Water Injection :)

[maximtaylor]

I think we\'ve contaminated this thread enough

Start a new thread if you have any questions / thoughts

[sdminus]

I think we\'ve contaminated this thread enough

Start a new thread if you have any questions / thoughts

LOL... :Talking1  :rollin  :spank

[fro]

Stock correction factors are:

Thanks Max, that\'s nowhere near as bad as I thought (and I might do the same with the correction table)

[dre]

Very interesting stuff, just as i\'ve bought my WI kit for RS3.

I\'ll leave the setting up to JayDee  :god  :god  :god  :Giggle

[antnicuk]

just one last question then.......... please.

Why does it put less fuel in when the intake temps are high?   commons sense says if intakes are high you are more likely to det, so more fuel would help prevent that?  why does it need less then?

in ley terms please Gents........

[fro]

I guess it\'s because hot air is less dense than cool air, therefore with cool air you\'ll need more fuel to attain the same a/f ratio?  :2Confused

[FD3UK]

I think Rob(Fro) is correct, fueling is changed to maintain the A/F ratio. The PFC retards ignition in both high air and water temps to ward off detonation.

Snap shot from datalogit shows the amounts, don\'t think you can see/adjust on the commander though.

[Mr J.T]

is this a neccissary(spelling) change? not sure what my temps are running at i usually intake at around 26-32 should i change some of the hotter temps

[sdminus]

I think Rob(Fro) is correct, fueling is changed to maintain the A/F ratio. The PFC retards ignition in both high air and water temps to ward off detonation.

Snap shot from datalogit shows the amounts, don\'t think you can see/adjust on the commander though.

That correction table is not the one Max was refering to. That one is ign timing related. Try settings 2 inj Vs air temp.

Scott

[FD3UK]

The PFC retards ignition in both high air and water temps to ward off detonation

Is that not what I said  :3Confused

[Mr J.T]

should i change my temps then?

[sdminus]

LOL. i think the picture said it with out being as blunt LOL

[FD3UK]

Perhaps I should explain myself better.

As std PFC uses the inj vs temp table to takes fuel out as the temps rise to maintain the same AFR. The table I posted is for air vs timing and water temp vs timing which shows a progresive retard as they rise to protect against detonation.

Mr J T - My advise is not to change anything unless you have a good understanding why, or recieve good advice from a tuner to do so.

[Jonathan_F]

Its no more dangerous than sitting heat soaked at the lights, then gunning it. Same thing happens - intakes drop, sensor drops slowly.

A variable WI kit wont make the sensor work any quicker!

The best solution would be to move the sensor from under the plenum to a cool location where you get a true measurement of intake temp without influence from other heat sources, but you find me a spot under our bonnets  

I believe you are mistaken.
I am warning that the moment the water switches on the temperature of the charge drops instantly as the water vapourises (latent heat of vapourisation). The ecu will find out much later as the temperature sensor is slow acting. You then run lean for a period of time at say, 0.85barWOT. This could cause det.

At the lights the intercooler and sensor both heat soak. As you drive the intercooler gradually cools and the charge does too. The sensor cools with it and the ecu corrects the fuelling at the same time. You don\'t have the same level of fueling mismatch.

In any case most tuners will have a 15% safety factor in their MAP to accomodate these shortcomings.
A better solution would be to have a fast acting sensor.
You would expect to be avble to see the inlet charge temp fluctuate with rpm and boost as the intercooler cannot cool linearly with flow rate. You do not see this because of the sensors large time constant.

If you want serious power you need to get closer to the detonation threshhold and thats when this type of water injection system could prove dangerous.

Jon

[BlitzBoy]

whoohoo Jon do you realise who Max is?? do you really think Max is mistaken?
I think I leave other people to tell you....ok I give you a clue he has mapped more RX7s then you have had hot dinners :rollin