Note: skip to the end if you know all about the USDM vs JDM 3S-FE and 3S-GE My girlfriend is wanting more power out of her 89 GT convertible auto, but she's unwilling to give up the convertible top and auto transmission for a GTS stick. I know the 3S-FE isn't a good modding platform, but we don't have the tools or space for a GTS engine swap. I've read the USDM 3S-FE has 115 HP, vs the JDM's 140. Apparently the engine/intake/exhaust is exactly the same, but the JDM has 12* BTDC ignition timing compared to USDM's 10*. This alone wouldn't account for 25 HP, so the rest must lie in the ECU. So I've been looking at the DIY ECU Megasquirt. I have computer/programming/circuitry skills, as well as time and dedication. With proper tuning and ignition timing adjustment(possibly going distributorless via the Megasquirt), I should be able to expect 140+ HP, right? I then thought, since the Megasquirt will be entirely transferrable to a future 3S-GE, I might as well collect some 3S-GE parts and bolt them up to her current 3S-FE. I know the exhaust manifold will fit. But what about the intake manifold? To sum up my questions: 1. With adjusted ignition timing, EGR block off, replace AFM with MAP, and Megasquirt, could I expect an otherwise stock USDM 3S-FE to output 140+ HP like the JDM? 2. Will a 3S-GE intake manifold bolt up? (Megasquirt can control T-VIS) 3. If not, will a 3S-GE throttlebody bolt up to the 3S-FE intake manifold?(I heard this is the 3S-FE's biggest intake restriction) 4. How much power can the 3S-FE bottom end take before damage/reliability issues? 5. How much power can the A140L transmission handle before damage/reliability issues? 6. Could the engine/trans handle the above, including 3S-GE exhaust header, high flow exhaust and intake, and milled head for 10:1 compression ratio? 93 octane premium gas would be used.
jdm didn't get the gen1 3sfe. they only got ge. even if there is a jdm fe there is no way it has 25 more hp from usdm. the 3sfe bottom end (usdm) is garbage. very weak rods. (if you keep the stock computer): you cannot change timing, tps or afm (if you go megasquirt): you'll be spending all the money and headache for less than 10% gain. no ge engine part will bolt to it. if you really want a easy swap use a 2nd gen 5sfe (6th gen, camry, ect). its easy to do and readily available. the 3sge is a far superior engine to the f series motors. a proper ge can rev past 10K rpm and have over 200hp.
also exhaust wise the only header available is the pacesetter (fe) you cannot mill enough off the head and block to get 10:1 compression without compromising the quench area (and god only knows what else like finding a timing belt, head bolts, ect) if you want to see 140hp on a 3sfe, use NOS. a 50 shot will get you there easy. it wont last long.
Hmm, you're right. There's some misinformation out there that appears to come from the JDM GT having the 140 HP 3S-GE vs USDM GT having the 3S-FE. So the most powerful gen1 3S-FE(Europe) is 125/125 HP/TQ vs USDM 115/124 HP/TQ(a couple people have dynoed and seen more like 120/124). It appears the only differences are EGR, ignition timing, and ECU. I also read that the USDM's may run a little richer to aid the catalytic converter in burning off NOX, but it can be leaned out a tad by adjusting the cog wheel in the AFM. So it may not be in the ECU much, if at all. EGR block off, ign. timing adjustment, and AFM adjusment might bring it to about Eropean spec. I assumed the 3S-FE's lack of response to intake/exhaust upgrades was due to the ECU. But it's sounding more like head design is the limiting factor. I was hoping to use her 3S-FE as a Megasquirt learning experience, but if the gains are so small, I wouldn't even be able to notice any tuning changes. Looks like we should just find her or I a GTS. If it's an auto I can also install Megashift on top of Megasquirt to control shift points and custom install paddle shifters!
