Aquamist WI strictly as a SAFETY measure?

denial · Mar 8, 2006, 02:31 PM

I've looked through the water injection forums and perused turboICE's WI paper but still didn't quite get the answer I was looking for.

All I want is that the car not blow up on me when I take it out on a very HOT and very HUMID day for a 20 minute lap sessions or after it's been sitting and heatsoaking right before an autocross run.

Normally I would throw in a couple of gallons of race gas and call it a day. But I was thinking instead of the race gas, why not use a power permanent setup ie Aquamist.

Most of everything I've read is focused on being able to lean out the AFR's, advancing the timing, getting a better mix, and getting more power. I don't any more power for right now, I just want to be able to flog the car damn hard without worrying about anything else.

Assuming I already have a good, non-aggressive tune, how do I go about doing this? Should the water/fuel mixture be less than the recommended 10-15%? Could I just add let's say the Aquamist 2d setup, throw on a 0.5 mm jet (or something smaller perhaps), and call it a day (@ ~350 whp)? I mean, would this be equivalent in terms of knock resistance as adding race gas to a tank before a track day?

jj_008 · Mar 8, 2006, 03:03 PM

That is what I do w/ my Aquamist 1s system. I use it for extra security on hot days.

denial · Mar 8, 2006, 03:05 PM

what jet are you using and what psi is your pressure switch set at?

jj_008 · Mar 8, 2006, 03:17 PM

I use a .7mm, but I have a bigger turbo. My system activates at 16psi.

denial · Mar 8, 2006, 03:21 PM

How much hp you putting down? I can figure out the water/fuel % from that roughly.

So do you just spray this thing on top of the regular tune with no specific maps for the WI?

jj_008 · Mar 8, 2006, 03:28 PM

400whp on 92 oct, which is the only time I use it. I run a windshield washer fluid that is roughly 30-40% methonal/alcohol. I have no map for it. I do know I lose HP doing it, but my knock logging shows a decrease in noise.

denial · Mar 8, 2006, 04:06 PM

thanks for the input.

EDIT: with 400 whp and that 7 mm jet (flow 260 cc/min @ 5 bar) that's about a 9% water fuel mixture. Guess I'll shoot for somewhere around that too.

denial · Mar 8, 2006, 08:14 PM

anyone else have any comments?

suggestions/opinions on the water/fuel mixture I should run with my goals?

Richard L · Mar 9, 2006, 11:20 AM

Quote:

Originally Posted by denial

anyone else have any comments?

suggestions/opinions on the water/fuel mixture I should run with my goals?

Had some trouble with my server, not able to access the internet after work ( do most of my net-work in the evenings).

A 0.7mm might be a bit over-kill with 100% water, overall cooling effect is equavalent to injecting 520cc/minute of methanol. If you can run 50W/50M, it will give you good balance inlet and in-cylinder intercooling without affecting your a/f ratio too much.

running 10% w/f ratio, it is a good all round safety measure. If you go for more methanol, you need to incease your jet size as well as trimming some fuel. If the supply is interruped, you will run the danger of over lean.

Richard L

denial · Mar 9, 2006, 12:40 PM

In reference to water methanol mixtures: when you're calculating the "water" part of the w/f ratio, do you make the simplification that the "water" part is still indeed all water despite it actually being a 50/50 mix of water/meth?

So if I have ~410 hp at the crank, I would need to flow ~205 cc/m for a 10% w/f ratio. I'm thinking a 0.5 jet for my car.

Just to be sure I understood you: for maximal inlet and in-cylinder cooling with minimal effect on the overall AFR, run a 10% w/f ratio, the "water" being 50% methanol. Correct?

Thanks for your help Richard.

Richard L · Mar 9, 2006, 02:07 PM

Quote:

Originally Posted by denial

In reference to water methanol mixtures: when you're calculating the "water" part of the w/f ratio, do you make the simplification that the "water" part is still indeed all water despite it actually being a 50/50 mix of water/meth?

So if I have ~410 hp at the crank, I would need to flow ~205 cc/m for a 10% w/f ratio. I'm thinking a 0.5 jet for my car.

Just to be sure I understood you: for maximal inlet and in-cylinder cooling with minimal effect on the overall AFR, run a 10% w/f ratio, the "water" being 50% methanol. Correct?

Thanks for your help Richard.

You can inject between 0-100% water/methanol. As you approach beyond 50% mix. The alcohol content begins to have some effects on your a/f ratio. If you don't trim your fuel according;y, you will start to loose power due to slowing down of flame speed from excessive CO.

At 10% fuel to "mixture of 0% to 50/50", the afr change is mimimal. But you will get a great deal of cooling due to the latent heat of water. As you run more % methanol, The overall cooling effect will be reduced (methanol has only 50% latent heat value of water. So I am advising you to use a bigger water jet to compensate the loss of cooling by latent heat.

I have created a chart last year which I posted to this forum but received little interest as the concept of water injection was not very well known on this community. It appeared after six months on, the same topics is being discussed by the community without prompting. I suppose I was over keen to discuss this aspect of WIA concept a bit too early.

You can see how the WIA ratio change depending on your application. The charts are for the sole purposes of visually showing the cooling effect of each ratio. It has been done on separate charts rather than a 3D-surface plot.

Aquamist (Water injection) questions and answers here...

I hope those are the answers you are looking for.

Richard

TTP Engineering · Mar 9, 2006, 02:13 PM

Quote:

You can inject between 0-100% water/methanol. As you approach beyond 50% mix. The alcohol content begins to have some effects on your a/f ratio. If you don't trim your fuel according;y, you will start to loose power due to slowing down of flame speed from excessive CO.

At 10% fuel to "mixture of 0% to 50/50", the afr change is mimimal. But you will get a great deal of cooling due to the latent heat of water. As you run more % methanol, The overall cooling effect will be reduced (methanol has only 50% latent heat value of water. So I am advising you to use a bigger water jet to compensate the loss of cooling by latent heat.

I have created a chart last year which I posted to this forum but received little interest as the concept of water injection was not very well known on this community. It appeared after six months on, the same topics is being discussed by the community without prompting. I suppose I was over keen to discuss this aspect of WIA concept a bit too early.

You can see how the WIA ratio change depending on your application. The charts are for the sole purposes of visually showing the cooling effect of each ratio. It has been done on separate charts rather than a 3D-surface plot.

http://forums.evolutionm.net/showth...t=153292&page=1

I hope those are the answers you are looking for.

Richard

Showoff

The world is ready to accept your knowledge now Richard.

denial · Mar 9, 2006, 03:38 PM

I did see your graphs when I was initially researching the topic, but at the time I honestly didn't pay attention to them. I should have given them another look now that I better the concept. They have all the information that I need.

Thanks for your help.

denial · Mar 9, 2006, 04:35 PM

I'm somewhat hesitant to ask this, but I have a question about reading the graphs (addressed to anyone):

All the graphs were for a 3% water/fuel ratio, but what would the A/F ratio be for the 12% water/fuel ratio given the same water/methanol mixture? Is there a graph of the estimated A/F ratio for different water/fuel ratios using different water/methanol mixes? Or is it extrapolatable from the current ones?

Sorry if this is blatantly obvious, or if I am just not even understanding it right; I'm honestly just trying to sort some things out.

Richard L · Mar 9, 2006, 06:33 PM

Quote:

Originally Posted by denial

I'm somewhat hesitant to ask this, but I have a question about reading the graphs (addressed to anyone):

All the graphs were for a 3% water/fuel ratio, but what would the A/F ratio be for the 12% water/fuel ratio given the same water/methanol mixture? Is there a graph of the estimated A/F ratio for different water/fuel ratios using different water/methanol mixes? Or is it extrapolatable from the current ones?

Sorry if this is blatantly obvious, or if I am just not even understanding it right; I'm honestly just trying to sort some things out.

The charts only showed the cooling effect of different combination of water/methanol mixtures at a given gasoline a/f ratio. It was not intended to show the resultant a/f ratio of the mixture.

I can add another trace to show the indicated afr of the mix. Please note the when you are injecting 100% water, the resultant afr plot will be the same.

Glad you have pointed that out, people may read the chart as a calculation of afr and not a calculation of cooling by evaporation.

There must be some mathsmaticians here willing to make up another chart for that purposes.

Richard