Doing Meth
 

I see a lot of water/meth setups in the rotary realm. I'm currently sporting an AEM setup with the Sake Bomb tank in the rear. I'm injecting boost juice which is a 51/49 mixture of water/meth.

However, I'm looking to push the envelope a bit and I was talking with a Shawn (tunedbyshawn) on the phone today and he was recommending I run straight meth for the injection and no water. He said it was much more predictable from a tuning standpoint and still yielded the cooling (and knock) capabilities I was after (hoping I remembered the details of the conversation accurately). Furthermore, he stated I could half the injection rate which to me, seemed really appealing because it meant the tank lasts twice as long. :)

So with that in mind, two questions...
1) What are the pros and cons of running straight meth vs water/meth?
2) What sort of temp drops are typically yielded by meth only injection?

And for context, my setup consists of the following....
-Turblown cast manifold IWG EFR7670
-M2 Large SMIC
-AEM water/meth injection
-Xcessive lower intake manifold
-Newly rebuilt streetport engine
-Walbro hellcat fuel pump
-Stock 550cc primaries with 2200cc secondaries
-Currently on a Link ECU likely going to an Adaptronic.

Do you intend on filling up the SB tank which is inside your vehicle with a highly flammable fluid with no firewall between you? Because, that's a terrible idea. Straight meth is also harder on the WI components. Id stick with 50/50, and a Link ECU. Join the water meth group on Facebook, there's some good info there.

Straight meth is a terrible idea imo, the idea that less is required seems pretty backwards. Meth is HIGHLY flamable, adding just a smidge will likely have the opposite effect of what you want. Not to be a jerk, but if you're chasing bigger power than I'd swap turbos before getting rid of water, the 7670 is great for what it is but it's not a peak power monster.

Stick with the boost juice, its far safer and far more predictable. If anything I'd go straight distilled water, you won't get more power but it's available EVERYWHERE and it won't kill you, also running out of that won't potentially blow your engine.

I want to say that Howard Coleman slowly learned the hard way that small amounts of straight meth blows motors.... if you DO run straight meth than you need lots of it.

Not looking for huge peak numbers. 400whp and 400wtq would be about where I'd like to be. I know the 8374 is a killer turbo but I think it's just larger than what I'm needing. At the goal power level I think the 7670 is certainly sufficient. I have 93 octane available at pretty much ever pump near me. I'd also have a low boost map that I could switch to for track racing or times when 93 is not available (like God forbid I go on a super long road trip).

Shawn seems to really know this stuff inside out and swears by it. I'm not totally onboard with the 100% meth idea either but I figured I'd poll the audience just to gather experience from multiple individuals.

My other option would be a flexfuel setup. I have PLENTY of fuel pump in this car specifically if I wanted E85 in the future. But I liked the idea of water/meth because of the additional cooling properties since I live in Texas...

Oh don't get me wrong, I'm all about the 7670 for the exact same reason! I just would NOT sacrifice safety for a little more power, which is what you'll likely be doing by going straight meth.

Meth is a fuel that's beneficial because it atomizes SUPER fast which will help lower your intake temps. It's also highly combustible. It pairs well with water because they bind to each other (meaning the meth won't evaporate off or be as likely to spontaneously combust) and while the meth atomizes early, the water doesnt atomize until the combustion cycle. Meth leeches heat from the intake charge, water leeches heat from the combustion chamber. Combined they're solid.

Adaptronic doesn't even have functionally reliable knock monitoring or control iirc, so you've got no way of really even being sure of that value when you're running that unit.

would not do straight meth, in addition to it being a flammable fluid in the car, its also more volatile in the engine
and for 400hp you probably don't need it

neither the (excellent) Sakebomb tank or the AEM ai system, with it's plastic push on lines, should ever see 100% meth though both are great for water or water meth.

my view is 100% meth delivers advantages should you be running in the 500+ hp area... around 900/1000 CCs.

most water or water meth apps are happy around 400 CCs. check your nozzle as perhaps it is too large. you should find an "M" on it followed by a number... each number is 63 CCs/Min at 100 psi. for instance an M10 flows 630 CCs.

as to tuning... meth being more "predictable".... assuming you use either water, or a constant % mix of water meth or 100% meth it is all predictable.

if you are serious about your setup i suggest you make certain that whatever ECU you choose that it have an active knock system. knock data is key to proper tuning and longevity.

Hi,

I have tuned multiple cars at 20+ psi that are still on the street with a 250cc nozzle of meth. They are very predictable and tuned up very nicely. This combination + heavy premix 2oz has been a reliable combination for my customers I do agree any form of fuel in the cabin is dangerous - meth or water/meth they are both flammable liquids.

Thanks,

Shawn Christenson

Boost juice is way less volatile than straight methanol. Particularly if it's in the cabin of your car.

Yeah... I strongly disagree with the idea that going 100% meth is a good idea in anything other than relatively rare circumstances where it's the primary fuel (and then a LOT is pushed!). Tuning for pure meth injection in a street car is not something I'd ever sign off on for my own vehicle.

I'm fairly certain I remember seeing technical papers several years ago that covered historical trials for 100% meth, 100% water, and 50/50 mixes. The results weren't really favorable for 100% meth as I recall.

Curious why you are switching from the Link ecu to adaptronic?

Absolutely nothing wrong with the Link. Only reason I would change would be at the preference of whatever tuner I go with. Still exploring options. Unfortunately tuning isn't something I'm interested in learning. There are a lot of things I can do myself; tuning won't be one of them.

Link is great, I'd try to find a new tuner before I swapped to an inferior ECU.

Please explain how its inferior? Not saying link wont get the job done but the safety features are lacking. When I went to PRI and asked the guys to setup the safety features in a way to benefit remote tuning they did not have a way.. So please explain.

Cheers,

I'm not a fan of remote dyno tuning to begin with, although I do understand the need in some situations. Lackluster customer support would probably be one of my main concerns. Adaptronic seems to be playing second fiddle to Haltech in that regard. Is there even a manual yet?

Link support was 24/7, although I'm not sure that's still the case. There have been quite a few reports of less than stellar software stability for Adaptronic as well, but that's heresay and not something I've seen myself. However in my experience, where there's smoke there's usually fire. Link has Lambda, Knock, pressure and temperature fail-safes, what else would be specific to remote tuning that it's lacking?

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No manual. No updates. Constant bugs. Adaptronic was released before it was ever fully tested and those who bought it based on hype have been hamstrung and left to crawl for help. You want to attack remote tuning availability as one flaw against a product that has repeated hardware failures?
Maybe stop touting an inferior product just because you profit from selling it, and rearrange your business model for one that provides a quality product with quality support.

Here is a manual - https://s3.amazonaws.com//adaptronic...GENE_HOME.html

Sure looks like updates/bug fixes are still happening -

Modular_1.073
Release 2020-May-20

• Fixed JC20B ignition mode not using split table.

Modular_1.072
Release 2020-Apr-17

• Added initialisation for closed loop boost
• Added user temp #1 to output fuel level on Haltech V2 CAN protocol
• Corrected fuel pressure reading on Haltech V1 protocol

Modular_1.070
Release 2020-Mar-07

• Added early Lotus / Rover K trigger type 36-1-1-1
• Added interrupt delatching on trigger inputs (improves stability with certain trigger types)
• Added BMW VANOS outputs
• Fixed scaling on EGT outputs on Haltech CAN
• Added fixed rising edge trigger on CAS 4/5 frequency measurement on Subaru magic edge switching mode
• Changed pulse ignition output test to handle inverted ignition output conditions
• Added RX8 EU ABS Mode 2 compatibility.

I provide the support and tech support for my customers - I do my best to organize and facilitate any trouble that does happen from start to finish.

Also the profit argument is really laughable as I could very simply become a link dealer. I simply sell Adaptronic Modular ECUs because its the platform I know the best and can provide the best customer support per product for my customers. Adaptronic Modular ECU's now go through the SAME quality control as the Haltech Elite line and the SAME warranty process as all of the Haltech products. If any issues are found to be a problem they are fixed as soon as they are found.

Yes link has AFR protection but it is not based off the target AFR table also it is not a 3D protection.

Cheers,

Shawn Christenson

thank you for the info Shawn