intercooler design one for Dave?
Turbo Mini Forums

How can you tell by looking at a intercooler if its an inneficient design? i have a brand new Mercedes intercooler ready to go in mine but after reading another post where dave said a landy one was crap i dont want to go to the trouble if its dog $hit

i see alex's intergrale intercooler install in his and after going out in his very sweet ride i was mighty impressed! if i can get the same acceleration as his car i will be a very happy bunny

In VERY simple terms, You just need to weight up internal and external area, and make a judgement based on what you see and what kind of temperature / pressure drop you want to see across it...
Internal fins (turbulators) will, by virtue of their prescence, result in a pressure drop - more pressure if the fins are more tightly packed - but you need to weight this up against actual surface area. External fins ideally want to be tightly packed - but not so tight that air will want to flow round the intercooler...

For example:
Landrover Tdi intercooler:
External: pretty good - reasonably tightly spaced fins, good thickness.
Internal: lousy - thin, flat tubes, with very few internal fins.
Pressure drop: medium

Volvo 740 turbo intercooler:
External: Very widely spaced fins resulting in insufficient area. Only makes account of itelf because of the sheer size of the unit.
Internal - again, widely spaced fins, but because of the huges internal volume, the airspeed over the fins will be lower, hence improve matters...
Pressure drop: very low.

Escort RST series 2:
External: Tightly spaced fins - curved sides to internal turbulators to promote airflow, etc. adequate surface area for the internal area.
Internal: tightly spaced fins, but perhaps a little lacking in intenal area for really high power units (As my mini proved).
Pressure drop: low/medium

you get the idea...

Pressure drop across an intercooler should be low - but if you go for a huge internal area, this needs a large amount of space - is it worth it?
You also need to consider internal vs external area for your application / charge temps.

Just put your thermodynamics hat on and consider what you've got in front of you, and how well it'll do the job...

Dave, someone suggested using a Porsche intercooler (maybe something along the 914 or 924 variety). Do you know anything about these intercoolers?

**************************************
1967 Cooper 's' Turbo build @ www.drjing.com

Nothing at all...

I wouldn't just assume that they are great because they were from a porsche either...

Ask Sauber200, he knows something about Porsche intercoolers.

Sorry, I thought I'd get in first before Jon.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

LOL!

I bit my tongue when typing my first answer!

if you want to do a rough flow restriction test pour a couple of litres of water through one and time how long it takes , then compare to another one

I really like that idea stu... so simple!

We better all have a play and compair results!

I've got 2 rst ICs, VW sharran, Focus...

Alex

AlexF

me goes off to get the hose pipe and batch of intercoolers. Top tip stu never thought of that. i iwll post my results as soon as i get the chance

All that measures is restriction however - if you had an RST intercooler and ripped out all the internal turbulators, it'd have a lower restriction, but have a much lower efficiency.