Once you start burning things other than gas, you really need to think in lambda. Hell, even most gas today has ethanol in it, so AFR 14.7 for stoich is no longer valid. Lambda 1 for stoich will always be valid. With that said, I shoot for around 0.78 lambda on and off methanol, and I shy on the rich side.

I have yet to come up with a good solution for a failsafe. As mentioned, the IAT may not react fast enough to prevent engine damage. In my setup the IAT doesn't change all that much when spraying, it basically holds the IAT steady. Daily changes in outside temps cause more change in my IAT than spraying does, so pulling timing due to high IAT is not feasible.

I keep my eye on the wideband in boost. The hobbs switch to monitor methanol line pressure is a good idea, with EFILive COS5 you could run the signal to the PCM to pull timing or add fuel based on the switch. The tricky part is making sure these settings won't screw with daily driving out of boost.

 

It's been my experience when the sensor and nozzle are positioned correctly the sensor reacts very quickly. I agree there is no fool proof method. I have an led that changes from red to green to tell me the pump is at full pressure, but I also keep my ears open for knock, and have aborted full throttle passes when I thought I heard knock. Only to look at the log and see none. I have yet to toast an engine with my setups, and I have had two different meth pumps fail. The led is the easiest way to keep an eye out, if it doesn't turn red to green then let off.

 

Did this LED come with the methanol kit or installled it yourself? Any pics or link to this LED lights?

 

It comes with alky control kits.

 

That LED comes in Alky Control kits. Even if the pump dropped pressure though, by the time you saw the light and had a chance to react, damage would have been done. Maybe that's just me though...I push my stock engines a lot harder than most of you guys

 

The LED does come with Alky Control kits, but you can rig up your own. I don't see how you wouldn't have time to react and lift before you damaged the engine. Unless your setup is already beyond the limits of reasonable safety. As I said I've had two pumps fail, and no engine damage resulted, but my setups aren't on the extreme verge of reliability, but they are well beyond the power level most people on this forum claim. I learned that the last 20hp isn't worth the risk of damage, especially considering you can't even tell the difference when your already making huge power.

I also have not measured reaction time to the color change of the LED, but I feel certain it would be measured in fractions of one second before the throttle was released. There is no question I can see that light out of the corner of my eye much faster than I can see the readout on my wide band gauge.

I hear turbo guys telling stories regularly of boost controller/ wastegate failures resulting in huge boost spikes and lean ratios, but almost always they react and lift with no permanent damage. I'm sure there are examples where some people have toasted an engine, but I would say it was likely because they weren't paying attention rather than not having the time to react.

 

I dont run meth anymore as I converted for E85. The fail safe method I was thinking of was using the valet mode in the EFI Live COS. I used an old coolant reservoir with the low coolant switch. I never wired it up as I stopped using it, but if the coolant got low, it would force the truck into valet mode then you can pretty much do anything you want with the engine. I was going to let it not rev past 3k so I could still drive it.

Im not sure what the light is that you guys are talking about. If it comes on when the pressure is low, you could tap into that wiring and run that to the valet mode.

 

Things happen very quickly when 1000hp is hitting the ground. I wouldn't even bother with a failsafe unless it was instantaneous. I don't design things to have a margin of error...if I am gonna go to the trouble to design a failsafe, its going to have a 100% success rate. Not just 'good enough'. But that's just me..