What will the engine need to go FI?
 

Hey guys. As most recent threads have touched on, this engine is going to be pretty maxed out and it sounds like we won't see many gains from NA mods. So it looks like if we want serious power gains it's either FI or new engine.

Going off of what we think the engine will be, what sort of work will the engine need to go FI? What I mean by this is that because compression will be relatively high, will the engine need a whole lot of build-up before we can drop a turbo on it? If you think the stock internals can handle some boost, up to how much boost/power do you think it can handle? Let's get a discussion going on how much power this engine can handle stock and what it will need if we were to put a turbo or supercharger on it.

get a wrx

Hate subaru but thanks for the constructive addition to the thread

Without knowing any real details about the engine, it's hard to say.

generally, with a good tune you can bolt on a turbo kit with little problems, assuming you keep the boost low. If you're looking for big gains, however, you're more likely to need some work on the internals. This engine is most likely going to be sporting high compression pistons, so those would be the first things to swap out. Sleeving the block with steel liners would probably be a good idea if the block is aluminum. Aside from that, it depends on the quality of the rest of the parts. For example, you can look at the 2ZZ-GE from the last Celica. It had beefy connecting rods from the factory that could handle upwards of 500hp before you need to worry about them snapping.

I'm sure there's people with more experience putting FI on NA cars than I have that can fill in the gaps in the holes I surely left.

Not knowing anything about Subaru, I'd like to hear more about this. But I recognize that we need an appropriate, separate thread for it. (And I don't want to appear that I am hating for hating's sake. I just want to learn the pro's and con's of Subaru.)

Biggest problem will be tuning direct injection

^not necessarily. thanks to the fact that its D4-S rather D4.
If you leave alone the DI charge via ECU and run a piggy-back that controls only the port injection and/or auxiliary ports for added fuel, you will have enough fuel at all ranges. Since we are using port to supplement the Lean DI mixtures, we don't need very large injectors to get the right EGT/AFR/LAMBDA unlike conventional EFI engines.

My recommendations are small (250cc-370cc)RC engineering Peak & Hold unsaturated injectors with inline fuel controller.

I'd be curious too. I've owned a Subaru for 4 years and this is the first I've heard of anyone hating them. In fact, Subaru engines seem to be a really popular swap into Boxsters and mid-engined kits. I'm planning to swap an EJ207 if it's easy enough. It's a proven platform instead of the new engine which is a big question mark at this point.

Has anyone had any luck tuning the other d4-s engines?

I think no D4-S engine has ever been turboed before...based off a quick search on google. Toyota ECUs seem to be pretty hard to hack into or something :O Makes me wonder how exactly people are going to tune this for forced induction.

If they stay true to their word, keepin this car a enthusiasts car, they won't make it hard to hack, hell it might even be slightly programable, whose to say for now.
General rule of thumb for a high comp high rev engine, with stoc internals you are looking at more than likely 12psi tops and thats being generous. But that's not to say you won't see good power improvements from that, remember that this will/should be a good engine to start with. A safe tune for a NA->FI engine is around 9psi

So at 9 psi how much extra horsepower would you expect?

a maxed out engine out of the box doesnt' sound bad to me :D

Ideally you are adding 1.6 times of air/fuel over atmo so ideally you are looking at 60%~ more power, but that's ideally and it depends where you want that boost to be. You will either get a more from the get go with low lag and end up choking your exhaust high up and making heat, or you will have more power later.
In reality you can get about ~40% more if boost is where your peak power was originally, but I can't stress enough about this not needing it of it's light and nimble as promised. If anything, a turbo that is at full boost at 5-6krpm and a redline of 8-9 is perfect for track for small car like this. Otherwise you will be smoking tires and feathering the throttle. That's my opinion, but I'd prefer a screaming NA, or a centrifugal charger or turbo with very low boost (like 5-7psi if anything)

Even with 40% increase in power you're talking 200hp to 280hp in a car that should weigh less than 2700lbs. That's pretty awesome