Quote:
Originally Posted by BlkReaper
If anyone has a concern with carbon build up, look up N54 Walnut blasting. The N54 is a DI twin turbo i6 BMW engine. Comes in e90 335i and a couple other cars. It's treated as a maintenance item. These engines have been tuned for years and no one complains about DI anymore. At the beginning they noticed carbon build and spent their time coming up with solutions not data just to prove people wrong.
1. If you're going to keep your engine mostly stock, buy a catch can get it walnut blasted about every other year.
"But I don't want to pay the dealership to do this"
Here, buy this this and that and you can do it yourself at home.
2. If you are going to mod your car add meth injection. Meth sprayed into the intake will "steam clean" the valves
3. If you will be heavily heavily modding your car add 6 more injectors for port injection.
Mind you, option 3 was only thought of because the n54 had problems with the High Pressure fuel pump which has since been resolved by BMW and aftermarket options. If DI was this wicked evil technology that it's trying to be made out to be, I would add 8 port injectors before I swapped the LT for an LS.
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This.
I come from the N54 platform, and I've had my car's intake valves cleaned twice over the course of 50k miles. That's more often than most, but I didn't mind, if it helped the motor breathe. Took an hour or two each time, and was about $250.
The port injection kits came about because the HPFP can't flow enough to support more than ~600whp, but you're right the HPFPs on the n54 had terrible reliability.
Meth, or a port injection kit are the real solutions to this problem, at this point. Toyota came up with the hybrid injection first, with the 2GR-FSE V6, in the IS350. During warmup, the engine ran port injection, but direct at all other times. The reason for this was that the DI had high emissions at startup, but the PI also had the yet unknown benefit of fighting buildup.
I don't remember it personally, but I'm fairly sure EFI had issues when it first came around. When new tech comes out, it has drawbacks, but those drawbacks are mitigated as time goes on.
QUOTE=mikeSS;9064845]Its not like you can even buy your way out of this problem either. EVERY car is getting it or already has DI.
all 911 models have it, BMW has it , benz has it, even Lamborghini has all DI engines.
engines shouldn't be losing power at 20k miles, period.
I hope with time they can actually do a better job with this problem.[/QUOTE]
They will, just give it some time. The HPFPs on the n54 were terribly unreliable, but after a few revisions, BMW got it right. Just like that problem, carbon buildup will have a solution in time.