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KnifeEdge_2K1
07-04-2004, 10:30 AM
How much power could this device possibly yield? is it worth the extra space and weight it takes up?

Sweeney921
07-04-2004, 10:44 AM
i dont think it really adds any power, it's just supposed to help the engine from overheating.

KnifeEdge_2K1
07-04-2004, 01:17 PM
i was under the impression that it was suppose to lower the temp of the air going into the engine hence creating a denser mixture, but considering the volume of air going into the engine i was hesitant to believe that a little bit of water could make much of a difference

Sweeney921
07-04-2004, 01:50 PM
hmmm, thats a point, but i doubt it would make much of a difference

Egg Nog
07-04-2004, 02:17 PM
Any method of lowering the temperature of an intercooler will increase power, through the same principle as the intercooler itself. A colder air mass can hold more fuel molecules, and thus, achieve greater output.


I recall an excellent thread about this a looooong time ago! I started this one more than a year ago! Read up :)

http://www.ultimatecarpage.com/forum/showthread.php?t=338

Ferrari Tifosi
07-06-2004, 01:47 PM
I don't know how much there would be to gain from waterspray. Now, I know there are also kits that spray nitrous oxide into the intercooler to cool the intrake stream. Also the nitrous works as a great oxidizer in this situation, same as in its normal use.

YAY, 500 posts, now I'm a senior member.

Coventrysucks
07-06-2004, 05:07 PM
i was under the impression that it was suppose to lower the temp of the air going into the engine hence creating a denser mixture, but considering the volume of air going into the engine i was hesitant to believe that a little bit of water could make much of a difference

In the old days, before they put the chicanes in, they used to get an extra 20mph down the Mulsanne straight at Le Mans at night, due to the cooler air.
That is quite a bit of extra power to gain 20mph when you're at 200mph.
:)

Max Legroom
08-01-2004, 02:33 PM
Hi, I'm new to this site. I realize this thread is 3 weeks old, but if anyone's interested there is a consideration which need to be addressed with water spray. The intercooler has a high thermal mass (compared with air or water) and exhibits what's called thermal hysteresis, which means the temperature of the metal the intake air is blowing through doesn't change immediately when the temperature of the air changes. If you only stomp on the accelerator occasionally then water spray won't do anything for you beause the intercooler metal won't have changed temperature very much. However, if you've got a top mount intercooler and have to sit idling for a long time (like when waiting for your launch time at the drag strip), spraying water at the intercooler will make a tremendous difference with the heat soak problem. Likewise if you're in a track race and have the pedal floored the entire time, the intercooler temperature will rise dramatically and having water sprayed at it the entire time will make a large difference. But if you want to race the turkey in the next lane from the red light you're sitting at, pressing the spray button just before you launch will make virtually no difference whatsoever.

The opposite is true for actual water or nos INJECTION. The thermodynamic cooling affects are virtually immediate.

crisis
08-01-2004, 11:46 PM
My mate has a 100 series Landcruiser with a supercharger and water injection which sprays water into the mixture.

Ferrari Tifosi
08-02-2004, 09:22 AM
In the old days, before they put the chicanes in, they used to get an extra 20mph down the Mulsanne straight at Le Mans at night, due to the cooler air.
That is quite a bit of extra power to gain 20mph when you're at 200mph.
:)

Really, that's quite suprising, usually the horsepower gained by cooler air is outweighed by the aerodynamic drag that the cooler air creates.

crisis
08-02-2004, 06:39 PM
Really, that's quite suprising, usually the horsepower gained by cooler air is outweighed by the aerodynamic drag that the cooler air creates.
I read in a book about superchargers a similar story where test driving Nascars or something on a track with cool moist air near the sea would give noticeably better performance than when the same car was driven in dry warm inland areas.
Ive posted this anecdote before but for the benifit of newer members the story of water injection (into the mixture) dates back to the develpemnt of the RR Merlin engine of WW2 (theres a bit of that lately). When testing in the mornings they would achieve higher HP readingd than later in the day.I was found to be moisture from the nigh before gathering in the fuel system and cylinders. Thus they decided to spray moisture in all the time.

KnifeEdge_2K1
08-02-2004, 07:52 PM
I read in a book about superchargers a similar story where test driving Nascars or something on a track with cool moist air near the sea would give noticeably better performance than when the same car was driven in dry warm inland areas.
Ive posted this anecdote before but for the benifit of newer members the story of water injection (into the mixture) dates back to the develpemnt of the RR Merlin engine of WW2 (theres a bit of that lately). When testing in the mornings they would achieve higher HP readingd than later in the day.I was found to be moisture from the nigh before gathering in the fuel system and cylinders. Thus they decided to spray moisture in all the time.

water injection into the cylinder is used to avoid detonation/knocking under high boost

wrc cars use em cuz they run at i think near 30 psi or somewhere around that range

im not sure if they're still allowed by the fia but i know the older lancer wrc cars had em, the Vs and VIs

Max Legroom
08-02-2004, 09:45 PM
Water injection is almost always introduced into the air intake stream, not into the cylinder. You would need a seriously modified cylinder head with an additional water injector to inject into the cylinder. The power and efficiency gains might be worth it, but it's not often done. But just injecting water into the intake stream allows you to lean out your A/F mixture and adjust timing to get a lot more dependable power from an engine. You could tune to the extreme if you had a separate water injector for each cylinder, but as I said it's not often done.

However, we were discussing intercooler water spray, which is a different matter. It can be used to advantage under extreme conditions, like drag or road racing, but my point was that under normal driving circumstances the thermal delay is large enough that you wouldn't really benefit from it. If you pushed the cabin "spray" button at a red light to race the jerk in the next lane it probably wouldn't help. You'd feel more power a little later on, but not at the time you pushed the button. That won't help if he beats you to the next stop light!

You also need to keep in mind that water weighs 8 lbs/gal, so if you keep a water spray system going all the time just so you can have the extra power to beat the jerk at the light, you're going to need to refill your water tank quite often, and it's going to add to your vehicle weight. Hey, maybe beating that jerk is worth it.

Water injection is a wonderful thing, and if you're looking to find a way to increase power and decrease the amount of gasoline you use (water will displace 15% of fuel in the mixture and deliver more power, with lower emissions and lower cylinder temperatures) you would be doing yourself a favor to look into it. You'll find that it was used in WW2 fighter planes to increase power and range (made a major difference if you wanted to return home alive!). Why it hasn't been more widely adapted into our car engines is a matter of serious speculation, the best theory being that gas was really cheap when the majority of R&D on cars was being done, so nobody cared about adding another tank for water which the complete idiots who owned the cars wouldn't be able to keep filled anyway...

Water spray is a simple way to reduce intake temperatures over a relatively long time span. Nothing more. In short time frames it will not allow your engine to run more efficiently and you can still detonate your engine to death if you expect immediate power benefits and tune accordingly. Water injection, in contrast, will allow an engine to be tuned for immediate power gains which you can immediately trust throughout the power band.

KnifeEdge_2K1
08-02-2004, 10:24 PM
sorry thats what i meant into the manafold, eash

anyways the theory behind it is that it lowers the air/fuel mixture temp so it won't detonate prematurely

i think, im kinda tired i dunno what im saying