How is tuning different with 50/50 vs 100% meth??

[Iron Indian]

Just curious, I'm assuming straight meth will make things richer.

I'm wondering if a 100% will work on a root blowen motor? I'm running 50/50 now but I wonder if there are more gains with 100%. I have a 1999 GTP BTW with a few mods on it already....

 

[QUIP'6']

yes it will be richer and more stable of a tune since it is 100%. the problem is if you switch you have to retune all over again. stick with one

 

[Razor]

yes it will be richer and more stable of a tune since it is 100%. the problem is if you switch you have to retune all over again. stick with one

Correct.. as long as it doesnt pickup knock.

I never liked the idea of water through the blower. But thats just me.

 

[4-71/Z-28]

i remember hearing somewhere that the octane boost comes from the meth, and the cooling comes from the water since it had the ability to absorb heat better. does that make sense to anyone, ive had water and meth on my hands before and the meth is defiantly cooler, but is that just because its sucking the moisture out of my skin?

 

[Iron Indian]

I've heard the same myself, that water helps cool, and meth provides the octane. Any truth to this? Any Roots blown guys in here? (I know this is a mostly Turbo Buick board, but i've seen other types of cars here before). I've also heard 100% meth is a hell of a lot harder to tune than 50/50.

I wish I was lucky enough to have a car with an extensive aftermarket muchless and extensive aftermarket with Alky injection. Not many do this to the S/C L67s (3.8L Series 2 V6) because its pretty much forbidden by our 2 top/main venders who bad mouth it. And the few that have tried it failed. I know that it can work, I just wish I wasn't the only one experimenting...

 

[Iron Indian]

Ttt

 

[Razor]

The 50/50 works as it doesnt need a lot of tuning. But.. it has the issue of damage to blower and hydrolock. When the volume injected starts going up.

The straight meth works. If you look into the LS1 crowd with the 4th gens, trucks, Vette's that use the Magnusson blowers you'll see a pettern there. They use straight alcohol and tune the engines in no problem.

Your L67 I believe the issue is tunability afforded. Meaning the ability to making changes to injector pulse width to make up for the extra fuel the methanol injects. Years ago I had a customer who developed weird issues tuning the computer on his L67. As he would pull injector PW, his car would start to short shift. The explanation at the time was the GM computer would see a lower than anticipated PW and since it also controls the transmission, would cuase the condition protecting itself. Kind of like the computer sees 15 PSI boost, 5000 RPM's, it expects "X" amount of fuel. When it sees 20% less than "X", it short shifts.. I dont know if those issues are addressed with the current versions of software by HP, EFI live, etc.. Not having an L67 to play with, or having shops with L67 based engines its hard to develop "fixes" for a market that is small.

Meaning the L67 is a niche market, few shops, and more set in their ways. Let alone the owners have a push for trying to buy the least expensive systems they can get away with. So the end result is poor performance, unpredictable results, and the current state of mind.

Coupled with other issues like the TB/Maf issue so nozzles get complicated. Cars losing value, part replacements getting higher, its tough.

HTH

 

[SloGN]

I have used a 50/50 mix or straight meth.

i have a friend that has a 85 hot air car and I have helped tune it quite a bit and his combo seems to perform better with the 50/50 mix than the straight meth. His air temps have come down another 20 degrees more by using the mix over the straight meth.


Razor

i would think that hydrolocking the engine would still be a possible issues no matter whether your using a mix or straight meth.

Actually when using a mix you would be injecting less liquid if nothing was changed to the setting dude to the water having a denser structure to it VS the meth.


Also when using a mix of meth/water you don't need as big of nozzle due to the water has a better cooling effect when atomized than the alky.

But i know that there is people that has very good success using both systems

 

[Razor]

Problem comes in with temperature as well. See meth flashes at 70 df, water is 180. 50/50 is about 125. So if you dont have 125df that water goes in drop form. Engine he is dealing with is a roots blown application. Meaning nozzles are shot through ambient air and the blower does the heat.

On hotairs its difficult due to distance and volume. Let alone the funky intake they use. Go figure you need to run smaller nozzles as the water in volumes cuases more issues than it helps. I have plenty of below ambient datalogs on straight alcohol.. on thousands of cars.

Water is again great on limited tuning applications. Or applications like turbo diesels. And there are others.

On pump gas I get 14-16 PSI boost typically. With water injection I can get that up to 20 PSI, with 50/50 I can get up to 24-26 PSI.. on straight meth.. have been over 30 PSI no knock. They all work.. one just has added headroom over the others. The difference primarily is straight meth works whether its hot or cold, doesnt need tinkering to keep a tuneup. So what works for winter works for summer. Due to the low flash temp.

Hey its what works for me, your results may vary.. and what works for someone.. doesnt always work for someone else. The idea is that if it works for the majority of the people the majority of the time.. then it is the pattern to follow. From there your on your own.

Did you not see the thread from Brian on the rotary using no IC at over 20 PSI at ambient temp using straight methanol.

 

[SloGN]

The best thing to have when using a 50/50 or a 70/30 mix is to run a tad smaller nozzle and use a pump that can make around 150+ psi so that the water can atomize better instead of the larger droplets. I would think that using meth this would work better as well.


The neatest thing that i have seen is a guy has a expresso machine pump that makes around 250 psi using a m10 nozzle and man that thiing makes the ultimate fine mist.