Water/meth injection: a theoretical and practical discussion

[bobhatton]

I've been thinking about water injection for my rev3 turbo. I'm using an arc smic running 1.2bar boost. After a few pulls my Inlet temps reach about 50-55 degrees. So I have a couple of questions
1. Will running water injection drop these temps?
2. I don't want to map the car again for water/meth say a 75/25 mix, will it run alright?
3. Would mounting the jet in the IC cold pipe be alright?
Cheers for any advice

1. No, water injection drops the temperature in the combustion chambers only, it does nothing in the inlet.
2. It depends how it is set up at the moment, it will run richer as you are adding fuel
3. No, they should be in each manifold runner for water or methanol.

[2mad]

1. No, water injection drops the temperature in the combustion chambers only, it does nothing in the inlet.

So you say, this cant be proven Bob.

2. It depends how it is set up at the moment, it will run richer as you are adding fuel

True

3. No, they should be in each manifold runner for water or methanol.

I would like to try this but how? with out massively over doing it spray wise.


I and people all over the world have been sprying after intercooler before the throttle body with great effect.
I would defiantly recommend this because i know it works giving a nice boost in performance



Kev.

[bobhatton]

1. No, water injection drops the temperature in the combustion chambers only, it does nothing in the inlet.

So you say, this cant be proven Bob.

2. It depends how it is set up at the moment, it will run richer as you are adding fuel

True

3. No, they should be in each manifold runner for water or methanol.

I would like to try this but how? with out massively over doing it spray wise.


I and people all over the world have been sprying after intercooler before the throttle body with great effect.
I would defiantly recommend this because i know it works giving a nice boost in performance



Kev.

I would love to see the proof that water does any cooling in the manifold, never seen any yet, so come on prove it

The first water injection site I went on are now are selling direct port injection after requests from their customers. So at least some people understand how it should be fitted and are not one of the sheep.

[2mad]

I am not a sheep Bob, I am using the wisdom of crowds, the internet says direct port w/m injection works great, you get an even flow to each cylinder, draw back not enough time to cool incoming charge.
Single jet w/m injection 12/15" from throttle body after intercooler, cools charge but posable unequal flow of w/m to cylinders.

The internet seems to say incoming charge is deemed cooled, only you from research say it is not.

It really does seem to me that everybody on the internet is wrong and your right

As for proof, if you come up with a theory to prove your theory (disprove mine) I would be happy to test it. I only want the best for my car and if your right I will gladly apologise and swich setups

[JD]

Plus how do I run 4x 0.3mm = 1.2mm of jet flow at the 0.7mm of flow I need,

Are you sure 4 x 0.3 jets = a 1.2mm jet?

How do you know 0.7 mm gives the flow you need?
How are you determining the flow you need?

Lol you've really put me on the spot here, I lost my notes from a couple of years ago and my memory is awful.. but i'll have a crack at it.. it goes something like this...


On my old car..
4 x 440cc injectors = 1760cc

1760 x .85 = 1496

15% of 1496 = 224.5cc

On this chart .. http://www.aquamist.co.uk/forum/flowrate4.gif

224.5 = 0.6mm jet but you go up one if your running meth =0.7mm jet


For 540cc injectors I have now..

4 x 540cc injectors = 2160cc

2160 x .85 = 1836

15% of 1836 = 275.4cc

On the chart above 275.4 is between 0.7mm and 0.8mm so I really should round up to a 0.8mm.

So to run 4 jets I need a 0.3mm jet to flow 68.85cc or thereabouts.

Still researching 0.3mm flow rates at the mo but I think there around 155 cc/min way to high

Hmmmmm.

I've just been on the phone to coolingmist about which injectors to use with a direct port setup for between 350-400fwhp on my MR2 and they just said their 'CM2' which is the smallest they do. They advertise these injectors as flowing at between 180cc to 250cc per minute, and I was thinking that this just seems way more than I need. Devils own sell a wider range of injectors (all the way down to 63cc per minute), without mentioning size, just flow rate.

According to your work I need to think about going for the smaller Devilsown rather than the big little ones from CM?

[2mad]

The 63cc per minute jet would be perfect for me running 550cc injectors if my pump flowed the same as a devils own pump, I will look in to it , cheers buddy ... For you your looking at flowing 15% w/m at what ever your max idc is, say 85% .. Its not an exact science from what I have learned you can be out a bit .


Try and find a devils own calculator to work out your exact flow if you can this will give you the jet size you need .. but you would need to be running a devils own system. The pump probably flows at a different rate to aquamist .



Best of luck

[JD]

Devils Own calculator seems to have bitten the dust and doesn't exist on their sites anymore so I would steer clear as it's potentially been taken down for a reason

DO pump advertised at 1.0 GPM / max 300psi
CM pump advertised as 1.3 GPM / max 300psi

DO nozzles available:
DO1 (63cc/min)
DO2 (126cc/min)
DO3 (189cc/min)
DO4 (252cc/min)
DO5 (315cc/min)
DO7 (441cc/min)
DO10 (631cc/min)
DO12 (757cc/min)
DO14 (882cc/min)

CM nozzles available:

CM2 (180 to 250 cc/m)
CM3 (250 to 300 cc/m)
CM5 (280 to 340 cc/m)
CM7 (10 GPH)
CM10 (approx 800 cc/m)
CM12 (1100-1200 cc/m)

I think I'm leaning toward the 63 cc/m nozzles from DO - can the more scientific among us confirm this as the best course of action?

[2mad]

Without knowing your injector size I cant work out how much you will need to flow (cc/min) per jet . If you know your max injector duty cycle number, even better.

[JD]

Gonna put 800s or 850s in (SARD or BLITZ - whichever I get because the set I previously had was too unbalanced)

Max duty cycle on my 540s is 97%

[2mad]

@800cc guessing your idc is 85%

4 x 800cc injectors = 3200cc

3200 x .85 idc = 2720

15% of 2720 = 408.0cc

408.0 divided by 4 = 102.0cc


This is the maths most use if im wrong people please point it out .


Remenber this only works with 100% devils own system. I dont know if a aquamist shurflo flows the same .


To work out your atcual flow in cc/min ..

You would need to bench test so to speek..

with your system hooked up, car running ..

switch on your w/m system with each jet in a 2l bottle .. run for one minute .. then visually check all 4 flowed the same ..

Then pour one bottle in to a beaker measuring in milliliters ..

The amount of milliliters in the beaker is your cc per min iirr.

This will give your accurate flow per jet per min.



Hope i'v remembered right its been years since I researched this

[2mad]

Remember you can be out a bit, your looking for 10 to 15% of your injector sizes max idc .. Going over a little bit wont hurt .

[2mad]

Max duty cycle on my 540s is 97%

With this setup (running 540cc injectors) just like mine, running a devils own system and a 4xdo1 jets would be fine .

[JD]

i reckon with 800cc injectors, the DO2 with the CM pump will be fine. I know it's not calibrated and exactly to spec but i'll speak with DO tomorrow and see what they say :\

[2mad]

i reckon with 800cc injectors, the DO2 with the CM pump will be fine. I know it's not calibrated and exactly to spec but i'll speak with DO tomorrow and see what they say :\

Don't see why DO2 jets wouldn't be ok for your application (see what DO say).. I would love to see your progress pics if you go ahead with it .

[JD]

Well, after speaking to DO, and factoring in that I'm realistically not going for anything more than 400fwph, if that (GT28RS), they recommended the DO1s and said that using these with the CM pump will be fine.

[2mad]

I'm not going to argue with devilsown they should no best .. really looking forward to seeing your install jd if you dont mind posting a few pics and letting us know how you get on with the setup


Best of luck

[JD]

thanks for your advice and certainly will do a few pics when i'm done. since I've decided to go direct port I've asked Rogue to do the work. Once I've sourced all the bits I'll get it up there and let you know how I get on

[JD]

I picked up a spare inlet mani from IMOC's own Julian KV (many thanks) earlier this evening and since 1:30am is not even close to bedtime at the minute (ugh) I have sat down and thought about marking up were the injectors will go.



This look alright to y'alls? Too close to the head? I'll be using 90º holders for the injectors.

Considering proximity is it worth upgrading to a phenolic gasket?

[2mad]

I would have gone as high up the runner as i could .. to give atomization a chance (giving w/m time to mix with incoming charge) and probably fitted the jets to the rear just for clearance .. I dont think there's a wrong way jd as long as you have no clearance issues , just my thoughts and its very early lol .

[masterbateson]

Havent had a chance to read this thread, but as i have just discovered a water leak from the bathroom is coming through my dinning room ceiling I'm not going to get the chance for a bit.

But I did want to mention on a slightly related subject.

Over on mgrover.org there was a thread on a car that was for sale on Eblag, basically it was a rover 25 diesel that some clown had decided to inject Propane into

Now Allegedly/apparently you can do this (if you do it properly with a proper setup)
This joker though had just piped up a calor gas bottle behind the front seats in the footwell(not secured) ran some of that orange rubber hose under the carpet and thru firewall and looked like he was just sticking other end of pipe into the airbox!
I think before long he is going to get a much improved bang for his buck.

One way of improving the detonation.