Ozzie831 Posted October 13, 2014 Share Posted October 13, 2014 Hey hows it going? I'm running these duel Flex-a-lite fans they seem to be using a crap ton of power. I don't know how much power electric fans are supposed to use and this could be normal but they seem to be using too much power and it is affecting my car's performance. With the car running and the fans disconnected the battery is at 13.50 volts, with the fans connected the battery goes down to 12.70-12.80 volts. With the fans connected it seriously bogs my car down. It also seems to be throwing off my megasquirt due to the power loss and there is a 100% change in how the car runs. Feel free to ask any questions and I will try my best to answer them. Any information is appreciated Austin Quote Link to comment Share on other sites More sharing options...
Miles Posted October 14, 2014 Share Posted October 14, 2014 Hey hows it going? I'm running these duel Flex-a-lite fans they seem to be using a crap ton of power. I don't know how much power electric fans are supposed to use and this could be normal but they seem to be using too much power and it is affecting my car's performance. With the car running and the fans disconnected the battery is at 13.50 volts, with the fans connected the battery goes down to 12.70-12.80 volts. With the fans connected it seriously bogs my car down. It also seems to be throwing off my megasquirt due to the power loss and there is a 100% change in how the car runs. Feel free to ask any questions and I will try my best to answer them. Any information is appreciated Austin As a start, go to the Flex-a Lite fan website or to Summit Racing and find what the rated amp draw is for the model fan you have. Check the actual amp draw of the fans when they are running. Does the amp reading exceed factory specs for the fan? What is the rated amp output of your alternator? Go to Autozone etc. and have the alteranator checked. The tech should be able to tell you the voltage and amperage output for your alternator. Write down the test results. Also, check the battery while at Autozone. You could have weak or failing alternator and/or battery or undersized alternator. Providing the above data will help others diagnose the problem. Quote Link to comment Share on other sites More sharing options...
Ozzie831 Posted October 14, 2014 Author Share Posted October 14, 2014 Cool thanks for the suggestion. Sounds like a solid plan, Ill do that tomorrow. I have a sneaky feeling that the battery is the culprit Quote Link to comment Share on other sites More sharing options...
Ozzie831 Posted October 14, 2014 Author Share Posted October 14, 2014 well that's awkward, I just realized that my original post didnt keep the link to the fans........http://www.summitracing.com/nv/parts/flx-420/overview/ Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted October 17, 2014 Share Posted October 17, 2014 You could also try staging the fans. Maybe use one ms output to turn one fan on at say 180, then another output to turn on at maybe 200. Quote Link to comment Share on other sites More sharing options...
TimZ Posted October 17, 2014 Share Posted October 17, 2014 (edited) Hey hows it going? I'm running these duel Flex-a-lite fans they seem to be using a crap ton of power. I don't know how much power electric fans are supposed to use and this could be normal but they seem to be using too much power and it is affecting my car's performance. With the car running and the fans disconnected the battery is at 13.50 volts, with the fans connected the battery goes down to 12.70-12.80 volts. With the fans connected it seriously bogs my car down. It also seems to be throwing off my megasquirt due to the power loss and there is a 100% change in how the car runs. Feel free to ask any questions and I will try my best to answer them. Any information is appreciated Austin If you are using a stock 70A alternator, that amount of voltage drop for a 22A draw sounds a bit high, but not inconceivable. Where are you measuring the voltage - at the battery posts or somewhere else? Also, how are the fans wired? Where do they get their power, what size wires, relays, etc.? Also, I'm not a MS expert, but it should have no issues whatsoever with running at 12.7V - pretty much any EFI has to be able to function properly down to 10V (often less) in order to be able to get through the cold startup phase. What exactly is it doing when the fans come on? Also, what is the proximity of your timing pickup to the fan motors? Edited October 17, 2014 by TimZ Quote Link to comment Share on other sites More sharing options...
ktm Posted October 18, 2014 Share Posted October 18, 2014 Also, I'm not a MS expert, but it should have no issues whatsoever with running at 12.7V - pretty much any EFI has to be able to function properly down to 10V (often less) in order to be able to get through the cold startup phase. What exactly is it doing when the fans come on? Also, what is the proximity of your timing pickup to the fan motors? The voltage affects the fuel pump which then, in turn, affects the fuel flow/pressure. I compensated for voltage drop in my fuel table (when I was running Wolf) by increasing the injector pulse width as the voltage dropped to account for the reduced fuel pressure. If the fans are the Flex-a-lite 210s, then they should really draw no more than 20 amps. However, if you are running a stock alternator but have upgraded other parts of the car, then you may have issues with insufficient power. Additionally, when do you experience the performance issues? At idle? If it's only at idle, then that is a function of the alternator curve. The alternator output is not 70 amps at idle. JeffP and I were chasing amperage issues with our builds. I went with a CS144 alternator at the time to help with the amp draw at idle as well as provide a sufficient capacity for the car. Quote Link to comment Share on other sites More sharing options...
RPMS Posted October 24, 2014 Share Posted October 24, 2014 I'm going to be "that guy", who throws another variable into the mix. Is it possible that the fans are throwing enough noise into your electrical system that it is affecting your fuel injection computer? Low, fluctuating voltage can really mess up an otherwise stable system. Just a thought. Quote Link to comment Share on other sites More sharing options...
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