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Old 09-11-2019, 02:22 PM   #10
Scooby Specialist
Member#: 447898
Join Date: May 2016
Chapter/Region: BAIC
Location: W Sac, CA
2016 WRX (traded)
2019 STI CWP


Originally Posted by xX_STI_Xx View Post
Personal experience with Direct Injection cars, they are difficult to tune, cost way more to modify, and overall incorporate technology to improve fuel efficiency and weight rather than durability and reliability. People talk **** about the EJ25, but it's a proven platform for modding and tuners have them dialed in (tuning, parts, etc...).
The FA engine will be more efficient due to modern technology with the added benefit of fuel efficiency. It'll have a better powerband (more area under the curve) and a higher specific output.

Modern cars are heavy, but that has little to do with the engine (look at the current STI & WRX curb weights). Modern engines are actually lighter in most cases.

The cost of modification really depends on what your end goal is. For less than $2k, you can modify the FA20 to 320+ whp with only an AccessPort, flex fuel kit & tune. You can't make that level of power on the EJ257 for that price. You'll have to upgrade the fuel system first.
If you want to go over 400 whp then you'll want to build the blocks of both engines.
Over 500 whp, the fuel injectors are the limitation of the current FA platform. You have to add auxiliary port injection to push further.
Overall, I wouldn't say that the FA is more expensive to modify than the EJ. They're both relatively expensive to modify.

The FA has been pretty reliable so far. I'm not saying that it's Toyota level reliable, but keep in mind the EJ's oil issues, ringland failures and the rod bearing settlement... it wasn't still isn't perfect after 15 years. The FA suffers from LSPI (common for turbocharged DI engines) and bends rods at higher power levels. The EJ & FA engines both have their strengths and weaknesses. I'm not saying the EJ is a bad engine, it's just old and inefficient by today's standards.

Any manufacturer can solve carbon build-up by adding dual injection (DI & port injection) like the BRZ has to wash the valves. Dual injection has other advantages as well. However, Toyota owns the D-4S dual injection system used in the twins so we're unlikely to see it on the next STI.

Tuners have had over 15 years to develop parts & tunes for the EJ257. The FA20DIT has only been around for 5 years (and only in the WRX). Give it some time. There's already a lot of aftermarket support and there will be an even higher demand for parts once the FA is in both the WRX & STI.

Edit: I may have felt differently about the FA vs EJ debate if we got the EJ207 instead of the EJ257.. but we didn't.
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Last edited by WRXnick16; 09-11-2019 at 02:41 PM.
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