[yota1280]

Ok, I am trying to get some info for hooking up a contour fan for my car. It's going on an A9L setup. I have read several threads regarding this and from what I gather, I would need to hook up the relays to pin 41 for high speed control and then I believe pin 10 for the fan control of the fan? or would the eec control the fans via pin 41 when the ac turns on? next question. I am also looking at the dcc controller for PWM fan control, which I like, however the problem with that is the controller only kicks on 50% DC when the ac is on. my problem lies in that I just had installed the Hose Wizard R-134A retrofit setup and it nees a good bit more air flow than the stock r-12 setup. Glenn mentioned that he would prefer to see 4300CFM flow, but I don't know that will happen. where my problem lies of course is that 50%DC on the DCC controller won't even come close to where I need to be on CFM for the new AC setup. What I would like to do is to setup a 40amp PWM controller to the high speed fans which ramps up to 100%DC over a second or so to cut down on the in-rush current, but not sure of a setup which would be able to handle underhood temps. Any ideas here wold be great, I need to have everything ready to put on next weekend so I have a few days to get this figured out. I know there are some electric geniuses on here, of which I am not one, however I have stayed at a Holiday Inn Express a time or two.

[Paulie]

4300 cfm just for a/c seems rather excessive. The late model Ford vehicles which have PWM fan control from the factory run the fan at about 25% just for a/c. I personally like the idea of the DCC fan controller. I would think 50% from a contour fan would be plenty for A/C as long as you don't have a front mount intercooler or something else restricting airflow.

[yota1280]

I was thinking the same thing, but I am not the one who designed the system, he is. I do know that the factory clutch fan without a shroud with a be-cool 2 row rad is enough to keep the car cool even in Houston Tx summer heat in traffic, but not even close to being enough to move enough air for the A\C. Tried it yesterday when filling the AC and no go. no real surprise there though. he said that the contour fan was used on a vette install with a thick griffin rad and it was enough, I just don't know if it was used on high speed or low speed for the fans.

[yota1280]

Anyone have any ideas?

[decipha]

4300 cfm isn't that stout, thats the typical airflow of a single fan setup on most v8 performance engines

most stock-type performance dual fan setups typically flow about 9k+ cfm on high speed

I personally recommend at least 5,000 cfm of airflow regardless whenever the a/c is on so me and your a/c guy are in agree-ance

I wouldn't even be concerned about the voltage spike, if its THAT bad you can always toss a car audio capacitor on the relay battery feed to soften the hit

I would just turn them on high and be done with it, no point in making something so simple difficult

[cgrey8]

When I did my V8 conversion, I knew I was going to have to go with 2 pusher fans. I went with aftermarket PermaCool fans which have twice the airflow of the same diameter Flex-A-Lite (their competitor).

I went with an iDelta DC fan controller and have had great luck with it. It modulates the airflow from warm to HOT. It's relatively easily configurable (with the documentation to tell you how to set the jumpers). And there's an AC input that will set PWM at 50% regardless of radiator output temp. The temp sensor is a thermistor you put on the radiator as close to the output as you can get it. You can either afix it to the output, tape it directly to the lower radiator hose, or push it into the fins. This way, it's modulating to what your engine needs based on how well the radiator is cooling the water...and what temp you tell the controller to maintain.

At the time, I too was concerned about the inrush of turning 2 high output fans on at the same time. As it turns out, that was probably an over-reaction. But now that the unit is bought and installed, I wouldn't undo it for anything. I rather like the attention it gets when the fans start turning on in traffic. It sounds like a jet engine taking off...not because the fans are that noisy when spinning, but because of the frequency of the pulses the controller is running the fans at. The frequency lowers as the pulse-width widens to run the fans faster. I'm not sure if that's specifically by design or just how it was easiest to implement the controller's logic.

[yota1280]

I already have a 1 farad cap hooked up for the stereo, so I suppose it would help with the fans also, even though they are on different sides of the car, the cap is fed by I think 0 gauge or 2 gauge wire. coming home today i noticed that with the lights on, the vent fan on high and idling BE said I was around 13.5 volts with the 130 amp 3G alt. Hoping that will be good enough. good to hear that I should be ok and not to worry about the spike. Will I be able to just run the relays for the fans on pin 41 and call it a day? (after getting settings right on the tune) I am a bit confused on the eec fan hookup. I am worried of the relays pulling too much current for the pin on the eec to handle. I am thinking I will just add a small relay to trigger the two larger relays. These are the relays I will be using http://www.summitracing.com/parts/rfw-ar79/overview/

[85GT]

I run the contour on the 85 with a r134a conversion. It still only runs on low through the fan's factory resistor. Have yet to even connect high speed. It and the ac has performed fantastic on days where it's been 98 degrees, sitting still on the expressway. Temps got up to around 214-218 in this condition. Low if I recall right, drew about half the current compared to high, so it's probably around 50% Think you'll be fine.

[Shaker666]

I have the same setup in my '89, but I soldered in the missing chip on the EEC, and made a small inverting logic board to run the low speed fan output on the EEC. This gives you dual independent computer control of the fans. Also using Glenn's kit but used custom hoses to clear my supercharger. 2 relays do the power handling as well as a 50A circuit breaker.