Thought I would share what I came up with for a safer meth system using my electronic boost controller.

This spring I pieced together a meth kit consisting of the factory windshield washer fluid tank, Devil’s Own Tank tap and Cooling Mist pump/solenoid/nozzle. Since I already had a Turbosmart E-boost Street I decided to use it as the meth trigger. I also added a momentary switch to ground so I could test fire the system. Lastly I added a separate circuit for an LED to tell me when the meth was spraying. I used a 50psi fuel pressure safety switch tee’d into the meth line just before the nozzle to trigger the LED. It’s one thing to know when you tell the meth to fire and another to know when you have pressure at the nozzle (why I used the fuel pressure safety switch as close to nozzle as possible). This is still NOT completely safe though; it is possible to have a clogged nozzle or meth line come loose after the safety switch. I normally check to make sure I see a change on my wideband when test firing the system.

This first diagram below is how I currently have everything wired. While this worked great at first I soon found myself forgetting about the LED and would wonder after the run if the meth fired. If I was logging I could usually tell by the IAT’s but I don’t log every time I mash the gas. Potential disaster waiting to happen…


After some thinking I figured out a better way using $5 in extra parts (another relay and arming switch). The E-boost Street has an option to switch between boost settings using an external switch (I’m not sure about all electronic boost controllers but I suspect most have something similar?). The diagram below is how I am wiring up my meth currently (just got the relay from amazon yesterday).

Here’s how it works: Since I tend to max out my boost controller (running as close to 2x WG spring pressure as possible) I tune so that I don’t need meth at the lower setting. With the first diagram I would set the meth trigger slightly higher than gate pressure. With the new setup below I will need to set the trigger below gate pressure. When I want to run on low boost (around town or when meth tank is empty) I turn the meth off and go on my way.

When I want to run on high boost I just turn the meth on. As long as the meth is triggered lower than the low boost setting, meth will fire and my 50psi safety switch will trigger my new relay which will ground my external switch and bump me into the high boost setting. If the tank is empty or something else happens and meth doesn’t fire, the car will not go into high boost and instead stay at the lower (no meth needed) boost level. If your low and high boost settings are too close together this may not be as safe.

An added benefit is that I won’t forget to switch to a high boost setting before racing. The E-Boost Street always reverts to “set point 1” when the car is turned off and this happened to me a couple of weeks ago. I was in the staging lane ready to go when a car oiled down the track. I turned the car off while waiting and of course forgot to change it again when starting the car several minutes later.

 

Just found this and wanted to say, good job. This looks like a great setup. How has it been working?

 

I have been running this setup for over a year and it's been working great. I had to make 1 change to the wiring which was to run the status LED and relay in parallel vs in series like I have shown.

I've tested things out and it seems to be a pretty good safety - I've run the tank dry (just for test) and verified that it doesn't go into my high boost and I also learned that unhooking a meth line even after the fuel pressure switch won't allow it to enter high boost (high volume, low pressure).

I now tune my VE table in high boost to my desired lambda without worrying about meth failure. I just make sure that the "cliff" in VE happens at a higher MAP value than I could ever hit on low boost.

 

Subscribing, in case I ever add meth to mine. I'm also running an Eboost Street 40. Nice setup.
BTW, I was just in Grand Rapids a few days ago getting my car back from Baker Engineering Wish I'd have seen this sooner.

 

Some places sell a flow meter for this reason.

Far far better than any setup using pressure switches. A blocked nozzle would still show pressure, a partially clogged nozzle would still show pressure.

A flow meter would give an accurate picture.

Pretty sure Aquamists controllers have built in safety features like this too, so no need to **** about with lots of wiring and switches externally.

 

haha that's funny. I just saw a pic of your car on facebook earlier this week with people wondering whose car it was.


Don't worry, I'm well aware of the short comings of this setup but I already had the boost controller and meth kit so this was a simple way to make it much safer than what I was running.

Your comment on the wiring makes me laugh because I don't doubt that aquamist is much better (and safer) but I'm pretty sure it requires way more wiring and I would still need a way to tie it back into my boost controller. Not to mention the cost; I could replace my engine 2 times for the cost of aquamist. Another thing to note is that if any of my "crazy amounts" of wiring fails, it fails in a safe condition (i.e. low boost with no need for meth).

 

That must be one hell of a cheap engine !

Aquamists stuff may be slightly more expensive than the cheap kits, but it certainly isnt that expensive.

 

Nice solution Dave. Hows that new turbo treating you? Been back to the track yet?