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Originally Posted by 82mm 4g63
What kind of experience do you folks have with Toyota's DFI systems? I have none. However, I have seen some nightmares from Porsche's DFI and when I first heard the Subieyota was going to have DFI I was nervous.
It seems to be a safer way to increase compression/boost and control knock, but it's not like the non-DI engines are lagging much. This is from an 08 Porsche Cayanne:
I'm not 100% positive that build up is a result of the fuel being dumped on the valve or if it is PCV crud.
I've heard a lot about fuel dilution in the oil with DFI. Seems to be a big problem. I remember reading a Nissan study on it and I'm guessing that is why they still use port injection. I also know it was a huge problem with the CX-7 and Mazda not covering it under warranty.
Question for you, is the FR-S getting Subaru's AVCS and if so how does Subaru's AVCS compare to BMW's VANOS/Double-VANOS?
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I haven't had a lot of personal experience with Toyota DFI, im a little more familiar with Mazda's Direct Injection. They practically work the same with a few different variations.
While port injection guys have same issues, I think the major problem (atleast just with more frequency) some mazdaspeed3 guys have been having was carbon deposits from oil coming back into the intake charge. Since Fuel isn't injected at the intake manifold anymore to clean the intake valves..they get murked up. I'm really only seeing this kind of build up with people who baby their car and turbocharged vehicles. I am not sure if flogging the motor would help, but its worth a try. I have to rev my rx7 at least once a day to break down carbon.
As far as AVCS....im not entirely sure if the FT86 will use AVCS...especially if Yamaha might be in charge of the head design, we might see a Toyota VVTi in the FR-S if this is a case. But if they plan to further boost torque and economy, having a VVTi will help. Vanos is just BMWs technology...they virtually all accomplish the same thing.