Here is a quick write-up of my recent experience with having Meth Injection added in addition to adding 2 psi of boost.
A quick overview of Meth Injection
Meth Injection is a relatively simple idea. It provides numerous benefits especially in boosted applications. The methanol is typically injected mixed with water. It's mixed at up to 50/50 water and methanol. It is stored in a reservoir similar to the reservoir used for your windshield washer fluid. Speaking of windshield washer fluid, this is often used in place of pre-mixed solutions. The -20 degree fluid you typically use is just a water/methanol mix at about 30% methanol.
The mixture is injected in most applications into the intake post intercooler and FI device before the throttle body. In some situation people will inject it after the throttle body. When this mixture is injected it drastically increases the overall octane of the fuel as it is combusting. Most people say to around 116 octane. It also significantly decreases the intake temperatures. The injection stream is a very fine "atomized" spray. It's not like your spraying a stream of fluid directly into the intake and the heat from the intake temps is absorbed as the mist mixes with the intake air. Lower inlet temps and increased octane = less detonation. The impact is greater than running C16 race fuel in a boosted application. This means you can run more boost and more timing.
So I picked my tuner after speaking with several in and around Michigan. The shop I chose was West Bend Dyno Tuning in WI. They are not only a certified ProCharger Install shop, they are also certified through Snow Performance which is the kit I chose for my setup. The folks at West Bend really did everything they could to explain all of my options, discuss my goals and make sure I wasn't overlooking anything along the way. They suggested a Stage 2 kit which would be triggered by boost pressure. It's a 2 stage kit controller (not to be confused with Stage 2). You basically pick the low end of your boost that you want to trigger the kit to start spraying. They chose 2 psi. Then you pick the high end point where it's spraying 100% of the kit and nozzles capacity. They chose 8 psi as my high end. The nozzle size is based on whp that your car is capable of putting down. So when the kit kicks on a 2 psi, it's spraying at 10% then it increases in relation to the boost up to 8 psi where it's spraying the full 100%.
I requested they do a baseline pull. For my baseline pull with the ProCharger tune and 4.10" pulley (8 psi) the car made 404 hp/341 ft-lbs tq. After they had the baseline they wrote my tune, installed a 3.85" pulley (10 psi) and installed the Meth Injection kit. The tuner mentioned that without adding Meth Injection, increasing my boost the 2 psi would have typically called for pulling approximately 2 degrees of timing across the board to handle the increased temps. This is where increasing boost starts to have an offsetting effect. You can only go so far before the inlet temps and chance for detonation start to take its toll on the tune. With Meth Injection on this kit he was able to add in an extra 2-3 degrees of timing across the entire power band. Once he had it dialed in they did several pulls and the results were fantastic. My best pull came in at 451 hp/364 ft-lbs tq.
Overall I am very satisfied with my results. First of all, I needed a dyno tune no matter what. I could have just added the smaller pulley and just ran with that but my results wouldn't have been nearly as good. I'm also tuned extremely conservative at this point.