When it first came out, the Lexus IS-F could be summarized by the classic phrase "close, but no cigar," especially in the suspension and steering departments.
This 2011 Lexus IS-F (and the 2012, as well) incorporates numerous tweaks meant improve the handling and steering while making the ride less brittle. It worked well enough that the boys in the office pronounced the reworked IS-F cigar-worthy after driving this one around a few days and testing it at the track.
Much of what Lexus did consists of invisible suspension recalibration, but it's worth a look anyway.
And you've probably figured out by now that these are homemade photos taken before we installed our new Rotary 2-post lift.
Like all Lexus IS of the current generation, the ISF rides on double-wishbone front suspension.
The upper wishbone (yellow) is made of stamped steel, while the lower one (green) is more of an L-shaped arm that's been welded up from several smaller pieces of steel.
Compared to the 2010 IS-F, the 2011 coil-over front springs are softer by 5 percent while the damping levels generated by the shocks are between 10 to 20 percent stiffer depending on what shock piston speed you're talking about.
The L extends towards the rear in the IS. The fore-aft component of larger impacts is turned through 90 degrees in this sort of layout, with a large-volume bushing is waiting at the far end to absorb them as in-out twitches.
We can also see hints of the aluminum front subframe that cradles the engine and carries the lower elements of the suspension.
From here it's a little easier to see the aluminum front subframe and how it is mounted to the body above.
Interestingly, the IS-F employs an aluminum knuckle (green) with a separate steering arm/ball joint carrier (yellow) bolted to the bottom.
This design makes it easy for Lexus (or some enterprising aftermarket company) to make meaningful tweaks to the front-acting steering geometry by producing a substitute piece with altered dimensions. In fact it is likely that such a change was made for 2011, but none of my Lexus contacts can confirm it.
We can't see the electric power steering head unit, but I have been able to confirm that its assist curves were altered for 2011 to produce more natural feel and feedback.
The 2011 IS-F uses the same front stabilizer bar as last year, and the arm of the electronic height sensor (yellow) piggybacks off it to measure body height for comparison with the other three corners in the ECU. This placement works because both of these move together in lock step with the lower control arm via a shot stabilizer bar link (green.)
On the right, the necked-down end of the shock absorber (black) suggests that these are twin-tube shocks, made by Tokico, as it turns out.
The wheel bearing and hub assembly contains the required wheel speed sensor, and the whole mess is held to the knuckle (aka 'hub carrier') with four bolts that make for easy service.
This close-up shows how the upper arm is made from light gauge steel that's been folded to give it extra strength. The high-mount arm placement keeps the loads low in the arm and the upper ball joint.
Six-piston Brembo fixed calipers and 14.2-inch ventilated and cross-drilled cast iron rotors handle the stopping chores. Cooling air comes their way through ducting built into the front bumper and grille.
These calipers feature an "open window" design with an easily removed bridge bolt for quick pad access.
Out back it's a multilink suspension with five distinct links and a coil-over shock,
A pair of upper links are splayed apart to approximate an upper arm while a forward link controls the toe angle.
Many of the rubber bushings contained within the end links we see here (and later down below) have been re-tuned for 2011 to make them stiffer laterally for precise wheel control but softer torsionally so the members move freely and don't bind so much to reduce harshness.
The inner end of the toe link features an eccentric cam for toe adjustment.
Like the top, two lower links work together to behave like a one-piece a-arm. The outer end of the rearmost lateral link (green) pivots on a spherical joint (pillow ball in JDM terms) for high lateral rigidity when cornering and almost zero torsional friction.
That main lateral link is beefed up like that because it carries the load of the spring and shock at a motion ratio of about 0.7-to-1 and the stabilizer bar at 0.5-to-1 or thereabouts.
2011 and later cars also benefit from a much needed increase in rear negative camber, which increases from negative 0.75 degrees to negative 1.5 degrees. Whether this was done by making the top links shorter or the bottom links longer is unclear. Because of cost it is unlikely that Lexus retooled or re-machined the aluminum knuckle at their outer ends or altered the subframe ears to which they attach at their inner ends.
The rear suspension height sensors (green) attach to the main lateral link using the same bolt that holds the stabilizer bar's drop link in place.
Unlike the front, the rear coil-over shocks are made up of monotube dampers, and the spring rate is unchanged from 2010.
Smallish-looking 2-piston fixed Brembo calipers put the squeeze on the rear rotors,
The rotors they grab are 13.6-inch ventilated and cross-drilled units. But the hat-section of the rotor (and a cable on the other side) indicates the use of hidden drum brakes for parking.
Finally, a Torsen mechanical diff resides in this housing. Before, a brake-based torque vectoring pseudo-LSD was employed, but there's usually a delay associated with that kind of system. No to mention that asking a computer to dab the inside brake when you're hard on the gas seems a bit counter-productive.
That system is still in place, but with a Torsen mechanical diff things go much more seamlessly as it operates more subtly in the background.
And all of it rides around on Bridgestone Potenza RE 050A summer performance tires. The fronts are 225/40R19 tires and 8-inch wide wheels that together weigh 49.5 pounds mounted and ready to roll. The rears likewise are 255/35R19 tires and 9-inch wheels that weigh 54.5 pounds.
These changes don't sound like much, but never underestimate the value of good tuning, particularly bushing tuning and shock valving. And that extra rear negative camber is nothing to sneeze at, either.
For me, these changes transform the Lexus IS-F from a boy-racer car with an aftermarket vibe that made it feel less than polished to a factory-tuned car that comes across like everything fits together and works as intended. I enjoy driving this car much more than its predecessor.
hondacura4 says:
05:10 PM, 12/21/11
Being that a high performance variant was NOT in the initial development stages of the IS I really have to give Lexus some credit as it is a worthy car. Many do not know that the IS-F concept was conceived well after the car was on the market. The next generation IS and ISF should be much much better in terms of performance and tactile performance. It should be more than able to at least match the 3 Series.
explorerx4 says:
06:09 PM, 12/21/11
I don't see the front suspension being a 'double wishbone'. More like upper 'Wishbone' and lower 'T'.
blackdynamite1 says:
09:09 PM, 12/21/11
An Epic Walkaround!
BD
gtrguy2012 says:
09:14 PM, 12/21/11
IS-failure. Does anyone buy this thing? I've seen 10 times more M3s on the road to these.
louiswei says:
09:21 PM, 12/21/11
I see 100x more 911s than... Ah what the heck...
cino_iconic says:
09:46 PM, 12/21/11
@gtrguy2012 Yeah, I've also seen 911 100times more than GT-R. What a failure Nissan product, right?
agentorange says:
09:50 PM, 12/21/11
I recently looked at the IS-F as a possible buy, but was put off by the interior. It comes in any colour you like, so long as it is black.....and EVERYTHING is black. The seats, carpet, dash and even the headliner. It is like being inside a black velvet jeweler's sack. I loved motor and all the toys, but I just could not take the interior, especially as I live in Las Vegas.
blackdynamite1 says:
09:52 PM, 12/21/11
I've seen the IS-F with an orange and black interior
BD
tempesting says:
01:50 AM, 12/22/11
Great car but with that money.. I'd probably look at somewhere else.
ptcdawg says:
06:55 AM, 12/22/11
Nice car.
Love the black interior, I have a black interior GS and it's fine. FWIW I also live in the humid south. ATL area.
duck87 says:
07:01 AM, 12/22/11
The ball joint carrier is actually a really good idea. If you're raising or lowering the vehicle, you can raise or lower the steering arm location to reduce bump steer, and even change steering ratios just by swapping that part out. The 4 bolts for hub to knuckle attachment is a really thoughtful touch- in my old car you needed to press the bearing out using a special tool, a PITA. The rear dampers still seem slightly compromised, as the damping ratio isn't close to 1:1- I'm surprised Lexus is using a coil over spring arrangement for this rather than separate damper and springs. The negative camber and reduced binding should really improve cornering quite a bit.
What is that little keyway in the rear rotor, marked with a yellow dot?
transpower says:
07:18 AM, 12/22/11
I like the Torsen LSD. But the bottom line is: what is the skid pad number?
gtrguy2012 says:
07:30 AM, 12/22/11
No one in the right sense would buy this over a 4 door M3. Come on seriously, looks, performance, quality everything.
fordson1 says:
07:53 AM, 12/22/11
I don't think that is a keyway - think it's something to do with the rear drum parking brake.
With the tire weights I can find, those wheels are 24.5 and 27.5 lb each, front and rear. That sounds like cast wheels to me. Lexus has always had nice quality wheels, but at this price point, this kind of vehicle, and especially in a case like this, where they were struggling with a handling/ride balance issue, forged wheels seem more appropriate.
@actualsize: Can you confirm those are cast wheels?
duck87 says:
07:54 AM, 12/22/11
@gtrguy2012: I'd buy one used... something I wouldn't do with any of the previous 3 generations of M3s.
louiswei says:
08:57 AM, 12/22/11
I'd buy one used over an used M3 too. Reliability is kind of important after the warranty period...
typer_801 says:
11:26 AM, 12/22/11
Another great walk around! The insight on changes from the '08 models is also very helpful for those of us considering a used IS-F.
Agree with others on reluctance to consider a used M3 due to reliability concerns, the IS-F may not be quite as stellar as a driver's car, but will likely be much cheaper to own.
exnevadan says:
11:55 AM, 12/22/11
this is the one new Toyota/Lexus car I'd buy with my own money (presently own a Sienna)
has to be far more reliable, especially long term, than an M3
certainly has most of the performance - sounds amazing too
bummer there's no manual
shaddai says:
12:57 PM, 12/22/11
I'm shocked a car of this "magnitude" has steel suspension parts...
shaddai says:
01:22 PM, 12/22/11
Given the price tag, I'm surprised this has stamped steel and not aluminum suspension parts...
csubowtie says:
03:12 PM, 12/22/11
I'm kinda suprised by the front suspension. I like that it's a double wishbone, but the control arms seem too cheap for a vehicle in this league. Which is funny, since it seems like the rear suspension would be excessively expensive, with 5 individual links each requiring some kind of bushing/bearing at each end, fastening hardware, and the time/cost it takes to install all those components.
BTW: This is the second time I'm typing this comment. Does anybody else have the problem where some of your comments just don't seem to show up?
sherief says:
05:58 PM, 12/22/11
Still just an 8-speed auto? Yeah? then it's M3 4-door for me every single time. Save the manuals!
sherief says:
06:05 PM, 12/22/11
As far as reliability goes, E9x M3 reliability reports prove that they have had minimal problems. Unlike the 335i, the M3 does not have direct injection, so it has no high fuel pressure pump or carbon deposits to deal with (the biggest knocks against the 335i).
Routine maintenance will be more expensive, naturally.
Even if it wasn't, and even if the M3 was only available with a flappy paddle gearbox, I'd still take it over the IS-F. Every single time.
city_ says:
07:19 PM, 12/22/11
Does anyone know if the changes in the MY 2012 ISF suspension will further improve comfort and ride? the euro and OZ spec will be getting "low-viscosity dampers made by Sachs to improve initial bump compliance while at the same time slightly stiffening the springs all round to ensure flat cornering." - do you think this would make much difference?
e90_m3 says:
08:43 AM, 12/23/11
"Haters are always going to HATE. I dont even need to go into the technical arguement about why the IS F is better than the Germheads and there OVER-RATED M3. Driven both, Own the Obvious, never looked back. Expect more from BMW though: they cost more $$$, they get MORE Maintainence Alerts, there are more M3's out on the road with sedans/coupes/hard-top convertibles and a variety of fobby asian, to older women drivers behind the wheel. Enjoy being associated with that crowd :)"
Geez, you dislike the M3 so much you need to offend people from two continents, as well as half of the world's population. The M3 is a car. It cannot care less whether you love it or loathe it.
You, my friend, needs help. Now.
e90_m3 says:
08:45 AM, 12/23/11
... and you are also offending the "fobby asians" who make the car you love so much...
fundango says:
09:29 AM, 12/23/11
Great walk-around, always appreciated.
@hondacura4 -- It is impressive that the IS 250 and 350 share the same basic suspension layout (double wishbone front / multi-link rear) as the higher-performance IS-F. Unfortunately that is only half the story when it comes to handling. Case-in-point: BMW is using a less effective mcpherson strut front suspension design on its 3 series, and the 3 series outhandles the IS 250/350. I'm not sure Lexus has the enthusiasts' mentality/philosophy necessary to make the IS into a true drivers' car.
ultimatemxcn says:
09:26 PM, 12/23/11
Glad they finally gave it a real LSD though it is probably too late.
When the ISF was introduced it carried more serious hardware than the current M3 yet it hat a fake LSD.... it didn't make sense.
leftlanedriv3 says:
09:19 AM, 12/25/11
AWESOME ride !
I love the ISF such a rare machine loaded with toys, luxury, tech and track performance AND you get Lexus relibilty !
I would pick this over a M3 in a heart beat.
Looks better, sounds better and the interoir is awesome. On car and driver lighting lap it put down the same track time as the M3 only sheep buy the boring M3... its like the civic of the class.
friendinthebiz says:
01:07 PM, 12/30/11
fordson1 and all,
The wheels are forged BBS, 19 x 8 front and 19 x 9 rear for 2011.
They have been enlarged to 19 x 8.5 (f) and 19 x 9.5 (r) for 2012.
One item published from Lexus as a change going into 2011 was a
revision to the rear subframe mounts as well as the EPS improvement.
A couple additional minor changes for '12 include Red replacing the
former Orange/Black seats, illumination added to the HomeLink garage
door opener buttons and the "VSC" traction control defeat moved from
the lower right dash to the lower left side (where the coin holder was).
A more meaningful change for 2012 for this forum is a change to Sachs
suspension dampers and further revisions to the suspension tuning.