Hi there,
My previous objections to fitting water injection have been that once the car is tuned for it, if you run out of water on full boost one day the engine can go pop.
I don\'t want this.
Therefore, what about this possible solution:
*) Change the air temperature sensor for that fast reacting one (http://www.mazdarotaryclub.com/forums/showthread.php?t=26579) in another thread.
*) Change the apexi PFCs AIT retard facility so that it retards the timing a lot earlier - say at 40C degrees
Then, if you run out of water and the temp shoots up, the PFC knows about it much quicker and the timing is retarded to save the engine.
What do you guys think about it? :)
Cheers, Paul.
If your running a boost controller, then you could force the lower boost setting when the water runs out.
I plan to use an eManage to control larger injectors, and in addition control the water injection based on boost pressure. If the water runs out, the eManage can limit the power available.
Quote from: ProfIf your running a boost controller, then you could force the lower boost setting when the water runs out.
I plan to use an eManage to control larger injectors, and in addition control the water injection based on boost pressure. If the water runs out, the eManage can limit the power available.
Thats the other way to do, i guess. Don\'t think you can do that with the PFC, however. :-/
Cheers, Paul.
Why not just run a water level sensor with your water injection kit, with an led inside the car that lights up when you are low on water?
If using the ERL injection kit, just add the DDS 3. This will show how much water is flowing.
Fish
Problem with that is the interface between the seat and steering wheel does not always react correctly to the led :driving :D
In all seriousness, if you can provide some kind of automatic \'ease-off\', it may prevent damage in a moment of over exited driving. :Thumbs-up
Has the FD got a warning level indicator on your washer fluid? If so perhaps you could use that for your water injection? I dont use my washers as I did want to drill holes in my bonnet :)
Quote from: rotaryimports.comWhy not just run a water level sensor with your water injection kit, with an led inside the car that lights up when you are low on water?
I\'d rather have something totally fool proof, because as Prof says, **** happens! :)
Ta, Paul.
If you are that worried, why dont you just have the water there for safety.........i.e dont tune for it?....that way your covered either way?
Quote from: Ed_RX7If you are that worried, why dont you just have the water there for safety.........i.e dont tune for it?....that way your covered either way?
I guess because if i had it on there, i\'d want to tune for it, otherwise you miss out on all that potential. :)
Also, my plan isn\'t actually difficult to implement - the temperature sensor should plug right in and a mapper can adjust the PFC\'s retard threshold really easily.
I was just trying to gague whether ppl thought it would work, really...
Ta, Paul.
Just having a look on google and found this level switch.
http://www.enginerunup.com/parts/low-level-sensor-float-switch/prod_11.php
When i ordered my cooling mist kit i also got them to send me a low level switch as well that fits in their supplied containers, when i finally get round to fitting the WI i will fit the sensor a few inchs from the bottom so when it does go off i still have plenty left, couple that with the fact that the injectors have blocked nozzle warnings that light up LED\'s on your dash will make it a pretty safe system.
Nick
I have the coolingmist kit as well - with the clogged nozzle detector.
I was planning on having a larger tank in the boot, and using a switch to feed a low pressure pump to top up the smaller tank in the engine bay. This keeps the piping short for the high pressure side.
I was still thinking of an elegant way to kill the low pressure pump and cut the max boost when the water nearly runs out in the engine bay tank - maybe I need 2 switches set for different levels, or 1 switch in each tank.
I still think vxer is on the right track by wanting to build in damage limitation. It\'s way to easy to ignore a led on its own - a buzzer is a bit more difficult to ignore ! :D
Also why bother with WI if you don\'t need it / haven\'t tuned for it? :confused:
I suppose if you was good with electronics then you could fit a boost controller with a high/low switch, then instead of having the manual HIGH/Low boost switch remove the switch and connect the wires to a relay that was switched by the low level sensor in your water bottle.
That way you get high boost when you have a full bottle and as soon as the low level sensor triggers it switchs the relay and turns your boost controller to low level boost only till you top up again.
Nick
I\'m using the profec B spec 2 - which has a switch input - problem is it toggles the boost setting rather than switches to Hi or Lo. :(
sounds to me like its getting a bit more complicated than it need be......
Complicated for sure, but then having a WI system that also has a failsafe built in is never going to be easy to do.
Nick
the more complicated you make it the more likelyhood there is something may go wrong, especially DIY jobbies that arnt tried and tested. Aquamist seem to think that a flow indicator is all that is needed. i dont think many of the people using w/i to run seriously fast cars have much more than that.
I was quite lucky as the TII has a headlight washer bottle with a low level indicator in it and a warning light on the dash board. I removed the low level sensor and fitted it in my w/i bottle.
You gotta remember that you only get a light on your dash if you oil runs out in most cars, Rx7 also have a buzzer. Your engine may survive without w/i but it wont without Oil.
I\'m sure it would be very simple to wire in a buzzer and light with a low level sensor. That together with your flow sensor is more security than you get for anything else on the car failing....
Just my thoughts and experiences though.
I quite agree Ant, my WI when i fit it will have the clogged nozzle detectors and low level warning and thats all.
But the original post was asking how to make a WI system with a failsafe and thats never gonna be an easy thing to do and the only way i can see of doing it is to have it connected to a boost controller of some sort.
Be nice if there was an easy non complicated way of doing it tho.
Nick
All valid points chaps - and I do subscribe to the Keep It Simple Stupid school of thought.
The simpler a thing is, the more likely it is to work. That said, the worse performing part in any control system is usually the human/machine interface. :Hammer
There are probably lots of simple things that can be done to prevent a WI system failing and possibly doing damage to an engine, which don\'t involve a human having to do anything.
Don\'t forget even Mazda put some fail safe features on the REX - if the boost solenoid dies you get spring boost only, if too many sensors register problems the ecu goes into limp home mode, there\'s the disastorours rear rotor fuel cut, apparently even the rotor housings were teflon coated - when the engine is first run, the teflon melts into the micro pores in the surface, and if the engine overheats, the teflon comes back out in an attempt to stave off an oil loss overheat.
For me the best form of failsafe is one that operates its own control - not tied into any other system so it\'s not dependant.
Be intersting to see what results ? ;)
Running a two stage system on mine i\'ve wired two mega bright LED\'s to each boost switch a red one when its off and green when its on. So as i come on boost i can see when each stage comes on line as the led\'s switch from red to green, also makes it easy for tuning the system as you can see each switch on point. Don\'t forget if running W.I. and you start running a methanol mix that its corrosive to Aluminium so your as well using the plastic washer bottle with the bonus its got a low level light. If your worried about capacity you can always get a second bottle with built in pump plumbed into the main one. I use a gen 1 one Then when you get a low water light its just a case of flicking a switch to top up on the move from the reserve bottle.
Kevin
I also agree that simple is best. However, i still can\'t see the problem with my original proposal?
All the components already exist, its just a sensor change and a remap parameter - you may even be able to adjust the setting through the commander!
Job done? :)
Ta, Paul.
Nice thought, but......
If you tune fully for the full advatanges of water injection as you suggest, that\'ll mean running far leaner than you would otherwise, as well as running more advance.
Using the Air temp retard function as you suggest would work for timing (what about heat soak, hot days??), but you would still need to somehow work out a way of either dumping the fuel back in if the WI system fails, or automatically lowering boost.
As NixRX7 has said, you need to detect blocked jet, water out, pump failure and you could link this to a boost controller.
As Vxer has said, the technology does exist.
Most boost controllers such as the Greddy Profec b have a connection for a remote switching harness (to switch remotely between high and low boost).
Most WI kits can be supplied with means of detecting blocked jet and no flow with an output signal which could be linked to this switch.
Do some hunting around and I\'m sure you\'ll manage it in the end!
Et voila :)
http://www.aquamist.co.uk/cp/806-425/806-425.html
Look at this diagram and you can see what you need to do:
Quote from: maximtaylorIf you tune fully for the full advatanges of water injection as you suggest, that\'ll mean running far leaner than you would otherwise, as well as running more advance.
Using the Air temp retard function as you suggest would work for timing (what about heat soak, hot days??), but you would still need to somehow work out a way of either dumping the fuel back in if the WI system fails, or automatically lowering boost.
Ah crap. I\'d forgotten about that pesky fuel thing! :) Heh heh, guess thats why i don\'t tune my own cars, huh? :)
Its a shame i have to invest in a boost controller... Actually, if i could lower the boost when i needed to, would that cover the possible lean condition?
Cheers, Paul.
edit: i\'ve just realised that its obvious that it would sort the lean condition! Duh. Anyway, i wonder if there is a way to get access to the PFC\'s second boost setting and automatically triggering it somehow....?
Quote from: vxeredit: i\'ve just realised that its obvious that it would sort the lean condition! Duh. Anyway, i wonder if there is a way to get access to the PFC\'s second boost setting and automatically triggering it somehow....?
yes there is, but you\'d need the datalogit box to do it with!
If i were to run water injection *without* tuning for it, i\'m presuming the ECU can adjust fueling to compensate for lower AIT (since it would need to cope with winter, for example) and therefore gain performance*?
The question is, if i was able to tune for WI what margin of power difference are we talking about?
Cheers, Paul.
*) Currently 50 degrees AIT is the coldest i get during a run(!)
The Power FC corrects for air temperature, yes.
You could probably gain around 5-10% power by leaning the a/f\'s out.
But you are low on safety margin if things go pete tong ;)
What are people using as water tanks and where are you fitting them?
Thanks
Fish
im using a ali fuel tank in the boot a 4.5lt one only usin the wi for a safety feature, not to tune too |:)
i am using the uk rear washer bottle..depend on how often u use the boost as reagards refilling..i wldnt leave it longer than a few days in between though.better to keep it topped up
Fuel cell in the boot - 5 gallon, but i tend to run it half full.
Max is that half water, half meth? ;)
Being a UK car, I have the rear washer bottle, but I prefer to keep that as a windscreen container.
Fish
100% water most of the time, around 20% meth when I remember to put some in :Hammer
Just got to work out where to put the pumps now.
Remind me, why do we do this?
Fish
It stops us getting bored - watching big brother, and other brain destroying reality shows ;)
Quote from: maximtaylorThe Power FC corrects for air temperature, yes.
You could probably gain around 5-10% power by leaning the a/f\'s out.
But you are low on safety margin if things go pete tong ;)
Sure - i think the only way i can go with water injection is to not tune for it. Seems a shame, but its the only way to be fool proof.
Now, is there a formula for AIT drop vs power increase?
Cheers, Paul.
stupid question mode on (yes my specialist subject) how do you test for what with WI cause i think mine has stopped doing it\'s funky thing judgiung from the intake temps not going down now when i give it some boost. Unscrewed the actual nozzle & i can blow thru it so presume it\'s not blocked (awaits to be told wrong) & it has water in bottle. HGaven\'t checked for any loose pipes etc as yet but is there an easy way to test various bits. I recall Pip used a hand held thing he plumbed into pipes to squeeze & give boost without engine being on, was suggested elsewhere i kud try a footpump with small adapter to do this but seemed a bit bodge to me....
Guess there\'s not much to go on but any cunning plans or help wood be appreciated?
Ta
Si
Can you not trick the pump into working? Might be a fuse or something.
Fish
thats kinda what i was guna try & do by sticking sum pressure in the pipe so it thought it was over .5 bar or so & should work, if not then obviously with kmy skills i\'ll need to get my wallet out & get sum1 with knowledge to check such things :D
Ta
Si