Temp switched relay?

[Dell'Orto]

Am thinking of using a fan switch to trigger a relay to turn on the pump for my W2A. Using a 4 pin relay, would I use the fan switch as an earth (assume the fan switch is NO) or a switch to turn the pump on?
Edit: In my head I had it something like this, would this be correct?

Brad

[gt4dude]

really? I'd just get a positive output from the whatever electronic thermostat as the relay tripper, the relay itself doesn't need an acc feed since the electronic thermostat already has one.

[Dell'Orto]

Electronic thermostat?

[gt4dude]

Like the one in the bottom of ur radiator, tells the fans to turn on

[Burning Angel]

most fan switches are NC and the fan is wired to the NC contacts on the relay so when the fan switch reaches temp or is unplugged it goes open circut and the relay is de-energised switching the fan on

[gt4dude]

Yeah thats the one, if you forget to plug it in your fans run full time

[gt4dude]

switching on the intercooler pump should be done by another method though, like with psi, throttle or speed.

st205 runs for 20 sec triggered by pressing the throttle,

reason being is if you circulate water while stationary, you spread heat soak through the entire system, so when you do get moving, theres more water that needs to be cooled down before you can get your charge cooler full of ambient temp water.

i think circulating water by temperature is going to either give you a delay in activation, or triggered by heat soak while stationary

So perhaps if going the temperature route you also run some fans on the heat exchanger

[Dell'Orto]

switching on the intercooler pump should be done by another method though, like with psi, throttle or speed.

st205 runs for 20 sec triggered by pressing the throttle,

reason being is if you circulate water while stationary, you spread heat soak through the entire system, so when you do get moving, theres more water that needs to be cooled down before you can get your charge cooler full of ambient temp water.

i think circulating water by temperature is going to either give you a delay in activation, or triggered by heat soak while stationary

Hmm, thats a good point actually....maybe a micro switch on the accelerator pedal could be a better way to trigger it, but then I'd need some way to keep it going for a set period after lifting off - electronics isnt my strong point!

[gt4dude]

Jaycar has some really useful bits of kit which will do the trick aslong as you're handy with a soldering iron, I think it would be a simple kit too with a 555 Timer.

Unfortunately theres nothing you can quickly steal from an ST205 since it's ECU driven.

[neo]

speed trigger ?

[Dell'Orto]

How would that work though? Speedo is cable driven on the early MR2's so no way of easily raxing a signal. Unless maybe a MTB speedo setup would work

[gt4dude]

speed would be almost perfect, throttle activation gets you covered from the moment you start revving there will already be a differential between lower and upper water worth starting the pump for

[Dell'Orto]

Also another con for temp switching - ice box would be pointless Wouldnt mind working out a speed switching way though!

[MrOizo]

Maybe a arduino could be something to consider. Might be hugely overkill but could have different triggers. A temp trigger and a speed one.

I'm only getting into arduinos but they almost limitless! They're a microcontroller. Good fun to muck around with:)

[gt4dude]

How are you planning to make your ice box?

At first I considered running the W2A coolant directly through a box of ice,

But thinking about it, once the ice runs out, it's going to fill up with warm water and the charge cooler will never get cold, then another idea struck me

if you tack down a couple oil coolers into a closed box you could keep the W2A water and the ice separate so there's no reservoir for warm water to collect, and every time your ice melts you don't have to tip out coolant.

it also means you don't have to switch on taps every time you go racing and then back to street driving

[sergei]

Intercooler pump:
switch it by duty cycle - say, 1min on 3 min off, factory algorithm is a bit more complex (it depends on Throttle and speed sensor as far as I am aware).
Intercooler fan:
switch it on using the water temperature sensor - off the shelf thermo-switches will not do - switching temperature too high for them (~90'C?). When water above ~50'C you will need to turn on the fan.

I will be controlling these two things using spare Inputs/Outputs on my Link G3 (with G4 firmware). So all I need to wire is a bosch water temp sensor (~$40 with plug, from msel.co.nz) and couple of relays.

Toyota thermoswitches are normally connected (they open circuit when temperature is reached), so you will need to use contacts that are disconnected under power on relay.

[Dell'Orto]

Maybe a arduino could be something to consider. Might be hugely overkill but could have different triggers. A temp trigger and a speed one.

I'm only getting into arduinos but they almost limitless! They're a microcontroller. Good fun to muck around with:)

A who? Remember, electronics not my thing. I'm interested in the speed switching one, I see VDO do a few types of speed output units, but fitting one somewhere could be the fiddly bit.

How are you planning to make your ice box?

At first I considered running the W2A coolant directly through a box of ice,

But thinking about it, once the ice runs out, it's going to fill up with warm water and the charge cooler will never get cold, then another idea struck me

if you tack down a couple oil coolers into a closed box you could keep the W2A water and the ice separate so there's no reservoir for warm water to collect, and every time your ice melts you don't have to tip out coolant.

it also means you don't have to switch on taps every time you go racing and then back to street driving

Hadn't really thought about it too hard at this point, its definitely something I want to do in the future. I like the idea of using a seperate heat exchanger in a enclosed ice box though!

Intercooler pump:
switch it by duty cycle - say, 1min on 3 min off, factory algorithm is a bit more complex (it depends on Throttle and speed sensor as far as I am aware).
Intercooler fan:
switch it on using the water temperature sensor - off the shelf thermo-switches will not do - switching temperature too high for them (~90'C?). When water above ~50'C you will need to turn on the fan.

I will be controlling these two things using spare Inputs/Outputs on my Link G3 (with G4 firmware). So all I need to wire is a bosch water temp sensor (~$40 with plug, from msel.co.nz) and couple of relays.

Toyota thermoswitches are normally connected (they open circuit when temperature is reached), so you will need to use contacts that are disconnected under power on relay.

Ok - so how would I achieve something similar with a stock ECU? Fan switch is a piece of cake though.

[sergei]

Maybe a arduino could be something to consider. Might be hugely overkill but could have different triggers. A temp trigger and a speed one.

I'm only getting into arduinos but they almost limitless! They're a microcontroller. Good fun to muck around with:)

A who? Remember, electronics not my thing. I'm interested in the speed switching one, I see VDO do a few types of speed output units, but fitting one somewhere could be the fiddly bit.

How are you planning to make your ice box?

At first I considered running the W2A coolant directly through a box of ice,

But thinking about it, once the ice runs out, it's going to fill up with warm water and the charge cooler will never get cold, then another idea struck me

if you tack down a couple oil coolers into a closed box you could keep the W2A water and the ice separate so there's no reservoir for warm water to collect, and every time your ice melts you don't have to tip out coolant.

it also means you don't have to switch on taps every time you go racing and then back to street driving

Hadn't really thought about it too hard at this point, its definitely something I want to do in the future. I like the idea of using a seperate heat exchanger in a enclosed ice box though!

Intercooler pump:
switch it by duty cycle - say, 1min on 3 min off, factory algorithm is a bit more complex (it depends on Throttle and speed sensor as far as I am aware).
Intercooler fan:
switch it on using the water temperature sensor - off the shelf thermo-switches will not do - switching temperature too high for them (~90'C?). When water above ~50'C you will need to turn on the fan.

I will be controlling these two things using spare Inputs/Outputs on my Link G3 (with G4 firmware). So all I need to wire is a bosch water temp sensor (~$40 with plug, from msel.co.nz) and couple of relays.

Toyota thermoswitches are normally connected (they open circuit when temperature is reached), so you will need to use contacts that are disconnected under power on relay.

Ok - so how would I achieve something similar with a stock ECU? Fan switch is a piece of cake though.

According to this: http://www.main.experiencetherave.com:8 ... c_data.zip legacy pump operates in simpler mode:
~half power below 80% of throttle
~full power anything above 80% of throttle.

Simplest way to achieve this you will need the following:
1) microswitch (similar to used in NOS systems)
2) relay
3) fuel pump resistor (any Celica 3SG(T)E has one)

You wire the pump in such way:
When relay is off the pump is powered on by ignition feed via fuel pump resistor (in series with pump).
When relay is on, it short circuits the resistor, so the pump is given full power.
You set the microswitch to be triggered at desired throttle opening (just like in a NOS system) and microswtich energises relay.

Alternatively you could do it other way around (so in case of microswitch failure the pump will be on all the time), in this scenario you use normally closed pair of switch which energises the relay which is opens the contacts that normally short circuited the resistor.

[sergei]

What car is that for?
If it is for race car, don't bother with switching and just run the pump 100% all the time...

[gt4dude]

This is true, you aren't exactly stopping for red lights and intersections on a race track so heat soak shouldn't get a chance to set in.

The ST205 method is theoretically the best in my opinion, good setup for street and track