Methonal Mixtures

[jgkurz]

Hi Folks,

 

I'm in the process of deciding what methanol injection I want to put on my turbo L28. I thought I would do 100% methanol injection but there is varying opinions as to whether that is safe, necessary or even harmful to the equipment. Some manufactures say you get the most benefit by going with a 50/50 water/methanol mix. Personally, I thought straight methanol would be best but now I'm not so sure. My goal with the new system would be to protect against detonation at high boost levels while using 92 octane pump gas. Also I want to bring down my exhaust temps.

 

What's everyone's opinion on straight methanol vs a 50/50 mix with water?

 

Also, where are you getting your methanol?

[big-phil]

well I like 100% myself. I have cast pistons and have yet to hear detonation at upwards of 26-27 lbs of boost. Also I can feel a bit of a "kick" when it starts spraying.

 

At first I used windshield washer fluid and that was ok, but when I put 100% in it was night and day. I will stay with 100%.

 

I get my Meth at Alamo speed shop. But I have seen it on e-bay also.

[ktm]

John,

 

Please visit the following sites:

 

www.rx7club.com

www.evolutionm.net

www.turbobuick.com

http://www.aquamist.co.uk/phpBB2/ - Aquamist Forums

http://www.innovatemotorsports.com/forums/index.php - Innovate Motorsports forums

 

There is A LOT of reading to be done regarding methanol injection. I need to thank Bernard for recommending Turbobuicks and RX7club.com. There is some fantastic information there.

 

The Aquamist site is another FANTASTIC resource. All three sites get into the technical details about the differences between water and methanol injection.

 

Aquamist, as you may or may not know, is used exclusively on World Ralley Cars and they are/were primarily focused on water injection. Saying that, the discussions on those forums will give Hybridz a run for its money.

 

Basically, water has a higher latent heat than methanol. What this means is that water will be able to absorb more heat than methanol, which results in cooler IN CYLINDER temperatures and slightly cooler INTAKE temperatures. Also remember that water is not a fuel, it is not combustible therefore it does not protect against detonation by increasing the effective octane rating of your fuel, but rather by lower cylinder temperatures.

 

If you are looking for detonation protection only, water injection or a 50/50 mix of meth and water is the way to go.

 

Methanol, on the other hand, has an octane rating of around 118 and it evaporates much quicker than water. However, it's latent heat is lower than that of water. What this all means is that 100% methanol will SIGNIFICANTLY reduce your intake charge temps (for instance, my temps dropped from 31 degree C to 12 degree C at idle when I was playing around with my duty cycles), this is the "kick in the butt" that Phil experiences.

 

Methanol will have a minimal impact on cylinder temperatures. However, methanol protects against detonation by raising the octane level of your fuel. Remember, though, that methanol by itself IS combustible and IS a fuel. Therefore, when running 100% methanol you need to tune for it by pulling primary fueling to take the most of injecting 100%. You can add QUITE a bit of timing as well as pull quite a bit of fuel. Methanol burns slower than gasoline, and as a result the timing needs to be advanced.

 

There is some speculation in Phil's thread regarding his turbo that his overly rich condition caused by injecting 100% meth and not pulling fuel may have caused his turbine housing to overheat due to unspent fuel combusting in the housing.

 

You will make much more power running 100% methanol than you will 100% water or 50/50 water/meth. In order to do so you need to tune for it. Running 50/50 or 100% water is a much safer way to go for just detonation resistance.

 

As for where I get my methanol, I called around to a few local speed shops and found a few that can order it for me. I pay around $35 for a 5 gallon can of Torco methanol.

 

Lastly, I would recommend that you look into systems like Aquamist and FJO Racing for their PWM controlled high speed solenoid injectors. Places like Snow Performance, Devil's Own, and Alky Control vary the injection output by varying voltage to the pump. Aquamist and FJO Racing control the output just like an injector.

 

I am using Wolf to control my FJO injector with a 32x16 map, similar to my fuel injector map.

[Bernardd]

John,since you have a standalone, I would consider injecting 100% meth with a solenoid, pressure switch, a couple of large nozzles and having the ecu switch to the aux fuel/timing maps. With a progressive controller you will find that if you tune for rolling into the throttle, you might have a lean spot when you nail the throttle and just the opposite when you tune for quick wot, you will be rich during slower rate throttle transistions. That will hold true for meth pump controlled systems. You could also find yourself with a sputter during on off throttle transistions when shifting. Higher water content in the mixture will amplify the bog. Coolingmist, aquamist and FJO have fast acting solenoid injectors that can be mapped like the regular fuel injectors and remove the issue. IMO why map two systems when you can take care of it with your ecu. There is a lot of power to be found with 100% methanol if you're willing to tune for it. What afr is best to tune for? The last time I was on the dyno I tested various mixtures. The more methanol I used, the wider the window between the point of losing power to being overly rich to gain power by leaning the mixture became. At 10.7:1 I began losing a bit of power, at 11.5:1 I stopped gaining any power. It's something that you'll have to figure out for your motor, but I tune for 11.3 or so. I buy my methanol at a couple of local hardware stores. Hope that helps.

[jgkurz]

Great responses everyone. Thanks so much for taking the time. Now I need to digest the info and get going with a system. I was originally thinking my Tec3 could control the methanol injection but I was told that that would be undesirable by a methanol injection vendor. I'm now more convinced that using the Tec3 to control the meth injection is the way for me. I'm sure I'll have more questions as I design the system but for now this thread has been a huge help.

[jgkurz]

John,since you have a standalone, I would consider injecting 100% meth with a solenoid, pressure switch, a couple of large nozzles and having the ecu switch to the aux fuel/timing maps.

 

 

Coolingmist, aquamist and FJO have fast acting solenoid injectors that can be mapped like the regular fuel injectors and remove the issue. IMO why map two systems when you can take care of it with your ecu.

 

 

Bernardd, I found this setup that looks like it's just what I need to hook it into my Tec3. I would need to buy a tank but other than that it looks complete. Do you agree?

 

http://www.coolingmist.com/detailmain.aspx?pid=shsvecu

[Bernardd]

Agreed. You want to make sure your ecu can drive that injector and I would buy another/larger nozzle for your hp level. I would at minimum use the m10 and m6 supplied and you might find you need more.

[jgkurz]

Agreed. You want to make sure your ecu can drive that injector and I would buy another/larger nozzle for your hp level. I would at minimum use the m10 and m6 supplied and you might find you need more.

 

Below is how my Tec3 GPO's (General Purpose Output's) work. They use PWM and are compatible with the frequency of the Coolingmist setup.

 

Are you saying I may need two or more nozzles? If I understand correctly, the Coolingmist kit comes with one valve which can control one nozzle. If I want to control two or more nozzles I would the same amount of valves and a separate PWM signal for each valve. Am I on the right track?

 

I might have two GPO wires from my Tec3 still available. If I need a separate PWM signal for each valve I will likely be limited to two.

 

[Bernardd]

You'd probably be best off asking coolingmist. I would run at least an m15 sized nozzle or nozzles to start.

[jgkurz]

You'd probably be best off asking coolingmist. I would run at least an m15 sized nozzle or nozzles to start.

 

Thanks for the nozzle recommendation. I just called Cooling mist and I do need a valve for each "controlled" nozzle. I could use one valve for two nozzles but they would be not independently controlled.

[ktm]

Agreed. You want to make sure your ecu can drive that injector

 

This is not necessarily correct if you mean the ECU literally drives the injector like a fuel injector. The FJO Racing setup has an HSV/injector driver that is controlled by the PWM output from the ECU (similar to the ECU sending a signal to the stock turbo ignitor that then drives the coil).

 

John, does your Tec3 have map switching capabilities on the fly? I ask because you will WANT a failsafe if you tune for meth or water. Coolingmist has a clog detector and FJO has a pressure sender. I use FJO's pressure sender as my fail safe. If the pressure drops below a value, Wolf will switch the map to my non-meth map. It works seemlessly.

 

Another thing you need to consider is the minimum duty cycle of the HSV. I know that FJOs minimum DC is 10%; below that the opening time is close to the response time of the injector and you do not get consistent performance. In order for my 700 cc/min HSV DC to be 10%, I start spraying at 3 psi at 3000 rpm. Any lower RPM or boost and the DC is less than 10%.

 

If you send me your fuel map, I have a monstrous spreadsheet I made that calcs HSV DC versus MAP and RPM based on the fuel map, meth mix %, amount of meth injecting as % of primary fuel, fuel injector size, fuel pressure, etc. It gets you in the ball park (are you at 30% or 60% DC).