Importance of Intercooler Dimentions

[darkstar]

I was thinking of getting a new intercooler, while the rest of the car is being assembled.


I have came across a BAR AND PLATE core that measures 700x300x130.

Yes about 5" thick!

Im wondering whether his is true overkill, and if a lot of lag will be significant.

The cooler is to go onto a VL turbo, with about 12-14psi maximum.

I have heard that if the intercooler is THICKER, then it has less pressure drops, and is also more efficient.

The intercooler ive got on, about 600x270x65 is doing fine, but there always could be better.


When people say fitting a larger cooler reduces throttle response and also increases lag, is this because of the pressure drop in the cooler itself? or is it related to the dimentions of the cooler, as in too thin.

While the lack of fiances prohibit the making of the car into a wepon, i thought that if it could be picked up as a bargin, why not :)

here is a picture of the cooler.

I think it has a 3" outlet.

http://board.performanceforums.com/forums/attachment.php?postid=178316

[cadet]

Originally posted by darkstar


The cooler is to go onto a VL turbo, with about 12-14psi maximum.

When people say fitting a larger cooler reduces throttle response and also increases lag, is this because of the pressure drop in the cooler itself? or is it related to the dimentions of the cooler, as in too thin.

While the lack of fiances prohibit the making of the car into a wepon, i thought that if it could be picked up as a bargin, why not :)



it seems a good core but i think a bit big for your needs unless you upgrade the motor later on. the lag comes from the volume of a larger cooler, it takes longer to fill the space with air.

[GTSBoy]

And the amount of additional lag will be so small that only a superhuman could detect the difference between that core and one that was 3" thick.

Usually the only time it is valid to bitch about increased lag is when you go froma system with no IC or very short plumbing (like a top mount) to a front mount with large bore piping.

I put a large FM on my R32 with the long return pipe and all...and noticed no more lag at all.

cheers

[[SPESHAL]]

I tell ya I noticed more lag from in my car.
But that is going from a TMIC with about 30 cm of piping to a FMIC with about 3m.

[Zac]

Those EJ20s seem to have the longest intercooler piping once you have fitted a FMIC. cos the throttle body is on the rear I suppose.

GTSBoy,

As for being thicker meaning less pressure drop (in the original post), wouldn't the total area of the air passages decide how much pressure drop there is? ie, get the total area of the air passages in the intercooler to equal or greater than the total area of the inlet piping which in this case is area of a 3 inch circle.

Why do people use really thick intercoolers, woldn't more frontal area be preferable? I guess space is a limitation there.

[darkstar]

I looked at it from this prospective.

Any radiator like device benefits from increase fin area. There is only so much area you can put into a sized core, then you start to get fitment and mounting problems.

The air passages for the intercooler are longer if the core is thicker. the fins go all the way to the end of the intercooler, so yo will get more fin area in a thicker core, than in a longer core i would say.

also the cooling properties are enhanced because of this, and there will be less pressure drop because the channels are thicker and not longer.

But then again, its all come to how practical a core size is :) The core that i have does its job pretty well, but i was thinking about going a highflow with about 18psi or so if i can afford it.

But for 14psi, would this core be overkill?

[Cplus]

Zac, Zac, Zac,

You shouldn't be asking silly questions like that :). Intercoolers "cool" the air by removing heat from the air. Thicker cores make for more mass of metal - hence greater heat absorbing potential. On a "real" street car It's all about how much heat the core can remove from the boosted air. Passing air over the core keeps the core cool, not the air. When the core is heat soaked then it doesn't work, usually about the time you're off the gas anyway.

You need to work out what mass off material you need to remove x amount of kilowatts of heat from the air, then calculate how much surface area will be required to cool the metal in x amount of time. I'm sure they're a formula around for it somewhere in one of my thermo books....

[Zac]

Cplus now thats why you are the engineer :)

but what if you can cool the core (with surface area) before it even gets heat soaked? or is that waste of cooling air?

[GTSBoy]

Ah, well you see we have several competing problems and you need to find the optimum combination of all the effects.

The bigger the core is internally the less pressure drop the intake air will see. So bigger is better for retaining boost. But if you get to be real wide (in either direction from the point of view of incoming induction air) then you can find yourself having distribution problems and not using all the core effectively anyway. Careful end tank design is required, and what is best for even flow might not be the most obviously smooth design either.

On the outside of the core, the thicker it is, the harder it is to get ambient air to flow through the fins, so for any given car speed a thicker core will have less air flow through the same frontal area. And so a thicker core will have reduced ability to shed heat to the ambient air. In addition to this, the increased amount of time that the ambient air spends in amongst the fins (due to slightly reduced air speed and the longer path length) means that it rises to a higher exit temp out the back of the core which has the effect of artificially keeping the core temp higher than it could be if it was thinner.

So in this case the core wants to be as thick as you need to keep internal delta P down without making the external delta P too big.

I will state that I do not know, nor do I care to perform the calculations to determine what sort of thickness is optimum, or whether the optimum is a narrow range of thickness or encompasses our whole range of possibilities (ie 2" thick out to 6" or so).

Clearly, as Zac said, the more mass you have that can effectively contact the induction air then the more heat you can pull out of the air and into a (not heat soaked) core. The heatsink effect gives us the most benefit in boost on - boost off driving, but any core which is subjected to solid heat input like ona race track needs to have good steady state performance too.

And to answer Zac's question more specifically....the tubes are internally finned and so have more frictional effect than an equivalent open area of pipe, so your core area needs to be somewhat more than the pipe area to avoid having too much pressure drop. Again without doing any calcs I would guess that it might have to be at least twice as much open area as the pipes.

cheers

[awill4x4]

I looked at the photo and my only thought is "what a shocking waste of an intercooler core" That end tank design is terrible, all square corners with no effort to maximise flow. I hope it's supported by more than those angle brackets on top, as I guarantee that they will fracture where they are bent to 90 degrees. They also shouldn't be welded directly to the core top plate, after a while, with vibration it's possible to tear that plate out of the header plate. A compensation plate should have been welded on to an extra dress plate, then if there's any problems it will only tear away from the compensation plate and not damage the cooler core.
I'd like to see where the inlet and outlet pipes are located and if any attempt at air deflection has been used, but looking at that I very much doubt it.
Everybody take note, "this is the way intercooler endtanks SHOULD NOT be made"
Regards Andrew.

[darkstar]

The intercooler outlet inlet are both 3" and are behind the endtanks i belive

Ie: they are out of view.

here are some pictures of another intercooler, NOT THIS ONE, fitted to a Vl turbo.

http://www.axg.net/gg/ct/images/chill/cooler.jpg

http://www.axg.net/gg/ct/images/chill/cooler2.jpg

http://itftkd.hypermart.net/chill_wheel2.jpg


What are your comments on this?


Also how should endtanks be manufactured, and what is an example (pic) of? Im interested as i wouldnt mind making my own intercooler to learn and cut down on costs.

[GTSBoy]

Well the tanks on that new one are OKish, as they have tapering from the inlet to the dead corner of the tank. I would think it might have been better to have the inlet and outlet pipes angle "up" into the core...basically where they are now, just pointing up into the tank a bit. But if you are going to do that then you can make the sort of tank that is wider in the middle and tapers to both ends and all sorts of goodies like that.

Back to the original core. Having inlets on the back, and a fat core will definitely waste the back portion of the core because there will be prerfential flow through the front of the core, unless extreme efforts are taken inside to control the flow.

cheers

[Ustasa]

Your optimal intercooler would have a large as possible frontal surface area and the thinnest cross section which will not cause a significant pressure drop. This can be further optimised by placing end tanks on the ends which would give the most amount of air flow channels which the heated air passes through.

[GTSBoy]

Geez,

That's a nice succinct way of saying what I didn't manage to do in dozens of lines over two or three posts Ustasa!!!

cheers

[awill4x4]

Darkstar, do yourself a favour and have a look at http://are.com.au/index.htm
It's after having close looks at what they produce that makes a professional welder want to try and produce similar results.
I've been a Tig welder for a lot of years now and I'm not easily impressed but their work just blew me away. The welding machine they use (Miller aerowave) is the best machine in the world and is used for the aerospace industry. I was so impressed, I priced one here in Melb. List price is $18,000. It was too rich for me so I bought the 2nd best machine in the world and had it imported from Japan and as they wanted one here in Oz to showcase their machine they gave me a good deal.:)
ARE's work is the equal to anything around the world it's just a pity their in Qld, as I wouldn't mind learning some more welding tricks from them.
Regards Andrew.

[OVL087]

darky
pls do as awil4x4 said. have a look at A.R.E , Richard is a good mate of mine , and if there isnt enough info on his page then send him a mail (or i might go there for ya) he knows an undecribeable amount about this type of shit.:)

[darkstar]

Great page ARE is... learnt a lot about the cooler and flow side of things.

Cleared up a lot of info :)

[dabigbolf]

hey,

what sort of price would u pay for an intercooler like the one on the VL commodore. That looks "PHAT".

[dabigbolf]

hey,

what sort of price would u pay for an intercooler like the one on the VL commodore. That looks "PHAT".

[darkstar]

well if i was to intercool my vl with a bigger cooler, i would want performance over looks.

Why bother stuffing up your car, making it crap to drive with all the lag, with a 'full sick habbibi lebo job' intercooler hanging so far to the ground that half of the core is damaged, rendering it useless and pinging the crap out of the engine.

Ive sprayed my cooler black, for the reason that its a sleeper and its also stealthy.

I get no joy in pleasing the dickheads out there who judge people by their cars and how good their particular example is. If it drives well, ill ride in it and enjoy it as much as possible. I find it sad yet extremely humorous seeing all the wanks down chapel street pumping their crap tunes and showing off the neon lights, while letting off bovs/coolers to be seen and heard. Little to they know that the car looks like trash, the driver looks like a wanker, and those over showing off and those with true car know-how look at these poor sods as the wanker of the day. hehe, also very funny when these stereotyped people get pulled over by the motobike police force, but at least they are fair, because they do pull up rust buckets, but also pick on the P platers, who are 90% of chapel traffic friday and saturday nights.

Anyway, back to coolers, while looks can be attained, i think the focus should be more so on the performance aspect. An intercooler serves to cool the charge air therefore increasing the boost potential and also the performance of the car, which is why turbo and even supercharged cars are intercooled. Having said that, looks are a side thing, but generally speaking if most of the coolers are low hanging and really visible down low, they are either mounted to low or just too big for the application.

Bigger cooler != bigger performance.

Its all about optimisation. Personally i think the ideal core for the RB nissan engines is about 600x300x75, like the GTR cooler. If putting a 800x450x80 core was the most optimum for GTR feel and performance, i think Nissan would have gone for that option if it was economically viable and performance effective.

Long post i know, but when it flows it just gets punched through :) Enjoy!

[dabigbolf]

Hey,

If u were to ask most people who drive turbos running a bit of boost i think most would say that they like the attention they get, when driving past someone on the footpath.

I say, if it doesn't whistle it ain't a missle.

If everyone wanted sleeper type cars, the roads would be a very boring palce. U are pretty much saying that making a car look good is a waste of time. This would mean, no sick spray jobs, no rims, no loud exhausts, no BOVS, nothing, just boring cars. Why not buy a VOLVO.

I understand your problem with loud music, thats a whole different scene. BUt when u start bagging front mounts, which can set a car a Lite'", its a whole different thing.


Get your head out of your ass and loosen up those jokes.



:D :D :D

[darkstar]

maybe you should carefully re-read ALL of what i posted before.

I think the idea of having a huge frontmount for the wanker factor is stupid. Sure people choose to rice up their car with their drone exhausts, rice stickers and glowing disco lights, but hey, they are the one that look like the fools in my eyes, while the uneducated idiotic society thinks its as 'fast' as it looks :D

I see an intercooler as a performance modification FIRST, the noises and looks etc. come second. Therefore, i would personally opt for a suitable sizing for the performance application, rahter than sound wooshing past letting off noises as the throttle gets released. Sad thing is, there are a lot of sheep in every catagory. I modify cars for myself and my own pleasure, show off tactics and so forth come last on my list.

I drive a VL, already many would say that that is very non-orginal, but i tend to like my VL and my friends, but hate the others :P hehe

I did not mention paint and rims etc, so i think thats your misinterpritation. In my opinion, intercoolers serve a performance application for a performance situation. Having a HUGE wank and innefficient/unoptimized front mount i think is very laughable. Remember, it takes nothing to earn the respect of those that no nothing about your car or cars in general, but its a lot harder to impress those that know and give a shit about their cars. I only try to impress and satisfy myself. I cop it as it is driving a vl from some family/friends, but given the amount of man hours and personal customization they respect that and i feel more attached to my car than other vls out there.

Show cars are show cars, and performance cars are preformance cars. Its when one tries to be the other with dodgy equipment and shit/cheap/show-off parts that gets peoples who have the knowhow attension for the wrong reason.

Either way you cant impress them all, but do what suites you, if you can handle the backlash :OP

bleh another 4am rant, im going to sleep. Hope it made sense (cents), dollars, drahmas, Euros, and all the other currancies inbetween :P

[dabigbolf]

Yes well,

Stickers and neons are certainely on the TOY list.
But having a big front mount, which could be oversized for the car ain't too bad. At least they look good, and they still do a job compared to not having one, or a much smaller one.

But anywayz its everyone to themselves. If people want their cars to be sleepers or for show who cares. A cars a car. What ever is done to make it look a bit different i reckons good.

Look at the vl. So many people have them. Whatever is done to make it different from the next i say is for the better.

anwayz going now.

and what the **** are u doing writing at 4:00am

[VLCalais]

What is the dimensions of the cooler on chilled's car?

[OVL087]

darkstar
you should go to bed i think. anyway , i know you read are homepage but if you want anymore info i can have a chat with the owner (good mates) just email me. cheers
andrew

[darkstar]

cool thanks OVL, ill keep that in mind :)

yah, more sleep would be a good idea ;)