Okay, Do Electric Fans Make a Diff?

[SubLime440]

I keep reading articles in magazines... and then talking to people... If you switch from your Clutch Fan to electric fans & your belt driven water pump to an Electric Waterpump, do you really pick up much HP? I've heard magazines say "Yeah" and other people say "No"... so what gives... Does this work or not... Anybody done this and measured the results... specifically on a 440?

[Doug Wilson]

By switching both, you can likely pick up 30 horsepower at the rear wheels at RPM above 4,000.

[70Ted]

30hp at rear wheels is 35Hp at crank. I think not.

[Tim_K]

10 horsepower, yes. 30, NO WAY.

[jelsr]

Most published figures for HP loss from the fan is around 14. Can't say on the water pump, most tests consider it an integral part so it's not listed as parasitic loss. Water is heavy though, so it would take some oomph to move it around.
Ted,
Your crank to rear wheel ratio is way high. The recent Nascar test of the top 5 after the Bud
shootout showed 372 HP for low and 380 HP for tops on their chassis dyno. By your figures the best one would only have 450 or so at the crank. I'm sure you would agree they put out considerably more than that, even with the restrictor plate.

[cuda66273]

Doug
If your thinking about an electric water pump on your project I would pass. The extra HP is outweighed by the unreliability of the little electric pump motor. They are designed for short trips of about 1320 feet and will not last on a street driven car....we always carry a spare for that reason

[cuda66273]

My guess on the fan/waterpump combo would be about 20 HP at the crank, which is about 15-18 at the rear wheels.

I did it for that and to get rid of the fan belt, which always wanted to get out and walk about 1/2 track.

[NewBlackDak]

Well, I did some underdrive pulleys, and electric fan on a 2.4 Nissan I was driving way back when. It made a big difference. Of course when you only make 90 or so RWHP you notice 10-15 HP easier. Dunno about what it would do on a real engine.

[Doug Wilson]

Well, I read an ad or an article just recently saying that this particular pump was worth 20 rear wheel horses, and I thought the electric fans were good for at least 10, so that's where my number came from. It must have been an ad or press release. It was some newish water pump company. And yes, I was considering it on the sailor Son's Barracuda. Are you pretty sure that it would be a bad street idea?

[SubLime440]

Those CSI waterpumps flow 30 GPM... That ain't bad... They are expensive but isn't everything nowadays...

[Doug Wilson]

The CSI pump - do they say that they are good for street use?

Also, do they pump the same volume regardless of engine RPM? Seems like 30 GPM might be a lot more than you need sometimes - maybe keeping the engine TOO cool??