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Push+Pull efan setup? HAving a hard time hotlapping.

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Push+Pull efan setup? HAving a hard time hotlapping.

Old 07-05-13, 12:21 AM
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Push+Pull efan setup? HAving a hard time hotlapping.

I know a push+pull setup would not work best in normal driving conditions. But I"m not driving normally.

I'm Drifitng. Now, the problem is i'm drifintg a streeported s5 n/a so I'm normally off the limitter 8000+ rpm.

I'm having cooling issues trying to sustain multiple runs. My clutch fan gave out (sustained high revs no doubt) So i went with a flexalite 16" that supposedly pulls ~2200cfm.

It only covers 2/3s of the rad so i tucked it over to the left side (easier to weld on mounts to my N flow koyo)

I can do 3-5 laps before temps creep up to 110C where I have to stop and do cooldown laps. Ambient air temps are ~20-25C. Motor has about 40 hours on it.

My only two solutions is to add another efan in front for a push+pull setup or add a direct drive fan. I dont see how getting a bigger rad will help, also remember ther eis no "real" airflow during drifting. I havnt seen anyone run a push/pull setup in an automotive setting and its usually used in stationary heat exchangers.

Any insight on what you guys are doing would be helpful. Or any recommendations on a direct drive fan i can use.
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Old 07-05-13, 04:00 PM
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vented hood and ducting from bumper -> radiator help a ton. if you can duct from the fan to the hood, even better
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Old 07-07-13, 08:19 AM
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Chrysler 300M fans. It's a pair of large diameter shrouded fans. I have similar operating situation but with less airspeed. The fans require two dedicated 40 amp fuses/relays. They will overlap the radiator a little bit and I don't know what will have to be moved on an FC. On an FB the battery tray needed to be removed for fan clearance.

2200cfm is not enough for a rotary at full power. As a guess, the 300M fans pull over 4000cfm when on high. They're good enough to cool the engine down in real time. Last outing had runs in the 2 1/2 minute range, air temps in the 30c range, and the engine wasn't getting over about 90c coolant temps.

edit: Also get a small diameter crank pulley. The OEM setups start to stall at about 6000rpm, so if you're holding your engine speed high all the time then you're operating the engine with no coolant flow. A lot of my problems went away when I installed the RB single groove mini-pulley.
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Old 07-10-13, 12:29 PM
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Old 07-11-13, 12:51 PM
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No, that is for a 300C. The 300M one is the one to get because of the height. Think front wheel drive 3.5l car. There is maybe three inches between the fan and the engine, in an extremely cramped engine bay with a tiny radiator, so Chrysler made a really badass fan for it.

Should be only about $150-200 at the junkyard. New is something like $260 per motor.
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Old 07-11-13, 01:47 PM
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I don't drift, but I've been using this one for over 10 years, and no issues:


Flex a lite also offers the extreme fan, which is rated at over 2000 cfm

How about installing a water injection kit that sprays water to the radiator? I would set it based on coolant temp, anything past 185F, and let it spray on to the front section of the radiator.
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Old 07-12-13, 12:29 PM
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I used to have one of those and it was marginally okay, and then it broke. The 300M setup owns face in comparison. More fan area, more motor power, and the blades are shrouded so it is more efficient. (Plus quieter!)

Another thing that I forgot to mention is pullies. The stock water pump and pulley combination cavitates at high RPM, generally around 6000-7000ish depending on the exact combo. What this means is that the flow from the pump stalls/stops because the pump's blades are not moving water, they're just creating water vapor from the low pressure area behind each fin. So when yo're holding RPM up at 8000rpm you don't actually have any coolant flowing. Solution - slow down the water pump if you're going to hold RPM high for longer than a couple moments.
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Old 07-13-13, 05:29 PM
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Wow think great info. I think I might try out the 300m fan but I am still interested if anyone is running a pug and pull set up? And where can I get a pull fan?
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Old 07-15-13, 10:56 AM
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Those are a bad idea. One will just end up fighting the other. Use pull fans and leave the front your radiator unobstructed. Make sure your ducting is good and no air can bypass the radiator when it comes into the bumper opening.

You may want to consider underdrive main and water pump pullys. The S5 n/a water pump will cavitate pretty good at 8000 rpms and you lose a significant amount of overall cooling capacity. I lost an engine partially to that. Once we put the underdrive pullys on and fixed the ducting we now never see over 190F water temps in the race car.
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Old 07-24-13, 11:33 AM
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A good fan shroud can make a big difference.

If you want to get more spendy, get a Davies-Craig electric waterpump and ditch the belt-drive model. No cavitation problems and no belt slipping issues either.

Last edited by DaveEstey; 07-24-13 at 11:35 AM.
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Old 07-26-13, 11:20 PM
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Get some Maradyne jet stream II fans. I have a full bridge FD making 810 RWHP (E85 only) getting ready to try 1000 RWHP on e85. Anyhow, I have the Maradyne fans. Cost about $300 new and zero cooling issues weather I'm drag racing or road coursing it in Texas heat during the summer which is usually 95-100 plus humidity puts it in the area of 100-110 degrees. With these fans I have never ever had my engine temps go above 89 degrees Celsius. That's about 188 degrees Fahrenheit. they will fit your koyo radiator and are also low profile.
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