Water Injection Nozzle Location

[iddrew 86]

Hi Guys,

 

So i'm finally chasing more boost and because of more boost, high temperatures on the island and crappy fuel i've decided to go for a water injection system. (Yes i know might be controversial but i'm confident it's going to work). The water injection will save me the 31 Euros Octane booster i have to put in with every tank of fuel (since inherently it deters knock), and allows me to have a more consistent, Air to fuel ratio without any surprises. Also keeps the engine clean from the inside which is a bonus

The 2 Main questions i would like to discuss with you bunch of bright monkeys are these:

1) Where should i place the water injection nozzle? I will also be fitting an IAT sensor to measure charged air temps which will be sitting right before the throttle body. My Concern is that if i don't find a proper location for the water injection nozzle, over time the mist will start to condense around the IAT sensor forming water droplets. Something the engine won't be too happy about. I was thinking about 2 possible locations, illustrated in this image below. Which location do you recommend? 1 or 2? :

2) Use a Water Meth mix or a Water Ethanol Mix. Adrian is an avid believer of Water Methanol and told me to go for that. But all the guys here inMalta are telling me to go with a water Ethanol mix. Their arguments are that ethanol is less corrosive on the block, you'll have to compensate less in your fuel maps for the added spray (since methanol and ethanol are fuels on the stock trims i'll be running rich so we have to dial the fuel back a bit to compensate) and an ethanol mix lasts longer than a methanol mix. What are your views on this?  

Thanks for all the help and opinions guys, really appreciate it

Kind Regards,

Andrew  
 

[smudge 1020]

Best to get in touch with @Mark@Abbey M/S

We've been talking about this as an option on my system for a while

[rob275 1817]

Now is the perfect time to unhide James' methanol thread  

James had his nozzle pre-charger though most who ran the sprintex in the states run it post charge at the back of the elbow. 

Completely different charger I know but I don't think anyone has suffered from condensation on the IAT Sensor. Which I believe is here on the Sprintex... wether that will make a difference i've no idea!

[iddrew 86]

@smudge have there been any developments on your kit? what are you leaning towards?

@rob275 i can understand the complications of having water injection with the sprintex kit since it's part of the manifold. On this HKS kit however it's much easier since there is piping between the charger+intercooler and the throttle body.

So, are you saying that the IAT sensor or whole MAF was positioned there? Or could you be referring to the MAP sensor? 
The reason i wanted the water injector so far back from the IAT is because i want to measure real charged air temperatures going into the engine as it has been cooled down by the water injection.  

Also, was there another methanol injection thread? i tried to find one in order not to double post but couldn't find anything?...

Thanks Chaps

Andrew

[Sonic 4]

hello

 

one of the best places for water injection is pre compressor

aim the jet at the centre nut to avoid eroding the compressor impeller blades

the water coming in pre-compressor will reduce the charge temp in the same way as post compressor injection but it will also mix really well  due to the compressor and help seal the compressor blades to the hosuing and improve efficency

 

and yes a mix of water / ethanol is superior to just water on its own as the specific heat transfer coefficent is better and you'll avoid corroding engine parts with any water that condenses out of the airstream furhter down the pipe

 

 

[Dan7954 35]

^ genuine question here as only just finishied my training.

I thought the specific heat capacity of water is higher than anything, including ethanol so how does the transfer improve if the ethanol lowers the specific heat capacity?  Like when adding glycol to water in coolant also lowers its capacity? Or am i missing something in this case? 

Edited October 21, 2015 by Dan7954

[iddrew 86]

@Sonic, Thanks for your input. I'm understanding your point regarding spraying pre-compressor but i might not have elaborated on my no1 reason for going water meth injection. maybe this would make a difference:

I would like to get the injection system primarily to reduce knock as much as i can so i will be able to run the same high performance map on our "below-par" 95RON fuel without having to add any octane boosters or accelerators to the fuel. (To my knowledge) having the injection system pre-supercharger will reduce temps by a lot BUT not much of that methanol will be left after going through the charger therefore not much will be left to go into the engine itself thus not getting the "best" knock deterrent possible. Where as if i were to put the nozzle right before the throttle body (post-supercharger) i might not get the lowest intake temps but i'll get the best knock deterrence possible. Is my information true or false?

Thanks for your input all

Andrew

[Jamie_GRMN 177]

To my knowledge, no water/mix injection systems are designed for the mix to be used as a fuel. They are either used as cooling in the intact tract (pre or post charger, I would always go post due to potential compressor damage), as some of your positions show. Or they are placed in the inlet manifold (or as close to) which reduces cylinder temperatures and therefore propensity to knock; this is how the set up is on a Toyota GT4 WRC for example, the water injection nozzle is just after the throttle body.

Please don't think there is any benefit from the actual ethanol/methonal being burnt as a fuel to reduce knock, this just doesn't happen.

EDIT: forgot to add where I'd put the nozzle... but I'd be going for a position close to the throttle body 

Edited October 26, 2015 by jamie_gt86