Radiator sizing

I'm trying to wrap up my project car, and the one big missing piece is the radiator. Ndoes anyone know a formula/ rule of thumb that can give you radiator size requirements?

I have a twin turbo Subaru ej20 stuffed in the back of fiat 850. I'm trying to mount the radiator close to horizontal in front of the engine/above the transaxle. I only have abou 14 inches of depth, but about 36 of width to play with.

Mid 80s vw radiators are close to his size, but I don't know if they have enough cooling capacity.

I may be misunderstanding the situation, but this sounds like a surprising amount of room. What height do you have available. If you're doing an odd angle fitment with a twin turbo engine I would think it makes sense to squeeze in as big of a rad as you can. Places like summit have lots of different sizes. You can have a custom rad made by many companies. eg. Howe has a rather detailed form you could fill out: http://www.howeracing.com/c-453-howe-custom-radiators.aspx

I have about 4 inches vertically, I've looked into custom ones, but I'm trying to go the cheap route and use an off the shelf one if possible. I have anyplace in town that will make one but they want 850 for the radiator

I'd look at Griffin radiators. One that should fit easily should be $250 or less.

Bigger is better, squeeze in the biggest you can. Period.

GameboyRMH wrote: Bigger is better, squeeze in the biggest you can. Period.

Not so fast...If bigger blocks air flow it might not be better. rads are sized in BTU's in the books see if you can find someone with a good book who can look up the rad that suposed to be with the motor and compair that BTU number to the VW one you'd like to use. Ducting will be manditory but you allready know that i'm sure. We want pictures! I recall waking up in the back seat of my oldest brothers 850 coupe as a Maine state cop handed him a ticket for 110mph....I was 7 or 8 at the time, we'd gone up to look at service stations for sale.

He still has all sorts of Fiat stuff being reclaimed by mother earth....

This intercooler has BTU rejection numbers.

http://www.surpluscenter.com/item.asp?item=28-1761&catname=engines

Good rad shop should have that info for rads too.

This rad has btu numbers too. http://www.surpluscenter.com/item.asp?item=28-1737&catname=engines

Radiator in the back also has airflow problems that need to be addressed.