rotarygod

And exactly when is this a practical application for a non forced inducted engine again? It's definintely not on the street or on a road course and I doubt it will make you faster in any appreciable amount to justify it on a drag strip either. I just don't see any small gains it gives and temporary ones at that being useful anywhere but on a dyno. Save this for forced induction only on a drag track when you need help for some reason. Naturally aspirated cars don't knock except for the ones that are tuned poorly. In that case a bandaid isn't the best fix, tuning is.

globi

It's only practical if you increase the compression ratio on a naturally aspirated engine.
But as I said this also means you have to build in some protection (reduce throttle opening) in case you run out of water, which is not inexpensive but not impossible either.

ShadowX

Some people actually like the thought of increased reliability. I'm amazed that this thread has actually been stretched to 3 pages. Water Injection has been proven time and time again. The fact that the first page and a half were talking about water sprayers just shows the level of ignorance of those replying. When someone says water injection, I only think of one thing: water being injected into the intake. Most of the arguments against injection have no basis of fact and a barely even intelligent opinions. All I see is a bunch of flaming. I'd love to see this thread culled a bit to make it more useful/informative. I will definitely be installing some sort of water injection system once I have a SC installed (if they ever come out for one), just for peace of mind alone.

hogcar

Water injection AND a Canzoomer! Now thats worth at least 50 rwhp. Seriously water injection will do nothing good for a NA rotary--- except lighten your wallet.

Moostafa29

What's up with the update on this? My tuner was mentioning this after he had to retard my ignition timing like crazy. Not sure that I want to do this, but I'd be interested in results.

globi

You might find more advice on this board:
http://www.aquamist.co.uk/phpBB2/index.php

coolingmist

The company that purchased our kit and was going to do the testing is backlogged and has not yet installed the kit.

You may want to check out this thread for an update on our tunable controller:

https://www.rx8club.com/showthread.p...ht=coolingmist

Thanks!

David

ddub

I don't want to get into a huge argument about this, and I don't have any first hand experience personally, but here is some interesting information I found from a tuner.

He was testing out an rx8 on the dyno about a year ago. On normal premium (92 octane) gas he hit about 191rwhp in stock form. With 100 octane gas, he hit 197rwhp. These are averages from the multiple runs done for each 92 and 100 octane gas.

This was odd to him, but he thought about it and realized, the only way this is possible is if the rx8 is detecting knock (ping) in stock form using premium (92 octane) gasoline. This is kind of frightening if you ask me, but that's another argument. Anyways, by increasing to 100 octane and gaining power, the rx8 was detecting less, or zero, knock (ping) and not adjusting (retarding) the timing due to the knock (ping) it detected. Thinking about that, a water injection system would make sense. If in fact the rx8 in stock form on 92 octane is indeed detecting some knock, no matter how small, and retarding timing to counteract this, then the water and/or alcohol injection would effectively work the same as increasing the octane of the gas, and thus gaining more power. Would it not?

This all banks on the fact that these dynos were accurate, though I trust the tuner/shop that did the testing.

rotarygod

I agree that if you are having knock issues that something is wrong with tuning. I don't see water injection being a fix to a problem on an n/a car. I see it as a temporary bandaid instead of a proper solution which would be a better tune. This assumes you are using it solely to control ping on an essentially stock n/a. You do have to admit that no one will ever feel a 6 hp difference though. Water injection may have it's place but it's only at a drag track or for bragging rights on a dyno regardless of who says or claims what. For street use, it has a very limited amount of time that it will work before running out just like nitrous which is also only at home on a drag strip.

ddub

I agree that no one will notice a 6hp difference, I was just bringing up something I had heard about

I'm still frightened of stock rx8's are detecting ping :| I need to get something to tune mine I'm thinking.

rotarygod

Yeah I don't like that either. Typically n/a rotaries have always loved the lowest octane you could get. If they don't like it now, it's a tuning issue.

adrian-1

I drag race and have an FI RX-8 so I'm interested but I don't want to be the first to try it. I'll wait for results from the shop testing it.

Moostafa29

I wanted more info on this, because I want my timing back that I had to loose because of the crappy CA gas. I might go ahead and do this, but it will probably be a few months.

coolingmist

I would not hold my breath on the shop. The fitted a custom turbo on the rx8 and I have not heard back. I guess they ran into troubles.

We are having a tough time deciding to do forced induction on the Rx8 or to buy a GT35 Single Turbo for the FD.

You would hardly be the first. We have sold more than 5000 kits this year. Our controller that we listed in the link below will be able to custom tune to your car.

http://www.coolingmist.com/controllerspecs.aspx

zoom44

goe start your car open the hood and as mazda maniac put yesterday bang on the alternator bracket . ithe car thinks it heard knock!! it didnt but it thinks it did and retards the timing. i bet the tuners issue had to do with noise from being on the dyno and not any actual knock.

water takes up volume in the combustion chamber. thats not needed. ask rick engman. call mazmart and ask paul to get mr engman to give you his thoughts on water injection. he'll tell you its a bandaid that can work but is not necessary if ther is proper tuning. especially on any of the boost aps you will likely use on th eroad in an rx-8

coolingmist

I am so sick of the ignorant posts like this. Calling water injection a band-aid, you may as well say an intercooler is also.

I have said it before and I'll say it again, tune your car to the best that you can and then put water injection on it and you will gain power. Its a simple fact. Nobody is saying that water/methanol injection replaces tuning. its another way to make power and help prevent detonation.

And for those of you that have popped your engine Im sure would agree that anything that can help prevent it is worth it.

"proper tuning" is nearly non existent with a rotary as it can be tuned "properly" and then change of temps or a bad tank of gas ruins your day.

Like it or not water/methanol injection is proven.

Moostafa29

So would it perhaps be a good idea to tune your car for use w/o the injection kit, then install it and enjoy whatever gains you get? Or install the kit, tune it, and enjoy those gains. It seems that the first example would be the safest option, so in case you run out of "juice", you won't detonate under boost.

coolingmist

Its really a matter of how comforitable you are with your engine. With the FD I never recommend to tune for water injection, with the Rx-8 I dont really know how reliable the engine is yet.

Precision Dynotune in New jersey dynoed one of our kits they put on an EVO. Out of the box with no tuning it gained 57 HP. they put it on the dyno and ended up with 82 HP. (this was a vehicle with well over 450 HP to start). In that case they felt comforitable with the engine.

With late model cars just about all of them make nice gains out of the box with no tuning (turbo and supercharged cars).

Thanks.

adrian-1

Sorry, I meant be the first to try it on an RX8.

globi

Actually the net charge density is almost always higher with water injection. Even though water vapor displaces some of the air, the density gained due to the cooling effect results in a higher net air density. This is especially noticed with higher temperatures (high boost applications), which explains why supercharged engines can actually gain more power without increasing boost when using water injection (even if these engines don't deal with knock in the first place).
This guy went through the math:
http://not2fast.wryday.com/thermo/wa...opt_mass.shtml

Note: If you use gasoline to cool the intake charge you are 6 times less effective and you end up having to run the engine rich which reduces power. Not to mention that gasoline is way more expensive than water.

Coolingmist, why should people choose your system over these?
http://www.aquamist.co.uk/
http://www.snowperformance.net/products.asp?id=1

coolingmist

Most people do research and end up buying from the company they like best. Our kits offer a warranty, 7 day a week support and our up-comming controller is far, far more advanced than the controllers that are offered by those other companies.



Thanks!

David

TeamRX8

iTrader: (25)

is this a forum thread or an info-mercial?

JoeMamma

Just to fan the flames a bit, here are some other things to consider.

Unlike traditional piston engines, the rotary combustion chamber is shaped like a bathtub. The engine uses two spark plugs and even swaps their firing to help minimize or alleviate the odd flame propagation and help to create a smoother idle. Water vapor should help to stablize the burn and create a more controlled flame front, shouldn't it?

In turbo applications, water/methanol injection can offset deficencies in air/air and air/water intercoolers. You can actually get pretty near to ambient.

Again, if you're tuning to the hairy edge and run out of water, you could be in for a big expensive surprise when you find the reservoir empty and your right foot on the carpet.

Moostafa29

Joe, you have this kit? How do you like it? If I do bite the bullet, and get this kit, I think I'll get a new washer resevoir, and put the wather/methanol in the one that comes stock. This way when it gets low, a light will come on and warn me.

JoeMamma

I have another brand of water injection. I have found it to make a pronounced difference in performance and drivability, especially in warm weather when heat soak can be an issue.

I mounted the pump under the nose, and the water tank between the battery and air filter. My oil separator is on the other side of the filter. I don't have a sensor for the water tank, and check it routinely. I usually use about 1 gallon of water/methanol per tank of gas.