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Old 04-28-08, 03:09 PM   #23
Dougal
IH8MUD Lifer
 
Join Date: Jun 2007
Location: Being stalked by 2 hillbillies
Posts: 1,425
Quote:
Originally Posted by joshoisasleep View Post
What ambient air temperature is that assuming? I thought that made a big difference...

In other words you sound like you really know what you're talking about as usual, but from what you're saying it sounds like there's very little point. With people reporting 200+ degree improvements to their EGT levels, I'd like to believe I would see those kind of results!!
Those calcs are based on 20 deg C ambient. I can redo them for whatever temp you like, but the differences aren't that big.
I'd expect you need either 20psi boost or a turbo working far outside it's best efficiency point to be able to get a 200F drop in EGT's from an intercooler.

Boost temps rise exponentially with pressure. So while 10psi is the point where an intercooler isn't really worth it, at 12psi and above it certainly is.

At 20psi boost.
Turbo outlet temp is 135 deg C
A 60% effective intercooler can drop that by 70deg C (160F)
The density is improved by 20%.

If you want to fit a massive intercooler then you could get more than 60% of the heat out, but many vehicles are restricted with what they can fit so 60% is a good starting point.


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