What's needed for a delayed off feature?
 

Glad this forum exists!

I'm contemplating some mods, and for a couple, it would be desirable for the function to automatically terminate after a prescribed time, like let's say 10 or 15 seconds.

So for example, if I want to have my horn buttons activate an IC sprayer, I'd like for it to stay on for a certain amount of time without having to hold down the button while driving. Is something like this doable, or reasonable?

Thanks much guys!

It's pretty easy....
 

There are lots of ways to turn a pulse into a timed event. There's a venerable 555 chip, and you set the time with a cap, and maybe a resistor, it's been a while.

What I was thinking about was somthing that

best case, monitored the CAN bus so that when boost was greater than X and IAT was greater than Y then squirt away!

Next best is to get the signals from the sensors. That takes more analog electronics, but is more alligned with my skills.

Third, is to get a switch, which is easiest, but I really am drawn to the automatic spray control. I was just looking at this this morning.... I'm thinking of ditching the Xenon sprayers to power a SC spray system. I can get the hose from the driver side hood hinge area, and route to the front of the SC pretty easily... I haven't thought about the wiring yet, but getting to the pump electrical connector is pretty easy (just got my Bentley manual two days ago and saw how to do it). Alas, thinking is all I've done so far:razz:

Matt

Matt, thanks for chimming-in!

Indeed, I love the idea of an automatic trigger based upon delinated criteria, such as IAT, boost, and/or WOT, etc. I know that the UNIChip has the potential to do such, and Randy is in the process for making this happen, but for an injection (water or alcohol) unit...

I never heard of the 555 chip. I'd like to learn more, but the automatic approach is more appealing...

I too was thinking of making use of the Xenon washer system, or as Alta does, the rear window one. Then part of me just wants to scrap those for weight lost, and put a tank or tanks in the rear for a more ideal weight distribution, and to keep the fluids in a more cool environment.

Ah, I keep the Bentley manual on the night stand :wink: . Matt, if and when you start on such a project, please let me know...

"Cool" idea. I've been interested in an appropriate trigger for a water/alcohol set-up using the Alta. Don't know squat about the electronics though.

I have a timer solution... Has enable and disable, as well as the trigger it will work for a manually adjustable time. Let me know if you need more info.

What trigger(s) do you use?
 

Seems there are a few candidates...

Pedal position, RPM, boost and IAT all seem like good one. Which one are you using?

Matt

Dan, thanks for chiming-in here. Matt (the doc) and I have exchanged a few PMs on this subject, and I too would be interested to hear what you offer as a trigger. If I had a first choice, it would be IAT :wink: . Heck, then I can use the horn buttons for something else, like maybe two devices that emit audible tones to alert others of my presence :lol: .

Here is a schematic on using the 555: http://www.aaroncake.net/circuits/relaytim.htm

Would an IAT trigger not be the most appropriate? The switch would only be an "arming" switch. Must find chrome toggle...

Nice find BFG9000! From my readings, yes, IAT is the most desirable. Matt has some grandiose ideas, and I'm not sure if the 555 will be the route taken, but nice to know that it's there for us. From a thread in the Peformance forum, injection pre IC yields more gain (compared to post). I could guess why, but it's just speculation...

555 is the way to go.....
 

If you're gonna build it yourself. Drive it with some front end logic, you may need a current drive on the output, and it's done. :wink:

TPS is a 0.5 to 4.5 VDC signal.
I don't have the output functions for the T-MAP sensor. (this gives temp and pressure after the SC).
I don't have an RPM input yet.

Matt

Matt, my Stewart Warner shiftlight gets it (RPMs) right from a wire on the coil, if I recall correctly. Don't know if that's any help...

Thanks...
 

No, I'm looking for a single low cost chip way to convert a pulse train into a voltage.... Then you can compare it to a pot setting and get easy RPM based adjustable switching.

Matt

Sort of thought so... I remain a spectator with regard to such conversation :wink: I find it quite interesting!