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Discussion Starter #1 (Edited)

If any recent Lexus model especially exemplifies the historical Toyota spirit of Kaizen, or continuous improvement, and the Passionate and Relentless Pursuit of Perfection, it's the IS F sports sedan. Debuting in the 2008 model year to fairly lavish praise, the IS F was nonetheless lambasted for an overly stiff ride and the lack of a proper limited-slip differential, relying instead on a recalibration of Lexus' VDIM (Vehicle Dynamics Integrated Management) suite of electronic nannies to create a "virtual LSD" effect. And, indeed, the effect was somewhat hallucinogenic or illusory, for chief among the 2010 IS F's improvements was the addition of a mechanical Torsen limited-slip differential. As to the harsh ride, the 2011 model year saw numerous improvements, tweaks and revisions to the electric power steering system, front and rear spring rates, shock absorber dampening, rear bushings and rear camber angle, which were detailed in <A HREF="http://my.is/forums/f41/more-2011-lexus-c-f-questions-answered-418884/">an earlier my.IS Front Page story</A>.

On paper, of course, these improvements should result in a better-handling, more track-worthy IS F. But is this really the case? Car and Driver magazine, in a very interesting comparison, proved conclusively that this is the case. For five years running, the magazine has been conducting the Lightning Lap comparison tests at the Grand West Course at Virginia International Raceway (VIR), near Danville, which, in C&D's words, is "a serpentine 4.1-mile circuit that is the nearest the U.S. has to the ultimate racetrack, the Nürburgring Nordschleife in Germany". The Lexus IS F's first Lightning Lap was in 2008, when it joined a whopping 15 cars in Car and Driver's LL2 class, defined as vehicles with a Manufacturer's Suggested Retail Price ranging between $30,000 and $59,999. The 2008 IS F reported a mid-pack 7th-place finish, with a 3:14.0 time around the track (that's 3 minutes and 14 seconds to the uninitiated) at an average speed of 77.9 mph. Embarrassingly, this put it behind its archrivals BMW M3 Coupe (3:05.6 time / 81 mph) and Mercedes-Benz C63 AMG (3:06.5 time / 81.1 mph). While praising the 2008 IS F's habit-forming aural accompaniment, grip and powerful, consistent braking, C&D noted that "at high speeds, particularly in VIR’s climbing esses, the IS F’s behavior morphs from eager to darty, eroding driver confidence...steering inputs were a bit dramatic and... A little attention to springs and damping might make this eager contender a real champ".

Lexus listened, and, three years later, returned to Virginia International Raceway to face a far smaller LL2 class of five rivals. This go-around, the 2011 Lexus IS F beat the Mazda RX-8 R3, Subaru Impreza WRX STI, Mitsubishi Lancer Evolution SE and Ford Mustang GT 5.0 with a time of 3:05.4 seconds at 79.6 mph. In the 2011 LL2 class, only the Ford Mustang Shelby GT500 was faster than the IS F. For the number-crunchers among you, that makes the 2011 IS F a whopping 8.6 seconds faster per lap than the 2008 version, maintaining a 1.7 mph faster average speed in the process. The numbers only begin to tell the story, though. As excerpts from Car and Driver's write-up inform us:

Lexus has...tweaked all suspension elements. Spring rates are down in the front and up in the rear, and there are larger anti-roll bars, stiffer subframe bushings, and longer bump stops, which effectively increase spring rates when the car is nearing its maximum roll angle. Lexus also lightened the front hubs and control arms and slapped a Torsen limited-slip differential in the rear axle. The result is BMW M3–matching performance around VIR (3:05.4). That’s heady company for Lexus to be keeping. Especially considering that the IS F weighs 3801 pounds (195 more than the M3) and makes only two additional horsepower, at 416...The IS F’s audible shift warning is plenty loud, even when you are wearing a helmet. While the alert is slightly obnoxious on public roads, it lets you keep your eyes up when driving on a track.

The old F rolled around on the track like a keel-less boat in gusting winds. The aforementioned updates quell this tendency and increase confidence. Our backside impressions are supported by numbers: The F exits sector two 13.1 mph quicker than before, at 109.1. Steering is communicative, and the chassis is set up for safe, moderate understeer, but vector adjustment is just a throttle tweak away—the torquey engine (371 pound-feet) can break the rear tires loose easily. The brakes are fantastic, too. The pedal might be a tad wooden (more pliant pine than hard oak), but the system remains fade-free after multiple laps of abuse, something none of the other large sedans could claim this year. The 180-degree character change performed by this Lexus gives us hope that Toyota can still make fun-to-drive cars. Now  where’s our Supra?
For more on this gratifying story (except, perhaps, to older IS F owners), follow the links to Car and Driver's <A HREF="http://www.caranddriver.com/features/10q4/lightning_lap_2011-feature">2011 Lightning Lap intro page</A>, <A HREF="http://www.caranddriver.com/features/10q4/lightning_lap_2011-feature/lightning_lap_2011_3a_ll2_class_page_3">2011 LL2 page</A>, <A HREF="http://www.caranddriver.com/features/10q4/lightning_lap_2011-feature/track_map_3a_vir_track_map_and_lightning_lap_2011_sector_times_page_7">2011 times and interactive track map</A>, <A HREF="http://carvideos.caranddriver.com/?bcpid=627028702&bclid=1111461688&bctid=730520629001">2011 LL2 video</A>, <A HREF="http://www.caranddriver.com/features/08q4/the_lightning_lap_2008-feature2">2008 Lightning Lap intro page</A>, <A HREF="http://www.caranddriver.com/features/08q4/the_lightning_lap_2008-feature2/ll2_3a_2430_2c000-_2460_2c000_page_5">2008 LL2 page</A>, <A HREF="http://www.caranddriver.com/var/ezflow_site/storage/original/application/29f64c2ec07fa8aef3548a5d3c4cd280.pdf">2008 times and track map</A> and <A HREF="http://www.caranddriver.com/features/10q4/lightning_lap_2011-feature/sortable_times_3a_complete_lightning_lap_times_2006_to_2011_page_8">overall times for all five runnings of the Lightning Lap</A>, including the vehicles breaking the much-vaunted 3-minute mark.
 

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Even though I own an older IS-F (2008), I'm still glad to see the F get the praise it deserves. I'm also glad to see that Lexus is listening and hopefully this will result in continued success for the F.

Jeff
08 Smoky Granite Mica IS-F
 

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C&D reviews are good. The real test would be in racing. Wonder how the line-up for this year's 24 hr LeMans would look like. Wonder if the IS-F races anywhere else?
 

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It is great to see the ISF finally getting the respect it deserves. I believe this shows that the original lap time for the 2008 ISF was a less than satisfactory effort by C&D though. I don't see how the LSD and suspension made a full 8.6 second lap difference.
 

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I can see the minor changes they made make a big impact. The ELSD holds us back big time cause it acts more like traction control. I noticed a pretty decent improvement in handling after I added thicker sway bars. I dropped a few seconds off my lap times on a two mile circuit so I think 8 on a 4 mile is reasonable.
 

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I can see the minor changes they made make a big impact. The ELSD holds us back big time cause it acts more like traction control. I noticed a pretty decent improvement in handling after I added thicker sway bars. I dropped a few seconds off my lap times on a two mile circuit so I think 8 on a 4 mile is reasonable.
What sway bar(s) did you add?
 
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