Jim Green's 90q 20vt - 636whp 07k

[chaloux]

Take the intercooler out yet? ;-)

[audifreakjim]

No, but when I do, I am going to squish Hank with it!

[Mcstiff]

No, but when I do, I am going to squish Hank with it!

It's probably bigger than Hank.

[my2000apb]

hank's taller but the IC weighs more

[Audilard]

hank's taller but the IC weighs more

Hank's been putting on some weight! Watch out intercooler, he can take you!

[Hank]

hehe

[audifreakjim]

I have suspected the system to be intermittent for quite some time due to the fact I never have to refill my tank. Go figure. So yesterday I installed one of these AEM Fail-safe Gauges to monitor what is going on.
http://www.aemelectronics.com/water-methanol-failsafe-device-1-4-sae-1184


I can't say enough about this gauge setup, If you are running water/meth as in integral part of your tune, you MUST have one of these.

As suspected, I was getting very little flow most of the time, and intermittent flow at high RPM and high boost.

The culprit is the old Aquamist High Speed valve that doesn't like 200PSI of inlet pressure. It works fine at full duty cycle, but can't open or close fast enough at that level. I reduced the pump down to it's minimum of 150psi and it is better, but still not stable. I am going to order one of the new fast acting valves that is designed to work at the higher pump pressures. They use the same pump am using in their kits.

On top of this I recently sealed up a bad exhaust leak that was throwing off my mixtures and I was tuning around it. After being sealed up the motor was running lean and I didn't catch it until I did a plug check yesterday. Yikes, luckily I didn't drive it much like this so everything seems to be OK.

So here are some thoughts/questions. Since E85 is pretty much a no-go to me, I played with the WI and tuning some yesterday with the WI at 100% above 15 psi. The motor ate all 900 cc/min up and I easily added 5 degrees of timing at 33 psi. Now we are talking, but i need to incorporate the fail-safe in some way.

1. In the traditional manner, tune for WI with extra timing and fuel above wastegate pressure, and use the fail-safe to disable boost control and lower boost in the event of an over/under flow condition. This is a pretty simple and effective solution.

2. I could use the analog output from the fail-safe to feed the ECU and add timing depending on sensed flow. As I type this, I see two problems with this. The ECU may add timing before water has reached the cyl, although maybe one ign event at max, but that could be a nasty one with an extra 5 degrees of timing and not enough water to support it. I think this is pretty unlikely as there will be some water, just maybe not the full amount. The second drawback is if there was a broken line condition and the flow went to high and there was no water and a bunch of timing.

3. Use both, 2 would allow for a more dynamic tune, kind of like octane on demand, leave the cells for really high flow at 0 degrees of extra timing, and have the boost valve disable extra boost above WG pressure. You could also trim fuel ratios based on the meth in the WI mixture.

I think I like the sound of 3.

[PRY4SNO]

Never have to refill your tank?

Like once every other tank of petrol?

[AngryTaco]

are you using a progressive setup or a simple on/off?

[chaloux]

+1 for the aem system. Dad is using solution number one, very simple and effective map switch. The whole aem wm kit is awesome, very happy with it so far.

33psi eh Jim, that's awesome. I bet your car feels insane.

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I'm glad someone else brought this up as I will be dealing with it soon enough. I am running an aquamist hfs-4 with the fail safe tied into my waste gate valve. I would like some more options with the vems and how I can integrate the two and have better options for a failsafe. I am likely going to tune with 94 octane first and then add meth and refine timing. I have also been toying with the idea of pre compressor injection with a mechanical system and possibly go with smaller injectors downstream.

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Also, what w/m mixtures are you running Jim? 50/50 seems to be the way to go unless you are doing direct port from what I have read. If I could get 33-35 psi on meth I would be plenty happy, you're obviously doing something right.

[bradyzq]

How about 100% water? At least to start with. Octane rating of infinity, and you don't have to mess with fueling.

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From what I have read a mixture of 50/50 has worked better for lowering it's. All the results I have seen seem to perform better with some sort of water to meth mixture. A lot of good info can be found at waterinjection.info

[audifreakjim]

50/50 mixture ->Devils own Sumped Tank->Devils own pump->AEM flow meter->Aquamist High Speed Valve->5 nozzles and 1 pre-TB nozzle.

The HSV is connected to an extra injector channel on my IIc ecu, the pump is switched on at 10PSI by a hobbs pressure switch. This delivers a consistent percentage of water/meth to fuel.

Sam pointed out on MG that 1D mapping of timing isn't such a good idea and I agree.

Now I think I will have a map tuned for no water injection around 28 psi. I have had the car running well like this for years. Then have a second map that is tuned for WI above ~ 20 psi and use the failsafe to either switch maps or disable boost above 18psi.

Once I get the system reliable I will start playing with different mixtures. Since I am running port injection, it might make more sense to go with 100% water.

I have also been wanting to try pre-compressor injection. The idea is to move the pre-TB nozzle over there some day. I have a few things I need to address first. My dump valve releases onto the header so I need to re-route that. They say 50/50 is not flammable, but I don't care to test it. Again, 100% water would fix this.

I'll probably be on the dyno in April when I am in Vegas so the goal is to have the car very sorted so we can test a lot of this.

Running 33 psi was a quick test. I am waiting on new plugs to arrive so i can really dial it in. Going to try the NGK r5671a_8. It's a racing plug in the 8 heat range. I am running BKR7E plugs, but I think I can go one heat range cooler and they don't make a BKR8E. I also have a very open exhaust dump and a huge hotside to reduce backpressure on pump gas so it allows me to do stupid things like run at 28 psi on 91 octane.

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Yeah with direct port I was told water only is best. I was thinking water only for pre compressor and water/meth post I/c. I have two 550cc nozzzles post I/c right now so I'll toy with that first and then try pre compressor once everything is running right and maybe try smaller jets.

I am excited to try playing with the boost/IDC settings on the aquamist, hopefully it is as good as they say.

What compression ratio is your engine Jim?

[audifreakjim]

8.5:1 which also helps

[SEStone]

28psi on 91 octane is pretty healthy. I am running junk for timing on 91, keeping the car around 23psi. Sucks so hard :(.

[audifreakjim]

I never claimed to be running any real timing:) I does run well however. If I can keep egt around 1450-1500 F at the exhaust port I am happy.

[my2000apb]

Yeah with direct port I was told water only is best.

why water only with direct port?

[audifreakjim]

I did some looking around on this as well. I think the theory is that the Meth helps cool the intake charge more than just strait water. So if you are not measuring iat to add timing it is better to just run water and tune the car for it.

[my2000apb]

hmm, well I wanted to do a single nozzle just post IC (midsize to larger) and (6) smaller indiv. on the IM runners, as the post ic nozzle would let the IAT see the temp difference

so many options to contemplate

[audifreakjim]

No kidding. I can't hardly wait for my new valve to get here so I can go test all of this and log some data

[my2000apb]

im in for data, the more the better, id prefer not to change the setup a few times haha

[AngryTaco]

I did some looking around on this as well. I think the theory is that the Meth helps cool the intake charge more than just strait water. So if you are not measuring iat to add timing it is better to just run water and tune the car for it.

H2O has a higher specific heat vs CH3OH. Water has a specific heat of 4.184 j/g-k whereas Methanol is 2.51 j/g-k. Water will absorb more heat (energy) from the surrounding air without increasing in temperature thus providing a method of higher octane in the cylinder (less detonation prone). Meaning it takes 4.184 joules of energy to raise 1 gram of water (1-ml) 1-degree kelvin. Since the specific heat of air (and this is just a general #) is 1 j/g-k this means Air will drop 4.184-degrees Kelvin for every 1 degree increase in the water's Temperature. This does not take into account pressurized air which will be slightly different vs 1.0BAR air.

One advantage to water is also steam power. Methanol has an advantage if you are NOT adding fuel to compensate for the increased volume of oxygen now entering the cylinder. The ideal gas equation PV = nRT states that more mols of gas will be present with less temperature if pressure and volume are static. This is why you will still need to add slightly more fuel even with water injection only.

So if you are running 2 BAR of pressure on a 2.2L system with an intake temperature of 80-degree F (299.817 K) the equation will follow if lets say you are using water injection only:

(200kpa)(2.2L) = n(8.314)(299.817K) = .176517 mols of GAS (not 02 - take a percentage to get the actual o2 number. Air is comprised of 20.95% oxygen)

Pretend this is the equation without any water or w/m injection at 120-degree farenheit (322.039 K):

(200kpa)(2.2L) = n(8.314)(322.039K) = .167973 mols of GAS

This translate into more heat per particle in the combustion chamber which means = higher risk of starting a chemical reaction (breaking the chemical bonds)

You can sorta calculate the difference in between by using W/M injection vs water only but I'm not in the mood to do the math. Water only injection for the win. To get an exact number you would need to measure the temperature difference between W/M and Water only to get a precise number. Also remember 2 BAR is 14.7 psi of BOOST. 3 BAR would be about 29.4 psi of BOOST. These numbers are dependent on your current elevation. 1 Bar at sea level is NOT the same as 1.0 BAR at 10,000ft