we run about 22 to 23 degrees of timing and have run 45 lbs of boost. we have no intercooler. we did try spraying the fuel in the intake tubs to cool the charge but saw no difference. we have played with blower motors in the past and starting line temp means allot about how the car will run.
Your timing looks good for peak level cylinder pressures (peak torque). If you have to go any less than that, you have a mixture problem. Of course, as the engine runs through its rpm band cylinder pressure levels will vary. Fixed timing is an elephant from the past (lazy mans tuning). If a timing curve system is available to you, you should be taking advantage of it. Fixed timing is a compromise. It is usually set to take care of the timing needs for a particular rpm range (a very narrow one). All other areas will be less than optimum.
Idle will be much happier with a little more timing.
A/F will usually be leaned out and timing will slightly increase after peak torque is past. This may or may not be true in your case. Every methanol engine is its own animal. Be careful taking advice from the Toyota camp. What works on their engines may not transfer over to yours.
I'm going to say this again. And its very important that it sinks in. 'Every methanol engine
configuration is its own animal.' What works for one, may be totally wrong for another.
Spraying the extra fuel may not have increased power, but it may be, at least, moving your mixture from being dangerously close to an auto-ignition state. Keep in mind. Methanol fueled engines always go the fastest, right before they go boom! You should have increased your fuel until you started seeing a drop in performance or you noticed raw fuel out the exhaust. That will establish your tuning window.
Your correct about starting temps at the line. This is very important with a methanol engine. If your tuneup is less than safe, you don't want to be hot at the line. If your tuneup has a safe cushion, you will want to be hotter at the start. My best times are usually done when I get caught in the water box waiting for the person from the previous pass to pickup his chute and get off the track. This would be a coolant temp of 180F. Of course, at this point, my tuneup is relatively safe. The difference in power from having a hotter engine at the start of the run is because I've changed the vaporization synchronization or curve that the fuel will go through as it passes through the 4 cycles in the engine.
It all comes down to controlling the intake charge temp (starting temp), rate and amount of vaporization throughout the 4 cycles of the engine.
The rate of vaporization throughout the 4 cycles of the engine, along with the amount of fuel available for vaporization and the quality of vaporization from the start of the process will change with differing tuneups, and engine, and fuel system layouts. Just the fact that someone decided to use heat barrier coatings on just their pistons can change this very important synchronization of vaporization with the 4 engine cycles.
As the mixture is compressed, the mixture is heated.
The heat from compression helps to vaporize the mixture. How quickly and how much of the mixture that vaporizes is important.
As the mixture vaporizes, it absorbs heat and helps control the temperature of the mixture. It's important that the mixture never rises to auto-ignition temperatures during this phase. If more fuel is needed to provide more vaporization and hence temperature control, then more is added. And yes, sometimes at the expense of power. Aftercooling will help lessen the level of extra fuel that would otherwise be used for mixture cooling purposes alone.
Depending on the engine (different animals again), it may be necessary to have enough un-vaporized fuel available during early stages of the power stroke (early and critical phase of ignition) to control mixture temperature and combustion flame speed.
Fuel injector location is just one of the many variables that will have much to do with the required bsfc of the engine.
Fuel injector location will have much to do with the initial state of vaporization of the fuel before it passes the intake valve.
Fuel injector location will have much to do with the density value of the air as it passes through the intake port.
Intake port volume will have much to do with the air velocity through the intake port, which will have much to do with the vaporization level of the mixture before the intake valve.
With methanol its vaporization cycle and synchronization, vaporization cycle and synchronization, vaporization cycle of the fuel and synchronization to the 4 cycles of the engine. And
everything has an effect on it. Even the smallest tuning change.
Theoretically, it's possible to tune a methanol engine to the point that the fuel is detonating at just the right point to achieve maximum pressure rise at just the right point in crankshaft rotation. This is something that is normally stumbled upon and not tuned for. The engine components would have to be able to withstand the quick pressure rise also.
There really is so much more to this. I hope I did a good job of summarizing it for you. Good food for thought?
Happy methanol tuning to all!