Intercooler + aux injection seems to be a wonderful thing for turbocharged rotary motors. On anything but a dedicated go fast toy, however, ditching the intercooler and relying only on the injection system doesn't make a lot of sense. Not only is there the inconvenience factor of frequent refilling, but you're also 100% reliant on that system to avoid engine damage.

The arguments I've heard for aux injection on a intercooled turbo setup sound great - they are mostly centered around increased reliability. This new direction sounds like something else altogether.

 

if you want to run no IC go to it. a proper AI IC-less system will do the job under boost.

OTOH, i consider my ASP large IC to be an essential part of my power system. it is always removing heat from my engine under boost and vacuum. further, if you do a comparison of an AI system w and without an IC you will find the IC setup will deliver cooler air... which has more oxygen per volume and can create more power. yes, 1000 hp rotaries running methanol don't generally use ICs but they are running 35-50 psi and that is a whole nuther world and if you want to discuss it start a thread.

this thread will continue to focus on 300-500 hp applications of AI and it is great to see people checking in sharing their experiences.

hc

 

Heet is 98% Meth. You need 11 bottles of Heet to equal 1 gallon. If you are mixing 1 bottle of Heet into a gallon of water you are running something like 92/8 ratio. That is almost the same thing as running straight water. If I were you, I'd just run straight water.

 

I do not think it is the water to blame, most people don't tune for water, as in, running 12.5-13 A/F's with atleast a 12% water to fuel ratio. Thus, they lose power.

 

Why would you run 13's on water? You'd be losing power.

thewird

 

Water DOES cool intake charge, just not as much as meth would. I have proven this on my own car many times. As mentioned, water does most of it's work in the combustion chamber.

 

That's debatable.

FYI, Riceracing used to run 13.7 A/Fs on just water with a 12% mix. He hasnt been on the forums for a while now but if you look at his old dyno numbers, they speak for themselves.

And believe it or not, H20 does add to the combustion process, and is in a way, a fuel. There is a thread about this floating around here somewhere. Maybe Howard knows where it is?

 

https://www.rx7club.com/single-turbo-faq-122/best-f-single-turbo-3rd-gen-212850/

I personally do not have the ***** to run 13.7 A/F @ 20PSI, but like I said, it's been done and you can make good power.

 

I think most people lose power because their ignition system isn't up to the task. If you run the right amount of water and atomize it properly you can run 11:1 afrs without power loss. Crank up the boost and watch the power go up like crazy.

 

since my decision to go for a water AI kit from Snow Performance ive already began to consider an ignition amplifier kit. im looking at the HKS Twin Power currently, i dont think my car's stock ignition will be able to effectively handle water. also, since the AI kit im purchasing is also rated for meth...i am already starting to lean to 50/50 of meth and water.

 

From what I remember, the Twin Power only adjusts dwell. You can do this on any stand-alone worth its salt though if I recall the PFC adjusts in increments of e-shaft rotation and not MS. Thanks for the thread Howard, though I don't agree with some of your decisions, its very enlightening!

 

Sorry to bump this thread.

I have found a deal on a Aquamist HFS-5 Kit & Rear washer bottle for a tank. Does anyone have any experience with this kit? Or any info on it? I cant seem to find any tech specs on their website regarding the kit etc.

Thanks in advance.

Ceylon.

 

Never mind - found some info on the HFS-6. I will go for that instead

Thanks.

Ceylon

 

I’m sold on Water Injection, my question is what is the benefit of a 50/50 mix if you’re not tuning for it. Hope I’m not repeating this question I just didn’t see it answered it the thread but tons of great info.

 

i believe you may have to tune for it if you go 50/50. i know i will be after i get my kit installed so i can get more power out of my set-up and maybe have an extra setting with a higher boost level.

edit: im going to be running 50/50 mix

 

Tuning with 50/50 will depend on how much you inject. Methanol doesn't lose as much power under rich conditions compared to gasoline, so it might be that running it without tuning won't change power output much. This is provided the afrs aren't extremely rich now. Obviously its best to retune, you can now safely tune more aggressively and make more power. If you don't retune then your not making use of the cooler air temps. If it's just for a reliabe under 400 hp car then water is probably a better option.

 

My first concern is reliability; I’m good with less than 400hp. That’s what go me started following Howard’s thread. I’ve seen several post’s about running a 50/50 mix without tuning, I’m guessing you run cooler than just water. Someone on here will know for sure.

 

You run cooler intake temps by adding alcohol, but water cools better in the engine. A mix is easier to burn if you have a stock ignition, but if your goals are under 400 you only need about 300cc of water which should be easy enough to burn. 50/50 will require more to be injected to have the same anti-knock effects.

Many of us are pushing over 500 hp reliably with water alone, there's a thread by rx72c and he's making over 700 hp with water alone. There's also many people running mixes and straight meth would good results. Best thing is to just try different things and see what works for you. but If you're just looking for reliability you really cant go wrong with water. If you're trying to gain every drop of power from every lb of boost then a mix, or straight meth will give you some added power from lower intake temps. For me personally water keeps my intake temps in check, while eliminating knock and allowing me to run 23 psi reliably. I'm not concerned with a few extra HP at 15 psi or 18 psi when stock width drag radials already spin at 100+ MPH. Once I get traction under control and I desire more power, I can just turn the boost up another 2 psi.

 

perhaps this has been discussed, but I plan on purchasing this kit:
http://www.coolingmist.com/detailmain.aspx?pid=01250TBF
in the next month or so (I have a few other things to take care of first), and I was wondering if I should run the nozzle(s?) before or after the intake temp sensor which is currently located on the intercooler piping before the elbow. I plan on running 100% meth. The shop that sells meth/has a dyno said it should be after the intake temp sensor, but my gut reaction was to have it before the temp sensor. I'm using the temp sensor that dudemaaanownsanrx7 is selling too.

Mod list when the meth will be installed: Greddy V-spec FMIC, 4x850 injectors, walbro and rewire, non-seq stock twins, efini y-pipe, Koyo rad, HKS filters with hard intake pipes, full 3"exhaust, no cat, PFC, wideband, greddy boost controller.

 

I have pondered that question myself regarding meth injection. The sensor is sheilded so in that regard it won't matter. This is the advantages/disadvantages from what i can see:
.
If it's sprayed before the iat sensor you can see exactly the effect it has on air temps. This is a big plus in my book. It tells you the system is working and how well it's working. After some time you will know exactly what to expect and that will help warn you when something else happens. (higher temps for instance), but because the iat table is going to add fuel for the cooler charge you will have to pull more fuel from the base map. If the meth was after the iat sensor temps will read higher, less fuel will be injected and less fuel will need pulled.
.
Since you're running the iat sensor farther from the uim that means you will have to inject the meth closer to the throttle body. This might not be as effective and may not give the alcohol the optimum time to flash and pull heat from the air.
.
Personally i would want to KNOW the temps going into my engine so i can precisely tune for it. Given the sensors much faster reaction time, a cooler mixture will be adjusted for pretty much instantly, so worrying that the air is cooler then it reads isnt a problem like the stock sensor.

 

you've basically came up with the exact same debate I'm going through in my head. I'm still running the stock elbow, so it's not like I can't drill my own hole for the meth nozzle wherever I want in the elbow. At the same time having the temp sensor relocated also isn't that big of an issue, if I want to move the sensor back to the stock location, it's not gonna be a big issue to take the cap from the stock location just switch around the sensor and cap.

however I'm not completely sure what you mean by this:
Since you're running the iat sensor farther from the uim that means you will have to inject the meth closer to the throttle body. This might not be as effective and may not give the alcohol the optimum time to flash and pull heat from the air.

 

I have seen this topic come up regularly, it will all depend on what your ECU does when it see difference temperature readings.

If the sensor is experiencing a wet bulb condition, ie the evaporation is taking place at the sensor tip (always colder) or reading the actual air temperature. Placing the jet as a different location has different effect.

I don't think there is a right of wrong location, just pick the best location to suit your particular set up.

 

My comment refers to running the meth after the IATS. Say the IATS is in the middle of your plastic elbow. If you decide to run Pre- IATS then you would have to have the meth nozzle pretty much right at the front of the throttle body inlet. This doesn't allow much time for the alcohol to flash and cool the intake temps. Many people have found colder charge temps by moving the nozzle farther away. So in this case if you want to move the nozzle farther away you also need to move the IATS farther to keep it in front, this reduces the accuracy of the temps going into the engine not only under injection, but also during idle and cruise.

I personally feel the fast IATs is best used in the stock location. When you're just idling, the throttle is closed and the temps entering the engine are hotter then when the throttle is open. Stock location allows the sensor to adapt to this change and it improves hot start idle quality. Myself and several others have noticed this.

Since you have to tune for the meth anyways, it doesn't make much difference if you have to remove 30% fuel from the base map or 27%. If it was my setup I would run the sensor in the stock location, and spray meth before the sensor right after the intercooler if you're running one.

 

you see in the aluminum pipe in between the IC and TB elbow? that's where my sensor is mounted.

my engine bay before I relocated the sensor


it's actually in the bend of that aluminum pipe on mine.

 

My goodness you could perform open heart surgery on that first FD's engine bay. I think I would go insane trying to clean my engine to that caliber.

I see that you still have plenty of room after the IATs for the meth injection. I would still run the meth before and have the IATs moved back to stock. (my stock one was relocated and I chose to go back to stock location with the fast reacting one) I would either inject the meth in the elbow where your IAT sensor is now, or the one before it in the elbow right above the radiator. PS where is your BOV?