mroberts

From what I generally understand, more air = good thing = more power.

What would happen if you took the compressor from an old turbo, grafted it into the intake box of a NA 10v, and ran a belt to an extra pulley from the engine.

Maybe add a flap of some sort so at low revs the engine sucks, but closes when the pressure from the turbine is enough, and a simple spring operated waste-gate system.

It would take some tweaking to get the pulley diameters right, or replace it with an electric motor ?

I'm certainly open to comments on this idea, and the fact that no-one does it means there probably is some compelling reason not to !!

cuatrokoop

its not as simple as that...take a turbo apart sometime (I have, recently actually), and you'll see why.

the compressor wheel is press-fit to the shaft (which is cast as one piece with the turbine wheel), so take the cartridge and exhaust housing off, and you are left with a shaftless, non-lubricated housing with a compressor wheel floating around inside.

Plus, you'd still have to flow more fuel, and figure out how you'd drive the compressor (as in, what pulley size, what belt length, where do you run the belt from, etc).

Its not a stupid idea, just one that would take more engineering effort than its worth, IMO.

Rob K

I believe this is what you are describing, you have to run a gearbox on the compressor, because the compressor wheel needs to turn close to 100,000rpm. Adding more air to an engine won't do anything without ensxuring you also add an appropriate amount of fuel as well.<ul><li><a href="http://www.vortechsuperchargers.com/">http://www.vortechsuperchargers.com/</a</li></ul>

mroberts

This is a pretty solidly written article on water injection.

If no-one can give me any serious downsides of this plan - putting the water intake into the air boot just in front of the throttle - I'm tempted to try.

By my reckoning, you get the extra mass of water, but since it should remain liquid until it's into the cylinder it wont influence the fuel / air ratio until it ignites. Once the mix ignites, the water vapourises, increasing the pressure in the cyclinder and hence giving more power.<ul><li><a href="http://website.lineone.net/~dave.cushman/mannject.html">http://website.lineone.net/~dave.cushman/mannject.html</a</li></ul>

Playerseightball

Still don't know where to obtain one yet. Its an electric supercharger that was originally designed by turbodyne for detroit diesel to eliminate turbo lag, emissions, and increase mpg. I read somewhere that turbodyne sent some prototypes to VAG and other car manufacturers in 2000. Then turbodyne was merged or bought out by honeywell (garret).
Brad
Playerseightball@aol.com<ul><li><a href="http://www.turbodyne.com/products/1500.html">http://www.turbodyne.com/products/1500.html</a</li></ul>

Merkin

also ya need a ecu and injectors for that.

Merkin

humidity slows cars, water injection won't help, also decreasing combustion temperature so not burn as clean=wasted power.

90quattrocoupe

Some of the best times in drag racing are achieved at those drag strips closest to sea level and higher humidity.

Fremont up near San Francisco used to have some of the best times. The humidity condenses the air fuel ratio and increases the compression ratio, increasing power.

In the middle 70's when car maufacturers were still trying to use the carb and resisting FI, we used water injection to help our cars. This was also because of the bad gas we were getting in those days.

Water injection does work, just how to use it with FI is another problem to be worked out.

mroberts

From my very limited flying experience, humidity is bad - humid air is effectively less dense - consider the moleculat weight of water is 18, nitrogen oxygen 28-32.

If you're sucking in water vapour BEFORE the air flow sensor, you'll be running rich, because the water vapour doesn't burn, but the car thinks it's flammable.

From what I've seen, most of the water injection systems (and the ones used in aircraft) inject liquid water, so that it doesn't displace oxygen.

Sea level is definitely key, but are they getting better times in high tmeperature high humidity, or low temperature high humidity ?