Intercooler choice
Turbo Mini Forums

So heres the situation with my intercooler...I now have 3!

from a 200sx, Skyline and Ibiza.



They are actually all the same capacity, ish, they are all 2.2 Litres but if you wanted to be more specific they are 2.27, 2.24 and 2.21 respectivly, which is only 60ml differance from largest to smallest. Worked out using LxHxW.

At the mo it looks like the Ibiza is the winner as it will sit in the gap above the starter motor, but should I try and make one of the others fit as coolers are more efficient with a larger front surface area and with more cooling tubes.

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

Tip:- Get a mini pre-engaged starter as the solenoid it at a 45 degree angle instead of 90deg and gives you a touch more room up front

But I like the Ibiza cooler for the reasons you mentioned.

If something is worth doing, it's worth doing half of.

As you realise yourself, the physical size of the core isn't the end of the story...

It's the surface area of the tubes and the surface area of the fins that really matters - the one I'm attempting to use has even got fins inside the tubes.

To compare them you need to try to work out the surface area of the tubes as a minimum, not just LxHxW.

Schrödinger's cat - so which one am I ???

Well heres some accurate-ish maths on the subject.

(WxHxD in cm)

Ibiza, 5 Tubes, 30x0.9x8.5 = 1147.5cm3

200sx, 18 Tubes, 18x0.5x6 = 972cm3

Skyline, 15 Tubes, 21x0.5x6 = 945cm3

So the Ibiza has a larger area of tubes BUT a much fewer of them, and more is better than less. so what is more important, number of, or overall size of tubes?

nice little link here: http://www.niseiengineering.com/images/Int...lerTutorial.swf

Edited by Simon on 24th Jun, 2010.

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

First, for the surface area of the tubes it isn't WxHxD.

It's (((WxHx2) + (WxDx2))x number of tubes)

assuming W is the length of the tubes (width of cooler)

Then the amount and surface area of the fins become important.

On the Ibiza one, can you see if there are fins inside the tubes - this is only usually done with large tubes (small number of tubes).

EDIT - just looked at that link, there are some very basic false statements in it.....

Edited by Rod S on 24th Jun, 2010.

Schrödinger's cat - so which one am I ???

ah, using your formula (yes W is the width of cooler) its a different story:

Ibiza: 2820
200sx: 4212
Skyline: 4095

Yes there are fins inside the tubes on the ibiza cooler, and the skyline cooler infact. i cant see inside the 200sx one just yet.

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

Basically a small number of large tubes can have a smaller surface area than a large number of small tubes.

Surface area of a rectangular tube is length x height twice (the front and back faces) and length x depth twice (the top and bottom faces).

But although there might be less tube surface area on a design with a low number of large tubes, it does give the option of better fin design, especially if you can fit fins on the inside of the tubes as well as the outside.

There is no simple calculation because there are so many variables, after the basics of tube surface area and fin surface area would come wall thickness of tube, flow rate of air inside and out at a given pressure drop and many other factors.

The best comparison IMO is what BHP the engine ran that it came from and whether you can make it fit ......

Schrödinger's cat - so which one am I ???

Use a tube & fin core and not a bar & plate core!!:)

Graham

If it doesnt ahve fins inside the tubes...it would be pretty crap.

Based on external appearances, I'd be using one of the left pair.

The rightmost one looks very small and crap.

What is important is the ability of the core to remove heat from the air, and also a core large enough that the air will spend enough time getting cooled.

ie bigger is better.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

the 2 on the left are only 60mm thick, the one on right is 85mm, so it makes up for front area with depth.

further investigation shows all 3 have fins inside the tubes.

i still work it out that physical air capacity is the same in all 3 so air will spend the same time in each.

the ibiza one is rated to over 200bhp so should be fine, even if the others do work out to be more efficient surly if its rated over what i need and actually fits then thats fine?

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

If a larger one fits, that's what I'd fit. Surface area is key as well I'd say.

Intercooler cores normaly come in either 50 or 60mm width cores, go for a 50mm tube this gets the air through the core better and out the other side, too thicker core causing the air to slow down Surface area is key!

Graham

Thicker is not always better. A larger frontal surface area is always better than a small area, thick core.

Going thicker is purely a space compromise when frontal area cant be achieved. It will assist airflow through the core, but the thicker it gets, the more cooling ability is lost.

And a "200bhp unit" beans absolutely nothing.

a 2.0 turbo engine making 200bhp at 5 psi boost will generate nowhere near as much heat as a 1.0 200bhp engine using 25psi boost.

Yes the core may flow 200bhp worth of air.....but can it also cool the air properly as its passing through it ?

And tube design also plays a huge part. Large open tubes might look great for airflow, but the air sill simply shoot straight through with little or no cooling taking place. So it defeats the point.

Edited by stevieturbo on 25th Jun, 2010.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

As mentioned above There are so many variables to take into account that it makes your choice difficult.

• How much air will your engine be sucking in to make the power you want compared to the effective cooling of your intercooler at that specific flow rate
• What is the ratio of surface area to volume, the smaller the volume to surface area the more efficient heat transfer will be.

Also remember that the metro turbo rad was made thinner than the standard rad so as to allow more air to pass through thus improve the cooling and most cars on here run with 2 core rads rather than the greater capacity 4 core for much he same reason. There is a trade off Where it is I do not know but As you can see from the above posts your path is a slim one.

One other question why are the surfaces of these units not coated to be black surely a black finish would aid in heat dispersion?

Own the day

i have seen people paint them black, but im pretty sure thats just going to block them up, but your right perhaps they should be made black.

some interesting stuff here, hope it helps a few others too.

The skyline one is out, the ports are pointing in the wrong directions. The 200sx one looks an interesting one but actually getting the damn thing to fit could be the tricky part!

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

some one on here once said an intercooler isnt the iceing on the cake, it is the cake.

with an intercooler think large, you know at some point your going to turn up the boost, you can never have enough boost, its adictive and thus you will require a bigger intercooler

i dont want to have a cooler hanging out the front, while the car isnt exactly subtle a bit of a sleeper look on the fact its got a turbo would be nice.

this is the option with the 200sx cooler, would put a vent hole or two in the bonnet too.

http://turbominis.co.uk/forums/index.php?p=vt&tid=170151

Looks like it would provdie good flow, especially with a hole in the bonnet, maybe louvered sort of to force air down into the motor? Or am I talking out my ass?

I reckon if you used a pre engaged starter with the matty trick and a ND alternator you could fit all 3 up front.

In the 13's at last!.. Just

if you have a look at oneeyedlizzared build, theres a good chance you could get a bigger one in there with small mods.

with the flip front you dont have to deal with the inner wings. rotate the starter motor, maybe a denso alt, you should be able to fit a full lenth intercooler, 600mm.

there again, theres the rs that should fit. good luck :)

Get an intercooler custom made.

Graham

You must suffer from the same disorder! Your intercooler is the size of a small cow.

On 25th Jun, 2010 wintersurferuk said:

On 25th Jun, 2010 theoneeyedlizard said:
I reckon if you used a pre engaged starter with the matty trick and a ND alternator you could fit all 3 up front.

haha only you could fit all three with your OCD

In the 13's at last!.. Just

pmsl!
my intercooler does two things, cool's the boost and catches the oil spewing out of the turbo!

just because its twice the size of my rad, dont meens its to big!

On 25th Jun, 2010 theoneeyedlizard said:

You must suffer from the same disorder! Your intercooler is the size of a small cow.

On 25th Jun, 2010 wintersurferuk said:

On 25th Jun, 2010 theoneeyedlizard said:
I reckon if you used a pre engaged starter with the matty trick and a ND alternator you could fit all 3 up front.

haha only you could fit all three with your OCD