Jump to content

Engine Fan


lekonna

Recommended Posts

Can you please add an option to the engine fan that if speed is above x it will not turn on ?

I took a look at my log while driving more than 100km/h and the fans get turned on and off, since they are quite powerful fans it shows as a voltage drop, which then affects injectors and coils.

I'd like to keep the fan start temperature lower than the current setup allows, i've noticed that with the 2jz the pump is not really circulating water very well if revs are under 3000rpm, so this means that while driving the engine temp will creep up to 93/94 degs, with a 89 thermostat. (can be verified by shifting down so revs go over the 3000rpm limit, while keeping the same speed the temp drops to 90/89.

Now if i have the engine fan setup at 91 degrees it will start to run even the wind from the speed generates more airflow than the fans can.

Link to comment
Share on other sites

Setup the Aux output that your fan is running from as a General Purpose Output.

Use any combination of 3 variable switched inputs as Switching Conditions

EG

Switch Condition 1 = SPEED less than 100 km/hr

Switch Condition 2 = ECT greater than 90 deg. celcius

Switch Condition 3 = RPM less than 3000.

Obviously you require a SPEED Input to the ECU, through a Digital Input.

So that Digital Input needs to be selected for the switching of the Speed Condition.

NOTE: Properly setup Injector Deadtimes SHOULD rectify the effects of voltage changes to your injectors, keeping them operating (responding) properly regardless of voltage changes.

Do you have your Ignition fed power to your coils on there own relay source.

I always run a seperate relay to supply power to my Ignition coils, bypassing all other vehicle looms and accessories.

Link to comment
Share on other sites

yes i know i can set this up with aux out but whats the point of having an engine fan option if i'm not going to use it? Its going to affect my idle and the aux option does not allow for compensating that.

The fans are powered through a relay of their own and have independent fuses in case one of the shorts (learned this the hard way ;) ). The coils are powered the same way save for just one big fuse. I've got the dead times and dwell times setup for all voltages, i'm just playing it safe, since 034 coil needs tons of dwell even with normal voltage. (5ms) it means that increasing it due to low charging voltage will start to limit my rev range quite fast.

Link to comment
Share on other sites

Good morning,

How much of a voltage drop are we talking about here? Are you still using a standard charging system?

As Dave mentioned, the deadtime values do take changing voltages into consideration.

Cheers,

Scott

Link to comment
Share on other sites

Good morning,

How much of a voltage drop are we talking about here? Are you still using a standard charging system?

As Dave mentioned, the deadtime values do take changing voltages into consideration.

Cheers,

Scott

fans pull enough juice on startup to melt a 30A relay ;). at 9000 rpm, my coils are draining constant 40 with a peak 60A of current/cycle, the fuel pumps take 15 each, that makes it 90A. i did upgrade to 120A charger but whats the point of pushing current to the fan when its not needed? I can take the log on the voltage drop, it was something around 0.5V.

http://zonediscgolf.fi/media/supra/dwell_9000rpm.png here is a picture on how the coil dwells overlap at 9000 rpm, if i have the increase the dwell from 5ms i get more current load. though this is not absolutely correct since the drain is not linear.

Anyways just a suggestion, if its too hard to implement i'll just hack around it. though its standart stuff on some ECUS.

edit: here is a log with the fan activation effect showing on the voltage:

fan_voltage_drop.PNG

i don't want those spikes occuring while im going WOT near the rpm limiter, especially when it does no good to start the fans at that point anyways.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...