What makes the pre 98 1UZFE inferior to its younger brothers

[Lextreme II]

The stock first generation 1UZFE is rated (US Spec in bhp) 250 bhp with 260 tq and the later engine with similar size is rated at about 300 bhp and 310 bhp. They are both have similar cubic but the later model makes alot more hp and tq. What makes the VVTi some powerful and so desireable.

1. Head flow rate?
2. Cams?
3. VVTi?
4. Valve size?
5. Others

If that is the cast what do we need to do to make the first generation 1uzfe up to 300 bhp without make mods?

 

[bango]

Good question...Higher compression,better head flow,and better headers...valve sizes im not sure..

 

[MWP]

All the above.

The VVTI 1UZ is quite a different engine from the earlier 1UZ.

 

[ed_ma61]

better flowing ports
better intake manifold
+90mm throttle body
TVIS
+1mm valves in and ex
5.5mm valve stems
SUB lifters
(ie lighter valve train overall)
higher compression
vvti

wheres the comparison? as MWP says - its a different engine

 

[Toysrme]

Ok. So I downloaded all the FSM's for it. Like I said it's mainly the cam profiles.
The exhaust cam remained the same. The intake cam went from 232* duration to 230*. Lift has been added on the cams. (0.01" for each) The differance being that the intake cam can spin an extra (maximum)*20 of advance/retard. (Retard accounting for alot of the past pre '97 horsepower peak gain, i.e. the not so fast fall off.)
Valve size increased to 34.5mm(33.5) intake, 29mm( 28) exhaust. (Hey that's been the v6 valve sizing since '87) Valve stems shrunk from 6mm to 5.5mm.
Sissors gear moved from center of cam to front of cam.

The intake manifold gained ACIS. (Which we v6 owners hate. Yall have the type of system design we should have...) A good portion of the horsepower Looks to come from the ACIS that actually works.
You can see the bump of the ACIS flap going from closed to open to shorten the runners in the provided dyno.

***Modification opportunity***
Toyota is sorta like Honda when it comes to ACIS/Vtech. We v6 owners find that the ACIS activates abit too late. By activating it earlier, you can get a few horsepower for a few hundred rpm where you wouldn't have it. No big deal.


Intake manifold gasket is multi-layer steel, with a composite core to reduce heat soak to the manifold. (Think cheap OEM insulating gasket. I use to sell them to the v6 guys for $15 a pop made out of 1/4-3/4" aircraft ply. Mine worked... Heat soak was markidly reduced after a 1/2 hour of run time, in the order of 15-25c on my CompUNurse.)

The compression bumped 0.1 CR (10.4:1 to 10.5:1).
Intake ports were made more upright.
Combustion chamber & piston face change to tapered squish.
Air assist was added to the injectors (dang we had that in 92)
Injectors went returnless, 50psi and 4 hole.
Direct ignition
Muffler change (longer tail, but the schematic of it looks like it has better bends in it...)


That's for the 98 LS, the 98 GS seems to only really differ in having the slightly better style exhaust manifold & straight through resonators.
A 3 stage electric cooling fan, 3 stage fuel pump & the fuel pump was moved in take to a jet version.


That's about it AFA I can tell by readng the papers & outlining it. But it's pretty much just the cams. Take your pre '98 cams, retard them 20*, and you'll likely have shifted alot of the powerband up top.







I can tell you, the similarites at reading the v8 papers to the v6's I work on all the time is huge. Reading them more in-depth, Personally, It's like looking at the 94, 97, 98, 01 1mz-fe's & the 03 3mz-fe. The parts look nearly the same construction in the drawings. The feature lists of constructio & modifications are the same. The dimensions for various parts of note are the same, if not very similar.

The cam profiles are within degrees of each other... The lifts are the same terrible sizes...
For instance. All the 1uz exhaust cams differ from my engine's only by 1* of duration. Doesn't mean the profiles are about dead wringers, but there you go...

It's 4am. I've been on techinfo for way to long. Have a good one.

 

[ed_ma61]

i think youll find its actually TVIS rather than ACIS

ACIS is the mid plenum type butterfly varying plenum volume aka 7mge/2jzge

the vvti 1uz runs the 8 individual butterflies mid intake tract shortening the harmonic length - ie TVIS. same/similar to the variable tuning harmonics of the 4a and 1g series

 

[turboandrew]

The biggest factor, IMO, is probbaly the vvti. Just look at what vvti did for the 2UZ, which probably did not change much between 2004-2005. It jumped from 235 HP to 285. Not sure if the 2005 2UZ got the variable length intake, but that could help a lot as well.

 

[bango]

Beside the power factors,are the internals the same?ie same size connecting rods? 6 bolts mains etc?

 

[JBrady]

In addition to the above mentioned improvements the LS and the GS had nearly identical exhaust manifolds. The LS go this style in 95. The SC400 kept the same lousy exhaust manifolds from 92-00 with the exception of no EGR after 97.

The intake manifold is MUCH better. The TVIS is a very good design and the actual overall manifold design is superior to the 89-97 design.

Compression is improved as is quench/squish design.

Cylinder heads have much better intake ports that are fed by the much better intake manifold. These ports are more up and down vs. the lay down design on earlier models.

Not certain when the connecting rods were lightened but they are in 98+ vs original design. This makes for a lighter reciprocating assembly but also a weaker design for forced induction or nitrous applications.

To improve the earlier engines you need to make them breathe better. Swapping 98+ heads and intake assembly along with matching pistons, headers and an ECU system to control the TVIS and possibly the VVTi.

Personally, I am not a huge fan of the VVTi design. There are aftermarket cams now available for the 2UZFE that MAY retrofit into the 98+ heads. The 2UZFE was not a VVTi engine (at least earlier engines) and coverting could eliminate the VVTi and gain aftermarket camshaft profiling.

This is all fairly unproven ideas but I feel the early engine can be built to exceed the 98+ engines STOCK output.

 

[Lextreme II]

John,

Great info! From what I examined the pre and post 1uzfe block. Its identically the same. However, the mains are little beefier in the post 98 then the pre 98. Secondly, the post 98 have skinnier rods then the older brother. The pistons design is different in the pre vs post. One way to improve performance on the early UZ would be change the post 98:

* Pistons
* Heads
* Upper and Lower Intakes along with accessories
* Engine Harness
* ECU

Basically you need to find a blown post 98 engine (thrown rods) to do that. What are other ways to accomplish this goal with the existence heads and intakes?

 

[Toysrme]

It's not TVIS, it's ACIS. TVIS has seperated runners of differing lengths in the heads / manifold that are opened & closed.
ACIS simply has a normal runner of long length, and in the pleumn chamber, there is a flap<s> that let the air flow mix earlier than the start of the runner. There by shortening it.

Personally, I am not a huge fan of the VVTi design.

I'm not either. It's nothin more than a way for Toyota to get rid of EGR (Which I'm all for), and keep from putting descent cams in a vehicle. I will say that I would love to see a set of reground cams for a vvt-i v6/v8 on a dyno. It would be interesting. Then if you don't like the outcome, disconnect the vvt-i oil pressure sensor electronics.

Just to make another v6 corrilation:
We jump from 230-232* cams to 272* cams with 0 torque loss at 2500rpm (We can't dyno any lower with our A/T, nobody wants to risk burning the torque convertor clutch by locking it).

 

[Toysrme]

Basically you need to find a blown post 98 engine (thrown rods) to do that. What are other ways to accomplish this goal with the existence heads and intakes?

Looks like mildly ported head & a good valve job. I'd bet money from my experiances on similar Toyota engines, if you did a good P&P witha valve job, you'd push that peak power up there & keep the stock cams from falling on their face so fast.
From there, your typical light mods would likely make up any differance left.

Make a new intake manifold.
If you're staying N/A shoot for around a 2.4L pleumn volume, FI, as big as you can within reason. (4L+) Obviously, if you go to the trouble making a new intake manifold. You might aswell get on ebay & snag a 90mm q45 throttlebody like everyone else is doing.



Anywho, That's how I would attack that if I was given one tomorrow. & if that plan didn't hit atleast the target power. Out would come some regrind cams & the Toyota valve shim chart.

 

[ed_ma61]

It's not TVIS, it's ACIS. TVIS has seperated runners of differing lengths in the heads / manifold that are opened & closed.
ACIS simply has a normal runner of long length, and in the pleumn chamber, there is a flap<s> that let the air flow mix earlier than the start of the runner. There by shortening it.

my point precisely - there is NO butterly IN the plenum, the butterflies are on the runners and shorten the runners directly - this is not the typical function of the ACIS system. by design the 1uz manifold doesnt needs individual sets of runners to achieve variable intake management, it can achive the variable length induction system by the intelligent placement of the butterflies in the runners.

there is no plenum harmonic/acoustic change in this setup at all

TVIS - toyota variable intake system
ACIS - acoustic controlled intake ststem - ie 7mge/2jzge plenum

perhaps toyota calls this 1uz intake harmonic management/length change ACIS but it certainly isnt in keeping with the typical ACIS tuning theory

 

[ed_ma61]

If you're staying N/A shoot for around a 2.4L pleumn volume, FI, as big as you can within reason.

what are those recomendations based on??
thats very counter intuitive and goes against many engine/plenum designs ive seen

 

[ed_ma61]

It's nothin more than a way for Toyota to get rid of EGR (Which I'm all for), and keep from putting descent cams in a vehicle. I will say that I would love to see a set of reground cams for a vvt-i v6/v8 on a dyno. It would be interesting.

having seen pre and post functioning vvti (with non vvti and vvti specific profiles - around 256@ .050" and .500" lift) in a beams 3sge i can assure you than the fattening of the midrange found with the vvti makes it an entirely worthwhile venture.

 

[sideshow]

sss said they have a vvti 1uz coming in if i didnt buy a house recently i would have probably bought it and fitted it to my hilux

but when they do get it in ill go check it out

i think they got all the wiring etc with it too

 

[ed_ma61]

mos has already bought it

 

[Toysrme]

what are those recomendations based on??
thats very counter intuitive and goes against many engine/plenum designs ive seen

I'm not sure why you'd think that. Most of the mathmatics used to size the runners (length / area & volume), along with plumn volume all dictate the same rough stats & rules.
The larger the surface area (port) on the intake tract, the slower the velocity (Worse for low/mid range power), the less restrictive at higher flow rates.
The longer the runner, the lower the rpm the acoustical charging happens at.
The plumn, and runner volumes should be enough to feed a combustion chambers appetite N/A.
The larger the pluemn in FI to store the compressed charge, the better.


I'm sure there are acceptions, but that's how I've always understood it & calculated it myself.

 

[ed_ma61]

ok - example: trd gt300 3sgte plenum (FI)

versus, say, toyota's NA champ and F1 engines:

http://www.overclockers.com.au/~mwp...38950235.ChampEngine1.jpg&tp=1&ax=1264&ay=864
http://www.overclockers.com.au/~mwp...05/38950253.F1Engine1.jpg&x=1258&y=855&fill=0

 

[Smitherz]

Posting pictures of awesome engines that we cannot ever have shouldn't be allowed.