RC'er Dual Fan / Two Speed worthwhile?

[OKTurbo]

I'm wondering if hooking up the Ramcharger's to work "two speed" would be beneficial. Anyone done this?

Maybe I'm just thinking too hard....with my Extender chip the computer will command the low speed relay on at 155 degF, but the high speed relay is commanded by either the A/C pressure switch or the high temp switch (which is HIGH at 210 degF or so)

What I don't want to happen is that during the colder months for the fan to kick on at 155 when I have a 160 T-stat and have the fans run all the time. The T-stat will be closed at 160, but the fans will still run at high. The RC harness just turns the fans on with the low speed relay, but can easily be fixed with a short piece of wire to work off the Low/High/or Delay relays.

I can get the RC fans to run on two speeds by wiring up a couple of relays and use the yellow wire alone to run them at low speed and both the yellow and green wires together to get high speed.

If I do this at least the fans will only be running at low speed...if that really even matters to their longevity?!?! But the high speed won't come on unless it gets to 210 or the A/C is on.

So what do you think? KISS method or over-engineered method?

John (the engineer)

 

[IronEagle119]

The KISS (keep it simple stupid)method, havn't heard that since my CIS 314 - System Analysis and Design class. Well it doesn't sound too complicated to me.

 

[TurboDave]

Why you runnning your extender chip on it's cold setting?? If you have one of the latest one's, just switch it to default which runs the fans up in the mid 170's temps. That's really a better place for these engines to be running anyway.

 

[OKTurbo]

I must have been looking at some old info on the Extender chips...it said the fans come on at 155. Mine isn't that old. Maybe 6 months old...

Is there a way to adjust the fan on/off settings with the Extender? I looked thru the info I have and didn't see anything.

I'll have to perform a little test in the garage watching the coolant temps and see when the fan actually comes on....and goes off.

John

 

[TurboDave]

Originally posted by OKTurbo
I must have been looking at some old info on the Extender chips...it said the fans come on at 155. Mine isn't that old. Maybe 6 months old...

Is there a way to adjust the fan on/off settings with the Extender? I looked thru the info I have and didn't see anything.

I'll have to perform a little test in the garage watching the coolant temps and see when the fan actually comes on....and goes off.

John

Ya, you might want to check that, because I think the Extenders run the fan in the mid 170's. Unless you special ordered one with a real low temp like that.

The very latest version has a two temp fan control. One for street (usual mid 170's) and a race setting (mid/upper 150's).

 

[OKTurbo]

I haven't run the car yet to check the turn-on temp, but I did take a look at the Extender documentation I have.

Mine is a Revision E. I have four cells that I can program...nothing about coolant fan temps though.

What's the latest Revision on the Extenders? The Ramcharger's site says that Rev D is current!?!?!

John

(It's kinda a moot point since I've just about convinced myself to wire up the fans to run on High anytime it calls for fans)

 

[TurboDave]

I'm not sure if rev F or G is out on the street yet. They are the ones that have 4 more adjustable cells.