Date: Fri, 30 Oct 1998 09:25:33 GMT From: Neil.Haugheynopsam.com Subject: Re: Water injection?
In article <john-2910982214100001nopsamnas1.is3.u-net.net>, johnnopsam16.co.uk (John) wrote: > Dear NJH, > Sounds cheap at least - Not possible to damage the intercooler as its all > alloy, you may get the engine bay a bit wet but only the same as driving > in heavy rain. > The idea has been used on the latest Impreza Turbo's I think. Yes, I believe it is the 22B STI model. The one rumoured to have 350 bhp. > How are you activating the system ? - one way is to get an old pressure > overboost switch ( usualy found under the lower facia) these can be > adjusted to activate at any pressure and would be fairly simple to > incorporate in the system . As a first attempt I had intended mounting the switch either on the throttle peddle or butterfly somewhere. This way the system would be activated when on say 2/3 throttle. Using the pressure transducer would be a good idea. I am sure I could get a resistance sensitive switch quite easilly. > I don't think it will be effective on short sprints but on a long uphill > drag in the heat it should work. Exactly, that is the whole point to it since the conventional inter-cooler will be effective for the first few seconds (or whatever) of acceleration. After that too much heat will build up in the alloy since the rate at which heat can be removed by the air is less than the rate at which heat energy in the hot air in the inlet charge enters the intercooler. When you first hit the accelerator this is not a problem since the alloy is cool and has a high heat capacity (in terms of the effective heat energy reservoir of the alloy) compared to the mass of air entering it from the turbocharger. However after a short while this heat reservoir (the intercoolers alloy) becomes exhausted and all the heat loss from the inlet charge must be through the alloy and then the air flowing through the matrix from outside i.e. warming up the intercoolers alloy will not be sufficient to cool the inlet charge. > Also consider removing the whole air box and its intake pipe and getting > a sports filter that goes directly on the mass meter this allows better > air flow through the intercooler and a slightly better throttle response. That kind of defeats the object since the warm air from the intercooler gets dumped straight onto the air filter box. Removing the box and replacing with a cone filter will only allow the engine to breath in this warmed air. You either have to move the intercooler or build in some ducting for either the inlet air or the heated air from the intercooler i.e. to get it away from the inlet. > For the proper job put a water jacket round the inter cooler and make a > water cooled inter-cooler these are very effective and efficiently cool > the charge at high boost at high rpms the area where the conventional air > to air intercooler is not very effective. Yes Abbott racing make one but we are talking about Hundreds of pounds. > Here's how to do it; > Get a workshop that can weld an enclosed alloy box ( with an open side to > the fins ) on each face of the cooler with an inlet at the bottom on one > side and an outlet at the top on the other connect this inline with a > suitable radiator mounted infront of the standard radiator and a pump of > some sort to circulate the water ( use a high heat absorbing antifreeze). Another good place to mount this little radiator would be on the front valence on the opposite side of the car to the oil cooler. > Its a bit of a job but probably worthwhile the - standard 900 intercooler > is crap. Judging by the size of the thing you would think it to be pretty good. However when considering how bloody hot it gets after a hard drive I would have to agree. > Have a go > > John > You can bet I will. Neil H. -----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
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