Meth Injection

Why do you require meth?

• Once you reach the full bolt on mod level and run more and more boost, the cars are on the verge of running out of fuel at high rpm on the stock turbo.  This is the same reason I stopped tuning catless setups years ago.  Boost creep in cold weather can cause the cars to run out of fuel in cold temperatures.   
• When an STi or old EJ WRX run out of fuel they will gradually lean out and eventually knock whenever the AFR is gets too lean for the  octane or if the EGT's get too hot.  However, the FA's have an immediate adverse reaction when the fuel limitation is reached.  The millisecond the fuel limitation is reached, the cars will begin to misfire and knock which can can lead to engine failure in a single pull.   You will feel the car start stuttering and the CEL should flash during misfires.  The CEL won't stay on or throw an actual CEL unless the misfire limit is exceeded.  But if you ever feel your car begin to hesitate and stutter above 5,500 rpm, let off the throttle immediately and notify your tuner.  

What are the fueling limits?

• On a fuel injected car I prefer to stop increasing boost when the injector duty cycle (IDC) has reach 80-85% in an ambient temp of 70-80 degrees.  This leaves 15-20% fueling headroom to account for cold temps, boost creep, mechanical issues that result in a boost spike, injector variances, etc.  If the boost is increased until the IDC is 100%, then there is zero headroom to account for the scenarios just listed. 
• A direct injection car basically has half the available fuel injection time due to the fuel injectors being located inside the cylinders.  So the direct injection limitations are around half of the fuel injection limitations.  On pump gas I prefer to keep the IDC below 35%, especially on 91 octane.  Random misfires & increased knock events occur between 35-40% IDC.  Misfires and knock are pretty much a guarantee if the IDC exceeds 40% on pump gas.
• On ethanol I prefer to keep the IDC below 40%.  Since ethanol is much higher octane and can be run leaner, the misfires & knock counts begin to randomly occur between 40-45% and are pretty much guaranteed if the IDC exceeds 45%.

How are other calibrators able to get away with not requiring meth?

• The only way to decrease the IDC is to lean out the AFR, increase the injection timing or increase the fuel pressure.  A FBO car at sea level will easily be around 35% IDC on pump gas with an 10.8-11.2 AFR.  And on ethanol it will be at 40% with a 12.4-12.8 AFR.  
• On a SEND IT map the AFR needs to be leaned out to 13.2-13.6 to decrease the chances of running out of fuel.  
• I simply don't agree with running the cars super lean or jacking up the fuel pressure.  Leaning out the AFR increases EGT's and knock frequency.  Jacking up the fuel pressure can damage the fuel injectors and/or hpfp.  Nostrum used to say their HPFP could be run at 3,000 psi, but they lowered that back to 2,176 psi, which is the peak stock fuel pressure.  They did this because the potential issues aren't worth the minimal gains.  
• Nostrum rates their injectors for 460 whp on ethanol and claim they flow 10% more than stock.  If you do some simple math, you see that Nostrum's rating of the stock fuel injectors is ~420 whp.  A 10% increase at 420 whp is 460 whp.  420 x 1.1 = 462.  ~420 whp is exactly where I say the cars are out of fuel, which is why I recommend meth injection for stock turbo SEND IT cars and require it for larger turbos.  

What are the benefits of meth injection?

• increased octane (methanol is 120+ octane)
• decreased intake manifold temperatures (lower temps = less knock)
• cleaning the intake valves (cleaner valves = less hot spots from carbon buildup)
• added fuel overhead (more fuel = ability to run more boost safely)
• increased knock threshold (higher octane + reduced temps = less knock)
• cost is very close to a walnut blasting service
• If you're going to eventually spend $400 on a walnut blast to clean the valves, you might as well spend $500 on an AEM Meth kit and receive all the additional benefits of meth.
• If ethanol is not available in your area, then methanol injection is the next best solution to making power on these cars.  

Recommended Setup

• AEM 1.2 gallon Meth Kit - $500 (Part # 30-3300)
• AEM Meth Solenoid - $65 (Part# 30-3326)  ** REQUIRED **
• AEM Inline Filter - $32 (Part# 30-3003) ** REQUIRED **
• 1000cc nozzle
• 50-50 water/meth mix
• start spray setting = 10 psi
• full spray setting = 20 psi
• TMIC -  install nozzle in the intercooler outlet tank (reference the GrimmSpeed TMIC, it comes with a fitting already welded into the intercooler outlet).  
• FMIC - install nozzle in the intercooler pipe 6-8 inches before the throttle body. 

Miscellaneous Notes:

• I do not like the Snow Performance kits.  The throttle body spacer nozzle holder does not work well.  The nozzle needs to be before the throttle, not after.  
• AEM v3 nozzles are NOT compatible with 100% methanol.  A 50/50 water/meth mix must be used.
• As of July 2021, AEM will no longer warranty their kits if a mix over 50/50 is used.
• I do NOT recommend using Snow Performance Boost Juice or Devils Own Brew.  These options provide inconsistent methanol content.  You can go on YouTube and watch multiple videos of customers testing these products for methanol content and getting values as low as 10% methanol when it's supposed to be 50%.  
• I highly suggest sourcing pure methanol from VP and making your own 50/50 water/meth mixture.  This will ensure you truly have 50% methanol. 
• Running pure meth is more dangerous than a 50/50 blend.  Pure methanol has a boiling point of 148 degrees, so it can boil off if you live somewhere extremely hot like Phoenix.  
• Due to safety concerns and AEM no longer making the v2 nozzles, I will be recommending a 50/50 mix from now on. 
• AEM v2 nozzles are compatible with pure vpm5.  However, they are no longer in production. 
• ProMeth makes 100% meth compatible nozzles - https://prometh.com/collections/nozzles
• This 0.0362" orifice, 6 slot design nozzle should be 1,000-1,100cc https://prometh.com/collections/nozzles/products/stainless-steel-water-methanol-injection-nozzle?variant=39730506924101
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• AEM 1.2 gallon Meth Kit - $500 (Part # 30-3300)

                   -  wiring harness with controller and 35 psi onboard (Manifold Pressure) MAP sensor

                   -  250 cc, 500 cc and 1,000 cc nozzles

                   -  200 psi pump

                   -  1.15-gallon tank with integrated fluid level sensor

                   -  all required lines

• AEM 5-gallon Meth Kit - $600 (Part # 30-3301)

                   -  wiring harness with controller and 40 psi onboard (Manifold Pressure) MAP sensor 

                   -  250 cc, 500 cc and 1,000 cc nozzles                    

                   -  200 psi pump                    

                   -  5-gallon tank with integrated fluid level sensor

                   -  all required lines

•  AEM Meth Solenoid - $65 (Part# 30-3326)  ** REQUIRED **

                   -  Prevents water/meth flow into the engine when the kit is not activated.

                   -  If you park on a hill w/o the solenoid, nothing will stop meth from draining into the engine  

                   -  Should be installed as close to the nozzle as possible                                           

                   -  high flow capability (3,600cc/min) 

                   -  low current draw of only 0.75A that does not require the use of an additional relay

• AEM Inline Filter - $32 (Part# 30-3003) ** REQUIRED **

                   -  protects the pump, solenoid, nozzle and engine from debris in the water/meth mixture

                   -  helps prevent pump, solenoid & nozzle from getting clogged & preventing meth flow

                   -  can filter particulates as small as 40 microns

                   -  should be installed in-line BEFORE the water/methanol pump

• AEM v3 Nozzle Kit - $75 (Part # 30-3315)

                  -  includes 250cc, 500cc and 1,000cc nozzles

                  -  this does NOT need to be purchased, the kits come with these 3 nozzles

                  -  I simply listed listed it here for reference if anyone ever needs to replace a nozzle

• In 2020, AEM discontinued production of their version 2 nozzles.  The v2 nozzles were compatible with 100% and even VPm5 which contains nitromethane.  After having multiple customers have issues with v3 nozzles, sending data and failed nozzles to AEM, they added a note on their website stating the kits ere NOT compatible with 100% methanol.   
• AEM's new stance as of July 2021: "...using 100% methanol will damage the system's flow sensor and void the warranty on this component." - AEM
• AEM v2 Nozzles (100% Meth Compatible - ** Discontinued ** 
• AEM Meth Failsafe Gauge (30-3020)  ** Discontinued **