Intercooler shape/size

**d-shiznit** · 08-10-2006, 02:23 PM

Hey guys!

My project car - ae86 with a 3sgte, turbo - gt3040r.

Now before I had the 3sgte, I had a 4agte and was planning on a vmount intercooler/radiator setup.
I currently have a 510x150x76mm intercooler - long and thin, which I will be able to nicely fit for the vmount setup.
I'm abit worried as to how this will perform now..

Can anybody tell me what the diffrence is in having a long thin intercooler like mine, as opposed to say a more 'normal' 450x300x76mm intercooler?

My guess is more pressure loss at high boost, but similar heat exchange rate..

From rough measurements of my current 'long thin' intercooler core:
Each tube has volume 8 x 510 x 76mm = 310cm3
Core has 8 tubes so Total Volume = 310mm x 8 = 2480cm3

Compared to a 'normal' 450 x 300 x 76mm core:
Tube volume 8 x 300 x 76mm = 182cm3
Core has 16 tubes so Total Volume = 2912cm3

Both intercoolers have similar volumes, so I'd assume similar heat exchange capabilities..

However... Air entering the intercooler has 8 tubes to go through in the 'long thin' design, compared to 16 in the more 'normal' design...

I'm at a stage where I'm ready to get a radiator made.. so need to decide, stick with the original planned vmount with a long thin intercooler?
Or go with a front mount setup, and get a 450x300x76 intercooler?

EDIT: btw, planned boost will be low initially.. around 5psi.. But I would want an efficient setup being able to run say 20psi should I get bored with 5..

**jonra23** · 08-10-2006, 02:44 PM

What is the flow area of your cooler, being the size of the tubes the air flows through?

Rough rule of thumb for the minimum flow area (tubes that air flows through) for bar and plate coolers is 50square cm per 100 hp, and 30square cm per 100 hp for tube and fin coolers.

The cooler you require for 5 psi will be a lot different for 20psi, with higher boost you will be flowing a lot more air so tube area will need to be bigger and trying to get riud of a lot more heat so heat exchange area needs to be bigger.

Generaly more tubes and shorter run length will give better overall efficiency.

regards
jon