Batass

I heard that in doing this that it makes your impeller seem larger? Or raises the rpm for efficiency? Anyone know anything about this?

Trying to hit low 9's with my little s-trim.....

project89

iTrader: (1)

is ur setup intercooled?

paul_huryk

Water or meth injection cools down the intake air so you can make more power. Paxton in the old days had a simple but effective WI system on their kits. Made more power than using boost retard did...

Batass

No intercooler. Im well educated in water injection, but I had heard that when sprayed into the inlet of a blower or turbo, it changes the chart.

I have an injection kit, but have been holding it off because of plans to swap to ethanol.

My thinking is this. Max recommended rpm for my blower is 50,000. Guys have run them up to 55,000 and saw no extra boost, my guess is the extra heat created countered the flow, density change, blah blah, due to being beyond the efficiency level.

Spraying into the inlet could raise this? Less heat created in the blower=denser air=more pressure?

project89

iTrader: (1)

it could, the impeller wheel will further atomize the water alky,if using an intercooler u really dont want it going threw the inetercooler,though it can be done it just depends on the flow rating.

if using alky u need to be sure the seals inside the headunit can withstand the alky.long term use may cause errosion/wear fo the impeller wheel

Batass

What I read about spraying into it was that initially he had a steady stream of water being fed into a turbo. It eroded the blades, a well atomized stream didnt seem to harm it at all.

And of course my impeller spins much slower than a turbo.

Def no intercooler, that eats boost, and I can cool the air chemically. Many guys are running ethanol in carbs with close to 30psi and no intercoolers. Ethanol as in E85 (fuel) not spraying.

I'm just wondering if spraying some alky or water into the inlet could raise the level of rpm efficiency and I could see another psi or so.

Of course I could just about trade my s-trim for a t-trim on ebay, but whats the fun in that?

There is a fourth-gen camaro with this blower (basic s-trim) and a lt1 383 that made 780 crank hp. Blower is rated at 680hp. He just used a water-air cooler.

This made me wonder how far could I really take this thing if I get the air cool enough??

project89

iTrader: (1)

look at it this way, mount the nozle suction side and if it dont work its a simple move, really didnt cost u anything maybe what a couple $ bung to put in the pipe.

Batass

You're right it wouldnt cost me anything. Maybe I'll just install the meth kit, then swap over to E85 and see how the track numbers change. Then turn the meth back on.

junkcltr

iTrader: (1)

Read the first 8 pages of this:

http://www.aquamist.co.uk/phpBB2/vie...r=asc&start=75

It gives the Physics behind pre-compressor spraying and also some real world results. Overall, you should get cooler compressor temperatures and slight boost increase.
You asked, "is that enough?"..........not sure what enough is.......but you will see gains.

You will get a lot of cooling just with the E85 and have enough octane to keep the timing on the high side so you may not need the injection.

Batass

Good info, seems like I might be able to get my intake charge below ambient.

Saw something about adding acetone? It doesnt have a high specific heat capacity, but I know it does promote lower surface tension, perhaps making for better atomization?

Also looking at a specific heat capacity chart, ammonia ranks pretty high.

2.72 for methanol @104*
4.19 for water (but decreases drastically when the temp goes up)
4.86 for ammonia @104*

So adding ammonia may help decrease IAT's.

Edit: nm ammonia is a detonant...

junkcltr

iTrader: (1)

I saw the acetone comment too. For the amount added, I don't see the gain being worth it.

One thing that struck me was that of all of the more technical people (hotrod and a few others) that none of them talked about a carbon seal on the compressor side. When doing a draw-through carb it needs a carbon seal. Maybe because the water/alky is used so little that needing a carbon seal is not required. The alky part is what got me thinking about the carbon seal.

I would stick with the water/alky. I prefer running -32* windshield washer fluid ($1.25/gal). It has 70% water and 30% methanol. I then add Strip Kleen denatured (50% methenal / 50% ethanol) to make the injected mix 50% water / 50% meth/eth). The bad part is that the Strip Kleen denatured is $14/gal. A gallon lasts a while. I found a place that sells E85 for $3/gal and methanol for $6.50/gal so I may end up using that and spraying more fluid. The place that sells it is about 3hrs round trip from where I live. I am biased toward spraying straight E85 but I don't think my ShurFlo pump with Viton seals will handle it. The newer ShurFlo pumps have EPDM seals that will handle straight alky.

EDIT: Spraying straight alky is dangerous and is not recommended.

Batass

I haven't seen any hard evidence of ethanol eating anything but raw aluminum.

I'm not familiar with the carbon seal.

junkcltr

iTrader: (1)

The carbon seal would be to keep the water/alky from getting into the comp. side shaft (oil) bearing. Overall, I am not worried about it because of the little time that water/alky would be injected and how the comp. wheel will shield the bearing.

Methanol is more corrosive than Ethanol but I don't think it really matters in this application because the water/alky is only on a short time is doesn't sit for hours/days/years in direct contact with aluminum.

I found the thread info. about the "water/alky comp. wheel wear" interesting. Personally, I could care less if it actually did wear the comp. wheel fins because a comp. wheel is usually around $50. Real world is that it doesn't wear the fins..........but even if it did for $50 then who cares.

I started looking into this because I have an under-sized compressor I am going to try and use. If I can gain 10% airflow out of it with the pre-comp. injection it would put right about where I would like to be.

Batass

They were saying something about a 30% efficiency increase. I'm not sure how much power percantage that comes out to, but sounds pretty substantial. I wouldn't spray anywhere else.

I'm looking forward to seeing the time difference.

grover85

iTrader: (1)

My buddy sprays before his blower on his foxbody. Makes over 600 whp with no problems.

junkcltr

iTrader: (1)

There was another post in that thread going into more detail about the efficiency increase. They came up with about 20% using a realistic amount of water. Doing some of the math and playing with the calculators I get about 15 %- 20%. I think the best way to go is using 50/50 water/alky in a fairly heavy dose. The water will give most of the efficiency and the alky will help once the water saturates. It will also help in terms of octane a little bit.

The nice thing about pre-compressor spray is that you don't need a pump to over come boost pressure and a check-valve and/or solenoid. I plan on using a cheapo universal windshield washer pump unless I can find a 60 - 150 PSI shurflo pump cheap.

Batass

Yea, I've looked for the shurflo pumps before just for fun, I think most of them were around 140 bucks for 150 psi. I paid 200 bucks for my snow kit used off ebay.

I have a 600 ml jet with my kit, I think thats good for around 650 hp. Not sure if thats wheels or crank. I'll try it and see what happens.

junkcltr

iTrader: (1)

Coolingmist and devil's own have the 150 PSI for around $110 with EPDM seals which will do 100% methanol. The good thing about pre-comp injection is that a 50/50 mix is better so you can pick up used low-pressure non-EPDM seal pumps cheaper.

That 600ml at 100 PSI is (600 / 29.57) * (60 /128) = 9.5 gph
Usually people inject about 15 % of fuel.........so for 650hp that takes about 64 gph
and 15% of that is 9.5 gph

Batass

Ok, I'm probably making about 680hp. Hoping to make a baseline pass next weekend.