Why the 3vz-fe is superior
It's OBD-I ECU is the least trouble code throwing, least caring ECU in the line-up. 720cc injectors have been tuned to run acceptably on an N/A 3vz-fe. It does not throw/store codes from O2 sensor feedback - even if it is massively different. Black smoke rich to engine melting lean. It doesn't care.
1mz-fe's have horrible, over sensitive knock sensor problems. 3vz-fe's do not.
Fuel and Ignition
Like running a mild turbo, or N/A without much in the way of fuel/ignition tuning? The 3vz-fe has the large Denso AFM, and a distributor. Stock, off the bat leaning the AFM cog & adding 7* of timing (17*btdc base) advance puts the 92-93 3vz-fe 185bhp to the 94-97.5 3vz-fe's 200bhp.
200cc stock injectors are Bleh. But with a combination of a walbro 190+, FPR, and either an extra injector, or larger injectors (330cc @ 41/43psi), you can run up to 300bhp out of one without touching the ECU if you don't want.
Yes... You can install a FPR, 550cc's, and a Walbro 255 & use the AFM cog to tune over 350bhp... all without a piggyback. it has been done. You will need lots of money -- the car will be running very rich.
The 3vz-fe ECU is very accommodating when it comes to closed loop changes. Don't like the fact that a normal ECU likes to run stoich under boost until open loop? 3vz-fe's are not prone to tuning such changes out. If they do, we have it covered with $10. A relay +wire
3vz-fe also has a neat ability, transforming it into what essentially stand alone.
Run the TPS's output (VTA) through one side of a double pole double throw (DPDT) relay. Take the 5v TPS/AFM supply (VC). Run this through the other side of the DPDT relay.
Trigger the relay however you want, when you want to enter open loop mode. Be that all the time, a $3 ebay boost pressure switch, or an output for your piggyback.
Because of it's ability to run massive size injectors compared to stock, it doesn't care!
OBD-I > OBD-II
2)the one fuel trim change do not continue through open-loop
Afraid you'll miss OBD-II's anal retentiveness for troubleshooting?
The 3vz-fe has you covered. Tho the '94 1mz-fe had the world's first complaint engine/ECU, the 3vz-fe's do have an ace up their sleeve.
Diagnostic mode II. Yes... The 3vz-fe is the only v6, and one of two OBD-II Toyota's with DIAG2! This can't even be entered with the ECU OFF! It has to be done with the engine running! It will throw every code possible instantly. Guess what happens when you trigger it & you're not moving more than 6mph? Yep, wheel speed sensor code. All your temp & o2 sensors haven't warmed up? Ya - count all them too. Along with a half dozen other codes.
Anything triggers anything in DIAG2.
All MZ block engine's have a 139mph hard speed limit.
All 3vz-fe's have no limit... You need power VS Aerodynamics to do 190mph.
The 3vz-fe itself is *highly* resistant to detonation. Many times more than a 3vz-e, 1mz-fe, or 5vz-fe is. The most resistant to detonation of any of the v6's. I have personally run 22* of maximum advance over 6000rpm with my SMT-6 with no pinging. On Chevron 87.
Another ported & polished 3vz-fe went to a drag strip to test ignition timing. A base timing of 20* (stock is 10* universal to all v6's/normal Toyota engines) produced no pinging, but poor performance. On 87 octane.
The 3vz-fe has the strongest stock rods used on any v6. They are massive.
Huge... Iron... Block... We don't need sleeves, we don't need block work to lay down 600whp. It's too similar in construction to a 3000GT's v6 not to say maybe even 900bhp+.
Other than the cast pistons, the 3vz-fe is stronger part for part than any other v6. It has yet to be seen if the biggest stock 3vz-fe can take down the biggest stock 5vz-fe. Why?
Because Neither Sean, nor I have set out to do it yet.
Like oil? 3vz-fe's don't. Yes, even 3psi at a cold idle is in spec... If you're not on the gas, they don't have a ton of oil pressure. This is great for turbo life.
FYI Camry 3vz-fe's have no oil pressure sensor installed while ES 300/Windom's do.
As long as the red light of death is off - you don't have an oil problem, no matter HOW bright the yellow low oil level light is! (That's an inside joke. I killed my OLS when I installed my turbo oil return somehow.)
3vz-fe redlines a 6850rpm, and the fuel cut is at 7100rpm.
Toyota RPM gauges read very, very slow I have logged my engine at 7400rpm on my SMT6... A 5vz-fe would come apart at that rpm without cams, valve springs & other work. Not us. (We have very diminishing power on stock cams after 6000rpm, however it's best to shift at 6500-6900rpm to stay in powerband)
We don't waste money on cams... Our engine has the biggest powerband (except maybe a 5vz-fe) under 3000rpm. We have OVER 100whp at 2000rpm. Yes... That's right... Only a 3vz-fe has the power to spin tires on the Camry platform!
We get HUGE gains from head porting!!!
Seam McElligott got 30-35bhp.
I did my MYSELF and got 25-30.
A Camry owner had his done and got 25, possibly 30.
What do cams do on a 3vz-fe? Turn it into a 1mz-fe! <BLAH!> A cammed 3vz-fe made 220bhp on an MR2 with zero powerband.
We make 220bhp off P&P light N/A tuning, & a y-pipe... And still have the massive low rpm powerband.
The fully built N/A 3vz-e's made 320bhp.
A fully built N/A 3vz-fe should then make 370bhp. Hey... If two extra valves are good for 50bhps tock, they should be worth it built too!
The downside is that the 3vz-fe has stock cast pistons. Not a problem when you run the correct amount of fuel, however 1mz-fe's ahve cast pistons WITH a coating. They are minutely stronger (I say minutely because no 3vz-fe has hurt it's bottom end, stock 1mz-fe's have melted rings & pistons by running slightly lean at lower power levels than have been achieved by 3vz-fe's)
Despite what anyone says, the 5vz-fe has one important edge. Displacement... 11.7% displacement advantage will ALWAYS equal an 11.7% power advantage when comparing the same basic setup.
If you have money, this doesn't matter. A source once had a machinist calculate how far you could possibly stroke a 3vz-fe. 3.7L. The supposed kit that was coming from that was going to cost $4000+, and stroke to 3.5-3.6L.
I've worked on them all. Had a hand in one turbo 3vz-e, then turboed another from scratch. Turboed mine a few different odd ways so far. Rebuilt my 3vz-fe more times than you will ever want to know. Worked with 1mz-fe's & worked on 5vz-fe's.
3vz-fe JDM's have no EGR. US's can be throw away & blocked off. 1mz-fe1's? Nopers!
3vz-fe's have EVAP, but don't care if you throw it away. 1mz-fe's? Nope!
3vz-fe loose their 5-10bhp from carbon over a few years. 1mz-fe1's have HORRIBLY over used EGR systems. What a 3vz-fe builds up over a few years, a 1mz-fe1 builds up in 9 months. Guess what, that new 1mz-fe you bought? if the entire intake track hasn't been cleaned in the last 9-12 months, you can subtract 10bhp.
3vz-fe's are non-interference. 1mz-fe1's are also, 1mz-fe2's are not.
My 2 favorite demonstration pictures of all time.
Don't think that's important? I destroyed my first OEM timing belt doing a top speed run when I got to 143mph, but still made it home.
I split my second within min of if running the first time. Shutup. They were installed correctly...
Is a 3vz-fe perfect? No. is it more perfect than everything else? Yes.
It's the pinnacle of old & new engine design & controls when it comes to tuning.
SMT-6, or SMT-7's kick other piggybacks's asses.