Archive for category power upgrades
According to the Italian car magazine Auto Evolution, VW may plan on using a V8 engine for a special VW Touareg R hybrid. This car would replace the 333 hp supercharged V6 engine with a V8 engine. Combined with the electric motor, the goal is about 550 hp total. Does this mean that as discussed in this post: http://www.evwaudi.com/2010/cayenne-touareg-hybridsupercharger-upgrade-chip-tune/ , that the hybrid system can handle much more power? Would it be possible to chip the VW Touareg hybrid to increase the supercharger boost and fueling? The base 333 hp V6 is also used in the Audi S4 where it’s been found that the engine is seriously underrated in power and chip tuning is producing around 400 hp.
As you can see from the dyno graph chart showing horsepower (red line) and torque (blue line), most of the VW Touareg hybrid and Porsche Cayenne hybrid electric motor’s assist is at low engine rpm.
With the electric motor’s assist, the combined torque curve is almost flat up to 4000 rpm and then begins to trail down. This means the engine will have tons of pick-up and throttle response down low. The engine by itself is a supercharged V6 used in the Audi S4, the sport version of the A4, so it is no slouch.
The transmission is rated to handle up to 627 lb-ft of torque so there should be room for tuners to increase the boost and fueling on the supercharged engine. The question is can the rest of the drivetrain take it?
Click the image to enlarge the thumbnail.
The Porsche Cayenne S Hybrid, VW Touareg hybrid, and the just announced Porsche Panamera hybrid all use the same Audi S4 supercharged engine. With older supercharged engines, it was as easy as changing the pulley to increase boost and increase power. Does this this work on the engines in the aforementioned models? Will a chip tune also work? This is part 1 of an ongoing series of articles of how to increase the power of your hybrid.
Long story short, at this time, a smaller pulley will not increase the power of your VW Touareg, Cayenne, or Panamera hybrid.
The pulley is small to begin with so it would be a challenge to make it much smaller. Eaton makes the TVS r1320 supercharger that is on the hybrid and S4 engine and does not make smaller pulleys for it. Each supercharger is designed to operate most efficiently within a performance envelope (if you chart effiency on a graph it forms a “box”, really more of a blob) and going outside of the envelope is inefficient. Physically, the supercharger might be able to make up to 20 psi but it’s ecu limited to about 11.6 psi (0.8 bar). Any extra is recycled back to the supercharger through a bypass valve. ECU changes can close this valve and direct all the air to the engine. The reason the bypass valve is often open is to complement the design envelope of the supercharger with the engine performance for both high and low end power. Below is a video showing the insides of the supercharger showing the bypass valve.
Below is the compressor map for the r1320 supercharger (from eaton.com)
Some tuners for the Audi S4 have made up to 420 hp with just a chip and tune so I don’t see why the hybrid engine can’t be tuned as well. However, will the hybrid motor’s decoupler stand up to the abuse? The decoupler is essentially a clutch – can it hold the extra power? This is completely unknown and other than the additional engine tuning, will be the unknown factor in tuning the Cayenne Hybrid or VW Touareg Hybrid.
See the next article for more information on the supercharger and chip tunes.