1UZ Vs. 2UZ HP & TQ

[Lextreme II]

I have been studying the 2uzfe. Officially its rated at 245 bhp and 315 tq. However the pre 98 1uzfe is rated at 250 bhp with 260 tq. I wonder why is the 2uzfe is making such low hp? Would it be possible redline limitation? or the stroke?

Diagram #1: 2UZFE Engine Spec
Diagram #2: 2UZFE HP/TQ Curve
Diagram #3: 1UZFE Engine Spec
Diagram #4: 1UZFE HP/TQ Curve

 

[cebby]

I've always thought that when an engine is tuned for torque, there is a loss of HP. Plus, the 2UZ is probably also tuned for mid range power, not top end.

 

[Lextreme II]

Another interesting thing is the 3uzfe. Its rated at 300 bhp and 325 tq. However, the bore and stroke is slightly smaller. Possible the heads are little better for the 3uzfe.

 

[Toysrme]

All of toyota's trucks do that VS their car counterparts across history. basically since I've been alive.
The R's, the VZ's, the UZ's, the GR's...
It's the cam profiles. Toyota is conservative in all their cams across the board (Horribly so it seems).
The "problem" with the truck engines is that they have to get so conservative to give a potent low end, they have nothing up top, can't rev out & don't rev far. It doesn't matter in a truck. They have the gearing to take advantage of the shorter powerband. (In the same manner that it doesn't matter that a honda has no torque, they have gearing to take advantage of its powerband size).


It's all in the cams. From the cams, spawn every reason why the powerband is smaller.


If you change the cams to something more reasonable for what people here use them as (swap engines, i.e. not a truck engine) and pair management to suite the cams. Itll be a completely different engine.

 

[UZZ30-Québec]

The 3UZ has VVT-I, the 2UZ has not.

2UZ VVT-I has 282 HP. My brother has a 2005 Tundra and it's VERY torquey. I drove a dodge, ford and small block GM, all about 4.6 to 4.8 liter, and the 2UZ OWNZ them by a big margin. The throttle response is very good.

The 2UZ has lower compression
The 2UZ will probably have a more restrictive and smaller exausth system to improve backpressure.
The 2UZ will have soft cams for low-end torque
The 2UZ revs about 1000RPM less.
The 2UZ might have (didn't compare both) an intake to improve air turbulence (improved low-end torque)

Drive a 2UZ then a stock 1UZ, you'll understand that the response is a lot higher on the 2UZ.

290lbs/ft @ 1500RPM!!!

 

[WDoherty]

yeah lex, drive a 2uz and you'll see it has much more torque and response than an early 1uz. And in case you didn't know, early 2uz's (non-vvti) rated at 235hp dyno 200rwhp and early 1uz 's rated at 250hp dyno 180rwhp. There for the 2uz makes about 20 more rwhp or 25hp more and does it on lower compression and regular octane gas. The 1uz is overated from the factory and the 2uz is underated so if you switch the factory ratings around that is closer to the real numbers.

 

[Nick M]

It's the cam profiles. Toyota is conservative in all their cams across the board (Horribly so it seems).
The "problem" with the truck engines is that they have to get so conservative to give a potent low end, they have nothing up top, can't rev out & don't rev far. It doesn't matter in a truck. They have the gearing to take advantage of the shorter powerband. (In the same manner that it doesn't matter that a honda has no torque, they have gearing to take advantage of its powerband size).


It's all in the cams. From the cams, spawn every reason why the powerband is smaller.


If you change the cams to something more reasonable for what people here use them as (swap engines, i.e. not a truck engine) and pair management to suite the cams. Itll be a completely different engine.

Yep. They are tuned to produce max torque down low, not max torque on top.

 

[jibbby]

I found this thread to be informative...

Besides the obvious differences between HP and torque one must factor in the stoutness and strength of each motor..

What I do know is that the pre 1995 1uzfe motors can handle the most power out of the bunch (3uzfe's excluded) when boosted and have been proven to handle as much as 500whp with the stock internals.. Not so in the later model uz's.. Go figure?

Did Toyota over build the early model 1uz-fe motors early on and then realise this?.... As stated many times in previous threads the rod strength declined after 1995 in these UZ motors... Toyota should have known people like us on the forums would like to boost these motors and push them well over the stock limits...... Shame on Toyota as they designed the weaker internal motors thru the years that would produce greater and more powerful HP and Torque numbers year to year... That just doesn't make sense to me...

This is for the people that have never seen this rod diagram...


On a side note - I am really curious as too how much HP's and torque the stock 3uzfe motors have been reported to handle with those forged stock rods? Anyone got an idea? They look more stout then the pre 95 rods which leads me to believe the 3uz-fe may infact be more stout then the pre 95 1uz-fe's motors.. Hmmmm?

 

[cribbj]

This is for the people that have never seen this rod diagram...


On a side note - I am really curious as too how much HP's and torque the stock 3uzfe motors have been reported to handle with those forged stock rods? Anyone got an idea? They look more stout then the pre 95 rods which leads me to believe the 3uz-fe may infact be more stout then the pre 95 1uz-fe's motors.. Hmmmm?

John, it's been noted many times that the early (pre '95) rods from the 1UZ are the strongest of all the stock OEM rods. Both the 2UZ and 3UZ rods have puny crossections by comparison.

I'm sure you know that the rod pictured on the far right in that pic is the Lextreme aftermarket forged rod, not a stock OEM rod?

You may want to restate your question, as it's confusing.

 

[ed_ma61]

what the?

ok jibby, ya lost me. and btw - none of the oem uz rods are forged

 

[jibbby]

Ahhhhh - I had thought maybe the rod pic to the far right might be a latest model stock 3uzfe forged rod..... Now it is clear to me that it is a Lextreme creation and not a stock 3uzfe forged rod... Thank you very much...

Thanks for the clarification fellas... At times we can all get confused and delusional...:beerchug:


So then this confirms to me that the early model 1uz-fe motors pre 95 are more capable of handling more horsepower in stock form then the lastest model 3uz-fe motors. WOW....

 

[scotturnot]

Yep, lost me too.

 

[Lextreme II]

FYI,

Tell your Lexus buddies that we are offering a GP on the rods for $400 a set. Special expire on Oct 1, 2008.

http://www.lextreme.com/Forged-Rods.html

Ed,

Do you mind posting that in your site? Perhaps CL members can benefit too. Please all 15 weeks for delivery.

 

[ed_ma61]

no problemo, PM sent

 

[Tacoma_Kyle]

You do know that HP is a function of a engines torque at a given rpm, right?

What's the RPM, 5252 when HP and torque are ALWAYS the same? After, HP is greater than torque. Before, HP < torque.

2UZ's have a bottom-end tune because they are meant for work over street speed. If the peak output (torque) is in the 3-4k region, then the max HP number will probably be smaller. Also partially because truck engines are generally over stroked (in comparison) and longer stroked engines are simply more difficult to wind higher. More crank mass + more distance moved per rotation = more time per rotation + more energy needed to make it wind higher

 

[XR8tt]

In this case the stroke is the same..
Lighter rotation mass for quicker throttle response and power on latter model engines...

 

[cribbj]

what the?

btw - none of the oem uz rods are forged

Ed, you & I discussed this point awhile back. The OEM rods are not forged in the traditional sense, but Toyota does state in their technical literature that they're "....sintered and forged...." And what they mean by sintered is the powdered metal forging process.

By using the PF process, they can achieve more consistent manufacturing, reduce scrap, reduce finish machining, and improve their QC/QA. Powdered forgings also have a more predictable level of failure, so the designers can optimise their designs (OK, reduce their safety factors).

So although they don't have the grain structure nor the strength of a traditional drop forging, they're a huge improvement from the box stock non-forged rods that other engine companies put in their motors.

This is the only reason I keep making the distinction, because it is technically incorrect to keep saying these are not forged rods. Are they traditional drop forgings? No. Are they "not" forged at all, and only castings? No, not at all; they're in between those two extremes, and for some applications, the PF is actually superior to the traditional forging.

And this is straight out of the Toyota TIS about the 1UZ's rods:

 

[ed_ma61]

blah blah blah, ok so a forging die is used in their manufacture. technically correct

but you know as well as i do that the term "forged" when being tossed about carries a certain implication of material strength - based on the assumption of load axis grain orientation

no grain axis = not worth sh1t for stressing and high cyclic loading

to compare powder sintered rods to plain cast rods and to say "at least thyre better than that" - well i hope so!

lol - i like toyotas "very rigid" description. and as much as everyone here likes to piss and moan about these images, it certainly supports the rod's rigidity!! zero plastic deformation there!! kaboom!!

 

[JBrady]

blah blah blah, ok so a forging die is used in their manufacture. technically correct

but you know as well as i do that the term "forged" when being tossed about carries a certain implication of material strength - based on the assumption of load axis grain orientation

no grain axis = not worth sh1t for stressing and high cyclic loading

to compare powder sintered rods to plain cast rods and to say "at least thyre better than that" - well i hope so!

lol - i like toyotas "very rigid" description. and as much as everyone here likes to piss and moan about these images, it certainly supports the rod's rigidity!! zero plastic deformation there!! kaboom!!

Yep, rigid like glass.

 

[turboandrew]

non-vvti 2UZ motors don't have dual runner length intake manifolds either which probably makes a difference. However, IMO, cams are the biggest difference.