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Old 11-26-2007, 04:59 AM   #19
efahl
Registered User
 
Join Date: Jun 2007
Location: San Clemente, CA, USA
Posts: 55
Quote:
Originally Posted by pk2
Your W/A IC’s synopsis backs up what I’ve heard elseware. I get it, you’ve 2 “losy” heat exchangers instead of one. Couldn’t you though, just double up the size of the front water exchanger space permitting ? Also, Is the wet heat exchanger just a radiator?
Yes, increasing the transit time in the cooler can improve its efficiency somewhat, but there are ceilings on the improvement, so I'm guessing you'd need a really huge water-air one to get it significantly cooler...

Quote:
Originally Posted by pk2
So what do you think about the positioning of Gary’s IC?. Obviously works for his setup, but I heard of something called “throttle volume” meaning (I guess) the volume of air in between the SC and the throttle body. Apparently to much and you get something akin to turbo lag. I was told that a total of 4 feet of tubing (to the IC and back) “probably“ wouldn’t be noticeable…your thoughts?
You know, I used to think it was a problem, always rationalizing that increased volume between the turbo and the throttle was detrimental to throttle response, but in practice it doesn't seem to be a problem. My turbo cars have always had pretty small volumes, due to the IC being close to the turbo and intake, but I've ridden in cars with long pipes and they are plenty snappy, even right off the line as they're building boost...

Quote:
Originally Posted by pk2
Last but not least, any clearing houses that you know of for calculating a workable system be it W/C or A/A. I have this goal of milking another 25 hp out of this thing and I’m on the cheap at the moment. Right now can only semi educated guesses as to how components I cob together might behave.
Try the calculator I wrote years ago for this stuff. The list of maps it supports is way out of date, but the numbers are good.
http://www.not2fast.com/turbo/glossary/turbo_calc.shtml


Quote:
Originally Posted by pk2
P.S. Is water injection a valid option (no clue about it)
It's certainly a valid option (and probably a good one given our high compression motors), but it's another system you have to design, fab, plumb and maintain. The hardest part is finding decent injectors if you want fine (i.e., proportional) control of the water injection, but a simple system can be quite effective using just a fixed nozzle. One of the big problems with water injection that most people don't acknowledge is internal corrosion of the engine; a "typical" WI system can add a lot of water to the oil, which can cause problems and there's not much discussion of this anywhere that I've ever seen, but it's something you need to keep in mind.

Here are my WI notes, more theoretical than practical, but maybe useful...

http://www.not2fast.com/thermo/water_injection/

Eric
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