1999FirehawkLS1

iTrader: (21)

Doesnt venting out in the air cause issues of oil loss like the big long nasty Thread that comes up on here about PVC Routing Debate? lol

427 zeo6

Valve debris build up is a result of gasoline boiling on hot backside of intake valve, how is a catch can going to solve this problem. FYI the Audi RS4 already has a very exotic air/oil seperator circuit in its crankcase ventallation system. Oil vapors are not the cause of this problem.

SSCamaro99_3

iTrader: (1)

If gasoline is being injected in front of the intake valve into a small pocket just before ignition, how is it getting to the back side of the valve. What you describe sounds like something that would be on a port injected engine.

427 zeo6

It's called REVERSION and happens during valve overlap between the exhaust cycle and intake cycle when both valves are open, you get some travel of the fuel air mixture from the combustion chamber to the intake port. On high performance motors with long duration cams, you can see the effects of reversion into the intake manifold. Some of this can be cancelled out with injector timing and runner tuning but, like I said on a high performance motor like the B7 RS4 this build up is a major problem in the long term. For a motor with short valve timing it isn't as great a problem, for my Duramax truck it isn't either but for gasoline fuelled cars, this problem hasn't been fully addressed.

Wnts2Go10O

iTrader: (12)

i believe gm did a DI L92 test motor, modified the heads for it and everything. apparently it made nice lot of power. was an article on here somewhere

smokeshow

iTrader: (17)

I think direct injection for gasoline is fantastic, I can't wait until gen 5 and when aftermarket parts become a little more mainstream. Power potential for DI is massive in stock form, but when the fuel system capacity is exceeded, expect those modifications to dwarf all other vehicle costs...

Also worth a mention, PCV is going to need a complete redesign. I've never seen Audi's version, but I'm sure its exotic for a reason. Someone correct me if I am wrong, but if new-generation DI gas engines are anything like a diesel, they won't have a throttle body and therefore no vacuum... There would need to be some sort of vacuum pump to pull fresh air through the engine.

The valve debris problem is an interesting one...looking forward to progress on a fix for that.

Jimbo1367

From the articles I've seen, the DI pistons are drastically different than what normal pistons look like. I am sure when GM does interdue the DI V8, they will have to use torque management to keep their trannys (& rest of the drivetrain) under warranty.

Pumba

I think you may be confusing Common Rail Diesel Fuel Injection.

The DI system used by Corvette Racing three years ago operated in the 1250 psi range.

DI is given credit for 10% to 15% increase in power. 91 octane production cars from Europe are running 12.5 to 12.8:1 compression ratio.

I believe that in two to four years we will see aftermarket heads which have incorporated OEM Direct Injectors. Packaging and driving a pump will be interesting.

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1lejohn

iTrader: (9)

Like posted above it will be $$$ to modify. The oems are waiting on electrical operated valve tech(solenoid) to fully go this route. Imop. We shall see. The Gen 5 V6 Camaro is already DI. They have N20 kits out for it. So the aftermarket is embracing it some.