Dual fan control systems

[Beamer]

I am looking to go to dual fans. I see that Caspers sells the harness for the Ramcharger fan kit and Spal fans. I like the ability the Ramcharger system has with a switch for Ho/Low/ECM controls, and the Spal does not have that.

Why is that? And can the Ramcharger harness be used on the Spal fans easy enough. I am wondering if anyone has done this.

I would like to switch my fans on manually for like 10 minutes after shutting the car off, as I have that ability right now in my car with the single fan.

Also, Caspers harness for the Spal fans runs off the low speed circuit in the car, why is that?



Thanks for your help,
Mike

 

[turbo nasty]

I would steer clear of the RC fans as the bearings in the motors fail in short time. As far as the high and low speed circuit the low speed circuit went through a ceramic resistor on the stock fan assambly and thay Res created the low speed...FWIW

 

[scottyb]

FWIW, I went thru 2 ramchargers sets and gave up on them beacuse of failures. Last summer, I replaced them with a set of fans from the junkyard off a 98 Cutlass v6. they are the same exact size. Instead of monkeying around with hi-lo operation per fan, I simply wired one fan to the "low" relay, and the other to the "high" relay (one fan - high - seems stronger than the low anyway.) I have a switch like yours to operate high manually and if your delay relay is working, then no other changes are needed. I do have each fan gounded separately, as this seemed to be the "hot spot" when I initially wired up the ramcharger's unit to the factory harness.

 

[jamnut]

I'm running a Painless 165° theromstatic controller for 1 of my fans & the other fan is hooked to a relay that powers up with the AC compressor. Even in the heat of Louisiana & having a big front mount my car runs around 185 cruising & in traffic with just 1 fan running with an Fbody radiator. The fan that powers on with the AC compressor is also hooked to a switch that I can run it manually with for cool downs between rounds or if it would ever start to overheat for some reason.

 

[GNVenom]

I think the failures of the Intrepid ("RC") fans comes down to how we're using them. You don't see the failures in the Intrepids...they're mostly used on low speed for the OEM application.

Our cars want better cooling. If you run only one fan on low, the airflow is less than the original GN fan on low, so running both fans on low is slightly better than the GN fan on low. If you run both fans on high (which is desirable for the turbo cars), the airflow is considerably more than our GN fan on high. So, the answer is to run them both on high to get the best cooling. But, running them both on high wears them out prematurely.

We offer the SPAL dual kit because the SPAL fans flow more CFM than just about any other comparable fan. However, the SPAL fans use more current and would eat the OEM relay (and wiring) in no time. Also, when running dual fans, they need to be staged to prevent "locked rotor" current draw, resulting in a dangerous drop in battery voltage. The Caspers harness uses a time delay module on one of the relays to start that fan around a second after the first fan starts, to minimize the voltage drop.

The time delay is essential on any high current dual fan system to prevent the voltage sag during startup from getting to the ECM, ignition, and other sensors - which cause hiccups, backfire, stalling and possible damage to components.

 

[Slow91z]

I think the failures of the Intrepid ("RC") fans comes down to how we're using them. You don't see the failures in the Intrepids...they're mostly used on low speed for the OEM application.

Our cars want better cooling. If you run only one fan on low, the airflow is less than the original GN fan on low, so running both fans on low is slightly better than the GN fan on low. If you run both fans on high (which is desirable for the turbo cars), the airflow is considerably more than our GN fan on high. So, the answer is to run them both on high to get the best cooling. But, running them both on high wears them out prematurely.

We offer the SPAL dual kit because the SPAL fans flow more CFM than just about any other comparable fan. However, the SPAL fans use more current and would eat the OEM relay (and wiring) in no time. Also, when running dual fans, they need to be staged to prevent "locked rotor" current draw, resulting in a dangerous drop in battery voltage. The Caspers harness uses a time delay module on one of the relays to start that fan around a second after the first fan starts, to minimize the voltage drop.

The time delay is essential on any high current dual fan system to prevent the voltage sag during startup from getting to the ECM, ignition, and other sensors - which cause hiccups, backfire, stalling and possible damage to components.

I run my RC fans on low all the time and have no had a problem with them since install which was 3-4 years ago...For 2 of those years it was my daily also.

 

[GNVenom]

That's my point; running them on low, they'll probably last the life of the car. Trouble is, those front mount IC's need the fans running on high.

 

[Slow91z]

I have a precision front mount also...I have no problems with the fans on low with a good radiator and 160* thermostat.

 

[scottyb]

I think the failures of the Intrepid ("RC") fans comes down to how we're using them. You don't see the failures in the Intrepids...they're mostly used on low speed for the OEM application.

Our cars want better cooling. If you run only one fan on low, the airflow is less than the original GN fan on low, so running both fans on low is slightly better than the GN fan on low. If you run both fans on high (which is desirable for the turbo cars), the airflow is considerably more than our GN fan on high. So, the answer is to run them both on high to get the best cooling. But, running them both on high wears them out prematurely.

We offer the SPAL dual kit because the SPAL fans flow more CFM than just about any other comparable fan. However, the SPAL fans use more current and would eat the OEM relay (and wiring) in no time. Also, when running dual fans, they need to be staged to prevent "locked rotor" current draw, resulting in a dangerous drop in battery voltage. The Caspers harness uses a time delay module on one of the relays to start that fan around a second after the first fan starts, to minimize the voltage drop.

The time delay is essential on any high current dual fan system to prevent the voltage sag during startup from getting to the ECM, ignition, and other sensors - which cause hiccups, backfire, stalling and possible damage to components.

I read that they were Intrepid replacement fans, not the original.
Also, I wired mine to run on 'high/low" just like the factory fan, and it only runs on high when the AC is on (which in FL represents the majority of time). I assume that the original fans on intrepid also runs them on high for AC.

 

[GNVenom]

That would make sense, but you realize that the Intrepid didn't have all that extra heat to contend with (turbo). The failures that I have seen suggest dry bearings as a cause, which would explain it due to excessive heat.

Brian at RC sales told me some years ago (when they were in business) that the fans were OEM "surplus" - which can mean anything from excessive stock from the manufacturer (model year overrun) to rejected parts (failed the cycle test). The fans they carried then had Mopar OEM markings on them. I would doubt that the fans sold today are from the same batch though. I'd lean towards the possibility that we're simply abusing them, which could explain premature failure.

Fact is, they're inexpensive, so you're not taking a real big hit in the event of a failure. And some seem to live for years with no trouble.

 

[Beamer]

Thanks eveyone for your inputs.

I am thinking that I may want to replace my radiator with a F body like a lot seem to do. What model of vehicle fits best? And how much modifying is needed? I take it that those radiators are more robust and capable of cooling...

Mike

 

[Slow91z]

Just pick any 3rd gen F-body...Like 91 Z28 or something.

Now I don't know if you are using the stock engine oil cooler, but in the F-body rad you will only have 1 oil cooler which would be for your tranny...I just took mine off.

 

[Beamer]

I have the turbo saver being used as an oil cooler. The tranny does not go into the rad either, I have an external cooler for it.

Looks like I will be getting another rad soon...

Mike