Hey guys, im just wondering about something as I have had a look at different intercoolers for the FC, it seems that big front mouts are better for increase flow, but have lag, smaller uprated stock ones are almost as good and don\'t have lag cause of the smaller pipework, I was thinking if you could run both front mounted and top mounted, put have a vacuum acuated valve meaning for lower speeds it uses the top mount, and higher speeds switches to the front mount. I just thought of this as in my currently car (Mazda 323F with a GT engine) it has a VICS system that has a set of butteryfly valves in the intake manifold, which open or close depending if you want high torque or higher power depending on RPM, just thought I would ask if this had been done as it seems to make sense to have a larger IC at higher speeds, and the smaller but lag-less top mount for lower speeds.
Sounds complicated dude, more to go wrong too if actuators/solonoids fail. More weight and room needed for pipework, more likely to heat soak too with the extra alloy in the bay ;) Some run without an ic and inject methanol to keep inlet temps down, simple pipe from compressor to tb in that instance. If you\'re into reducing turbo lag porsche have variable turbine geometry which simply keeps the turbine a/r down at low engine speeds and the vanes enlarge to flow more at higher speeds - best of both worlds http://www.motortrend.com/roadtests/coupes/112_0606_2007_porsche_997_photos/vtg_turbocharger.html
Ah yeah, gotta love those variable vanes lol :) ok I just thought I would ask about it lol is there any way you can actually reduce the lag on a FMIC? I guess you might have to run higher horsepower to warrent 1 of those against just an uprated top mount?
Not necessarily, fmic = cooler inlet temps than smic, but with more boost volume to fill. Some run v-mounts which can put the intercooler in an almost horizontal position in the engine bay, this can reduce the length of pipework whilst having a more efficient intercooler (not blocking airflow to the rad).
Generally if you want less lag use a smaller turbo (maybe ballbearing gt), use smaller diammeter ic piping and less of it (routing), and a quality ic core. Manifold design also plays a part in it but it gets complicated here on :P I quite like a bit of lag, then bam the car takes off, old school and very simple: engine, turbo, and as little ancilliary crap as possible :D
Simple is always the best I guess lol I think I might just uprate the stock core when I get mine, plus change the IC pipework to ensure the best flow, what size pipework does everyone use? I know smaller diameter means a faster flow of air but can get restricted, larger pipes mean more volume, but slower flow causing lag
It makes no sence to do it as you get the worst of both worls instead of the best.
If your on the top mount at low speeds you get a problem with heat soak.
If you on the front mount at low speeds you have the lag
Than at high speeds neither should be a problem as there is enough air flow to cool the charge with either ic.
Ah ok lol that makes sense now lol I forgot that a top mouted IC also was basically a vent for the really hot rotary heat lol
A second shutoff throttle plate or large check valve could be used to hold pressure in the intercooler and pipe work, but still allow the pressure to be let off at the turbo. The only problem I could see with that, apart from controlling it, is that you will have \'stored\' boost in the system waiting to get through the throttle plates as soon you open them - could be a bit of a suprise. :spank
There are potentially other ways of cooling, but the current crop of ideas have been arrived at through much experimentation and calculation - they are the easiest, most cost effective and reliable ways to cool the charge.
If were talking random off the wall ideas for cooling, what about using the aircon systems refrigerant to cool a lengh of pipe down? (making a larger diamiter pipe that goes around the ic pipe) i know some people would say about the weight/extra drive on the engine but couldnt you drive this by an elctric motor? and would it actualy cool things down:Thumbs-up
Quote from: leonIf were talking random off the wall ideas for cooling, what about using the aircon systems refrigerant to cool a lengh of pipe down? (making a larger diamiter pipe that goes around the ic pipe) i know some people would say about the weight/extra drive on the engine but couldnt you drive this by an elctric motor? and would it actualy cool things down:Thumbs-up
Looked at this idea awhile ago - the amount of thermal exchange required would need a much larger aircon system, the result of this is that you would not gain anything worthwhile. I\'m looking at Co2 as the way forward....;)
well im glad im not the only one who gets these random ideas! Another one i got was cooling the fuel Now would that be of any benefit? :eek
You can get charge coolers from deamon tweeks that have a water cooled jacket around some pipes for the air, so a bit like an inline water filled intercooler, but they are expensive lol
Did RE Works do a PWR chargecooler kit or something? Sure I remember seeing some featured somewhere. I think the main drawback with a front mount isn\'t so much the lag, cos rotaries produce large volumes of gas anyway, so spool up a turbo fairly quick compared to a piston equivalent, but its the fact that the IC blocks air flow to the water radiator. So, your charge is being cooled very effectively, but to the detriment of the engine cooling, which is now suffering cos the radiator is recieving already-warm air from the intercooler. And we all know not to overheat rotary engines!
I suppose as with all these things, there are 2 ways to reduce the charge temperature going into the engine.
1) Is to cool it - with an intercooler, chargecooler, water/meth injection, and any other oddball schemes that you can think of
2) the other way is not to heat the charge up too much in the first instance.
Looking at where the heat comes from - there is some transferred from the hot side of the turbo, some from the act of compressing the gas, and some comes from heat pickup in the intake piping on it\'s way to the throttle body. By far the largest amount of heat comes from gas compression - so reducing the charge pressure will go along way to reducing heat. That means running lower boost. The same volume of air could be fed to the throttle by using a larger turbo on lower boost. The 2nd most significant heat comes from the turbo hot side. Use of non heat conducting materials like ceramics could help to reduce heat transfer, as will adequate cooling (oil and water cooling), maybe even using a dedicated rad for the turbo. Insulating the pipework should help reduce heat pickup in the engine bay, although it\'s entirely possible that the pipework may lose heat to the engine bay at some times - now where was that thermal imager ?!
Your right ive seen images of rx\'s under thermal cameras and there is an obvious glow at that side :Laugh I know if i had an FC id be playing a lot more with experimental things as they seem to have a little more room to manovour without bringing the engine to a dangerous level.
*RAMBLE*
Has anyone submerged a small intercooler in a very cold liquid so it would act like driving on a very cold day. That i supose is on a similar vein as flooding the area around the IC with refrigerant.
and what about having two smaller IC\'s in either of the oil cooler places and a oil cooler in the middle? colder oil would help keep the general temperature of the engine down, you could run a diferant thermostat to open up at a diferant point forcing the temp down as well. but i guess the above is a bit of an odd idea as from my understanding is that if you are going for power you require large diamiter pipes with the trade off being spool, Having all that pipework to connect 2 ic\'s at a large diamiter would cause a great deal of lag wouldnt it? and i guess you cant simply engineer a bottle neck to increase the pressure can you?
FC\'s have one large oil cooler mounted below the rad, so not practical. I think direct cooling using a stored gas charge is the way forward.
Apparently for drag racing a good perfomance boost is to spray the intercooler before the run with some of that cold spray that is used for sports injurys, spray that on the intercooler and it will cool the charge more effectivly cause the IC is colder lol :D
Quote from: leonHas anyone submerged a small intercooler in a very cold liquid so it would act like driving on a very cold day. That i supose is on a similar vein as flooding the area around the IC with refrigerant.
Pretty much a chargecooler. You would then need a rad & pump for that water to be kept cool.
Was thinking about a small nitrous jet hust after the I/C but that wouldn\'t last too long! :spank Still would cool the charge massively and do wonders for the fueling :D
Well as I come from the aircraft world we use several variations of getting any fluid cooled. The obvious is ram air and used whenever possible but only good at speeds. We also use fuel cooled oil coolers, fuel will always be cooler but we generally use this to cool gearbox oils. Air cooled fuel coolers whereby ram air or a \'induced air flow\' is used to cool the fuel and quite simply just ram air. Ram air is good at speeds and is very simply how the the cars rad and intercooler are cooled.
Could we used fuel to cool........yes we could but it does come with its draw backs as you need high tolerance couplings and more pipework for the flow and return and therefore a dedicated fuel pump but it is certainly something to explore.
As prof has already mentioned thermal efficiency, lagging etc then this area must never be overlooked as something as simple as £20 spent on lagging the downpipe and heat resistant spray will undoubedly give dividends in reducing heat. vents in the bonnets are not just for ram air to the coolers but they should also induce the flow of air from the engine bay and suck hot air out.
Heat will always rise but in a car you also have a lot of disturbed air so its very very important to fit those under trays as they are there for a reason and directing air is just one of them.
I think the idea of two intercoolers is in theory a good idea but the practicalities of devising control methods might become more complicated and therefore potential to cause problems. Where you mount the FMIC just does not have to always be at the very front, I know v-mounts have been mentioned but i am toying with the idea to mount the rad and intercooler together, seen it done before and as long as you have ducting from the front bumper, channeling the air, then this maybe an easier way to mount and less pipework. I am going to use 2 1/2" pipework on mine.
Going back to ducting and an aero engine. The entire engine is just a formation of con/di ducts that either increase pressure or decrease pressure to get the right velocity. Remember that if you increase pressure you increase temperature as well. quite surprised in a standard intercooler setup that the pipework is the same diameter. I would have thought that going from a pretty much standard 3" Bore cooler and dropping to a 2 1/2" would give you that much needed velocity of air but you would increase the pressure and temp in doing so. Its important to get the sums right, too many people go for bigger is better but not necessarily the case. it would be crucial to aim for a given BHP and work out the volume of air needed which would give you your intercooler size and that of the pipework to deliver the air. Quite hard for the average chap to work out.
Just to add after reading this that you could use fuel to cool the water as well but the last thing you want is the fuel to get too warm and also the risk of the two mixing if you have a failure. You would also have to be very care on just where and how you use fuel as a cooling fluid due to the risk of fire.
Occam\'s Razor is a law of logic (though it sounds like it should be a Goth band!) that states basically "Never look for a complicated answer when a simple one will suffice". Mazda kinda lost sight of this from time to time, and we have the rat\'s nest to thank them for!
It\'s all very well adding piping and cooling systems and valves and flaps to switch from one I/C to another, but the short version is that you\'re adding more things to go wrong. The basic air to air intercooler (or air to water charge cooler) is a very good compromise for the simplicity that it brings. Even with the idea of a chargecooler, you have to appreciate that you\'re just moving the thermal load to somehwere else in the cars\' systems, not actually removing it. Saving temperature from the charge there means the water cooling system is working harder elsewhere to compensate.
Adding pipes of aircon refrigerant all over the place just gives you another system to run and maintain. The effects would be far-reaching; worse fuel economy because you\'re driving another, not very efficient pump, increased residual heat due to other components being shielded from airflow by all the aircon gubbins, added weight from condensers, driers, etc. Nothing comes free with vehicles!
Compressed gas, like some drag cars and that have to spray cooling nitrous or CO2 or whatever is a good "free" way of cooling stuff cos the lines are relatively lightweight and narrow and thus easy to run and the system doesn\'t require significant power from the engine to run (just electrical charge to fire the foggers). But the cannister weighs a good deal and, once it\'s emptied there is no way of refilling it from self-carried means (ie from within the car) so it just becomes redundant weight.
On an (almost) related topic, one of our drivers once managed to run over a shovel that a track worker had left in the rail bed. It sprang up and pierced the oil-cooling matrix around his train\'s transformer (its shunting 25000 volts down to about 800, it gets HOT!). The resulting flamethrower of super-heated, high-pressure burning oil was a warming thing to behold, very pretty, but also downright scary! Ceratinly makes me think that the less relatively fragile fluid hoses I have in the same engine bay as red-hot turbos, the happier I\'ll be!
Phew. sorry, didn\'t mean to waffle on that long. Right, I\'m off for a gin now in the hope some of that ol drivel will make sense then!