First a picture says better than words can
Top left is the new HTA35 blade. Top right is the common 35R blade. The HTA has the same size exducer(82mm). The inducer is around 3mm smaller. The hub of the blade of the HTA is much smaller than that of the common 35R (almost half as small). What does this do? It makes the blades much bigger. The blade is also a lot lighter because a lot of the mass has been removed from the hub and the inducer is much smaller. Adding to this is that the HTA has 14 blades vs 12 blades of a common GT35R. This way the turbo spools up a lot faster, moves more air faster and doesn't have to spin as much to move the same ammount of air and it also reduces significantly the backpressure on the blade of the compressor.
That is how the blade helps reduce lag and helps to move more air at the same time. Adding to this is a better compressor cover with better anti-surge ports and the end result is that you get a much better turbo.
The blades below are that of a Mitsubishi 24v and a 25G. The 25g uses the same style as the 35R and the 24v uses the same style of the HTA35. Obviously most of the HTA's turbos are made by a 5 axis CNC.
There are companies that will do this upgrade to any turbo for around $450 and they put new blades and new compressor cover on the turbo. Forced Performance is a perfect example. Now doing this does take some time
Well now the dynos
AMS Kit normal
This is Bushur's car "bad bish" on a Mustang Dyno that tends to read lower...
Now the 35r is no the only turbo that offers the new blade design and the HTA Compressor. They are many options right now on the market but a very small # of people are aware of this type of turbine design. Mainly speaking for us but they are becoming a real hit on the import crowd.
There are also
VGT turbos
Variable Turbine Geometry technology is the next generation in turbocharger technology where the turbo uses variable vanes to control exhaust flow against the turbine blades. See, the problem with the turbocharger that we’ve all come to know and love is that big turbos do not work well at slow engine speeds, while small turbos are fast to spool but run out of steam pretty quick. So how do
VTG turbos solve this problem?
A
Variable Turbine Geometry turbocharger is also known as a
variable geometry turbocharger (VGT), or a
Variable Nozzle Turbine (VNT). A turbocharger equipped with Variable Turbine Geometry has little movable vanes which can direct exhaust flow onto the turbine blades. The vane angles are adjusted via an actuator. The angle of the vanes vary throughout the engine RPM range to optimize turbine behaviour.
[FONT="]In the 3D illustration above, you can see the vanes in a angle which is almost closed. I have highlighted the variable vanes so you know which is which. This position is optimized for low engine RPM speeds, pre-boost
[/FONT] In this cut-through diagram, you can see the direction of exhaust flow when the variable vanes are in an almost closed angle. The narrow passage of which the exhaust gas has to flow through accelerates the exhaust gas towards the turbine blades, making them spin faster. The angle of the vanes also directs the gas to hit the blades at the proper angle.
[FONT="]Above are how the VGT vanes look like when they are open. I’ve not highlighted where the vanes are in this image since you already know where they are, as to not spoil the mechanical beauty that it is
[/FONT] This cut-through diagram shows the exhaust gas flow when the variable turbine vanes are fully open. The high exhaust flow at high engine speeds are fully directed onto the turbine blades by the variable vanes.
Variable Turbine Geometry has been used extensively in turbodiesel engines since the 1990s, but it has never been on a production petrol turbocharged car before until the new
Type 997 Porsche 911 Turbo. This is because petrol engine exhaust gases are alot hotter than diesel engine exhaust gas, so generally the material used to make VTG turbos could not stand this heat. The
997 911 Turbo uses a BorgWarner VTG turbocharger which uses special materials derived from aerospace technology, hence solving the temperature problem.
VGT article from
http://paultan.org/archives/2006/08/...geometry-work/
HTA thanks to JG from carrito.net
Andrew
