TRDFantasy

This is just a simple analysis I am doing of the new 4.6L V8 compared to the old 4.3L 3UZ-FE.





As an aside, Lexus Japan lists the specs for the 4.6L V8 as being 283kW and 500Nm, which equates to 385HP and 369 lb-ft torque. Now, the Lexus Europe site lists specs at 280kW and 493Nm, which equates to 380HP and 363 lb-ft torque. Perhaps different tuning or slightly different standards, but it will be interesting to see final specs for US model.

Now, at 2000 RPM, the 4.6L is making about 116HP and about 310 lb-ft torque already. It's funny that some previews of the new LS mentioned the new engine had "lack of torque". At 2000RPM, this engine is already making about as much torque as the old 4.3L 3UZ-FE made in peak torque output at 3400 RPM. To compare, at 2000RPM, the old 4.3L makes about 108HP and 276 lb-ft torque at 2000RPM.

At 3000RPM, the 4.6L makes about 197HP and about 340 lb-ft torque. Meanwhile, at 3000RPM, the 4.3L is making about 163HP and about 302 lb-ft torque. Just as a curiousity, at 3400RPM, the 4.6L makes about 355 lb-ft torque. So compared with the 4.3L, the 4.6L makes about 14% more torque at the same RPM.

At 4000RPM, the gap only widens. The 4.6L at this point makes about 285HP and has virtually reached it's peak torque at this point, so torque is about 365- 368 lb-ft. The 4.3L makes about 217HP and by this point torque has already dropped to about 305 lb-ft.

Finally, lets compare the output of both engines at 6400RPM, and see how much "juice" each engine still has at such a high RPM. At 6400RPM, the 4.6L reaches peak HP of about 380-385HP. It also, incredibly, is still making about 310 lb-ft of torque at this point. The 4.3L on the other hand, is just about running out of breath, making about 250HP and a lowly 240 lb-ft torque. It's also quite evident how much racing technology and inspiration went into this new 4.6L V8.

Also, if you look at the accompanying 2GR-FSE graph, you'll see that it's HP curve is very similar to the 1UR-FSE's curve. That means Lexus designed this new engine to be more sporty, with a high HP increase as revs increased, yet maintain strong torque. Also we can see that the new 1UR-FSE was tuned a bit more towards HP than torque, again for increased sportiness. Whereas the 2GR-FSE has a very flat torque curve though, the 4.6L V8 has a "mountain" of torque, typical of a V8, designed to give that big torquey "punch".

The upcoming 5.0L V8 which will be first seen in the LS hybrid is for all intents and purposes a bored-out version of the 4.6L V8. This 5.0L unit is already being used in the Rolex Sports Car Series in race form. The torque curve for this engine should be even more impressive. I also personally think that in a few years this engine will be offered in the standard LS as an option, or possibly replace the 4.6L V8. Also latest rumours are that the upcoming Lexus supercar will use a high performance version of this 5.0L V8. If this is the case, it will be the perfect opportunity to showcase what the new 5.0L V8 can do, outside of racing of course.

Finally, here are some pics of the 1UR-FSE along with the accompanying 8 speed tranny:





EDIT: Speculation on upcoming 5.0L V8, and made a few spelling corrections.

XeroK00L

Excellent analysis, TRDFantasy!!

Hopefully C&D will do another performance test on a production LS460 and prove once and for all what this gem of an engine is really capable of.

Stevekil

Thanks! This seems to be an absolutely explosive power. Much better curve than M5.

Can anyone post the torque and hp bands for S-class and 7-series V8s (not V12s). I searched on google and could not find a link.

It will be an interesting comparison side-by-side. lexus may emerge to be a new lord of torque.

Steve

But Lexus needs a new diesel V8 and V12

flipside909

Because of the direct injection system, the valvetrain of the 1UR-FSE sounds exactly like those found on the 2GR, 3GR and 4GR-FSE powerplants. I wish I had taken sound clips of the LS460 from the inside at idle and WOT. Analyzing it on paper is one thing, driving it and experiencing the power in person is a whole different story.

Stevekil

great comment, but paper analysis is still needed to analyze. Enjoyment is more important though.

TRDFantasy

Some other members already posted some videos where you hear the roar of the engine, they're hidden somewhere in the LS reviews I think

omarg

Wow i wonder how my old 4.0 compares to the new engine. The new LS is gonna change the whole market again, 17 years later.

rominl

iTrader: (4)

wow, awesome review there trd, great stuff! i love how you put together the numbers and did the comparisons, very information

about the comment on "lack of tq", i guess maybe it' has to do with the weight as well. here we are talking about engine output solely, however we shouldn't forget the fact that the new ls is about 400lb heavier than the previous one. that's pretty big difference

GSsnarl

WHAT Can you post aa link to the videos please? I don't think I saw them!

vraa

iTrader: (2)

When it starts making 590lb-ft torque, than us Lexus folks can brag about performance, until then...

4TehNguyen

iTrader: (1)

so anything less than 590 ft lbs isnt a performance car, that basically rules out 99.5% of cars

vraa

iTrader: (2)

That's not what I said.
You'd credit yourself if you read and comprehended a little better. It'll do wonders.

spwolf

Is LS460 an performance car? I am curious, what makes 590lbs?

spwolf

new LS has better power to weight ratio than old one, at any time... question is only by how much.

I think in the case with mags, it is pretty simple - reviewer sees maximum torque at 4k, hence car does no have any torque before... which would be true if we were talking about 4cly engines and not V8's :-).

GFerg

A special edition S65 AMG. A lot of exotic cars dont even make that much.