Author Topic: Pure Methanol vs C-16 Race Gas Spooling Rate  (Read 14488 times)

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Offline NathanStewart

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Re: Pure Methanol vs C-16 Race Gas Spooling Rate
« Reply #15 on: July 01, 2016, 06:31:55 PM »
Blast from the past.  Thought I'd share some actual data on this.  For the past two years we've been running VP C85 ("race" E85) and this year we decided to make the jump to gas.  Being that the AEM Infinity EMS is airflow based, we can change fuel and technically not have to do any tuning and that's exactly what we did.  In May, we dumped in 10 gallons of C16 and went and made a run. 

Below are two runs overlaid on top of each other.  I set them up so that the 3-4 shift occurs at the same point to show the difference in how the turbo spooled up in 4th gear.  Important things to note - there was ZERO boost control active during either run.  This was on wastegate spring only. The high boost, C85 run was 206 mph and the low boost gas run was 191 I think.  Oh yeah, also notice the same target Lambda on both fuels.  Only other tune change was that I pulled out 2° of ignition timing.
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Offline dieselgeek

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Re: Pure Methanol vs C-16 Race Gas Spooling Rate
« Reply #16 on: July 25, 2016, 08:16:17 PM »
I did some fuels testing for a company that builds turbo pro mod engines.   We found that the benefits of alcohol aren't nearly as much as everyone else says on the internet, I know that'll be an unpopular opinion.  Even scarier was the very neglible peak power difference versus C16.  Oxygenated fuels were also overhyped a lot, everything comes within a percent or two once you spend the time to get the tune right, for each individual fuel.  C16 (and similar fuels) likes to run low mid 12s AFR, leaner lambda than what you'd run alcohol to make the engine happiest.

Also, I know for a fact you'll be able to start an EFI alky engine down to at least 50* F cold soaked (left sitting outside overnight).  Tina Pierce's truck (girl from Street Outlaws TV show) has 16 x 220 lb/hr injectors, 8 of them sequential, and the truck lights right off *again with the correct amount of fuel* without preheating, etc.   And it even has a mechanical fuel pump, properly set up it pressurizes in well under 1 second of cranking the starter.   We idle the engine near stoich, it warms fast and doesn't milk up the oil.   Few people are familiar with methanol on EFI, most knowledge and advice comes from mechanical injection guys who don't have nice things like Warmup enrichments, cranking pulse control, or even an accel enrichment / pump.  M1, M5 are really not that bad to deal with on EFI in my opinion.

But honestly, if you're expecting alcohol to bring extra power to the table - it won't be much, and likely not worth the price of admission, based on my experiences.   I also don't believe in fast spool turbos on the salt, just no point in something that'll require power management to keep from spinning the tires (which, coincidentally, you will have).

-Scott Clark
« Last Edit: July 25, 2016, 08:46:12 PM by dieselgeek »

Offline Rex Schimmer

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Re: Pure Methanol vs C-16 Race Gas Spooling Rate
« Reply #17 on: July 26, 2016, 12:44:51 PM »
Thanks Scott for your input and you bring up a question I have regarding warming up an methanol engine. The car I am working on at this years Bonneville is powered by a mechanically injected 3 liter banger running methanol and as I understand most of the fuel pollution in the oil happens during warm up which on a mechanical system can be very rich. I have seen fuel engines that were started and warmed up on propane, which would certainly eliminate oil pollution but I was wondering if you could add a secondary bypass jet that would be only used for warming up the engine. This would drop the fuel pressure during warm up and reduce fuel flow and hopefully reduce oil pollution. Any one ever tried this?? As an aside I have also heard that using zero gap rings helps reduce oil pollution. 


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