Mixing methanol with petrol. help

Phil

Phil

Super Moderator
what sortof mixture could i safely run for a little extra power/just out of interest?

its not a long term idea but buying methanol in bulk(25litres) is cheaper than treating the car to some octane booster once in awhile. our drag friends like spuddy etc would use litre of booster every meet, but if we had a better idea on ixing methanol with petrol in the tank like you would octane boost then that would be an idea.

any help welcome.

Phil
 
Fatman

Fatman

Member +
As touched on in the link KrissyB posted, Methanol has a lower specific energy density than conventional petrol. As such you need to burn more of it to get the same 'bang'

Just bunging some in the tank then (in any percentage) isn't going to immediately increase power. Where the benefit comes from is the ability to increase compression ratio due to the powerful antiknock characteristics of Methanol/Ethanol. That compression ratio could be via a static increase (thinner headgasket, less dish on the pistons etc) or a dynamic increase, e.g more boost :D

Another additional benefit of Methanol/Ethanol as a fuel additive is its tremendous ability to soak up heat. An Ethanol blend significantly lowers combustion chamber temperature, improving v/e and again decreasing the potential for knock or detonation.

So, to get the benefit you need to run higher compression ratio and you need to make up for its lower energy density by injecting more of it.
 
KrissyB

KrissyB

Member +
Fatman said:
As touched on in the link KrissyB posted, Methanol has a lower specific energy density than conventional petrol. As such you need to burn more of it to get the same 'bang'

Just bunging some in the tank then (in any percentage) isn't going to immediately increase power. Where the benefit comes from is the ability to increase compression ratio due to the powerful antiknock characteristics of Methanol/Ethanol. That compression ratio could be via a static increase (thinner headgasket, less dish on the pistons etc) or a dynamic increase, e.g more boost :D

Another additional benefit of Methanol/Ethanol as a fuel additive is its tremendous ability to soak up heat. An Ethanol blend significantly lowers combustion chamber temperature, improving v/e and again decreasing the potential for knock or detonation.

So, to get the benefit you need to run higher compression ratio and you need to make up for its lower energy density by injecting more of it.
Click to expand...

I been looking it up recently for my Build but decided heavily against it due to its corrosive properties:(......
 
Fatman

Fatman

Member +
Serious research was done into this in NZ as the government has mandated that a given percentage of fuels sold must be renewable. This is pretty much exclusively achieved by Ethanol from agricultural waste processes. The government sponsored studies and asked car manufacturers about reliability or safety concerns with running an ethanol mix. The conclusion of the studies and auto makers was that a 10-20% is unlikely to detrimentally affect anything made after about 1995. Realistically the threat is almost entirely theoretical and I have yet to hear of ANY issues even on ancient rust buckets after one petrol station selling a 5% blend for about 4 years now.

The only lines in a starlet that would be affected is the short length of high pressure rubber hose from the banjo on the fuel filter to the fuel rail. Replace this with something newer and ethanol rated and you're golden. The original fuel pump may in theory be affected over the long term by the blend (i'm talking 10+ years) but realistically most of us have replaced them long before that stage :D
 
Phil

Phil

Super Moderator
thanks guys, the links you posted krissy are interesting i seen them when i did a search earlier, good stuff there.

would a small amount say a couple of litres in a full tank be off any benefit? even the cooler fuel/burn could keep temps down in the inlet/head would that provide even a few hp?

Phil
 
KrissyB

KrissyB

Member +
Phil said:
thanks guys, the links you posted krissy are interesting i seen them when i did a search earlier, good stuff there.

would a small amount say a couple of litres in a full tank be off any benefit? even the cooler fuel/burn could keep temps down in the inlet/head would that provide even a few hp?

Phil
Click to expand...

Possibly matey , If you have a decent ECU just get a map on a Mix of the stuff that could always help with squeezing a few extra HP's out of it and you know its been setup 110%.

Im sure that a mix will be safe though look @ Spuddy he uses it
 
Fatman

Fatman

Member +
Phil said:
thanks guys, the links you posted krissy are interesting i seen them when i did a search earlier, good stuff there.

would a small amount say a couple of litres in a full tank be off any benefit? even the cooler fuel/burn could keep temps down in the inlet/head would that provide even a few hp?

Phil
Click to expand...

Unlikely to notice much (if any) of a gain there Phil. The biggest benefit would be it ain't gonna blow up! Lower temps will naturally lead to a little less wear all round. There's certainly advantages, big ones if your car is tuned accordingly.
 
finx

finx

Member +
what fatman has said is pretty much spot on.
remember that because its less volatile and you have to burn allot more of it to get the same result your tune and a/f ratios will need to be checked out to make sure your not leaning out on high load.
 
finx

finx

Member +
Dutchstarletdriver said:
25 liter is allot. State is, that the stuff doesn't last very long. Doesn't know how long but not longer than a year.
Click to expand...

yup also [ays to note that once you open the drum it will have to be used fairly quickly. so its better to buy in small quantity's unless your running 100 meth set up as it will go off long before you get to use it all.
 
Phil

Phil

Super Moderator
spuddy doesnt use meth though, its me and him that buying this between us, so it'll get used quickly. ill maybe fire a few litres in and check the fuelling, and then fire a few in and head to the dyno, then spuddy can have the rest, he would be able to afford to run a mix of it all the time, given that the car gets used once a month plus tuning.

Phil
 
Fatman

Fatman

Member +
Make sure you tell your tuner exactly what percentage mix you're running as the stoichiometric ratio for methanol is significantly different to petrol. Petrol is 'lean' at 16:1 however pure methanol is dangerously lean at 10:1! There's a little bit of math involved as to what exactly you're aiming for depending on the percentage mix.

If you're less than 5% it's probably not worth adjusting for.
 
Phil

Phil

Super Moderator
it would be roughly 6%methanol mix. if i add 2 litres to 30litres of unleaded.

would i be safe without adjusting the map?

Phil

EDIT: or i could take that to 3%methanol, just put 1litre in and see if it makes any difference.

here is why im tempted to try.

i have just had the car rr'd two days ago.

and in one weeks time there is a rolling road day at the same rollers, which i could go to with the slightly different mix in and see what difference if any it makes. since it is just born out of pure curiousity maybe i should just run 3% to make as little difference as possible to keep things safe but interesting at the same time.
 
Last edited:
Fatman

Fatman

Member +
Impossible to say with 100% certainty as I'm not familiar with your setup, ecu or tune.. Unless you're right on the borderline of det I personally wouldn't be worried :)
 
You must log in or register to reply here.
Top