Water injection on a budget...

[Jamo]

If it is the Audspeed system then you halfway there to having a decent intercooler spray, I would change it to the IC spray.

The wirings all over the shop I have no idea where the sensors are, i'll have a look at some point.

[Flat on my back]

I can see it now...

We fixed your leak Sir, there was some non standard equipment on the car so we removed the whole lot!

[Rusty]

Been looking into fuel flow for the S2 to evaluate nozzle size and performance. Thankfully a contact in the automotive industry has data for a V6 S4 which is pretty much a scaled up I5 in terms of capacity and power. When the data is finished I'll post a few graphs to make the thread look technical

[VladaS2]

Thats great idea!

I also have Snow performance stage II and I am about to install it. I think it is a very decent kit, judging by the product appearence, manual and their support (answering emails). From what I understood it can be used as a supporter (cooling air/preventing detonation) or booster (mapping specifically for it, using higher boost levels).

My plan would be to install the pump and the container in the back of the car. I've seen it done that way in one coupe already.

[Rusty]

Right the. Here's some water injection requirements based on actual fuel flow data for a B5 S4 scaled down to S2 spec (2226/2671). Should be fairly close! The slope on the graph between 3k and 3.5k is produced by Excel, I have no idea what the actual response of the pump is like but it will be a constant whereas engine acceleration will cahnge dependent ofn load and gear so it'll be a bit like turo lag I susspose!

[Rusty]

...and a copy of the Excel spreadsheet I produced if anyone would like to look.

[S2central.net]

Interesting spreadsheet - I see you too the AIR mass from the map and then used AFR and specific gravity to estimate the fuel volume... Is there a reason for not taking the fuel volume figures (in l/h) off the map and converting those to ml/s ?

Maybe I'm missing a trick here - the differences aren't massive - just curious about the approach.

If you are going to do this - PLEASE get VAG-COM first so that you can log the IAT data with and without the WI system and/or the IC sprayer - that will be your best chance of objectively defining any gains. Oh an EGT probe would be great also...

I've wanted to get a twin channel air temp guage on my car for a while that monitors air temp IN and OUT of the intercooler. Along with EGT and AFR guages actually - Its all time and money that I aint got.

[Rusty]

Ooops! The spreadsheet was written before I got my hands on actual fuel flow data as I had originally been trying to estimate the air flow of the 2226cc I5. It's one of those things that organically occurs I suppose. Still, as you say, the numbers are close enough and indicate what I wanted to investigate quite well.

Paul, if you are able to fill in the spreadsheet with actual figures for a homefries then that would be very useful

I'm on the VAG com case!

[S2central.net]

Oh gawd - its a long time since I went thru the pain of those calculations...

You can actually reverse engineer the fuel flow numbers by measuring the injector duty cycle at max boost across the rev range... Knowing that, the fuel pressure and the flow rate of the injectors will get you volume per second !

VAG-COM provides some injector duty-cycle info on the ABY but I genuinely dunno how accurate it is - there may be some odd scaling factors in there.

Merits some proper investigation with VAGCOM and an Oscilloscope - preferably one that can log data !

[S2central.net]

You can extrapolate fuel info from this calculator that I created many moons ago -

The coloured cells are the ones you should adjust to taste - NONE of the others !

Cheers,

Paul

[S2central.net]

Column O gives you the estimated (temp compensated) air flow in g/s across the rev range at full throttle. I have used other calculations to estimate fuel flow (via air mass to fuel mass thru AFR) in ccpm in column AC. HTH !

[Rusty]

Cheers Paul. Based on the fact that the S4 makes similar power and torque to a remapped I5 it's not a bad assumption to just take the S4 data. I'll have a look through your spreadsheet and see how the numbers add up.

[Greg_S]

Looks like im gonna need a vagcom todo the calculations on this one. I have been looking at the aquamist injector solenoid for varying the amount of water inject making it mappable.

Now I remember in a conversation many moons ago that it may be possible to use the carbon canister valve to drive an auxilary component instead of the canister. My question is could a fuel injector be used to control the water injection by varying its duty cycle using the carbon canister wiring?

[Rusty]

The injector and duty cycle part = yes, it's used on many serious water injection systems.

I don't know about the other part.

[Jamo]

So where did you get to with this Andy?

I'm going to investigate getting my autospeed kit working on the new engine after some interesting converstations today.