My (mis)adventures in Meth Injection - "Is it worth it?"

cuper steve

Ready to race!
I have gotten asked this question a few times in posts and PM, so I'd figure I'd try to answer it publicly.

When some asks "is it worth it", I think in terms of value, which "I" determined by cost ($, time, effort, considerations ...) vs. gains (power, efficiency, longevity ...). All that being said, it really depends on where you are in terms of finances and use (DD, hobby, racing ...). Switzerland FTW!

Car Details:
2015 Golf R DCC/NAV
Burger Tuning JB1
Burger Tuning Methanol Injection Kit (CM5 nozzle)
VWR R600 Intake
Wagner Intercooler
CTS Downpipe
CTS Throttle Pipe
Michelin Pilot Super Sport (tires @39psi)

Things to take into considerations:
- Meth Injection Kit and Installation Costs
- Where to get your methanol?
- Where do you store it?
- Installation location - in the hatch, you may "smell" methanol ... you technically can't smell the fumes, but they are there.
- Mixing ... you need to pay attention when you're topping off (mix before refilling)
- Until you're comfortable with consumption rate, you'll be check it all the time (even when its not needed)
- Hatch based installation may interfere with your the use of the trap floor board and could eat up useful hatch space

If we look at the Mustang Dyno based data:

### Graph #1 - Map1-5.2 (93 octane) vs. Map3-6.0 (91+meth) vs. Map3-7.0 (104+meth) ###

The reason for the 104 octane was originally to see if there was any more left in the turbo when we remove octane as a limiting factor. What I found is that there isn't much left up there. Graph #2 will show very minimal gain for dialing up more boost+octane+meth ... i.e. literally "NO GAINS" for all that "effort".

### Graph #2 - Map3-6.0(91+meth) vs. Map3-6.4 (100+meth) vs. Map3-7.0 (104+meth) ###

When you stick the various meth runs together, there isn't much difference.

Notes (essentially facts)
- FYI ... 50/50 meth-water is what a lot of winter windshield wiper fluid is already ... I wouldn't be too concerned about the plastic washer reservoir leaching with 100% methanol (will try that shortly)
- When racing, you're living in the RPM range of 5200-6700 (so optimize for this)
- When Daily Driving, you're living in RPM range of 2500-4500 (so optimize for this)
- With my 335, I needed somewhere between 20-25whp (in the 500whp zone) to get 1mph better trap speeds (123-124mph) ... I will try and back into calculation for the Golf (later).
- Little/No difference in peak power (whp) between Map1-4.8 (91 octane) vs. Map1-5.2(93 octane)
- Small Torque difference (5wtq) between Map1-4.8 (91 octane) vs. Map1-5.2(93 octane) in the mid-range RPM

Recommendations (my opinions):
- If you do want methanol injection, make sure you get a progressive kit. You will fill LESS OFTEN since its only being used when needed. Mine only comes on ALL the following conditions: >3000 RPM, >70% throttle, >12 PSI boost and full spray by >18PSI.
- Please get have a failsafe method in place ... if flow is diminished/stopped (due to blockage or empty), you MUST DECREASE BOOST, to protect your motor.
- Make sure all the pump, solenoid and meth filter are in a place where you can see/access easily - makes dialing things in simpler and easier troubleshooting (once setup up, mine has been FLAWLESS).
- Run 100% methanol - the short runner and the evaporative effects of 100% meth, is good enough to cool and meth is a fuel (water is not).
- If you need are concerned about "safety" - get some methanol and expose it to a spark and open flame ... see what happens. If you are still concerned, then go to 10-20% water on the same test and see what happens. Then run that mixture.
- Use the windshield reservoir as the meth container
- Tap into the top of the cap to feed the meth pump (you won't lose the use of the windshield sprayer)

Closing Thoughts (more of my opinions):
- Its a good gain in the mid-ranged/Daily_Driver torque gain (nearly 20wtq across 3000-5000 rpm) ...
- For racing (peak HP), its a small gain unfornately (8whp).
- At 5800rpm --> 6whp/4wtq between 93 octane vs. 104+meth running 1.8PSI more ... seems like a poor ROI ... given cost, increase turbo stress, inconvenience .
- On other platforms, I want to see at least 15-20whp for every 1PSI of boost.
- For those with 93 octane, the gains seem "marginal" at best.
- It appears that we are more turbo efficiency limited at redline than octane/fuel.
- No, i'm not going to remove my system (that would be dumb!)
- But if you're on the fence, consider if the the gains are worth it to you or if its part of a bigger, future story (i.e. turbo upgrade).

What's Next:
- Going to back to the track and run Map1-6.0 with 93 octane and see if I trap nearly the same speed as Map3-6.6 (114.69mph) ... I don't think it will be much of a difference, given the graph data (and seeing other similarly modded cars trapping 114s). My first run of my last dragstrip day was Map3-6.0 trapped at 114.99mph (with only minutes after driving 125 miles to get there).

Please let me know if you have any comments or questions.

Thanks for reading.


Ready to race!
at work
I like the info methonal injection is awesome comming from a b5s4 a good meth kit with a fail safe and progressive controler is the shit. 50/50 mix gets the best results it seems. But not quite sure were id hide the kit in a gti

cuper steve

Ready to race!
@carbongmk7 - Thanks! From my other platforms, I saw the best results with 100% methanol. In fact on the BMW N54, I had 2xCM7 spraying pre-intercooler and another 2xCM7s spraying post intercooler!

With regards on where to install ... check out my other post:

@PRND - You are correct. It will keep IATs more consistent and keep engine output more consistent. Not sure how much, but you can guarantee I'll collect some data points when the weather warms up!


Ready to race!
at work
oh wow well it seems you guys spray alot further away which ill have to look into if i go meth on the gti. we sprayed about 3-4 inches away from the throttle body and had one in each bipipe ill look for a picture of my old setup for comparison. i love talking about go fast stuff haha