Can someone please explain to me how the TIAL 46mm wastegate works and how it works in the turbocharging system?

 

http://en.wikipedia.org/wiki/Wastegate

Thats a general rundown. Essentially a WG works to bleed off extra exhaust gasses from entering the turbine to prevent the turbo from producing more than a selected amount of boost (either set through the wastegate spring or through a Boost Controller)

 

This is about as simple as it gets: Link

Exhaust flow enters through the bottom and exits out the side. A vacuum signal is supplied to the side port and when the pressure reaches that of the spring inside the wastegate, the valve opens up so that exhaust flow is diverted. You can connect a boost controller between the top and side port so that you can adjust the pressure that the wastegate sees, which in turn has the effect of allowing the turbocharger to generate more boost before the wg valve opens. Without some type of wastegate or serious flow restriction to control the turbo, the turbo would free boost and just keep generating pressure until it blows up. Also, under WOT (when exhaust flow is basically unrestricted), it is physically impossible for the wastegate to allow less boost then that of the spring rate inside of it.

Please don't take this the wrong way but, this is also a nice writeup to help familiarize you with turbos unless you already know this stuff: Link I'm not saying you don't know this stuff but, maybe it will help someone that might not. I know for the longest time I had trouble trying to visualize how a turbocharger system works and operates. Being able to see the components and how they fit together really helps to understand how the entire system works. It's relatively simple when you really get down to it.

 

As well discussed (and often discussed) here, the holy triangle of basic performance tuning for 951 models is to upgrade to a dual port WG, add either manual or electronic boost control to regain boost pressure control from the cycling valve/KLM system, and upgrade the downpipe/cat/WG vent portion of the exhaust system.

I think adding an upgraded BOV and a good silicone vacuum kit also merit consideration in this first round of performance improving mods...neither of these adds any power, but they help insure that the vacuum/boost system operates with efficiency and air tight integrity.

There are wide horizons of chipping/MAF/fuel delivery mods that push performance to stratospheric power levels, but the mods above are low risk, relatively low dollar additions that account for 20 years of wear on factory wastegates, simplify boost pressure control and improve overall engine breathing.

IMO, starting with a chip is a bit like playing with fire, since the chip's parameters are so dependent on available fuel and physical boost limits. Chips can make 951s go instantly faster but can also turn them instantly into hand grenades if not compatible with air/fuel and boost pressure realities in any given motor.

My bet is that 951MAX chips which are specification specific upon ordering for your max boost pressure, fuel pressure and MAF/AFM choice are going to quickly become the standard for 951 upgrades and will be added the Holy Three as a mod to be done in the first round of ownership.