Afshin Posted July 15, 2008 Share Posted July 15, 2008 I have a meth injection kit which I’m in the process of tuning for my car (work in progress). I have seen highly significant differences in nozzle size and tunes and wanted to poll members here regarding their set ups and see if we could share some info in an organized manner: Application: open track (and street) Engine: l28et Turbo: T3/T4 50e Boost: 16-20 psi Fuel system: SDS Air fuel ratio: ~10.8-11.1/1 Spark plug: NGK bpr 8 Timing at max boost: ~22 Meth injection: Devil’s own progressive unit Start injection at 5 psi and maximum flow by 17psi Nozzle size: M10 (10 GPH; 630ml/min) Fluid: 50-50 water/methanol I recently tried 100% meth, which has yielded good performance results for some members, such as Bernard who runs very high meth flows, aiming primarily at peak power for ¼ mile applications. However my goal is more for detonation suppression and combustion chamber heat management on longer open track events. So far, I found 100% meth to require a significantly different fuel curve tune than 50-50 mix (which can run closer to a non-meth fuel curve tune). I also drive the car on the street a fair amount and don’t want to run 100% meth at high volumes all the time and would like the flexibility of decreasing meth injection volume when off the track without having to re-tune the car…so I have switched back to 50-50 mix, with good results. Regarding nozzle size, I first ran a 5 GPH nozzle but still had to be very careful with timing advance, as I could get brief knocking and then switched to a M10 with good detonation suppression, but can’t tell if it’s larger than needed and have not tried any other size nozzles yet. It would be interesting to hear of various experiences with different nozzle sizes, tunes, mixtures…. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted July 17, 2008 Share Posted July 17, 2008 Application: street/strip (mostly) Engine: l28et Turbo: T3/T4 (H-Trim/.82 stage 3) Boost: 18-26 psi Fuel system: z31 ecu Air fuel ratio: ~10.6-11.6/1 Spark plug: NGK bpr 8 Timing at max boost: ~24@5.2k/27 6.5k+ Meth injection: Autospeed diy controller kit Start injection at 2.5vdc/~3psi (maf based) max at 4.5vdc/~15psi Nozzle size: M10 (10 GPH; 630ml/min) + m15 Fluid: 100% meth (hic) 100% water will require the least amount of tuning and fluid. More meth requires more fluid but also yields the greatest power. IMO it is a small price to pay compared to an extensively built engine/DBB Turbo/MLS headgasket/etc etc. Methanol is very forgiving with regards to rich afr's. I didn't lose power until I got to 10.6 afr's and didn't really gain anything leaner than 11.5-7. I have my tune setup to rely on the meth to keep the engine together. I watch the wideband closely and when the boost is set on high, I always test the pump before boosting. Quote Link to comment Share on other sites More sharing options...
ktm Posted July 17, 2008 Share Posted July 17, 2008 I am running 100% methanol in my car as well. I am not running any of the pump-controlled kits like Snow Performance, Devils Own, Alky Control, etc., but rather a constant duty cycle pump with a methanol injector. I just dyno'ed at 388 wheel ft-lbs and 326 hp at 22 psi, my horsepower numbers are lower than they should be because I am fighting boost bleed-off after peak torque (it drops to 16 psi). I did a lot of reading and determined that 100% methanol was for me. I am not tuned to the ragged edge like Bernarrd, but I am tuned for methanol. I am adding, at the moment, 5 degrees of timing over my base fuel-only map, putting me around 22 degrees at peak boost. I have also pulled 20% of my primary fuel map to account for the methanol and I am still not done tuning. I still need to pull some more fuel. I am running a fail-safe setup on my car. My EMS is setup to switch maps to a fuel only map if the methanol pressure drops below a threshold. The switching is seamless and I would never know if I was on the failsafe map if it were not for an LED I wired in. You can not run 100% methanol, then switch to 50/50, then 100% water and not retune each time. Methanol and water fight detonation in two completely different manners. Methanol increases the octane of your fuel charge while water lowers the cylinder temperatures. If you are looking for detonation suppression only, I would go with water. I drive my car on the street all the time as well. You are only injecting when the car is on boost, so I do not understand why you are concerned with running 100% methanol all the time on the street. I go through 3 quarts every 2 to 3 gas tanks unless I am doing some heavy duty tuning runs, then 3 quarts last 1 tank. However, once you experience a tuned car running on 100% methanol, you may never go back. Quote Link to comment Share on other sites More sharing options...
texis30O Posted July 17, 2008 Share Posted July 17, 2008 I currently have a water injection kit on my car with a Turbo Tom set up. I have not dyno'd it nor have I checked the tune on it. I am starting to go through my car now and eliminateing the weak points. Would me mixing a 50/50 mixture help with detonation? and increase power? I also have two stages of gas on this setup and haven not used the gas yet cause I wanted to make sure that everything was back in 100% working order before I put it through its' paces...... Sorry to kind of thread jack.... Quote Link to comment Share on other sites More sharing options...
Afshin Posted July 18, 2008 Author Share Posted July 18, 2008 Well you guys are certainly making a good case for 100% methanol. One thing that made the various tunes for me a little more work pertained to the fact that SDS does not have memory for different maps and I must manually reprogram each time. For changing peak timing, I can do it very easily, but changing the fuel curve is more of a pain in the neck. On track days I need more flow as the car is pushed so much beyond street application, requiring a different tune. With less methanol, I was able to make changes in other parameters (flow, boost…) with less retuning. But then I really have not tried that many combinations yet, which is what prompted me to ask about others experiences. I guess I could keep playing with it on 50-50 mix and then when happy with the tune re-try 100% meth from a better platform. Bo, your set up sounds real nice. How did you choose the flow amount with the constant cycle pump set up? Did you pick a percent of the fuel injector flow? Do you approximately know how much meth you are injecting (in GPH or ml/min) at 15 or 20 or any given psi? Quote Link to comment Share on other sites More sharing options...
ktm Posted July 19, 2008 Share Posted July 19, 2008 Afshin, my methanol injector is fully mappable, just like a fuel injector. I can vary flow for a given MAP and RPM, just like my primary fuel injectors. My EMS controls the injector via an auxiliary PWM channel. Saying that, the company (FJO Racing - www.fjoracing.com) has a complete standalone methanol injection setup that uses EMS like software to fully control their injector(s). You can save maps, vary flow based on RPM and MAP, etc. It is a very slick system and one I would have opted for had my EMS not had the ability to control the injector directly. I estimated my flows based on my fuel injector pulse widths and used a replacement factor of 20%. I have a very detailed spreadsheet that I used to do the calculations. The calculations are not complicated, but I am using my actual fuel map to calculate the meth injector duty cycle. Quote Link to comment Share on other sites More sharing options...
jgkurz Posted July 20, 2008 Share Posted July 20, 2008 I watch the wideband closely and when the boost is set on high, I always test the pump before boosting. How do you test the pump? Do you have a manual switch that you turn on under the hood? Quote Link to comment Share on other sites More sharing options...
Bernardd Posted July 20, 2008 Share Posted July 20, 2008 I have the controller beside me in the cabin. With my controller, I can turn on the pump by adjusting the controller to see if the afr's go rich. Quote Link to comment Share on other sites More sharing options...
Afshin Posted July 23, 2008 Author Share Posted July 23, 2008 The devil's own unit I have has a led light that lets me know when the pump starts kicking in and then also when it's at maximum output, which is quite nice. There is a company that sells pressure switches to let you know if there is actual flow through the line: http://www.enginerunup.com/shop.php/parts/injector-nozzle-pressure-sensor/p_13.html Generally I'm not so worried about failure of the system as it should be no less reliable that the fuel injection unit. So knowing it's on and reading boost is enough to make me comfortable. We can just as easily have a fuel injector that flow less than the others causing lean conditions and loss of piston.... Bo, do you have an estimate of how much methanol you are injecting, such as 15 or 20% of fuel flow ? According to general guidelines I should be using 12.5 to 25% water/meth or 1-2 GPH per 100 horsepower which comes out to about a 4 to 7 GPH for my application. Bernard, you are running a LOT of meth, but in your case it seems to be more of a hybrid gasoline/meth fuel system than a traditional Meth/water injection system as a means to prevent detonation on a gasoline fuel injection. Obviously 50-50 mix would not work too well at those volumes. Texis300, 50-50 mix is generally believed to be a good way to get both cooling, detonation control and good power output. It's clearly the mix most recommended by various manufacturers. I would recommend that as the starting point. Quote Link to comment Share on other sites More sharing options...
ktm Posted July 24, 2008 Share Posted July 24, 2008 Afshin, I am injecting approximately 20% methanol. You base the percentage off of your initial fuel map before methanol injection. What you will find is that you will need to PULL fuel as you will be running too rich. Right now I have pulled 15% of my primary fuel and I am still a bit too rich. I am not recalculating my methanol percentages though. I left them alone and pull primary fuel. You can calculate how much methanol to inject based off your fuel map. The calculations are mass based, not volume based. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted July 24, 2008 Share Posted July 24, 2008 Bernard, you are running a LOT of meth, but in your case it seems to be more of a hybrid gasoline/meth fuel system than a traditional Meth/water injection system as a means to prevent detonation on a gasoline fuel injection. Obviously 50-50 mix would not work too well at those volumes. I like to drive around with the boost set on "absolutely freaking kill" psi. It makes the world a better place. Lol Quote Link to comment Share on other sites More sharing options...
Afshin Posted July 24, 2008 Author Share Posted July 24, 2008 boost set on "absolutely freaking kill" I can imagine you hitting maximum psi and grinning ear to ear in a cloud of smoke as you disappear into the horizon. BTW, regarding those furry creatures crossing the road, there are better ways to hunt. Quote Link to comment Share on other sites More sharing options...
letitsnow Posted July 27, 2008 Share Posted July 27, 2008 Application: street/strip (mostly)Engine: l28et Turbo: T3/T4 (H-Trim/.82 stage 3) Boost: 18-26 psi Fuel system: z31 ecu Air fuel ratio: ~10.6-11.6/1 Spark plug: NGK bpr 8 Timing at max boost: ~24@5.2k/27 6.5k+ Meth injection: Autospeed diy controller kit Start injection at 2.5vdc/~3psi (maf based) max at 4.5vdc/~15psi Nozzle size: M10 (10 GPH; 630ml/min) + m15 Fluid: 100% meth (hic) 100% water will require the least amount of tuning and fluid. More meth requires more fluid but also yields the greatest power. IMO it is a small price to pay compared to an extensively built engine/DBB Turbo/MLS headgasket/etc etc. Methanol is very forgiving with regards to rich afr's. I didn't lose power until I got to 10.6 afr's and didn't really gain anything leaner than 11.5-7. I have my tune setup to rely on the meth to keep the engine together. I watch the wideband closely and when the boost is set on high, I always test the pump before boosting. Kind of off topic, but, when do you start to see boost and when do you see max with that turbine? It's very similar to the turbo I'm going to run. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted July 27, 2008 Share Posted July 27, 2008 Kind of off topic, but, when do you start to see boost and when do you see max with that turbine? It's very similar to the turbo I'm going to run. In 3rd gear (jatco automatic) I see 5psi at 3k with full boost before 4k. Quote Link to comment Share on other sites More sharing options...
Afshin Posted September 24, 2008 Author Share Posted September 24, 2008 Well the tuning process has progressed nicely. It felt like the engine was bogging down with the large #10 nozzle combination and 50-50% mix, so I switched back to the #5 nozzle and set it to start injecting sooner at about 2-3 psi (after realizing that it was previously starting to kick in at 6-7 psi). The results have been quite good and the engine is more responsive, with no pinging at 22 psi boost, which is quite wicked, to say the least. I turned it back down to 18 psi for daily driving and engine longevity. I also took the car back for a full day at the track and it performed great! I think I will stick with the current tune and 50-50 mix for now. In short, water/alcohol injection is simply amazing for our detonation chambers. Perhaps I can go ahead with building a higher compression engine Quote Link to comment Share on other sites More sharing options...
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