[Mk2] [Turbo] Chargecooler core size

[pbmr2]

Hey all,

In a week or 2 will be fitting the new engine and have changed my mind on intercooling. Always wanted a chargecooler and now is the time to act.

Have been reading as much as possible and think I've got a handle on the entire setup save for one detail. The core size.

Some people seem to be happy with the results of a small 310x115x113mm core with decent pump and rad. But others have found they need to upgrade to the larger 280x220x115mm core.

Is the 75% larger core really needed for a target 300hp setup?
Or am I being short sighted by trying to reduce the weight and packaging using a small core?

Setup is gen 4 engine, ct15b turbo, about 17/18psi boost.
Looking to use the bosch 1200L/H pump, fiat rad and 19mm hoses.

Got some nice packaging ideas, mounting the core by the firewall infront of the gearbox. Keeps the weight low and central. Just have a filler neck up high for bleeding etc.

This is all using the ebay cores.

How has your set worked for you? All experiences welcome!

[Ryan S]

Pre-rad is more important than the core. Get a proper charg cooler pre-rad instead of a small car radiator. As for core size a gt4 core will do 300bhp as will the pre rad. Don't mess about with a fiat radiator

[pbmr2]

That's probably a very good point. A larger pre-rad would cool more water, better.

Hmm small core, large pre-rad. will look into it.
Thanks!

[Ryan S]

That's probably a very good point. A larger pre-rad would cool more water, better.

Hmm small core, large pre-rad. will look into it.
Thanks!

The main issue is that a proper pre-rad is way more efficient at cooling than a car radiator. Even if they were both the same size. Again a gt4 pre rad would most definitely do your set up 👍🏾

[kirk]

Personally I think the St205 core is more than enough for up to 400 with a well designed pre rad.

[pbmr2]

Thanks for the input, with this and another topic on the OC I've made the move.

Not using the GT4 CC because it's a pain to fit on the gen 4, went for a single core ebay jobbie, new high flow pump and a proper pre-rad. Should be more than enough for my low power goal.

Hurry up delivery man!

[tiff_lee]

What pre rad did you end up going for?

[pbmr2]

AVT 23" x 8"

was looking at the wider one but the fitment looked a bit optimistic.

[tiff_lee]

Yeah i've been contemplating getting that one myself quality looks good from the pics ive seen on here

[pbmr2]

Will take lots of pics on install.

Might even give the pump a test, run some hot water through it and see how well it performs. Measure the temp drop from input to outlet.

[pbmr2]

Well here is the pre rad.
Have seen higher quality products in my time but it's not rubbish either. Very lightweight.
Hope it does the job, can't be worse than a Fiat radiator.

[Lefty1991]

Well here is the pre rad.
Have seen higher quality products in my time but it's not rubbish either. Very lightweight.
Hope it does the job, can't be worse than a Fiat radiator.

The AVT core is what I'm running and I'm so pleased with the results, intake temps have dropped by 15 degrees over my old inter cooler and the temps drop after boost so much quicker