So I was sitting in class and I got bored and I starting thinking about a failsafe for alky injection.

I think I have an idea that could make an effective and cheap failsafe. I want feedback from you guys to help me figure out if this would work and what might be wrong with my idea.

In designing this system I am assuming that your alky kit provides a signal if it has a failure, we will use this signal to drop boost from a normal level down to wastegate pressure.

This design utilizes a $13 GM boost solenoid. I will test out this idea this weekend when I get some spare time.





Basically under normal conditions the solenoid allows the boost to pass through as normal from the MBC to the wastegate.

Under low boost operation, the solenoid blocks off the line from the MBC and instead allows the boost signal line directly to the wastegate.

 

Seems like that would be a good idea, Could you explain in more detail your thoughts?

 

I will try my best to explain more, although I'm not really sure what else you want to know.

The solenoid allows the system to work like normal while the alky is working, then when the solenoid gets a signal from the alky saying it is failing, the solenoid switches so that the boost source is connected directly to the wastegate. The effect this should have is that your car will work like normal when the alky works, and if the alky fails, this should reduce your boost to wastegate pressure (12psi).

What elese do you want to know?

 

Hey, I guess this would help ease your mind a bit for when you run out of alky...good idea! Makes me almost wanna try it.

 

That my settup for my failsafed W/M (snowperformance):

Solenoid energized when W/M flow drops






This is my new and improved setup that bypasses MBC bleed port - befor I got 19 psi spikes in low gears durring a failsafe condition.

 

Question for dudical26:

what would be the cause of low boost? why does it have to be a low boost situation to set all this up?.
Normally is the opposite, you get too much boost. Low boost never hurt nothing. Unless you explain the low boost situation I believe there is no sense theory.
Please elaborate. Thanks!

Remember, the failsafes suppose to activate due to:

low pressure in the alcohol kit
no pressure on the alcohol/methanol kit due to power issues
clogged lines
clogged nozzles
insuficient pressure due to faulty pump
erroneous boost reading from the controller boost line
injecting alcohol when the car already hit fuel cut(not the evo case)




Carlos

 

fromWRXtoEVO - you must not understand what my failsafe does....read my entire post it clearly says that if there is a malfunction with the alky kit this failsafe will cut you boost, thus avoiding engine damage.

 

C6C6CH3vo - can you post bigger pics, those ones are hard to see

I had some concerns about the bleed port on the MBC, but without trying my idea I was not completly sure how it would effect the system.

Thanks

 

Your car can select from 2 maps.. low boost and high boost.. and it all depends on the opearting temperature.. for instance when you first turn your car on and try to rip ip.. your car will run on the low boost map and preventing you to use your max boost and also to prevent engine damage on a cold start engine and after it reached optimum running temperature it will automatically shift to the high boost map so you can now take full advantage of the max boost.

When running the alky kit.. your will still run the low boost map so it is necessary to still look into this failsafe..

 

I believe Slowcar did this already utilizing the failsafe trigger from his Aquamist water injection system. I used a boost cut set up several years ago utilizing my Greddy Profec B electronic boost controller. I hooked up the failsafe trigger wire from my Aquamist water injection system to a Bosche relay. The relay would cut power to my Profec B if a problem was detected by my Aquamist and put me back to the stock wastegate pressure of about 11 PSI. This worked very well.

 

Redline06 - what you are talking about is totally irrelevant as we are using a MBC and the ECU no longer has control over boost.

EvoTio - Maybe Slowcar can elaborate more on his system. While this idea might not be new, I just wanted to propose a simple system that can be cheaply implemented by anyone.

 

I was hoping SlowCar would see this thread and give his input. BTW, it's great that you've come up with an idea to make an inexpensive failsafe set up for your water/alcohol set up. We need more people to contribute their ideas to help out the Evo community when it comes to this subject.

 

Hopefully I will get a chance to test the solenoid this weekend to see if it functions how I think.

 

I was thinking more about the bleed port on the MBC, I dont think it should cause a problem on this setup becuase the wastegate line on teh MBC will be cut off from any boost pressure, there for boost will not bleed out at all.

 

<Very interested in seeing the results I can contribute to testing if needed (SMC kit w/mbc)