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

[chaloux]

Nice post Jared. Saved for later reading.

Which parts of the exhaust, when leaking, will F with AFR jim? I assume we're talking up around the header or header-turbo connection, BEFORE the wideband. What about after, like DP to exhaust connection?

[ads]

I would also like to add that tuning for water only is easier than tuning w/m direct port. When injecting at the ports you are injecting water and meth only inches from combustion, this doesn't give a lot of time for the water and meth to evaporate and you can potentially get poor distribution and/or droplets going into the intake and cylinder. You have to make sure you have your mixtures injected at the correct time and with enough pressure. Also, when injecting w/m direct port, since you are usually injecting more fuel into each runner than you would if using a single or dual nozzle setup pre tb(of course its all dependant on engine displacement, # of cyl, boost, etc.), you most likely have to lean your base fuel(pump gas/e85) out to compensate for the extra meth fuel. This can be scary if you don't trust your meth kit or failsafes. That being said, well executed setups running direct port and or pre compressor have sometimes made more power with a w/m mixture than just water alone. Again, a lot of depending factors with this though.

I am no expert on the subject by any means, but these are some of the experiences I have read about. I am glad someone in this community is having good experiences with w/m and I look forward to playing with it myself.

[pkw]

dyno yet?

[audifreakjim]

Dyno will come in two weeks

[chaloux]

Dyno will come in two weeks

Eeeeeeeeeexcelleeeent.

[loxxrider]

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

Jared,

Have you considered that specific heat capacity might not be the driving property involved with cooling in the case of water/meth injection? Think latent heat of vaporization...

I haven't given this enough thought yet, but I suspect there is more to the equation than what you're arguing. I.E. phase change is happening, and that is a much more powerful cooling process than single-phase cooling.

[loxxrider]

Keep in mind, I'm talking strictly about the charge air before it enters the cylinder. Once it is in the cylinder under combustion, then the water definitely takes over in terms of cooling effect.

[vt10vt]

Jared,

Have you considered that specific heat capacity might not be the driving property involved with cooling in the case of water/meth injection? Think latent heat of vaporization...

I haven't given this enough thought yet, but I suspect there is more to the equation than what you're arguing. I.E. phase change is happening, and that is a much more powerful cooling process than single-phase cooling.

It's my understanding this is where the majority of the benefit of using water is. It won't burn like methanol will, so you only experience the cooling benefits of the vaporization. Specific heat capacity is not important, instead the amount of heat needed to convert the H20 to steam is where the cooling affect happens. Water doesn't stay an H20 molecule for long in the conditions of a boosted motor so I highly doubt you're actually gaining any benefit from it's high specific heat.

[vt10vt]

dyno yet?

Speaking of which, is your 20vt/20v ever going to hit the rollers?

[loxxrider]

Jared,

Have you considered that specific heat capacity might not be the driving property involved with cooling in the case of water/meth injection? Think latent heat of vaporization...

I haven't given this enough thought yet, but I suspect there is more to the equation than what you're arguing. I.E. phase change is happening, and that is a much more powerful cooling process than single-phase cooling.

It's my understanding this is where the majority of the benefit of using water is. It won't burn like methanol will, so you only experience the cooling benefits of the vaporization. Specific heat capacity is not important, instead the amount of heat needed to convert the H20 to steam is where the cooling affect happens. Water doesn't stay an H20 molecule for long in the conditions of a boosted motor so I highly doubt you're actually gaining any benefit from it's high specific heat.

Well... there are two things going on here. We have cooling during combustion, but we also have more mass air flow getting into the cylinder due to cooler (more dense) charge air temps. Specific heat capacity is relevent in the cylinder only because the latent heat of vaporization is roughly proportional to the specific heat capacity. I.E. if a substance has a high Cp, it will also have a high latent heat of vaporization.

What I'm mainly interested in for the purposes of this conversation is the cooler charge air and the effect that can have on power. It is the same effect as experiencing more power on a cold day in a car which doesn't utilize knock sensors. The power isn't coming from resistance to det, its coming from the ability for more air to get in the cylinder (all else equal).

So the question is, does methanol with its lower boiling point and high volatility make for a performance benefit due to extra cooling of the charge air? I believe it does and am trying to organize the equations that govern this type of evaporative mist cooling. The thing is, the charge air can only benefit from evaporative cooling from water to a very small degree. Meth will much more readily evaporate in the charge air. That is why, even though meth has a lower heat capacity and latent heat of vaporization, it probably does a better job at cooling in this case.

[vt10vt]

I think the benefits depend on the application, how it's put into practice and what you're trying to achieve, but I was speaking directly to Jim's setup.

For instance, injecting say the manifold runner, at that point you have less heat, less airflow, and less time, all of which plays to meth's strengths. In this case the meth is providing the most benefit because it can cool very quickly and also aid in making more power. H20 takes more heat to change states so it probably isn't happening until later, and with the velocity of the air at that point it doesn't give the water much time to condense the air before it's already locked into the cylinder with it. Meth makes more power, don't need any math to prove that, just look at real world results.

I think you would see the most benefit from straight water running like Cosworth ran some of their spec engines. H20 injected pre-throttle body using multiple, small injectors under very high pressure. This would give the water ample time to atomize and lower temps before it gets into the cylinder. Neatest thing I found about the Cosworth setup, that I've never seen really implemented outside this example is that they aimed the injectors against airflow at ~45* angle into the air stream to help atomize the water best.

I think the Cossy setup is an example of using H20 for it's ability to cool and condense charge air, while a setup like Jim and Tim's are relying on super fast evaporation but mostly vaporization doing cooling inside the cylinders, where water is not as an effective medium and meth makes a better solution. Now, on a 20v it might be a perfect option because there you're really trying to drop cylinder temps to fight detonation.

[Mcstiff]

It occurred to me earlier that this could run in the "Classic Imported" class of One Lap starting next year (older than 25 yrs is how I read it).

[audifreakjim]

For those not on FB, got out to Willow Springs last week. I switched to 255/40-17 from 275/40-17 and like them better since I can run less pressure due to the smaller sidewall. This 255 NT01 is more like a 265 unmounted, then get it on a 9.5 wheel and it is probably only 7-8mm narrower than the 275. Much better feel, easier to fit everywhere and cheaper
https://www.youtube.com/watch?v=nkNpP6_WW_I

[chaloux]

Nice Jim!

So, what about the dyno results eh!

[audifreakjim]

Oh yeah, here is a quick update. Got the water injection pretty well sorted(bad pump valves), swapped in some larger injectors, and hit the dyno at IMS.

Went in and did a heart braking ~440whp on the first pulls. This is on a setup that I know has more balls than my old one, and on the same dyno. Anyways, worked on the tune and retarded both 7A cams 3 degrees via an adjustable cam gear and the motor really came alive. Here is an overlay of 0 vs 3 degrees. I am out of fuel above this. I was running 60psi base fuel pressure, Hank suggested lowering the base fuel pressure to 45 psi to increase fuel flow just enough to keep things stable at this level. Tuning with the FIC 1100's was a breath of fresh air.

The car hauls ass now, as if it didn't before, it really pulls well up top. On the track tune of 18psi, I was on the bumper of a new 911 turbo S at 140mph down strait at big willow with a

The guy came by and asked what the F was in that thing after our session!

This plot is at 2bar of boost, or around 29psi. on pump gas and water injection.

[PRY4SNO]

Nice work!

[audifreakjim]

Thanks, the power curve on this setup is nuts, It will build .6-.7 bar of boost in 6th at 3000 rpms, and on the street it's fully boosted before 4k in most gears. Not bad for a 2.3l

[mushasho]

Thanks, the power curve on this setup is nuts, It will build .6-.7 bar of boost in 6th at 3000 rpms, and on the street it's fully boosted before 4k in most gears. Not bad for a 2.3l

With that QSV now dialed in, did you wish 3586 would've been chosen for that "solid 550whp" goal you had set?... Cuz quite frankly, that curve look amazing for pump fuel... Excellent execution!!!

PS: did you intentionally taper above 7200rpm? Or is that just the 7A's forging their signature on your graph?
Sent from my HTC One using Tapatalk

[loxxrider]

The car looks very fast on the track Jim... and I know that if it looks fast in video, it must be scary fast in person!

[audifreakjim]

7a cams, I almost pulled the trigger on cat cams after the dyno, but I would need another pump, new lines, etc to support them.

The car is in a really good spot now so time to just drive and enjoy it.

I am happy with the turbo, glad I didn't go any larger. The dyno numbers are just that, a a tool to measure improvements. Unfortunately even the same dyno can vary in consistency depending on operator and environment. I have hit the power goal without a doubt, just might have to go trap some quarter miles to prove it.

[SEStone]

Wow, 80whp from an adjustable cam gear!?

[chaloux]

Wow Jim. 500whp and boost by ~4k on pump gas. The cam difference is nuts! You didn't lose any spool by retarding the gears either.

This is absolutely a setup to be emulated. I think you have this thing dialed my friend.

18psi for the track why? I understand "why" in general, but was there any specific reason in your case?

[WOMBAT]

Wow, 80whp from an adjustable cam gear!?

My thoughts exactly... Put it on the list!

Really appreciate how stable your car is at this power level Jim, enjoy it!

[dana]

this has to be the most sorted out, dialed in and perfected 5 cylinder audi in the US. Its been epic from day one, and just keeps getting better. I was drooling over this car when I got into audis and I'm still drooling hard.

also this is the ONLY yellow car I have ever liked. Period.

[audifreakjim]

Thanks guys, I was surprised at the cam gear as well. I have had it on the car for a long time, and tried messing with it on the street but could never seem to get any positive results. I think I may have been advancing it in the past which does not work well. Hank and Javad both saw the same increases so it isn't new, but you really need a dyno to dial it in.

I run wastegate pressure on the track at 18psi for a number of reasons. The motor barely sweats at this level, no water injection needed, easier on cooling, brakes, etc. But, the biggest reason of all, it's exhausting driving this thing at full power for 30min in the desert around a track!

I'll flip on the high boost map when I need to dispose of a ZR1 or something that thinks they don't need to point me by:)