Manoj

How fast did you think IS-F is from the second video showing 40 to 85mph from 2.20 to 2.11 ~ 9 secs????

In the below Video :

YouTube - speedometer

M3 goes from 40-85 in like 6 secs


Is Lexus sand-bagging in that video ?

Nextourer

one's a concept and the other's a production car?

TRDFantasy

I timed the video and I got 60 - 85mph in 7 sec. Also keep in mind that video is taken while they are lapping the IS-F around Laguna Seca. They may not have been on a totally straight piece of track., or the car may not have been at full throttle. It's hard to say.

Also VDIM was on "Sport" mode. Maybe Sport mode might not be the best mode for straight-line acceleration.

TRDFantasy

I should also mention titanium valves allow for higher RPM due to their lighter mass, and they also reduce friction inside the engine improving efficiency and fuel economy. Titanium valves should help the IS-F beat the gas guzzler tax without sacrificing engine power too much.

RXSF

"F is everything you thought we werent" that is the tagline they should use in all their commercials. that is brilliant marketing.

lobuxracer

iTrader: (2)

That's a real stretch. They also conduct heat away from the source very nicely compared to steel which contradicts high thermal efficiency and good economy. There is a reason the SR-71 has a titanium skin.

TRDFantasy

I'm quite sure Toyota knows about the material properties of titanium. Chances are they are using a coated titanium alloy that minimizes heat conduction away from the source. Fuel economy improvement at most would be 1-3%. Not much, but combined together with the 8 speed transmission and other improvements it all adds up and makes it easier for Toyota to beat the gas guzzler tax without comproming power that much.

We also don't know yet if titanium or other materials are used in any other parts of the engine. Toyota could be using titanium valve springs, who knows.

One thing that's not a stretch is titanium's increased reliability and durability over steel valves, as well as the dramatic reduction in weight compared to steel. This will mean a lighter valvetrain, giving the ability for the engine to rev more freely (also due to reduced friction). A lighter valvetrain will put less stress on other components, such as the timing chains. Less friction also leads to improved fuel economy.

Mr Johnson

Care to cite a source for a swap to titanium valves offering a 1-3% improvement in fuel economy? If it were that simple I would expect a lot more cars to make that switch.

Carbman

Yes, and it reduces the linear inertia making the engine more responsive, in keeping with one of the engineering team's primary goals.....to enhance the instantaneous SENSORY experience of driving......and isn't that what driving pleasure is all about, what you sense in the moment and not what the stop watch says after the fact. The light BBS wheels also add to the sense of union between man and machine by reducing the rotational inertia resulting in less lag between pressing the peddle and feeling the acceleration.

Any doubts I had about this car dissipated when I saw the picture of the chief engineer with his helmet resting on the hood of his track car. One look at his face and it is obvious that he is a samurai who takes no prisoners.

TRDFantasy

It's mainly my own estimation. Coated titanium alloy valves will be much lighter and have reduced friction compared to steel valves. Less energy or force will be needed to move the valves, and combined with less friction will result in better fuel economy (my estimation 1-3%). Using an alloy and coating the valves will minimize or even negative some of the natural properties of titanium that would reduce engine efficiency.

Here is a link that talks about both titanium valve springs and valves, and gives a different estimate in terms of fuel efficiency improvement:
http://www.azom.com/details.asp?ArticleID=553

Also, the reason why titanium is not used more often in engines is simple: cost (and secondly complexity). Titanium is limited to race engines and high end cars due to the high cost of the metal itself as well as the complex engineering and manufacturing that goes into making titanium components, which is also costly.

I agree. This will make the engine feel more responsive and more "raw" to the driver. Just watching the videos on the website shows how freely the engine revs, and how raw the engine sounds.

lobuxracer

iTrader: (2)

Lots of speculation based on material science. Ti is a great material, but I wouldn't use it in a production vehicle for springs. Ever. I wouldn't use it for valve spring retainers in a production vehicle. Ever. I've seen Ti retainers fail in service in racing engines when steel did not. Sure it's lighter, but it frets more, and it fails sooner in valve spring retainer duty.

Ti is not particularly more durable than steel, and this is just one of the reasons you don't see Ti valves from the OEMs. Material cost and difficulty of machining are also reasons you don't see Ti in production engines (except in connecting rods in a very few applications where it is far better suited to the task.) Valves take a HUGE amount of abuse. Ti valves are a PITA to face or trim because conventional stones don't work well on Ti, so you have to use softer stones that wear faster, so the cost more and require facing more often than stones used on steel.

There are LOTS and LOTS of reasons why we don't see Ti valves in high volume production engines. It will be interesting to see how Toyota addresses those shortcomings with the 2UR-GSE.

TRDFantasy

Ti is almost never used in pure form in engines. It's almost always alloyed to another metal and often coated.

I respect your knowledge and experience lobux so I won't argue on the durabililty and reliability of titanium alloy valves vs steel valves .

You're right about one thing: LOTS of reasons why Ti is rarely used in engines.

We definitely will see soon enough how Toyota addressed any shortcomings of Ti in the 2UR-GSE. We will also see if any other parts of the engines used materials other than steel or aluminum. It's very likely there will be a long press release discussing in-depth the 2UR-GSE, not to mention technical documents from TIS.

Ramon

We already know that the redline for this engine is 6800 RPM's which isn't high at all, infact, it's the lowest out of the competition (C63, M3, RS4)

TRDFantasy

You're right. My point was that at redline, the IS-F should be quite efficient due to a light valvetrain and should still be making lots of HP and torque, and if you allow the engine to rev higher, the engine will continue to make HP and torque no problem.

We already know that if allowed to rev higher, the 2GR-FSE continues to make HP and torque, and that engine does not even use titanium valves. The 2UR-GSE should be even better than the 2GR-FSE at efficiently making power at high revs.

Out of the competition, the IS-F could quite possibly have the most technically advanced engine. Electrically controlled VVT on the intake side, direct and port gasoline injection, and titanium valves. This is considering we still don't know everything yet about the 2UR-GSE, while we have full specs on the competition.

Ramon

That may be true, but the bottom line is going to be it's performance against it's competition. I don't see it performing as well as the C63. That in itself isn't very surprising given the C63's significant displacement advantage. However, I don't see the IS-F responding to performance mod's as well as the C63 either. If we go by the preliminary reports, coaxing 500HP out of that motor (C63) is said to be mere childs play.