Large IC install/pluming

[Jamo]

I'm with Roger on this one too.

Each to their own on this one, I not up for a ruck today

[T2Andy]

These are indeed correct m=53 lb/min, Cp=0.25, U*A=20.1
lets start by assuming that the intercooler outlet temp = 140
Q = m * Cp * DT
Then DT = (350 - 140 ) = 210 and Q = 2782.5 BTU/min
Cooling air flow = 85.33 lb/min
DT for the cooling air = Q/(m*Cp)
DT = 2782.5 BTU/min / (85.33 lb/min * 0.25 BTU/lb-f) = 130.4 F
since DT = T out - T in, then 130.4 = T out - 85 and T out = 215.4 F

So the cooling air inlet is 85 F and the outlet is 215.4 F, and the turbo air inlet is 350 F and the outlet is assumed to be 140 F. Now calculate DTlm:
P=0.792, R=0.62, and F=0.75
DT1=134.6, DT2=55
DTlm=(134.6-55)/ln(134.6/55) * 0.75 = 66.7

Now calculate a new Q, Q= UA * DTlm
Q=20.1*66.7=1340.7

Since this isn't the same Q we got when we assumed an outlet temp of 140 deg, we have to get a new outlet temp and run through all this again.
I'll assume a new intercooler outlet temp of 170.
Q=(m*Cp*DT)=2385
cooling air DT = 2385/(85.33*0.25) = 111.8
Cooling air outlet = 85 + 111.8 = 196.8
P=0.68, R=0.62, F=0.84
DTlm=97.3
Q=1954.7 still not close enough

Last try!
T IC out = 182
Q=(m*Cp*DT)=2226
cooling air DT = 2226/(85.33*0.25) = 104.4
Cooling air outlet = 85 + 104.4 = 189.4
P=0.63, R=0.62, F=0.88
DTlm=111.0
Q=2232 close enough SPOT ON

[terrybullwon]

Good one

Heres a very interesting read Intercooler read

[4WheelDrifter]

No you don't get a pressure drop with a large IC. A too small one would get you a pressure drop.
A large one will give you a bit more lag (because there are a little bit more volume to fill), but no drop in pressure

I'm with Roger on this one too.

[s2_bo]

Hmm, i think you scored on that one Roger..

I don't really know enough about it to join in in this debate, but you certainly convinced me

Nice IC BTW

[Audi_CQ]

I think your find Jamo is right here,

eeeehhhhh, no

You are right about the lag as the turbo is going to have to fill the volume of the intercooler.

Agree

You really want a intercooler that will maximise cooling efficiency, minimise pressure drop. So to small is going to be usless any way!

Agree

Right air from the turbo is passed through core allowing heat to dissipate. The larger the core area the grater the loss. But equally a lager core will cool more air. (you need to create a equal medium)

Not 100% sure about "equal medium". Thinking about cross section of the IC?

resistance of a standard one could be say .05kg/cm2 at 1.2kg/cm2 of boost but the larger you go the bigger the drop.

Here I don't follow you
Lets look at IC's as pipes: Would you say that a small pipe has less resistance then a bigger one?
About drop you got it right in that the pressure will drop, but not because of resistance. As the air cools it gets denser and takes up less room. Pressure drops, but amount of air is the same. This is the IC's main function

Also you have to add the resistance of the pipe work.

Hense reverse inlet manifolds

( ,but the pipe resistance would be the same independent of IC size... )

Can you explain how you came up with this "theory" Roger?!!! Jamo is correct!

I'll try:
The turbo will deliver about the same amount of air independent of IC as long as the IC isn't so small that it becomes a major restriction (cross section inside IC is much smaller then other pipework) Agree?

The turbo will deliver most air when the resistance is as small as possible. Large short pipes and IC's with large cross section has the smallest resistance for a given amount of air. Agree?
(Going too large on pipes and IC's would of course at the end be giving more lag then the gain in smaller resistance could justify)

When the turbo deliveres the most air it will also deliver the highest pressure in the inlet manifold. Agree?

So as earlier said the only pressure drop a large IC will create is that as the air cools it gets denser and takes up less room and the pressure drops. The amount of oxygen would be the same, but in a smaller volume and therefor making it easier to get the oxygen into the cylinders. This is the IC's main function

Was that understandable or.... ?

Cheers,
Roger

PS: This is my IC:

[adamw]

just a small question... would the ic be more efficient if it was longer rather then taller? as u would get more air passing more of the ic? it made me think because half the ic is getin blocked by the bumper/ number plate.

[terrybullwon]

No you don't get a pressure drop with a large IC. A too small one would get you a pressure drop.
A large one will give you a bit more lag (because there are a little bit more volume to fill), but no drop in pressure

I think your find Jamo is right here,

You are right about the lag as the turbo is going to have to fill the volume of the intercooler.

You really want a intercooler that will maximise cooling efficiency, minimise pressure drop. So to small is going to be usless any way!
Right air from the turbo is passed through core allowing heat to dissipate. The larger the core area the grater the loss. But equally a lager core will cool more air. (you need to create a equal medium)

resistance of a standard one could be say .05kg/cm2 at 1.2kg/cm2 of boost but the larger you go the bigger the drop.
Also you have to add the resistance of the pipe work

Hense reverse inlet manifolds

[s2dude]

No you don't get a pressure drop with a large IC. A too small one would get you a pressure drop.
A large one will give you a bit more lag (because there are a little bit more volume to fill), but no drop in pressure

Can you explain how you came up with this "theory" Roger?!!! Jamo is correct!

[Audi_CQ]

Pressure drop, when fitting a larger intercooler there's more air space to fill inside it by the turbo charger. If the turbo can't fill it quick enough over the pipe length / volume space you get a pressure drop.

Hence my mantra you can have too big an IC.

No you don't get a pressure drop with a large IC. A too small one would get you a pressure drop.
A large one will give you a bit more lag (because there are a little bit more volume to fill), but no drop in pressure

[newsh]

The stainless pipe is 3mm thick? Thats pretty heavy. Can you get thinner stuff? 1.5 or 2mm should be plenty thick enough, I would think.

I'd like to order a crossmember if you're thinking of having some made

[travill]

http://www.s2forum.com/photoplog/ima...0__Medium_.JPG what you see in the picture intake mainfold I would liket to buy one, could you be so kind to help me in this matter?

[Jamo]

too big why would it be too big?

Pressure drop, when fitting a larger intercooler there's more air space to fill inside it by the turbo charger. If the turbo can't fill it quick enough over the pipe length / volume space you get a pressure drop.

Hence my mantra you can have too big an IC.

Bo is going to RS2 setup though so it's needed.

[Audi_CQ]

.

I used to get 1.4 - 1.45 bar and now its peaking at about 1.35

I think the IC is to big for the K24 - good thing that i'f got a K26 on the way

too big why would it be too big?

[s2_southwest]

Ok dan look forward to that!!

Finetubes @ estover would be a good place to get some ally tubing, nice and lightweight!