johnd-mkiv Posted March 15, 2007 Share Posted March 15, 2007 I have a koyo rad to go on my supra when the rebuild is done but not sure if the twin electric fan is a worth while mod over the standard toyota fan? let the arguments begin Quote Link to comment Share on other sites More sharing options...
Gamer Posted March 15, 2007 Share Posted March 15, 2007 People run them both ways, personal choice really. I am sure the stock fan/shroud is sufficient though. Personally, I like the extra room without the stock fan/shroud. Quote Link to comment Share on other sites More sharing options...
Kranz Posted March 15, 2007 Share Posted March 15, 2007 I'd say it would be if the fans were independantly thermostatically controlled. Would save a bit of fuel and release a bit of power. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted March 15, 2007 Share Posted March 15, 2007 In the end running a big or twin fans will take as much power from the engine as the viscus fan, don't forget that the increased electrical current draw will make the alternator work harder. Quote Link to comment Share on other sites More sharing options...
johnd-mkiv Posted March 15, 2007 Author Share Posted March 15, 2007 In the end running a big or twin fans will take as much power from the engine as the viscus fan, don't forget that the increased electrical current draw will make the alternator work harder. this is what I have been told which makes me think there is no point to buying the kit Quote Link to comment Share on other sites More sharing options...
Kranz Posted March 15, 2007 Share Posted March 15, 2007 In the end running a big or twin fans will take as much power from the engine as the viscus fan, don't forget that the increased electrical current draw will make the alternator work harder. Most of the time they shouldn't be needed i.e. above 30 mph the flow through the rad should be sufficient to cool the engine. This means that the stock fan is just a parasitic loss a lot of the time. And its a hell of a big fan to spin, even when not locked up. And having a bigger than standard rad will assist in the cooling, to the point that the fan is required much less than with a stock rad. Quote Link to comment Share on other sites More sharing options...
Soonto_HAS_soop Posted March 15, 2007 Share Posted March 15, 2007 I like the extra room without the stock fan/shroud. I makes things MUCH easier to work on, but I ended up buying the PHR alt and setting the fans to come on independantly. If you are into show or working on the car, then twin fans help a lot. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted March 15, 2007 Share Posted March 15, 2007 Most of the time they shouldn't be needed i.e. above 30 mph the flow through the rad should be sufficient to cool the engine. This means that the stock fan is just a parasitic loss a lot of the time. And its a hell of a big fan to spin, even when not locked up. And having a bigger than standard rad will assist in the cooling, to the point that the fan is required much less than with a stock rad. True, a bigger rad will help and fan/s shouldn't be on a lot, in theory;) i ran twin electric fans on my S14 with an HKS fan controller which incidentally is very useful for compensating for having a larger rad as you can set temps for fans to come on/off, but i found in practice the fans are on for quite a lot of the time, and i have popped 30 amp fuses with them starting up Quote Link to comment Share on other sites More sharing options...
Kranz Posted March 15, 2007 Share Posted March 15, 2007 i have popped 30 amp fuses with them starting up Yeah, they pull a HUGE start up current, but then settle down to something reasonable. 30A relays on my 8A twin 14" fans I'll be fitting..... fuses to be found by trial and error Quote Link to comment Share on other sites More sharing options...
SimonB Posted March 15, 2007 Share Posted March 15, 2007 Most of the time they shouldn't be needed i.e. above 30 mph the flow through the rad should be sufficient to cool the engine. This means that the stock fan is just a parasitic loss a lot of the time. And its a hell of a big fan to spin, even when not locked up. And having a bigger than standard rad will assist in the cooling, to the point that the fan is required much less than with a stock rad. The viscous fan is virtually no drag when it's not needed. Plus electric fans are much less efficient as you need the alternator to convert rotation to electricity, which is not that efficient, and then the fans convert it back to movement, which again is not 100% efficient. So you're not going to make any power gains, probably the opposite. You do free up a load of space though. Quote Link to comment Share on other sites More sharing options...
Sheefa Posted March 16, 2007 Share Posted March 16, 2007 I'm running a Koyo rad on an Auto John. Just got a tranny cooler installed. No issues so far, but am looking at Spals just in case for tracking and the summer. Will see how she runs in the meantime though. For manual, I'd run as is and keep an eye on the temps. MVP do a nice twin fan setup Quote Link to comment Share on other sites More sharing options...
johnd-mkiv Posted March 16, 2007 Author Share Posted March 16, 2007 think ill pass on this mod then thanks for all your help Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 16, 2007 Share Posted March 16, 2007 think ill pass on this mod then thanks for all your help Sensible, IMO. Pusher electric fans mask the rad of movement derived air flow, and even 2 big electrics can't match the airflow of the stock big *ugger with the viscous locked down tight at high temps. It can afford to be made to shift a lot of air, as it can, when required, call on 280 BHP to drive it I too agree the extra room to work wih pusher electrics is nice, but I would never fit one to convert a road car myself. Quote Link to comment Share on other sites More sharing options...
mikeyb10supra Posted March 16, 2007 Share Posted March 16, 2007 Is there a something that could be considered a better alternative to the stock fan dimensions Chris, ie something similar to a big belt driven Jaguar fan or similar etc, obviously something that can shift more air for a higer horsepower application, coupled with some cleverly placed bonnet vents Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 16, 2007 Share Posted March 16, 2007 Is there a something that could be considered a better alternative to the stock fan dimensions Chris, ie something similar to a big belt driven Jaguar fan or similar etc, obviously something that can shift more air for a higer horsepower application, coupled with some cleverly placed bonnet vents I'd leave it all well alone, just use a more efficient rad (which will cost a packet, the stock rad is superb) and if you are still struggling do a full coolant clean out and use some of the new "super coolants" that lower surface tension. they can drop temps substantially. I doubt any of this is needed, apart from *PERHAPS* a better rad until you do serious track work with a genuine 650 plus BHP car. NOT running a FMIC and removing the aircon condenser and it's auxillary fan will do FAR more good. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.