VGT turbo

suprahabsfan

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Sep 28, 2007
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A little off topic, but in that autozone article, about the twincharger system on the golf gt, it lists boost pressure when both supercharger and turbo are working at 2.5 bar??!!:aigo:
 

88supraTT

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Oct 2, 2005
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around the bend
u guys should see some of the crazy stuff over the road trucks are starting to use for the new emissions laws. to me they are producing all kinds of new innovations that cars should be following. 6-7mpg with a 14 liter engine hauling a load.
 

bigboost7m

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Apr 20, 2005
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Diesels are the way to go! lol. I work for Bosch, and ALL (100%) of the prototype model year 2010 and 2011 diesel engines are equipped with some type of device that aids in turbo spool up. The Cummins diesel has variable vane tech on the exhaust side, The new ITEC has variable vane tech on both the compressor and turbine side. So, there is no doubt that thats where the OEM is headed towards. The Holset on the Cummins is actually questionable as of right now, its been having repeated (7) failures of the actuator unit for the variable vane system, they just cant seem to get it right.....yet. But sadly both are too large to possibly fit on an 7M. The Holset on the Cummins is a standard T4 flanged housing, while the ITEC has a dedicated flange style. An ideal candidate for a 7M retro-fit would be the Mercedes Benz 4.0L diesel V6, it's equipped with variable nozzle tech. and spools rather quickly. Under load, the max engine RPM is 4,800, and the turbo achieved full boost (24psi, current testing) at 2,200 rpm, (under load).


Hmmmmm, 4.0L Benz diesel in an MK3..........:love:
 

Orion ZyGarian

Jeff Lange wannabe
Apr 2, 2005
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One thing I despise about Benz's are that they now use exclusively V6 engines. Fuck that. Also they are difficult to work on, whereas BMWs are a piece of cake. Otherwise they are a good company; the Dodge Sprinter is just a rebadged M-B with a Merc diesel, plus Merc owns a few different semi truck companies.

Anyways, VGT turbos are becoming almost standard now on diesels...just as turbos have. Pretty sure both of them on the new BMW twin turbodiesels are, probably on their new 4 banger twin turbo as well. The 1HD-FTE Toyota 4.2 diesel is, as well as their new V8 TT.

Common rail injection, variable geometry turbos, and piezoelectric direct injection. Ahhh, how technology continues to make a simple diesel engine into something increasingly efficient.
 

Adjuster

Supramania Contributor
I still think in the USA, and perhaps in other parts of the world, direct gas injection engines will remain popular.

However, outside of the USA, diesel is the way to go due to taxes, and outright power production (Tourqe) for day to day use of the vehicle. (Besides the slightly better fuel economy because of the additional energy contained in diesel v/s gas.)

That being said, the idea of a VATN setup would be very nice indeed. :) Even the possibly simple idea of using a divided hot side with a valve that forces all the exhaust gas through one side of the housing, promoting high velocity at low RPM, while opening up under more exhaust manifold pressure, and allowing for high flow rates, to bump up top end power as well...

Personally, an engine of about 3.0L, with a static CR of 11:1, direct injection, and a T-70 turbo with a VATN setup would be amazing.
Off boost, the high CR would make it drive quite well, plenty of getting around town power, and very responsive.. and the engine could be designed to "switch" over to a almost diesel like operation where the fuel is injected only when the flame front is wanted, just prior to TDC when the spark would normally ignight the air/fuel mix.. (And if you tried this on a port fuel injected design, the high pressures would light off that mix way too soon, and in a out of control manner.. Detonation basicly..) But with direct injection, you could run the engine at idle, and off boost like a normal 4 stroke, and have the smoother idle, mid point power and quiet engine operation.. but under boost, and high boost conditions, say 30psi... you basicly run the "gas" engine like a diesel.. and only inject the fuel when you want to burn it.. and the hot compressed air would light off the incoming fuel, but if it did not, you could use the spark plug to assist as well...

It's a very interesting concept, and I'm supprised nobody is working on something like this, and making noise about it. (It solves many pollution issues, and NVH issues consumers have about diesel engines in this country.)

You would need a pretty long stroke engine design to improve on the amount of time available to burn fuel... So it would not be a high rpm engine, but it would be higher than most availble diesel engines...

Again, I'm just thinking out loud.. :)

One more thing.. with the variable timing control, you could have idle valve overlap under "normal" gas operation very light, so few unburned HC's escape out with the exhaust, but when it's on full direct injection mode, under boost, the overlap could be insane! With both the intake and exhaust valves open, your forcing fresh air out the exhaust to some extent, and this would help to burn off any remaining HC's, could result in higher EGT's however depending on how much "Air" is added to the exhaust flow, but in theory would improve tailpipe readings to the point where perhaps a cat is not needed? Or smaller cats could be used?

The final thing is incoming pressurized air at high rpm, under high boost, at the end of the exhaust stroke should help to slow down the piston, and not just rely on the rod to do all the work.. Making long stroke engines possible with this type of valve and fuel control... :) Again, just thinking out loud..
 

bigboost7m

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Apr 20, 2005
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Very true statements above. GDI engines WILL (mark my words) be the industry standard in 2010. As stated above, I work for Bosch (The KINGS of GDI), and we havnt seen a normally fuel injected engine for months now. Every development engine for the past 10 months has been of GDI nomenclature. Watch out for the 2011 model year Cobalt SS, they are going to be equipped with GDI, 22psi, and VGT. The car is actually more responsive during the ENTIRE powerband than its supercharged predecessor, says a lot for turbo technology, huh? The development technology that is currently being used is just absolutely amazing, and I have the privilege to witness it day in and day out. Below I added an article from Wards Auto World to give you an example as to how much GDI technology is advancing. The company they talk about in the article, FEV, actually developed an engine with variable connecting rods. The connecting rod will actually increase or decrease in length to raise or lower compression!! Variable Displacement I thinks its called.



Wards AutoWorld Logo

FEV Concepts Advance Engine Downsizing, Flexibility
Mike Sutton
Ward's AutoWorld, May 1, 2008 12:00 PM

As Satisfying Upcoming Fuel Economy and emissions regulations will require the internal-combustion engine to be fitted with numerous advanced technologies, FEV Inc. offered a glimpse of what light- and heavy-duty powertrains might look like in the near future.

On display at the World Congress were downsized engines such as FEV's 1.8L Spray Guided Turbo 4-cyl.

Based on an existing production block, the rest of the powerplant was designed from the ground up to optimize the benefits of gasoline direct injection (GDI), turbocharging and a raft of complementary systems, says Jochem Wolschendorf, chief technical officer and vice president-vehicle systems.

The SGT engine uses lean-burn stratified combustion vs. conventional stoichiometric operation to achieve diesel-like fuel economy in a compact package aimed at replacing larger gasoline engines, such as a 3.0L V-6. Output is 215 hp and 236 lb.-ft. (320 Nm) of torque, accompanied by a broad powerband characteristic of GDI/turbo engines.

Fuel consumption is 8%-10% less than existing GDI/turbo engines, with a carbon-dioxide output near 130 g/km in the European test cycle, FEV says. It also is flex-fuel compatible, capable of Super-Ultra-Low Emissions Vehicle status in the U.S. and easily can be configured for use with hybrid-electric drivetrains.

Making the SGT unique is its built-in electronic tunability, as well as the flexibility to be scaled either up or down in size. For optimum combustion, piezo-electric fuel injectors are centrally located in the cylinders next to the spark plug vs. a more conventional position in the side of the combustion chamber.
 

Adjuster

Supramania Contributor
LOL, I was thinking more for power in the 650rwhp range out of a 3.0L motor.. v/s a 1.5L motor that makes 230ish, but has 40mpg or better results in todays sized cars.

For my motorcycle however, I'd love to see a simple NA design of 1.0L that makes 200+ hp at the wheel.. :) With GDI, it's possible on cheap gas no less.... (Heck, right now it's making 150hp at the wheel, so another 50 is not too difficult..

I'm curious, do most of the GDI's use a mechanical pump to raise the fuel pressure up just before it's injected into the combustion chamber? I'd think to run it from the tank at say 20,000psi would be difficult, it not dangerous as well... (Line fails, and then the fuel cuts through your car floor, and your leg for example...)
 

Orion ZyGarian

Jeff Lange wannabe
Apr 2, 2005
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Adjuster;1031911 said:
LOL, I was thinking more for power in the 650rwhp range out of a 3.0L motor.. v/s a 1.5L motor that makes 230ish, but has 40mpg or better results in todays sized cars.

For my motorcycle however, I'd love to see a simple NA design of 1.0L that makes 200+ hp at the wheel.. :) With GDI, it's possible on cheap gas no less.... (Heck, right now it's making 150hp at the wheel, so another 50 is not too difficult..

I'm curious, do most of the GDI's use a mechanical pump to raise the fuel pressure up just before it's injected into the combustion chamber? I'd think to run it from the tank at say 20,000psi would be difficult, it not dangerous as well... (Line fails, and then the fuel cuts through your car floor, and your leg for example...)

Oh god yes. They have a crank- or a cam-driven high pressure pump just before the fuel rail.
 

bigboost7m

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Apr 20, 2005
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Center Line, MI
Yes, all of the new GDI driven engines have a cam driven high pressure pump (a Bosch product!!:icon_bigg) and a smaller pump (another Bosch product! :icon_bigg) in tank to provide some way to get the fuel to the high pressure pump so it doesnt have to work as hard. The key idea is to get the HPP (high pressure pump) as close to the fuel rail as possible, and they usually achieve around 700-1000 psi rail pressure, the body of the GDI injector cannot handle constant pressure over 1800psi (at least the current ones cant). And no gains have been seen going over 1300psi as of right now anyway. The main concern with GDI as of right now, is that they usually smoke a bit during cold start up and typically during decel also. But that has more to do with the cam timing and injector firing time than anything else.

PS- Is it me, or has this post gone a little off topic?, :sarcasm:
 

Orion ZyGarian

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Apr 2, 2005
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Not at all. These two aspects are rather related; both are integral to the future of the internal combustion engine.

Porsche is switching all of their engines to DI this year, not sure about the turbo/GT2 though. I would imagine they, like BMW has recently found out, that DI and VGTs are the future
 

bigboost7m

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Apr 20, 2005
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Orion ZyGarian;1033253 said:
Not at all. These two aspects are rather related; both are integral to the future of the internal combustion engine.

Porsche is switching all of their engines to DI this year, not sure about the turbo/GT2 though. I would imagine they, like BMW has recently found out, that DI and VGTs are the future



You would'nt believe how many company's are going GDI. I can almost guarantee that these company's will have at least 70% of their vehicles powered by GDI technology in 2010:biglaugh::

Nissan
GM
Suzuki
Ford
Honda
Mercedes
BMW (obviously)