isn't this setup gonna be extremely hard on exhaust valves?

 

If it were gasoline and the associated egt that goes along with gasoline, I would have to say yes, very much so.
Since we're talking about methanol and nitrous, I would guess the egt is much lower. How much, I don't know for sure, but I do know it is less than it would be with gasoline.

Any mixture of fuel that is still burning past an open exhaust valve is not a good thing for the exhaust valve. The on-time duration of this system is no longer than about 2 seconds. I'm not sure how that short time will affect the exhaust valves. There is still a lot of data to be collected with this new system.

 

AlkyV6, are you running an AEM EMS? We just hooked mine up in my z31(custom job since they don't make one for the z31). I am not that familiar with it yet, still learning. Is there an option as to how many cylinders you want to drop during the ALS? So if you wanted (and the way you do it) you can keep from dropping any cylinders at all, but just retard the timing enough light off the mixture in the manifolds.

 

I'm running an Electromotive TEC3r w/WinTEC4 upgrade. The system gives me a few different options for aux rev control involving timing retard, fuel cut and/or coil cut. This new als system does not require the use of the aux rev control, at this point in development, anyway. I use a tight TC that, so far, does a good job of controlling the rev limit for the launch.
I do use a nitrous retard feature in the ECM. You're correct. The amount of nitrous retard I choose is just enough to light off the mixture in the exhaust manifolds.

 

Damn....if you and Boost Engineer lives a little closer to CT, I'd gladly buy you a coffee to pick your brain for a few hours. With your system, how do you account for temperature changes, elevation changes, humidity, etc??? With the system i described above, you can simply change how soon and how much the valve opens and at what RPM. Hell, you can even whip up a computer program to run it in a few days. Keep talking dude, I am learning.

 

One of the beauties of burning methanol. It has a very wide tuning range. So far, I have not had to account for atmospheric changes. Realize that I've just recently begun to understand how this system works. As time goes by, I could find that I'll have to make changes for atmospheric conditions, but I don't think that will be the case. Only time will tell.

 

hmmmm this is interesting....

reading up on this makes me wonder if there would be anyway a small amount of fuel can be injected directly to the turbine side for a brief period to allow instant spool.

3 issues come to mind with this

1. Will the turbine blades hold up
2. How much fuel would be enough
3. How durable of a injector is needed to withstand the heat

 

When you say fuel, which fuel are you referring too?

 

i know ur for meth but i am talking about a Gas application

 

Gas application, you would have to figure out a way to supply a separate air or oxygen supply to combust the gasoline.

 

wouldn't adding gasoline to the turbine ignite and work somewhat like a afterburner works on a turbojet airplane where extra fuel is just added to already heated gases with traces of oxygen? i mean if hitting the redline cuts the spark and dumps fuel into the pipes, making it ignite in a mean turbo backfire then the theory sounds plausible to me.

but then again im no engineer

 

In a gasoline als, typically the engine is run up to an aux rev limiter where the mixture is richened and spark ignition is dropped from random cylinders. Differing levels of ignition retard are then used to ignite the mixture in the exhaust. The way the gasoline system gets the needed infusion of air to burn with the gasoline in the exhaust is by the dropping of the ignition from random cylinders. The air from the intake charge that was not burned in those cylinders where the ignition was dropped is now available to be used to burn the fuel in the exhaust system.
Another method of supplying air to the exhaust system for a gas als would be to route an air injection system to bypass an air supply directly into the exhaust system, after the exhaust valves.

The Nitrous/Methanol DT ALS does not require any special effort to supply a separate oxygen supply to the reaction taking place in the exhaust system, since the nitrous and the methanol both contain oxygen as part of their molecular makeup.

 

Need some more testing data, man!

 

This Saturday! I'm starting to bite at the bit.

 

This is all very interesting.

The reason afterburners work in a jet is because, by its very nature, a jet moves incredible amounts of air. So essentially you have a very lean-burn situation with a bunch of unused oxygen in the exhaust. Might as well through some fuel in there for a lil extra thrust.

Something similar may be achievable with a diesel but most gas setups don't like to burn very lean so it's probably a no-go with gas... unless you could stratify the fuel charge in the combustion chamber, which it just so happens seems to be the case with the new direct injection engines... :hmm:

^^^Just thinking out loud...

 

You do need to get the nitrous/methanol ratio just right (very rich) for your particular combination to obtain the best spool up. That and the proper amount of ignition retard. You'll know you have it right when the a/f meter reads a flatline 14.64:1 when the system is activated.

 

well see, if somehow and i mean SOMEHOW u can fit a durable injector thats high heat resistent on the turbine side and only squirt fuel when trying to boost off the line, while still getting fed just enough air and heat to begin a burn then it should sustain itself with its increasing heat. this wouldnt be on for more than 1-2 secs either so a little fuel resovoir should be fine as to not be a huge fire hazard.

of course the air/fuel ratio would have to be played with to get the right mix for this to work.

 

Is it Saturday yet?

 

We want some data! Or maybe I'm the only tard interested in the chemistry here...

 

LOL Using the als with the spool valve was unproductive. It appears the spool valve created enough extra exhaust backpressure that it upset the als reaction.
Generally, with nitrous injection alone, the car nets a 1.69 60 foot.
With nitrous injection and the spool valve, 1.59 60 foot.
With nitrous injection, the spool valve and the als tune, 1.59 60 foot. Basically, the als is killed.
With nitrous injection, the als tune, and without using the spool valve, a 1.49 60 foot.

The als reaction is more sensitive than I thought. It's interesting to see that the ALS is more affective than the spool valve.