dunx

iTrader: (3)

O.K. Peeps chatting at t'club last night.

Once you have added more than 50% more power to a std. engine is it time for an upgrade of the radiator ?

Brand new OEM to be safe, or a big alloy unit for extra cooling capacity ?

Mine's fine, and so is Tim's... So who has one ? and where was it sourced ?

T.I.A.

dunx

Steve Whitehorn

iTrader: (13)

somewhere between 450 - 500 in a classic here
I just stuck in a brand new OEM item.
An alloy one of course would save weight
But a new OEM one did the trick for me.

Splitpin

What coolant temps are you typically seeing when the car is in motion? That's the only thing that ultimately matters, and even then you have some leeway to fiddle with the thermostat before needing to go to a bigger radiator core. If temps are going a bit high when the car's at a standstill you can remap the fan control, or fit more powerful fans.

Don't forget that the Impreza Group A and early WRC cars retained the standard radiator - in a context where they were running very high loads at fairly low average speeds (forget the 300 horsepower "claimed" figure). From the WRC2000 onwards they got smaller than OE size rads, for packaging/weight/aero purposes, which just demonstrates that you don't necessarily need to go bigger just because the engine is producing more go.

OEM, most probably. Again though there's little point guessing things like this when you have the ability to see what your coolant temps are doing. Other factors also play a part - like whether you're using a modine or a separate oil cooler (the latter will reduce coolant temps a bit).

Not quite sure how that is an "of course". OE Subaru rads have alloy cores and plastic tanks. Most aftermarket all alloy ones are bigger/thicker than standard, and of course have metal tanks. More likely to be heavier than OE than the reverse.

FB Tuning

iTrader: (30)

I ran with one of the Pattern ebay ones for 2 years on a classic with no issues at all, at 500hp - Typically ran at mid 80's when the car was on the move. I also had a Zerosports Stat, OE modene and a FMIC core infront of the rad.

Now i'm running over 600hp and have a Tabata Alloy rad fitted using stock fans, but with no modene - Temps seem to be down 2 or 3 degrees on average. - The build quality of it is excellent, and fits like a dream.

Last year the Zen Race car ran with a stock rad at 700hp - Albeit, fitted in the boot with an electric water pump assisting the stock one.