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Old 02-12-2007, 05:25 PM   #1
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Default using 5th injector for gasoline injection cooling?

One of the M.net $4000 for 200hp SC companies is using a 5th fuel injector and spraying gasoline the same way water injection is used to cool the charge. Any thoughts on how doable this would be to create, whether it's a good idea or is the charge from a turbo hotter than an SC and thus dangerous to use gas as a coolant.

This seems like a good idea since you wouldn't have to watch/ fill your water tank.
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Old 02-12-2007, 05:46 PM   #2
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If instead of the richer mixture, add about 10% (by mass) of water to the intake charge (0.008 kg Water/kg air), the high latent heat of the water would cool the charge by 18 degrees; about 4 times the cooling effect of the just a richer fuel mixture.

Plus the same amount of added fuel for the rich mixture can't burn because there is just not enough oxygen available. So it does not matter if fuel or water is added.

I really see it as a waste of gas, and it shouldn't be used as a way to cool the charge. SCs can get away with it becuase the have different fueling demands and heat delta.
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Old 02-12-2007, 09:06 PM   #3
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Braineak,

Thanks. Fast forward claims it works great with the supers. I didn't know if the same dynamics would apply to Turbo's.
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Old 02-12-2007, 10:00 PM   #4
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Waste of gas and not as efficient as a good water/methanol blend.

Plus, you'd be running super rich.
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Old 02-13-2007, 12:18 AM   #5
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I'm just curious as to know if any one of you even knows exactly how FFS uses the 5th injector?

The amount of fuel that is added is very very small. I think Tom even said it was as minute as 5% of the total fuel added. The way he tunes the SCed car, you get the AFR to about 12.5:1 and then add fuel using the 5th injector to get the AFR to around 12:1.

So how is this "super rich"?

Also, Tom has a video of his 5th injector aka "e-Cool" working on his car via an intake temp gauge.

If e-Cool didn't work, can anyone explain how I was able to get 202HP on a 112F summer day in Phoenix without WI or an IC of any kind without pinging or destroying my car?
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Old 02-13-2007, 12:18 AM   #6
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BTW, this reminds me of a question I always had about turbos. I'll start a new thread though.
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Old 02-13-2007, 01:04 AM   #7
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SCs can get away with it becuase the have different fueling demands and heat delta.
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Old 02-18-2007, 02:14 AM   #8
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the person i sold my '88 323 GTX does this. he uses a 5th ijector from a VW (he said because it was mechanical), toulene, and 21psi on a stock b6t motor. he uses a simple hobbs switch to control it. works very well.

gtx>evo
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Old 02-18-2007, 10:30 AM   #9
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Of course it works, it's just not as good as WI. Not ideal IMHO.
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