HPDI Injector ? for Rodbolt/anyone

[rodbolt17]

they made HPDI in a single driver and a dual driver,depends on the year model.

all the injector wires go to the driver.
the ECU controls the driver based on the pulser coil inputs.
injector ON time is con*****ed by various other sensors.

all the driver does is steps up the voltage from 12V to about 90V.
that is why I would assume the step up uses an inductive transformer similar to an ign coil.
typically step up increase the voltage and decrease the current.
it is an area where Ohms law quits and you have to use number of turns in the primary and secondary.
there is a formula for it.
you generate it,store it in a capacitor then discharge the cap using an SCR and a set of triggers(transistors).

a decent diagram of the internals to the driver would be nice.
not ever gonna happen.

you may see what 8-9 milliseconds of ON time max.
means that stuff is hanging out having a coke the rest of the second.

if one really wants to have fun figgue out pistion speed from BTDC (dead stop) to port closure at various RPM's see how many milliseconds are from port closed and injector on till the next injector on time.
that will show how long and any RPM the driver doesn't do much.
remember that piston stops twice per revolution.
kinda makes ya wonder how it holds together at 5500 RPM.

[cpostis]

Are Yamaha's HPDI Fuel Injectors "Peak and Hold"?
Below is an excerpt from this automotive link:
fuel-injector-testing Procedure
The peak-and-hold injector gets its name from its waveform characteristic. The actual current peaks at a certain level (4 to 6 Amps) so as to open the injector and then levels off at about 1 Amp to keep the injector open. Point (1 – A) is the injector turn-on. This is the point at which the ECM driver transistor grounds the injector coil. At this point the voltage goes low (grounded) and the current slopes up to about 4-6 Amps. The ECM does this to quickly open the injector. It takes a lot more current to force an injector to open (break the inertia) than to leave it open. This type of injector is used mainly in TBI applications, with it being bigger and heavier. The current needed to break the injector pinttle inertia is generally higher, hence the higher peak-current level. Point ( B ) is the injector peak duration. Injector peak times should never fall bellow 1.5 mS. Injectors with shorted windings will tend to peak much faster due to the low impedance of the windings. A range of 1.5 to 3 mS is normal. Point (2 – C ) is the injector peak current/inductive voltage kick. At this point the peak phase ends and the injector driver transistor goes into the hold phase of the injector pulse. Peak current range from 4 to 6 Amps, with voltage values of around 60 to 90 volts. As in the saturation type injector, a lower inductive kick is an indication of a problem with the injector circuit or coil windings. Point (3 – D) is the injector-hold time.


Have More Fun!!!

[99yam40]

I would not think HPDI injectors would be the same as automotive injectors seeing how high of pressures they deal with.
But I know very little about them

[cpostis]

99yam,
Sorry about the long history lesson, by here goes.
FYI…
Direct gasoline injection (See the other terms below) was first used in automobiles as early as 1952 (Developed by Bosch), also was used in aircraft engines as early as 1906. It has and in some cases still is being used in the automotive industry now and has been for decades. Some manufacturers are Mitsubishi, Nissan, Toyota, Renault, Volkswagen, Alfa Romero, Ford, BMW, General Motors, Isuzu and others.
The term HPDI meaning “high pressure direct injection” is Yamaha’s. In non-diesel internal combustion engines, it is also referred to as:
1. Gasoline Direct Injection (GDI)
2. Petrol Direct Injection
3. Direct Petrol Injection
4. Spark Ignited Direct Injection (SIDI)
5. Fuel Stratified Injection (FSI)
6. Ficht, OMC’s term

So, this technology is nowhere new, and not limited to outboard motor use. OMC was the first outboard manufacturer to use HPDI in 1996, they are the Ficht outboards. I believe 2000 was the year Yamaha introduced HPDI in their model lineup.
Now how it is con*****ed may be a different matter.

Rodbolt’s post #16 seems to suggest the HPDI driver as a “Peak and Hold” (Current Limiting) not a “Saturation driver”. Going back to the website link I posted # 17, I believe there is some good information our inquisitive members may find interesting, especially why 60-90 volts applied to 1 ohm fuel injectors only have a 4 to 6 amp draw. Maybe now we know why the leads to the fuel injectors don’t melt!

Look at the site and Kick it around guys!!!

fuel-injector-testing Procedure

[zenoahphobic]

99yam,
Sorry about the long history lesson, by here goes.
FYI…
Direct gasoline injection (See the other terms below) was first used in automobiles as early as 1952 (Developed by Bosch), also was used in aircraft engines as early as 1906. It has and in some cases still is being used in the automotive industry now and has been for decades. Some manufacturers are Mitsubishi, Nissan, Toyota, Renault, Volkswagen, Alfa Romero, Ford, BMW, General Motors, Isuzu and others.
The term HPDI meaning “high pressure direct injection” is Yamaha’s. In non-diesel internal combustion engines, it is also referred to as:
1. Gasoline Direct Injection (GDI)
2. Petrol Direct Injection
3. Direct Petrol Injection
4. Spark Ignited Direct Injection (SIDI)
5. Fuel Stratified Injection (FSI)
6. Ficht, OMC’s term

So, this technology is nowhere new, and not limited to outboard motor use. OMC was the first outboard manufacturer to use HPDI in 1996, they are the Ficht outboards. I believe 2000 was the year Yamaha introduced HPDI in their model lineup.
Now how it is con*****ed may be a different matter.

Rodbolt’s post #16 seems to suggest the HPDI driver as a “Peak and Hold” (Current Limiting) not a “Saturation driver”. Going back to the website link I posted # 17, I believe there is some good information our inquisitive members may find interesting, especially why 60-90 volts applied to 1 ohm fuel injectors only have a 4 to 6 amp draw. Maybe now we know why the leads to the fuel injectors don’t melt!

Look at the site and Kick it around guys!!!

fuel-injector-testing Procedure

Cpostis, good information.
BTW I have an early 50's direct injection two stroke Goliath car engine (father had the whole car)(probably Bosch but haven't looked closely).

My interest has been heightened by the Common Rail Diesel engines in my Prado and Mitsubishi Challenger. How closely has the technology between the modern diesel injecting and petrol injection become? I know way off topic, but the diesel injectors are electric and are "switched on" variably and con*****ed by the ECU - much so that faulty injectors can burn holes in pistons!

[rodbolt17]

a faulty spray pattern in the HPDI can and will smoke a piston.

[99yam40]

Common automotive gas fuel injection systems do not run at very high pressures.

HPDI and diesel motors do operate with very high fuel pressures.
What kind of difference is there between the low pressure and high pressure injectors, I have no idea. maybe they could be the same.

[boscoe99]

Common automotive gas fuel injection systems do not run at very high pressures.

HPDI and diesel motors do operate with very high fuel pressures.
What kind of difference is there between the low pressure and high pressure injectors, I have no idea. maybe they could be the same.

The difference is that between night and day. HPDI injectors are big burly metal things operating on 90 volts. Held in place by massive metal clips. Non-HPDI injectors are wimpy looking things made of plastic. Operating on 12 volts.

HPDI injectors can operate at pressures up to 1000 psi. Non-HPDI injectors nominally operate at about 45 psi.

Ever used a pressure washer and noticed the kick when pulling the trigger? This might be what the HPDI injector is feeling. Hundreds of times a second I believe.

Which reminds me that I once read of a guy on a ladder using a pressure washer. The kick when he pressed the handle on the wand caused him to fall off the ladder. Not good.

[boscoe99]

Cpostis, good information.
BTW I have an early 50's direct injection two stroke Goliath car engine (father had the whole car)(probably Bosch but haven't looked closely).

My interest has been heightened by the Common Rail Diesel engines in my Prado and Mitsubishi Challenger. How closely has the technology between the modern diesel injecting and petrol injection become? I know way off topic, but the diesel injectors are electric and are "switched on" variably and con*****ed by the ECU - much so that faulty injectors can burn holes in pistons!

Yes, good information. I have got to study up on the inner workings of injector drivings, step up of voltages in a DC system. etc. Yamaha tells us nothing about the inner workings of some parts.

Now if fairwinds had an HPDI he would take the driver into his lab and have it dissected in 30 minutes.

[cpostis]

Common automotive gas fuel injection systems do not run at very high pressures.

HPDI and diesel motors do operate with very high fuel pressures.
What kind of difference is there between the low pressure and high pressure injectors, I have no idea. maybe they could be the same.

We are only talking about GDI (Injects fuel directly into combustion chamber at high pressure), not MPI (Multi Port Injection, injects fuel to intake, lower pressure).
GDI (Gasoline Direct Injection). Again Yamaha's HPDI is their marketing term for GDI. ***, high pressure has to be better (although it is the same as GDI). Now, physically the GDI fuel injectors will have to withstand the higher pressures and temperature encountered in their design. It will take more power (current) to drive an GDI injector open, their are limitations on the wiring to current. Thus higher voltage and less current as in the circuit Rodbolt describes in his post.

We are not talking about diesel engines.



MFYI:
Per EPA ...

"In particular, vehicles utilizing gasoline direct injection engines (GDI) have been entering the market at a very rapid pace. In MY2008, GDI engines represented 2.3 percent of production. That number has grown to just over 45 percent of expected production in MY2015."

So, what is Common now?

[cpostis]

. HPDI injectors are big burly metal things

Just realized, I'm in the middle of an engine swap in my daughters 2009 Nissan 3.5L Altima Took a look at it and it is a GDI (equivalent to HPDI). Here's a picture of the burly fuel rail mounting on it.

[rodbolt17]

the current 4.3 gen V Volvo runs a variable rail pressure from about 500 PSI to about 2000 PSI.

[boscoe99]

That fuel rail looks like a wimp compared to the Yamaha fuel rail. Which appears to be machined from aluminum billet.

[99yam40]

My youngest son is a diesel mechanic.

a while back we were talking about injection systems and he told me the motors he works on have many thousands of PSI on their injectors.
I had no clue they ran that high, but the compression ratios of those motors are very high also

[boscoe99]

My youngest son is a diesel mechanic.

a while back we were talking about injection systems and he told me the motors he works on have many thousands of PSI on their injectors.
I had no clue they ran that high, but the compression ratios of those motors are very high also

I once visited a diesel truck (big rigs) salvage yard in search of a diesel saddle tank. I was amazed by the size of the stuff when it was up close and personal. I don't think that one big dude even is going to be able to pick up a crank shaft. Axles looked like tree trunks. It was all on another level of scale.