pumpless alky injection

[TransAm]

They claim that it has no mechanical parts and will spray using engine vacuum to draw water into the motor. but #14 on their FAQ's doesnt make sense.
"A turbo-charged vehicle and/or a super-charged vehicle, never, ever will it ever pressurize the intake manifold. The turbo-charge and super-charge only ASSIST the cylinder fill. In other words, assisting the incoming vacuum. In essence, the intake manifold actually has a higher vacuum range and a much more prolonged vacuum range."

Since when turbos dont pressurise the intake manifold?

please check out their site and tell me what you think http://aquatune.com/faq.html

I dont care about fuel increase but can this really work under boost if it needs vacuum to draw the alky thru the lines?

<small>[ October 22, 2003, 04:31 PM: Message edited by: TransAm ]</small>

[CallMeMud]

I always thought about this. If you have a nice tank that it teed into your compressor outlet where it would build pressure inside a closed container rated to say 100 PSI burst it would potentially be like a progressive setup pumping more alcohol into the charge as boost builds. In other words as boost increases so does flow into the motor. Depending on nozzle size it may work pretty well!

[TransAm]

CallMeMud:
I always thought about this. If you have a nice tank that it teed into your compressor outlet where it would build pressure inside a closed container rated to say 100 PSI burst it would potentially be like a progressive setup pumping more alcohol into the charge as boost builds. In other words as boost increases so does flow into the motor. Depending on nozzle size it may work pretty well!

but that would still require vacuum which we dont really have while boosting. also alky needs to be sprayed into a mist otherwise it would pool in the motor, and its hard to "vacuum" alky thru a nozzle designed for spraying a mist

[Steve Wood]

I think Steve Chlupsa's original idea was a pressurized tank but he evolved to a pump after testing.

[cew]

would'nt you have to have a pump? or, have a good pressure drop across the intercooler
otherwise would'nt it be like putting both ends of a 2 foot section of vacuum hose in your mouth and exhaling{no blowing here) and expect circulation through it? with a minimal pressure drop would'nt it just dribble in? i know i
personally don't enjoy big pressure drops across
the intercooler. hey i could be wrong,just a thought.

[Nasty Wendy]

Anybody that ever blew their up-pipe off at WOT knows that the turbo does infact pressurize the manifold.

[Ormand]

Maybe they are claiming the the 'intake' is the part before the turbo. You COULD spray alcohol into the turbo inlet, but I don't think I would want to. Unless you run a little tiny air cleaner, you won't have enough vacuum at the turbo inlet to pull in the alky, either. I guess you could put a venturi in the pipe from the MAF to the turbo, and generate enough vacuum in the venturi to meter in the alky, but it would still go through the turbo. Not a good idea, IMO.

[Joe Jagodzinski]

Folks, if the pressure in the inlet tract (at or just before the throttle body) is a function of turbo boost and the pressure in the alchy tank is also a function of that same boost, there would be no pressure difference - nothing to move the alchy out of the tank and into the motor. (We don't want alchy through the turbo or in the intercooler). A pump (mechanical or electrical) is needed to provide the pressure to move the alchy from the tank to the intake (given that the pump can provide enough pressure to overcome the boost which it should easily do).

The only way this makes sense to me is if the tank is pressurized as a "ramp up" to supply fuel need at increased boost levels. Ie: as boost increases, the in tank pump provides an increased pressure/volume of fuel to the spray nozzle consistent with increased pressure in the supply tank and intake manifold.

The SMC kit currently does not provide this feature. Maybe some of the more sophisticated (expensive)systems do this?

[Razor]

I provide it, its called a progressive alcohol controller.

You need to increase pressure being sprayed to offset the pressure within the intake tract. remember the pump is pushing a liquid into a pressurized intake. So the easy solution is have pressures so high it doesnt matter what the intake pressure tract is at.

My car typically sprays 10 PSI alky at 3 PSI boost and 100 PSI at 26 lbs of boost. Pump will make 150+ PSI at 30 PSI boost.

To make nozzles mist..you have to crank the pressure on them...

the referenced tuning fork to modulate the water is all hocus pocus moon and really designed around a motor operating on vacuum to suck the liquid in. In this fashion it works to increase combustion efficiency. Kinda like driving a chevy motor with no air cleaner in the rain.

HTH usa not sophisticated..but effective

[Orlando_87GN]

The turbo output will always be greater at the turbo vs. at the intake because of pressure loss in the piping and intercooler.

You could spray alky into the up pipe without a pump, but probably at less than 5psi (being the pressure differential).

Just thinking outloud here, maybe someone has tried this.

[Razor]

Dude.. shoot the up-pipe with a 125PSI.. and screw the differential. Works wonders

Let alone a 5 PSI differential is nill.. no atomization at low boost pressure.

[scottyb]

Regarding the original post, I believe the source of the "no pressure" theory is non-automotive. I flew a turbo Cessna for the first time a few months ago. The power setting concept in a high performance aircraft is all about manifold vacuum. Basically, you ALWAYS maintain a specified vacuum range, unless you are on final approach or initial climb. I grilled the owner of the airplane about the concept of a turbo and maintaining proper vacuum. He didn't know, so I did some simple research. My understanding is that the turbo on an aircraft simply runs to keep "atmosphere" at the same pressure as sea level. This way the engine, in theory, performs the same at all altitudes, increasing the service ceiling significantly. Long story short, this application is never under pressure.

FFT