Yes, someone was good enough to post that (I forget who, at the moment) and it finally sank into my head what he was saying.

But, still, the idea of fuel from the PI injectors "washing" the DI injectors and areas of carbon deposit seems farfetched. That carbon is going to be burned onto those surfaces, no?

i was under the impression D-4S helps reduce, but doesnt totally eliminate carbon build up. for me personally, it just comes with the territory so there is nothing you can do about it, besides get another car without DI.

but the ecu? that is a HUGE problem that isnt inherent, but a choice made by the car company. remember before the GT-R came out how they said the ecu was unbreakable? that shit got cracked in no time. i can understand why they would say such a thing, but they didnt go so far as to make it that way. all toyotas are made that way, and so i wait patiently to see if they intentionally dont encrypt the ecu on this model. that would be a giant clue that toyota wants you to mod this car. the FT was admittedly made as a tuner's car. but if they give it an encrypted ecu, we all might as well look for another platform...

Having to have the head taken off and redone (worked on, anyway) is not a big problem? Granted, it might not happen until 30k, 50k or 60k miles. But, still.

I don't know.

it's inherent to the design. you cant do anything about it, so why worry? if it bothers you that much, get another car! that's my perspective on it. ymmv...

oh and if i do get the car, i plan to have a built engine with SC, so pulling the head is not a big deal.

I agree. :happy0180:






Just trying to learn about the D-4S and make sure I wasn't missing anything.

im not really too concerned with carbon. From what iv seen and heard, the kind of carbon buildup that D4-S engines have aren't as bad as DI only Equipped engines.

even so this IS-F engine with D4-S and 30k had bad carbon deposits on the piston heads.
http://farm7.static.flickr.com/6065/...63a58218_b.jpg

Apparently Lexus has some new updates this year with a oil scavanging filter for their DI equiped engines to keep soot and carbon to a minimum. Im going to assume that the BRZ/FRS will also have the same tech.

That's a major problem that concerns be, I doubt I'll be able to have the head pulled and cleaned after only 30k unless its still under warranty!

thats what seafoam is for :)

Thanks, Wings.

I think part of what's freezing my brain on this is the idea that Toyota would bring to market a much-touted "new" engine with such an important design flaw. I know that companies make decisions — trade-offs — like this all the time, but I thought that Toyoda-san wanted to inaugurate a new era with the FT-86, or at least get back some street cred for Toyota in the sports enthusiast scene.

If this were an engine that we were going to use on Sunday and rebuild on Monday, like a race car, that would be one thing. But this car has to meet the market demand for a certain amount of user-friendly reliability and long life. And with VTEC and other technologies — even Toyota's own marvelous history with inline-4s — expectations are, with good reason, high.

Am I right?

Well all the other brands with Direct Injection including Mazda, Audi, Porsche, Ford, Alfa Romeo, WV, Nissan, BMW, Ferrari, Jaguar are all seeing similar carbon deposits. It just so happens that Toyota is the one that came up with Tandem Port Injection as a solution and Oil Scavenging Filter + baffler.

Its just part of the times, and i wouldn't worry to much about the reliability of it. Its not necessarily new technology. Just uncommon for the greater population of tuners.

I think this engine with the tech is going to be reliable. But a bit more challenging for aftermarket tuning because we have to learn a bit more information than we are use to.

Would you think using upper head cleaner ( im guessing its the same stuff as seafoam? ) useing it every 5,000 or even 2,500kms to keep any carbon deposits down to a minium?

Using that with the Oil Scavenging Filter + baffler means you wouldnt have to take heads off for a long time to remove carbon build up?

When it comes to carbon buildup, I'm really not too concerned either. I assume this car will be a huge hit among the tuners, so within 3-5 years there will be so many options for the car that switching out the engine or dismantling it shouldn't be that much of an issue for us down the road. Direct injection is relatively new in gasoline engines, and working out the long term issues is going to be something that comes with time.

However, with the amount of modding that will happen to this car, I don't think this is going to be too much of an issue. The engine die have large carbon deposits after 100k miles? use higher octane gas. Not an option? thrown in a turbo engine from Subaru. done.

^^Well, that's one approach.

But I am not interested in buying into that kind of hassle. You see, I have been spoiled by many years of Japanese reliability, low maintenance and general unbreakability. It sounds like you are used to having companies finish their r & d in the marketplace. Isn't that what computer manufacturers and app designers do? "We'll sort the rest of it out after 500,000 customers start complaining."

Eh carbon buildup happens. Unless there's some reason that the carbon buildup will cause an issue in this motor then I don't see any reason to be concerned. I've never disassembled a clean 100k+ mile motor. :shrug: