WOT switch with a @2 second "add on"

I am toying with the idea of adding a WOT switch that will control an Electric Fuel pump. I have a 5 speed and would like some sort of "device" that maintains power for a second or two after lifting for a shift. ( yes i have a TKO).

anyone have one of these?

sounds like you need a capacitor of sorts...

Check McMaster-Carr. I betr they have a timer that will work for you.

So is the pump normally off?
Is this for nitrous use?
why the WOT switch?
How critical is the timming?

I think a simple 555 timmer circuit with a driver transistor would work. Probbably cost less than $10 in parts?

Some vehicles had a WOT switch to disable the air conditioner. You could use one of those with a relay.

Google "microswitch", or "Micro Switch", and also using the Google "image" search. Microswitch, and other competing brands, make literally HUNDREDS of syles of switches.

Any heavy truck shop carries a few of these. They are used in various places in over-the-road trucks.

whoa, I wish I knew what you were talking about. The timing is not critical. I just do not want the electric pump to be on for 2 seconds, then off for a second or so an then back on for a few seconds. I just need to keep it on during the time period when i lift on the throttle and shift. Now I know i should not have to lift,,,,but i do have a TKO!

Any one know of a "store bought " settup?

If you are using it with nitrous you don't want the pump on the WOT switch anyway.

expensive solution. but get a RPM variable relay box made by areomotive to run your fuel pump. at low rpm it runs your pump at lower voltage. when you hit higher rpm's it automatically runs full voltage to your pump. you can run a over ride switch so you can run full voltage to your fuel pump so it runs wide open when you want it to.
i have one in my car. it has worked perfectly for 30,000 miles. i have a A1000 pump, bypass regulator for a carb with a return line, and a rpm relay box. expensive, about $900 for all 3 new from summit, but it works.

i know Barry Gant makes a relay box also that works similar to the areomotive but his is run by switches. there have to be other makers or relay boxes also. i don't think it would be to difficult to make your own with 2 relays and a resister. run keyed power to one relay that goes thru the resister to lower voltage when you are just driving around. and run switched battery power to the other relay to over ride the the resister when you want to get beat on it. if you want to get really fancy you could hook up your fuel pump to a rpm activated switch connected to your ignition system to get full voltage to your pump at a certain rpm.

I wish I had my schematic capture software. It is in storage from when I moved since I havent done any circuit design in five years. Got a job that is mostly software, so I haven't needed.

Found this on-line:
http://www.uoguelph.ca/~antoon/gadgets/555/555.html

This is more related:
http://home.cogeco.ca/~rpaisley4/LM555.html#20

Circuit #2 - When Switch S1 is grounded, the output go high, when the switch is released (open), the output will remain high for a time period of 1.1xRxC. The circuit shows a 10K resistor and 1uF cap for a 1.1 second delay.
To get two second delay, just double the cap or resistor value (I recommend replacing the capacitor with somthing like a 2.2uF low leakage version.) Anyhow, the output probbably dosen't have the drive power for the relay? (I would have to check a spec sheet.) Just use the timmers output to drive a transistor that is rated for about 1-Amp, aand use the transistor to drive the fuel pump relay.

ouch, what a read that is.

I am going to have to study that one. I think it is wayyyyyy beyond my ability to even begin to understand. I was hoping that there was some box i could just plug into.

can you just buy on of those timers?

I already have one of those Aeromotive speed controllers ( for sale in the parts section BTW).
I took off my entire electric setup ( now kinda wishing i had not)

I just need a littler boooster once in a while.

No NOS on car

RPM activated switch----that may something to look into. Say, have the pump come on above normal driving ( 3000 rpm)

I'm kinda confused here... no nitrous? What is this for? Meth or water?

Are you running more than one fuel pump? The fuel pump normally works full time. What exactly are you trying to accomplish? The acceleratoer linkage has nothing to do with the fuel pump running.

Its been years since I discovered this working at the dealer so details are foggy..

Go the bone yard and find a '80s RWD Lincoln (Continental/Mark/maybe Towncar) equipped with cornering lights. Attached to the column area underdash there are 2 cornering lamp relays. they look like t/s flashers but IIRC the two are spot welded together on a small bracket. They are fed from the t/s circuit and remain ON for a few (7?) seconds AFTER the t/s switch cancels. Prolly not enough amp capacity for a fuel pump but more than enuf for a relay.

Hope i got it right
Pete

In your current setup is the WOT switch used to ground the fuel pump relay, ot supply the +12 volts to the relay?

Simple solution. Don't lift while shifting.

Ok, seriously. This is a pretty off the wall idea, the 2nd pump but I don't think you'd hurt a pump turning it off and back on while you shift.

Sorry that i have not been more clear.

It probably would not hurt the pump, but it would give a more consistant flow.

This setup would be used to "Occasionally help" the Mechanical fuel pump that would be used 100% of the time. I do not want a second pump for any Nos or any other fuel line,

The Lincoln cornering light is along the line of what i was thinking.
I could always just put a toggle swich on the dash, fip it on , hot dog the car , and then remember to turn the pump off.

It is sure starting to sound like the simple solution. I just like gadgets ! I thought there might be some little box i could plug in and it would work.

Thanks for the ideas.

this could be a solution.

http://store.summitracing.com/partdetail...mp;autoview=sku

I could set it at 3000 rpms and it would stay on above 3000.