In progress my Custom water Injection! Need some Help!

[diegom6]

I'm currently buildingmy aluminum reservoir tank for add water injection in my turbo bimmer...I'm looking now for the propper Nozzle.

My main question is, how can I activate this etup when I only make enough boost and then from a "general" On/off switch can work?

I mean, ok, I turn the general system On, and the system is ready to spray, but just when is enough boost...what can I add at the engine to control this tricky part?

I was thinking to add a kind of 1-2 BAR MAp sensor, so when it reads enoguh boost (preset by me) activated the system...or there is another way to do this??

Thanks

Diego

[UNHCLL]

Are you running an SMT-6 or similar type engine management? I'm sure their must be some sort of provision in there to do exactly what you're talking about.

I'm not much more help than that :(

[Snowmann]

well I know MSD has their RPM activated switch that you can hook up to anything... not sure if they have something for boost or maybe you can rig it to work for your application :?:

[mspiegle]

i don't have my laptop in front of me, but i know in one of the option menus, you can select certain events that trigger a switch. I believe there are 3 options, 2 of which are rpm and throttle... i forgot what the other one is.

My idea on making water injection consisted of using a very small fuel injector hooked up to the SMT6's additional injector driver. Then, you can use the injection map (3rd one) to control the open/close of the injector. The only thing I don't know is if you leave a 0 in the map site - does that keep the injector closed? It would be kind of like building another fuel system. Also not sure if there are any corrosion issues with running water/alcohol through an injector.

I believe another option is a special boost-activated switch. I want to say its called a hobbs switch... but i can't remember for certain.

If I ever get the smt6 water injection method up and running, i'll let you know. I should hopefully have my 928 running with roots pushing 4psi non-intercooled tomorrow assuming i find all the goodies i'm looking for.

[diegom6]

Yes, I have SMT6 but I didn't finish wiring all the cables, left spark, fuel and other that are mostly for options...

Here is what other guy showed me...

But I would like to have one that can be regulated, it seems like you have to buy it with a preset factory pressures, if buy % PSI it will activated at 5 PSI I want one regulable!

and yes it's called Hobb Switch I didn't know that... :oops:

[E30godz]

are you talking about a system that shoots out more water when it sees more boost?

[diegom6]

are you talking about a system that shoots out more water when it sees more boost?

Nope, just activate the Nozzle or the system when it reads boost ( well I would like to have that switch regulable to set the boost level that I want) and then have a mnain On/Off switch inside the car, so if the switch is OFf for example...the sensor will read the boost (preset by me) but won't spray, but if I turn On the main switch I t will spray and tthat boost.

I don't want a system that reads some boost and spray certain amount of water/alcohol and then if is increased the boost pressure will increade the water/alcohol amount...no I don' twan it...justactivate it for a good amount of lfow preseted by me...

[E30godz]

quite easy to do, here is a great write up on it:

http://www.lehigh.edu/~erp4/saab/Upgrades/WaterInj.html

[mspiegle]

i don't really know jack shit about turbos, but do they make boost if you aren't really on the throttle?

I think it might be easier to just use the SMT6 to turn the mist on @ 80% throttle or something like that. And yeah... it sucks that hobb switches aren't selectable.

One idea that might be overly excessive... is there any kind of mechanical device that will stay closed until you hit a certain boost - then open and allow air through (isn't that a blowoff valve)? I'm thinking, you can put that inline before the hobb switch, and buy a hobb switch that activates at a low (4psi) setting. This way, you can select the boost with the "regulator" device, and when you hit your selected boost, it will open, flow to the hobb switch, which will activate (and it will always activate since your hobb will be a low psi switch and you're always going to send it more than that).

[skat 325is]

Diego, get a preassure switch to activate the water injection. Should work the same as with fuel injectors.

[diegom6]

Diego, get a preassure switch to activate the water injection. Should work the same as with fuel injectors.

yeah, but how can I set at the boost that I want the switch? I would like to get regulable switch, there is one out there ?

[PeterCip]

yeah, but how can I set at the boost that I want the switch? I would like to get regulable switch, there is one out there ?

Yes you can have a switch that you can set the preset boost pressure. My switch has an operable range form 3 PSI to 9 PSI. there is an adjustment screw( like the ones you would see on a FPR) that allows you to set the pressure. Mine came preset at 6 PSI and I adjusted it to run at 7 psi.
Look at systems like aquamist and the Spearco water injection systems. you cna either buy a switch from them or source a similar one elsewhere.
hope this helps,
-pete

[diegom6]

mmm that's good to know...there should be more bopost switches (high range of pressure ) out there...I wonder where to look more...I searched in ebay and found a boost switch from Porsche I will keep searching...but a regulable unit..

Thanks

[diegom6]

Found one in Ebay, I wonder if thids unit will do the job well...??

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2459384408&category=33557

[PeterCip]

Found one in Ebay, I wonder if thids unit will do the job well...??

http://cgi.ebay.com/ebaymotors/ws/eB...category=33557

should work just fine..