How long is it ok for a car to sit before worrying about corrosion. My car has been sitting for 3 weeks with a full tank of 100% meth. Should I drain the tank back into the 5 gal drum or can it sit for a little while longer with no problems? My car should be back up and running in the next week or two.

 

Mine has a thick walled 1 gal plastic tank (trunk mounted SMC kit)..... what type of tank are you running your meth injection from? With the plastic tank I have no corrosion worries.

Keith

 

Always safe to drain it.

 

I have the Buschur kit which replaces the intercooler sprayer bottle.

 

Bump.

 

most plastic bottles are made of polyethylene and methanol does not affect it. the only thing that happens is MeOH is hygroscopic, it absorbs moisture from the atmosphere....

 

Whats the difference if your car sits in one spot with methanol in it, or you drive around for 6 months running methanol injection daily with meth in the tank??? Yes its getting used but your refilling it as soon as it gets empty most likely. The plastic tank is fine, seriously.

 

as slowcar pointed out, the problem with letting methanol sit is that it absorbs water. if the system is alcohol compatable then corrosion will not be a problem. if the system is not completely sealed from the atmosphere the methanol WILL absorb water vapor from the air and it will become less potent. this WILL be a problem if you have it tuned to the ragged edge and then try boosting to high hell with water in the tank instead of methanol. make sure the system is sealed as much as possible. and don't drain the methanol back into your fuel drum if it sits. you will be putting bad fuel in with the good fuel.

 

edit....I should have read KevinD's post before making this one. He hit the nail on the head.

 

The trunk mounted SMC kit is well sealed, but the one that replaces the stock IC spray system is not sealed at all and will absorb water pretty fast up to a certain point.

Windshield washing fluid is a mixture of Meth and H2O, and I have never seen any warning that it will "go bad" from absorbing more water.... so at what concentration of water and methonal is the mixture no longer hygroscopic?

Anyone with advanced chemistry knowledge who can answer this correctly will be a great asset to the EVO "meth head" community. If we all tune for the "best" concentration that is no longer hygroscopic then we will not have any issues.... and a fresh from the drum batch would just be extra insurance then.

Keith

 

There is no such thing as a sealed meth supply bottle, if there was, it would create a vacuum as the meth was pumped out of the tank and would not pump after a while. All tanks are vented for this equalizing reason.

 

Of course. Some air comes in for every bit of meth that leaves.... this is not nearly as bad as a tank that is basicly open to atmophere with easy air exchange like the stock sprayer bottle.

Anyway, I am waiting for a chemist to chime in with the answer to the $64,000 question

Keith

 

simple to find out if someone with AEM or some ecu capable of logging timing/knock. Put water/meoh of varying v/v ratio..eg 95methyl alcohol/5water...90/10...85/15 in a car thats tuned for 100% methanol and see when knock and puling of timing occurs.

this will also show if "100% methanol makes the most power" is true

 

Sorry for bumping an old thread. I'm curious if anyone has the answer to Fourdoor's question. At what rate does a vented tank of 100% methanol absorb water, and at what meth/water mixture does it become no longer hygroscopic?

 

I have done extensive testing with different mixtures on my stock turboed nitrous evo and I run the same timing and afr's with anything from 50% to 100% so I run 50% all the time now as its cheaper...all the track slips are near identical with the different mixtures as well...there is only so much you can raise the octane...and the same for cooling...