F355 Cooling Fan Issue | Page 3 | FerrariChat

F355 Cooling Fan Issue

Discussion in '348/355' started by junglistluder, Jun 29, 2009.

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  1. Kokose7en

    Kokose7en Karting

    Dec 5, 2019
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    It doesn’t have to be this brand. I probably wouldn’t use the brand I posted, just a picture of a PWM for reference and discussion. I would probably make a custom plug-n-play version that doesn’t need any spicing or custom mounting, so it’s completely reversible. Installation should be as simple as changing the temperature switch on the radiator with an NTC sensor, grounding the wire that normally goes to the temperature switch to turn the relay on and last is hooking up the PWM in-line with the fan using the same connectors.

    Is this solution overkill? No, I don’t think so. I think the current factory fan circuit operates too aggressively. Fan has no resistor in the circuit, it either runs full load or none. A PWM in circuit would be a nice discrete upgrade that has many benefits. Does the F355 absolutely need it? No, the simple system works, operates and functions as intended. Simply, it does the job.
     
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  2. Targatime

    Targatime Formula 3

    Feb 22, 2014
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    If you make one, please make a second and sell it to me...
     
  3. Ferrarium

    Ferrarium F1 Veteran
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    #53 Ferrarium, Mar 10, 2021
    Last edited: Mar 10, 2021
    Variable fan is not really needed, its nice but the issue is fan kicking on not fan being on. PWM solve the actual issue.

    Took me an afternoon. I actually added one on both radiator sides, Shown in the post as well as wiring and part numbers. Huge difference. My persona opinions is its the best mod possible and COMPELTY reversible. It's 2 wires for gods sake.

    Ohh the post dopes not show it but I covered the writes with hi-temp fire proof & isolated silicone jackets. If I shows that you could not see the wiring in the photo before people start responding "you should cover those wires" :)

    Implementing Cooling Fan PWM Controller
    https://www.ferrarichat.com/forum/threads/implementing-cooling-fan-pwm-controller.608170/
     
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  4. watkinsgt

    watkinsgt Karting

    Feb 4, 2008
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  5. watkinsgt

    watkinsgt Karting

    Feb 4, 2008
    204
    Please make a third and sell it to me.
     
  6. Kokose7en

    Kokose7en Karting

    Dec 5, 2019
    207
    SF Bay Area
    Eric made a fantastic post on the solution. I think Miroljub post 10 on that thread is close to what I’m looking for. But instead of a modification to that particular Toyota PWM module, I’m sure there is one with a NTC sensor input for control. Custom making a mount and a harness would be the only thing needed. Splicing terminal to terminal for the least amount of voltage drops. Our F335s use Denso parts, A Toyota PWM with the extra input would be perfect.
     
  7. Ferrarium

    Ferrarium F1 Veteran
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    For me there were no mods made to the pwm controller I simply plugged it in. I use both fan channels for one fan in case one fails it's got dual path.
    Also you'll quickly find space is tight down there to put it someplace.
     
  8. taz355

    taz355 F1 Veteran
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    I guess I am just weird because I like the way the factory fans work
     
  9. Ferrarium

    Ferrarium F1 Veteran
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    Not at all. The factory fans work well. Its not really them working. Ferrari they added PWM controllers to later cars, I think they even did it to the fuel pups. All cars pretty much have them as its recognized that direct wiring the fans to the relays with no soft start was not the best idea rather its what the technology was.
    Seen 2 melted fuse panels myself so that was enough for me. Feel free to leave the cars as they are of course nothing strange about that.:)
     
  10. johnk...

    johnk... F1 World Champ
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    But the melted fuse panels are basically a panel problem. High contact resistance generates the heat. The contacts in the board and on the relays oxidize and cause the problem. You see this in 308 too with the bullet fuses. The contacts are riveted together and after many years they tend to melt at the fuel pump connections. Lots of people replace the connectors because they don't catch it in time. I just soldered the contacts at the rivets. I think with a 355 cleaning the contacts would help.
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  11. Targatime

    Targatime Formula 3

    Feb 22, 2014
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    I decided to get the Spal -050 fans and will clean the contacts on the circuit board as well. Belt and suspenders.
     
  12. Carmellini

    Carmellini Formula Junior

    Jul 16, 2019
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    Are these soft start fans with an internal PWM technology?
     
  13. Targatime

    Targatime Formula 3

    Feb 22, 2014
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    Nope, they're Spal fans that are identical to the factory except they have a sealed bearing for longer life and more importantly they operate at lower amperage, reducing electrical load when they start up. Search the forum for Spal 30102050 and all will be revealed...
     
  14. Ferrarium

    Ferrarium F1 Veteran
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    Double check, its still 40 amp initial draw. All fans reduce one running, 16 in that fans case, its the initial draw that's the issue. That fan does not address that initial draw. I'm just the messenger here.
     
  15. Targatime

    Targatime Formula 3

    Feb 22, 2014
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    I have not tested the draw on these fans myself, only going by what's been posted here a bunch of different times

    This thread has some good info as well:

    https://www.ferrarichat.com/forum/threads/new-updated-f355-radiator-fan-information.300662/
     
  16. Ferrarium

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    You can check the specs on SPAL's site they have a PDF buried that lists the initial draw and running map btw. It clearly lists a 40 amp fuse as well.
     
  17. Targatime

    Targatime Formula 3

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    Ok, why don't you post the tech specs that contradict every reference I've been able to find about the different current draws between the two fans (27.5 amp vs 21.5 amp). I don't really care whether Spal says to use a 40 amp fuse. They could list a 10 amp fuse or a 70 amp fuse and it would have no bearing on the actual startup draw and operational draw. If you have data, please post it.

    But based on the below I do not have great faith in your knowledge here. If these fans used 40 amps at startup as you claimed, Spal would recommend a bigger fuse than 40 amps.

     
  18. m.stojanovic

    m.stojanovic F1 Rookie
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    #68 m.stojanovic, Mar 19, 2021
    Last edited: Mar 19, 2021
    Not necessarily. The automotive fuses are "slow blow" type so the initial ,say 40 A or even more, draw will not blow a 30 A fuse as the high initial draw lasts for approx. half a second. I have not looked at the Spal info stating 40A but the starting current of DC motors is typically 2-3 times their running current.

    I am not sure how the high starting current may affect the fuse spade contacts as it is very short; it may cause some "micro-sparking/burning" of the contact surfaces every time which then slowly develops into increased resistance of the spade connection which then starts generating high heat during the normal running current and cause melting of the plastic. However, I believe that corrosion over time is the main cause of increased resistance at these spade connections (fuses and Relays).

    On my 348, I have installed the Toyota PWM controllers not so much to prevent overheating/burning if the spade contacts (periodical cleaning will keep them good) but to prevent sudden huge current load impact on the alternator at fans startup which, in the case of the 348, can be more than 100 A since two fans are started simultaneously. This repeated high amps impact may eventually blow one or more of the alternator diodes. I haven't measured the peak startup current of any of the 348 fans but when I measured the peak startup Amps of a 20 Amp BMW cooling fan with a clamp-on ampere meter, it recorded ~ 60 A peak.
     
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  19. Ferrarium

    Ferrarium F1 Veteran
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    Well I never said anything about 21 vs 27. You just jumped to that somehow.

    I'm not saying it takes 40amp to run but it sure does to start it. The specs are on spal's site it clearly says 40 amp fuse needed. it's in the documentation. I'm not going to go get it for you, go look it up.

    And again, I'm talking about the initial draw not the running draw, the initial draw is the issue is not the running draw. It's essentially the same as the oem one.



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  20. johnk...

    johnk... F1 World Champ
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    Starting current would be applied voltage divided by the DC resistance of the motor plus any series resistance (wires) in the circuit. It will only last instantaneously since as soon as the motor starts to rotate it generates a back emf, Eb, that effectively reduced the voltage across the motor to (V-Eb), thus lower current. The faster the motor rotates the greater Eb. The motor will continue to rotate faster and the current drop until the the torque generated by the motor (current) is just sufficient to balance the load on the motor (blowing air and frictional losses). The fans come up to speed very quickly. You can test that. The current spike is not the problem. Dirty contacts yielding high contact resistance at the circuit board is. The other issue would be a fan that doesn't come up to speed so the back EMF is lower, thus greater steady state current results.

    All this has to do with aging components. Wasn't a problem when things were new.
     
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  21. f355spider

    f355spider F1 World Champ
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    What everyone needs to remember is that the OEM 355 fan "ages" more quickly due to its design. Using the alternate, lower output, sealed bearing fan can help avoid melted fuse boxes, and blown fuses, that occur when the OEM fan ages. From my conversation with the SPAL technician, he said the fan motor Ferrari chose to use, is not designed for OEM applications, due to the non sealed motor design, with vent holes in the housing. This motor had added windings for high speed (and current load) and needed the openings for cooling, but he said this will allow water and dirt inside shortening its life. IIRC he stated they only warranted them for 6 months. He said they were specifically designed for custom applications such as racing, off road use, where maximum cooling speed was prioritized over long life.
     
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  22. johnk...

    johnk... F1 World Champ
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    Yep. Mine have only lasted 26 years, so far, with no problems. :)
     
  23. f355spider

    f355spider F1 World Champ
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    Probably common, as most Ferraris are not driven much. I replaced mine at 50k plus miles, only because I started blowing fuses occasionally, and didn't want to melt my fuse boxes. I used the lower amperage ones...surprisingly, even in 90+ degree weather, in slow traffic, no issues. Fans never seems to run longer either.

    I know the fuse issue can be a problem, as I have seen two friends cars that were purchased used, and had 40 amp fuses installed by previous owners or shops. Not sure how long that would have worked for...
     
  24. taz355

    taz355 F1 Veteran
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    yes too elimate the problem I changed the fans a long time ago to the little less cfm plug in fans, just for that reason. I think at the time it was very cheap mod maybe under 200 bucks
    When I tracked the car the second fan finally kicked in but not till I stopped in pits.
    Only time I ever saw the temp go beyond about 210
     

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