SL/R129: Why 3 Cooling Fans...
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Junior Member
Joined: Nov 2006
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From: Central VA (USA)
1999 SL500 Sport
Why 3 Cooling Fans...
I know there's a clutch fan for engine cooling; However, why are there 2 electric fans ? I could guess that one turns on for the A/C and the other is a helper for the clutch fan if it can't keep up with the temp ?
Anybody replaced that clutch fan ? I don't like there general design, but the bolt pattern doesn't fit any flex-fan out there...
Thanks,
Robert
98 SL600
Anybody replaced that clutch fan ? I don't like there general design, but the bolt pattern doesn't fit any flex-fan out there...
Thanks,
Robert
98 SL600
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Joined: Oct 2006
Posts: 59
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Whoa whoa whoa whoa. Hold the hell on now here.
I have a lot of experience with exactly this subject, so let me give you a few pointers:
1. Flex fans suck Or rather they don't suck. Or they suck, because they don't suck enough. Any clutch fan in the world will crap all over a flex fan. They're useless.
2. The point of the "clutch" in the clutch fan is to prevent horsepower loss. When you rev your engine, the fan pretty much freewheels at its current rpm and catches up with the engine. This causes a 1-2 horsepower draw at best. This has been tested again and again to death. Converting a working clutch fan to an electric will get you almost no horsepower at all. Any horsepower you get you will not be able to feel, and you will not notice any statistical gain in acceleration either.
3. A clutch fan sucks more air than anything electric, this side of twin Continental fans or something.
Trust me, because I have screwed around with cooling systems more than most people have their girlfriends. You will make no improvement upon a clutch fan/electric assisted cooling system. Never. Ever. Not unless you happen to know how to fab in a nice hydraulic cooling fan, but I doubt it.
I have a lot of experience with exactly this subject, so let me give you a few pointers:
1. Flex fans suck Or rather they don't suck. Or they suck, because they don't suck enough. Any clutch fan in the world will crap all over a flex fan. They're useless.
2. The point of the "clutch" in the clutch fan is to prevent horsepower loss. When you rev your engine, the fan pretty much freewheels at its current rpm and catches up with the engine. This causes a 1-2 horsepower draw at best. This has been tested again and again to death. Converting a working clutch fan to an electric will get you almost no horsepower at all. Any horsepower you get you will not be able to feel, and you will not notice any statistical gain in acceleration either.
3. A clutch fan sucks more air than anything electric, this side of twin Continental fans or something.
Trust me, because I have screwed around with cooling systems more than most people have their girlfriends. You will make no improvement upon a clutch fan/electric assisted cooling system. Never. Ever. Not unless you happen to know how to fab in a nice hydraulic cooling fan, but I doubt it.
