waterinjection.info

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-   -   effectiveness of WI in high humidity (http://www.aquamist.co.uk/forum2/vbulletin/showthread.php?t=1219)

zire61 06-05-2007 03:45 PM

effectiveness of WI in high humidity
 
hi,

i have a supercharged BMW that is not intercooled and am considering the use of a system 1s in lieu of an intercooler. however, i would like to know if the intercooling properties of WI would be compromised by the tropical climate i live in: 90-100% relative humidity and ambient temperatures above 30 degrees celsius in the daytime.

surely with such high humidity, there isn't much more room for water to evaporate and cool the air correct?

any advice would be greatly appreciated.

boostm3 29-06-2007 04:01 PM

I had a setup similar to yours.. Mine was a '99 M3 which I added the Dinan Vortech based superchargers kit to back in December, '99. There was no intercooler with this kit. Two yrs later, I went with a larger crank pulley and bumped my boost up from the Dinan kit's 8 psi to 11 psi. To support the increase, I installed the AA version of the Aquamist 1s kit, and drove it that way for a few years.

The water injection kit did its job at WOT, lowering peak Intake Air Temperatures (IATs) by 50-60 degrees on a dry day... In humidity, it became less effective. Here's my recommendation..... The problem with WI alone on a supercharged car like yours, and mine used to be, is that its only effective at WOT, especially if you run something similar to the 1s kit. I did alot of temperature instrumenting, and found that cruise IATs measured Ambient, as recorded by the on board computer, plus 100 degrees!!! Yup. Thats a heap of heat for just cruising around at part throttle. And Water INjection wont do a thing to help you with it. ON hot summer days after driving around for a half hour or more, the lag in responsiveness is HUGE. So, on an 80 degree day, when the brake duct thermocouple reports the ambient temperature as 80 which is what you see on the OBC in the dash, the temperature reported to the ECU by the IAT sensor is about 180 degrees F !! How does the ECU respond to these elevated IATs? Usually by pulling timing, among other things. And you, the driver, experience it has less sharp responsiveness when you press the go pedal. And of course, as temps to up through the 80s and 90s, it just gets worse.

So, its this realization which finally prompted me to do what I should have done as soon as I got the supercharger: get an Aftercooler. RMS had a good water to air unit which fit perfectly into the E36 M3. After its installation, using the 80 degree day as the example, IATs dropped from a previous 180 degrees to a current 120 degrees. In addition, the aftercooler all by itself got me an additional 20-25 whp on the dynojet, the same one I had been using to test all my other configurations. I kept the water injection system which I now use to augment the cooling provided by the aftercooler. Together, they make sure that even at wot at redline, IATs drop instead of climb!

Sorry I took this a bit off topic, but after the supercharger, adding the aftercooler was the single best upgrade I got. Water injection is a good helper system to augment the aftercooler, but as my numbers showed, I think its not the greatest substitute.

zire61 07-07-2007 02:19 PM

thanks for that Paul.

may i ask if your throttle body is located before or after your SC and how you think this may have had a bearing on your cruising IAT?

my throttle body is located before the blower and in theory, while cruising, the throttle plate is closed and the air supply to the engine doesn't go through the blower itself... which hopefully translates to lower cruising IATs. what do you think?

Richard L 08-07-2007 08:26 AM

Air's ability to hold water changes with temperature. If you exit temperature from the supercharger is greater than the ambient, water will continue to evaporate and cools the charge air.

zire61 08-07-2007 05:06 PM

Quote:

Originally Posted by Richard L
Air's ability to hold water changes with temperature. If you exit temperature from the supercharger is greater than the ambient, water will continue to evaporate and cools the charge air.

Hi Richard,

yes, i was searching some old threads on the forum and came across some references and figures about this as well. my exit temperature is definitely much higher than ambient!

just out of curiousity, are you still working on the axial nozzle mount for pre-turbo injection or has that project been abandoned? i have a centrifugal supercharger mounted in a very accessible place in my engine bay and would be interested in experimenting on the effectiveness of this. and what's the verdict on whether water damages the impeller? some of the threads were started a good one or two years ago, have you recieved any feedback since then from customers on the long term use of pre-compressor injection and if aiming the water at the eye of the compressor was the solution to avoiding impeller damage?

Solar_Subaru 18-07-2007 02:28 AM

For what it is worth, I have been squirting water, water/meth mix, and straight methanol into my turbo for about two years now(daily driver), boost level has not changed (no impeller damage?) and it adds up to 4 pounds of boost (over 14 without, 18 with straight methanol) on my diesel VW. My system does nothing to vaporize the methanol, just a windshield squirter bottle and a squirter jet stuck perpendicular into the turbo inlet hose, spraying at the tubing wall. I have been very suprised at the results, and have gotten addicted to it. (woo hoo!).

I am about to take the engine down, I locked it up a couple of years ago when the oil drain plug rattled out, it has finally caught up, and I am down a cylinder. Maybe I can take pictures of the impeller after it has been cleaned and post them/send them to you?

Tony

Richard L 18-07-2007 09:38 AM

Quote:

Originally Posted by zire61
Quote:

Originally Posted by Richard L
Air's ability to hold water changes with temperature. If you exit temperature from the supercharger is greater than the ambient, water will continue to evaporate and cools the charge air.

Hi Richard,

yes, i was searching some old threads on the forum and came across some references and figures about this as well. my exit temperature is definitely much higher than ambient!

just out of curiousity, are you still working on the axial nozzle mount for pre-turbo injection or has that project been abandoned? i have a centrifugal supercharger mounted in a very accessible place in my engine bay and would be interested in experimenting on the effectiveness of this. and what's the verdict on whether water damages the impeller? some of the threads were started a good one or two years ago, have you recieved any feedback since then from customers on the long term use of pre-compressor injection and if aiming the water at the eye of the compressor was the solution to avoiding impeller damage?

We have been steadily supplying the pre-turbo bracket on request as each one is made to fit the individual size of a turbo flange diameter.
I don't have a tubo car so my long-term test relies on feedback fropm others but unfornatunately people's interest changes and
I do not always get a steady stream of data - comaprison between the bracketed and non-brackleted PT injection. I am afraid things will remain this way until someone post more date me to compare.

Richard

zire61 18-07-2007 03:12 PM

Quote:

Originally Posted by Richard L
We have been steadily supplying the pre-turbo bracket on request as each one is made to fit the individual size of a turbo flange diameter.
I don't have a tubo car so my long-term test relies on feedback fropm others but unfornatunately people's interest changes and
I do not always get a steady stream of data - comaprison between the bracketed and non-brackleted PT injection. I am afraid things will remain this way until someone post more date me to compare.

Richard

Richard,

what a timely reply! i just paid a visit to your aquamist distributor in singapore, gan motorsport, this afternoon and in all likelihood, i will be installing a 1s next monday - just in time for my tuning/dyno session on tuesday.

could you send me a private message detailing the costs of getting a pre-compressor bracket made for my car? would it be feasible to run a 1s kit right now and when the pre-compressor bracket is ready, to use the same pump to supply 2 nozzles, one pre-compressor and the other, post-compressor?

also, the 1s kit here is sold with the 0.5mm, 0.6mm and 0.7mm nozzles but i'd prefer to use smaller nozzle sizes like 0.3, 0.4 and 0.5 since my main concern is intercooling and not detonation prevention. can i do the nozzle exchange with him or do i have to send the nozzles to you in england?

thanks

Solar_Subaru 18-07-2007 09:59 PM

I would be interested in a cost for this as well for my turbo Cosworth Vega project.

Thanks,
Tony

Solar_Subaru 26-07-2007 12:41 PM

Are there any online dealers for your PT injection assemblies?

Tony


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