1320MINI

Normal scheduled fuel injection is synchronous - that is it only gets injected once at a fixed point in the engine cycle (usually finishing around 400deg BTDC, so a long time before combustion).  So if you only have synchronous injection (like most ecus) and you suddenly stand on the throttle after the injection event has already finished, then the next combustion event will be lean because you only originally added enough fuel for the amount of air that was flowing at the time of injection.  
With Asynchrous injection the ecu is always watching the fuel calculation even after the injection event, so if there is a sudden change in airflow after the main injection has finished, then ecu will add extra injection events to "top up" the fuel that is already sitting in the port waiting to be inhaled.
The minimum async injection setting is only used to prevent the async from reactivating too often when there is only a small amount of extra fuel calculated.  I suspect the main thing that influences what is a good minimum setting is your injector size.  Probably around 1.0ms would be suitable for typical ~500cc injectors, and maybe 0.5ms for ~1000cc injectors.  All my cars started with 0.5ms in there and it seems to work good so I havent experimented with it much further.
Your little lean spike could be not ernough accel fuel or the min async is too big.  You really need to look at what was happening to accel fuel at the same time.  Also, dont be too concerned about getting a dead flat lambda, there are all sorts of interactions going on during heavy transients and measured lambda is not always a good indication of how well it is all working.  Aim for best response rather than flatest lambda.  
  
  
 

You need to use head phones that have a 3 pole 3.5mm jack, often referred to as stereo.  Most smartphone earbuds have a 4 pole plug as they also have a microphone, these won’t work.

Adam,
It worked for me also, 

I drew this circuit for someone the other day.  I havent tested it myself with a turbospeed sensor so no guarantees but I have used a similar circuit to divide a wheel speed frequency down.  Over here you can buy the 4024 binary counter for about $1.50 from Jaycar so I assume they should be easy to find anywhere.
 

With a 11% pulley you'll probably pick up 10-15hp easy, You talking about the "461" Catcam? Down low it will make the same as a "469".
Throttle is a good idea to restrict the air flow. 

Hi Alan, what power you trying to achieve? to get the torque up but keep the power low you could fit a camshaft with more lift and duration,then run a restrictor, This way you'll get more power and torque down low and stop it making loads up top.

I'm using AEM 30-2056 and for Highend Application Motec 9 Position. Doesn't matter much which one you use, it just should give you signals between 0 and 5 Volts. 
Besides, Adamw / Link ECU that would be a nice Accessory in your product lineup! 

I think its much better to have all universal function like virtual aux, timers, 4D, 5D, fual fuel table etc. than a dedicated NOS function. This way you can build your own NOS function excatly how you want it. You just habe to be a bit creative with the universal functions. 

For anyone else looking to run similar setups with Racepak dashes and a link ecu. Don't purchase the Racepak display dash or logger dash that has the standard 5pin v-net connector and 8pin Deutsche connected on the back. If you purchase the Racepak STREET dash it has a can module already built into the dash that can be programmed to most new ecus and I have tested and confirmed it on my link G4+ extreme.