not very good at transferring heat either to or from objects. On of the reasons why those big cooling towers you see at power stations are so big - to overcome the inefficiency of the process.
Just my two penneth - spend a lot of time working on heat exchange problems at work!
graeme
Quote from: soldave;717132Can I ask to see the figures you\'re talking about? Not Disputing what you\'re saying but I\'d love to see some evidence of the improvement an ARC top-mount might make.
These figures are taken from the emanage / temperature display which I built - there\'s a project thread on here somewhere for that, but suffice to say it reads the intake air thermistor (the one in the throttle inlet) and reports the temperatures in deg C on the display. I built it just before switching the intercoolers - so I got some details from the stock intercooler for comparison purposes:
Ok - some figures I have - these are the range of temperatures I took from the engine Intake temp sensor. In the first 2 cases, the car had been on idle for some time prior to the runs - so there is a lot of heat already in the system. Ambient temperature was high 20\'s (80+ Farenheit).
I took readings from the car with the stock intercooler and Rad:
The temp range for the engine inlet sensor 52.2 - 63.6 (125 F - 146F), temp at max boost (11.7 psi) was 54 C (129F). The inlet temps drop on higher boost because of the airflow, but after coming off boost and into trafic they went up to the max figure !!
With the ARC intercooler and stock Rad:
Almost identical conditions to the last run - e.g. idling for a long time, followed by the same run on the same bit of road :
Temp range was 47.6 - 54.1 (117 F - 129 F), temp at max boost (8.6 psi) was 50.9 (123 F).
Then I took some runs with the rad changed as well, these runs were from \'cold\'
Temp range was 30 - 46.2 (86 F - 115 F), temp at max boost (10.4 PSI) was 43.8 (110 F).
The ambient temperatures were give or take 1-2 degrees C on all these runs, the difference in the last run was it was from engine cold, with boost being built after 10 mins of running - water temps upto 80\'s ( >176 F )
I\'m in no doubt the ARC intercooler is more resistant to heat soak, brings temps down much quicker from standing heat, and is returning running temps at least 10 degrees C lower than the stock intercooler. Changing the rad also helped with heatsoak.
Nice figures. How did you take measurements from the intake temp sensor? You using a datalogger or aftermarket EMS?
Wondering if the ARC TMIC might be a decent investment for me to go alongside the Ron Davis radiator I have. Would ideally get a V-mount but am really unsure of the work involved in fabricating one of those.
Quote from: soldave;717325Nice figures. How did you take measurements from the intake temp sensor? You using a datalogger or aftermarket EMS?
Wondering if the ARC TMIC might be a decent investment for me to go alongside the Ron Davis radiator I have. Would ideally get a V-mount but am really unsure of the work involved in fabricating one of those.
I can log temps with the emanage, which piggy backs onto the IAT and water temp signals, but in fact I found the emanage loaded the outputs enough to cause rich running - so I built a buffer amp for it. Seeing as I had the signals available, I have a small microcontroller that converts the temp signals to a serial datastream for display on an LCD - which is accurate to about 1-2 degrees. So basically I am using the stock temp senders the ECU uses, but just hijack the signal.
This is the unit in action:
http://i112.photobucket.com/albums/n197/dcr1tch/temp_display/DSC00312.jpg
http://i112.photobucket.com/albums/n197/dcr1tch/temp_display/th_MOV00316.jpg (http://s112.photobucket.com/albums/n197/dcr1tch/temp_display/?action=view¤t=MOV00316.flv)
That\'s pretty cool. You fancy making me one of those ;)
Ok,
I\'m no genius but physics A level teaches you that the bigger the pressure difference flowing through the smallest path between the 2 areas measured means the greater the volume of air flowed, therefore the higher the cooling effect across whatever the air passes through, be it rad or ic, so making the biggest pressure difference is the best??????:confused:
Quote from: slater1982;718068Ok,
I\'m no genius but physics A level teaches you that the bigger the pressure difference flowing through the smallest path between the 2 areas measured means the greater the volume of air flowed, therefore the higher the cooling effect across whatever the air passes through, be it rad or ic, so making the biggest pressure difference is the best??????:confused:
Biggest pressure difference would be by having an I/C that had no holes through it, and that wouldn\'t cool at all. You need to balance the pressure difference with maximising flow through - you want maximum VOLUME of air reaching the front of it, and enough pressure difference that it flows through quickly enough to take the radiated heat away. One way to do that is to reduce the pressure on the engine side - V-mount and a properly vented bonnet will likely do that (reducing pressure) better than a front mount (but the trade off is reduced VOLUME of flow through the I/C because the air is split with the rad).
All about compromises, which is why no one can agree on what is \'best\'.
From what I\'ve seen, the biggest downside to a V-mount is that when you take an off track excursion you end up filling the space between rad and intercooler with grass and mud.
kind of going to open another can of worms what about the people doing v mounts but having the intercooler on the bottom i have seem a few cars doing this