waterinjection.info  

Go Back   waterinjection.info > Injection Theory (what it is and what it does) > Intercooler Effects

 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
  #1  
Old 09-03-2009, 01:46 AM
Greenv8s Greenv8s is offline
Member
 
Join Date: Sep 2004
Location: Milton Keynes
Posts: 26
Default charge temperature drop due to WI - any measurements?

I've been doing some estimates of the expected temperature drop due to evaporative cooling from WI. I'm sure this is well known, but I couldn't spot the numbers anywhere so I looked up the specific heat capacity and latent heat figures and tried to work it out from there.

My calculations suggest that with air:fuel:water at 14.7:1:0.1 by mass, the evaporative cooling from the fuel will drop the charge temperature by around 20C and the evaporative cooling from water will drop it by a further 15C or so. (Obviously increasing the fuel or water would increase the temperature drop.)

The fuel cooling figures stack up with well known effects of carb icing, and when I'm running on the upstream fuelling I routinely see frost forming on the intake. I don't have any practical experience to back up the WI figures though, and with the cooling only occuring under boost it's very hard to get accurate figures on the road.

Has anyone tried to measure the temperature drop - is it anywhere close to the figures above?

Not really relevant to the question, but for the curious the engine is a RV8 4.6 with an Eaton M112 producing 8 psi of boost, upstream injection plus port injection managed by MegaSquirt MS1/Extra, WI upstream currently just supplied by 1S but planned to upgrade to a mapped system later. I'm estimating charge temperatures of around about 110C on boost - not good.
__________________
Peter Humphries (and a green V8S)
Reply With Quote
 

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 09:26 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.