Lexus IS-F '07 -> '11

[iCyCo]

Lexus made some much needed suspension and chassis tweaks to the '11 IS-F so I was wondering if they're any tunes that can simulate this.


2011 Stats & Review Snippets
Power (SAE): 416 hp @ 6,600 rpm; 371 ft lb of torque @ 5,200 rpm
Final Drive Ratio: 2.937
Curb Weight: 3,780 lb (1,715 kg)

MotorTrend
Car and Driver - Lightning Lap

 

[jeremy_craig]

UPDATED!!!

I managed to get 1:57.946 on Fuji Speedway F with this tune so it's actually about 6 secs faster than the real one that does it in 2:03.4 and I am using sport hard tires.

Here are my setting as accurate as I could for the 2011 IS F

Buy the IS F DO NOT CHANGE OIL!!! or the torque will go up to 380.

Just buy:
FC suspension
sport hard tires
sports catalytic converter
chassis reinforcement
LSD

This will get you to 371 torque when you break it.
Bring the power limiter to 92.5-92.7% to get to 416hp. (again this is after you break in the engine)

add weight ballast 95 in the middle to get the weight right
LSD
int:10
acc:28
bra:10
height:-5/-5
spring:7.0/10.0
damp ext:8/6
damp com:5/4
roll:3/5
cam:1.6/1.5
toe:-0.02/0.28
brakes:6/5

transmission is good stock

 

[iCyCo]

Thanks, will try it.

 

[iCyCo]

Just tried the tune minus the tyres as I had earlier today set a time while comparing it to the M3 earlier (Almost a full second faster than M3 around Tskuba) with sports hard.

It seems so much easier to drive, turns much easier and somehow feels light and nimble even with the added weight thing is though I'm about a sixth of a second slower, thats using the DS3, I used the wheel earlier, will try the wheel next see if it improves.

Looking at the data logger I realized I had much better throttle control and was able to apply the gas a bit more early and steady. Lateral and longitudinal g-force graphs are basically mirror copies of themselves.

Definitely will try the Wheel and report back

 

[Supermelon]

Here are my setting as accurate as I could for the 2011 IS F

Buy the IS F DO NOT CHANGE OIL!!! or the torque will go up to 380.

Just buy:
FC suspension
sport soft tires
racing air filter
chassis reinforcement

This will get you to 372 torque at 5200rpm until you break it it then it will got a couple higher.
Bring the power limiter to 93.4% to get to 416hp at 6600rpm. (you might have to lower a little more once engine is broken in)

From my research they stiffened the rear by 50%, loosened up the front, adjusted the dampers and stiffened up the roll bars. They also added some camber to the back and dropped it 0.8inches which is basically 20mm so I believe my suspension set up is almost equal to the 2011 IS F set up.

add weight ballast 95 in the middle to get the weight right
height:-20/-20
spring:6.0/9.0
damp ext:8/6
damp com:6/4
roll:4/4
cam:0.0/1.5
toe:0.00/0.00
brakes:6/5

transmission was already good factory as well as the LSD.

So far I've found online about the 2011 IS-F is that the spring rates are soften at the front and stiffen at the rear but no solid percentage or numbers yet.
For some of the % and ride height values in your tune, I don't believe they are for the 2011 IS-F. I've found similar numbers on a website describing the suspension change from the IS350 to the pre 2011 IS-F.

 

[jeremy_craig]

So far I've found online about the 2011 IS-F is that the spring rates are soften at the front and stiffen at the rear but no solid percentage or numbers yet.
For some of the % and ride height values in your tune, I don't believe they are for the 2011 IS-F. I've found similar numbers on a website describing the suspension change from the IS350 to the pre 2011 IS-F.

Actually, I did everything possible to make it as accurate as I could without true specs. The original spring rates are 6.6/6.0 and they softened the front hence my 6.0 and they stiffened the rear by about 50% hence my 9.0. They also lowered it 0.8inches. So do the math and you'll see that 0.8inches~20mm so my ride height is also pretty accurate as well as my hp, torque and weight. Anyways if you don't like the tune don't use it and if you don't have stats then shut up. I was just trying to help someone asking for a tune and here you come nay saying everything when in reality you don't know what you're talking about and I did research to get my info.

 

[jeremy_craig]

Just tried the tune minus the tyres as I had earlier today set a time while comparing it to the M3 earlier (Almost a full second faster than M3 around Tskuba) with sports hard.

It seems so much easier to drive, turns much easier and somehow feels light and nimble even with the added weight thing is though I'm about a sixth of a second slower, thats using the DS3, I used the wheel earlier, will try the wheel next see if it improves.

Looking at the data logger I realized I had much better throttle control and was able to apply the gas a bit more early and steady. Lateral and longitudinal g-force graphs are basically mirror copies of themselves.

Definitely will try the Wheel and report back

I used sport soft and the thing drives like a dream to me. Glad it helped a little!

 

[iCyCo]

I used sport soft and the thing drives like a dream to me. Glad it helped a little!

I tried it with the wheel, got a little closer to the '07 stock time. Using stickier tires though negates what I'm looking for. Going to use your tune as a base and see if I can get anymore out if it.

Don't expect the vast improvements seen in the real world though, 2 seconds off Fuji & 9 seconds off VIR but I was expecting atleast a few tenths or so on a small track like Tskuba.

 

[Supermelon]

Actually, I did everything possible to make it as accurate as I could without true specs. The original spring rates are 6.6/6.0 and they softened the front hence my 6.0 and they stiffened the rear by about 50% hence my 9.0. They also lowered it 0.8inches. So do the math and you'll see that 0.8inches~20mm so my ride height is also pretty accurate as well as my hp, torque and weight. Anyways if you don't like the tune don't use it and if you don't have stats then shut up. I was just trying to help someone asking for a tune and here you come nay saying everything when in reality you don't know what you're talking about and I did research to get my info.

I didn't say anything about not liking your tune. I was just wondering about some of the numbers you used for the suspension settings saying that its for the 2011 IS-F, which from my research(yes I did do some before hand) is not. I am not questioning the effectiveness of your tune, I just don't want any misunderstanding on the 2011 IS-F's suspension changes. If you thought I was challenging either your tune or you in my first post, then I apologize.

Here is what I have found so far from my research.

In the Car and Driver link provided in the first post, it says that:

-"Spring rates are down in the front and up in the rear, and there are larger anti-roll bars"
-"Lexus also lightened the front hubs and control arms and slapped a Torsen limited-slip differential in the rear axle."

From a website I found called the CarGurus, which talks about the 2009 IS-F:

-"Starting with the basic IS 350 platform, Mr. Yaguchi and his friends kept the front double control arm layout, but substituted sheet steel for aluminum and made the lower control arm bushings 20% stiffer. The spring rates and gas shocks are 90% stiffer, while the front, hollow stabilizer bar is 10% stiffer and the rear solid stabilizer thicker and stiffer than that of the IS 350. The rear five-link suspension's spring rates and shocks are 50% stiffer, with the IS F an overall 0.8 inches lower to the ground. The car achieves a 54/46 weight balance."

http://www.cargurus.com/Cars/ExpertReview-c13999-2009-IS-F.html

Some information I found from the Toyota USA Newsroom on the 2011 IS-F:

-"The IS F sits an inch lower on its suspension than the standard IS models, which lowers the center of gravity and helps provide a quicker handling response."
-"Spring and damper rates are increased, and larger-diameter stabilizer bars are used. The rear-suspension control arms are specific to the IS F to optimize geometry for the 19-inch wheels. In addition, the monotube shock absorbers use a larger-diameter piston rod. As on other IS models, the sophisticated shock-absorber design utilizes multi-leaf linear control valves to help improve damping force, and rebound springs offer improved body control without degrading ride comfort."
-"Subframe suspension mounts are stiffer than on other IS models to help reduce sway and ensure control under acceleration and braking. The engine mounts are also stiffer for a more direct feel. Special jounce stoppers on both the front and rear suspension come into play early in the compression stroke to help reduce the sway angle when cornering and to reduce dive when braking."

http://pressroom.toyota.com/pr/tms/lexus/lexus-is-f-high-performance-sedan-163847.aspx?ncid=12470


So from my research I can only confirm that the springs in the front has been lowered and the rear springs and anti-roll bars have been stiffen. No real actual numbers on the 2011 IS-F was found except for the fact that the 2011 F is lowered by 1 inch compare to the 2011 ISX50. The 2009 IS-F is lowered by 0.8inches compare to the other 2009 IS models. By comparing these two numbers, I can guess that the 2011 IS-F is lowered by 0.2inches compare to the previous F.

Also a LSD is installed which contributes to the better handling. According to real life information the torsen LSD has only been installed since 2010. Since the IS-F in GT is from 2007, it will only have the VDIM to act as a LSD. I haven't installed a LSD yet on my IS-F in GT, so I'm not sure if it comes with one stock or not.

In conclusion the 2011 IS-F have gotten the following modifications which improves its handling considerably. (only settings that can be adjusted in GT is listed, so I didn't put the stiffen suspension mounts etc.) No real numbers have been found in my research. If there is, please post them up.

- Front spring rate lowered
- Rear spring rate stiffened
- Stiffen Dampers
- Stiffen anti-roll bars
- Torsen LSD installed
- Lowered by 0.2 inches compared to previous IS-F. (only my guess from information found on internet.)

Edit: More information I found on the alignment for the 2009 IS-F. Not sure how much has changed for the 2011 model.

http://www.clublexus.com/forums/is-...-just-ranges-from-alignment-rack-anybody.html

Front camber: -0.87 +/- 0.75 degree
Front Toe: 0.18 +/- 2mm

Rear camber: -0.78 +/- 0.75 degree
Rear Toe: 3 +/- 2 mm

 

[jeremy_craig]

Well thanks for your info.

So we can estimate spring rates and assume the alignment hasnt been changed to much. Unless we can find more up to date specs.

How can we set the toe to 3? Im confused here.

 

[Supermelon]

Well thanks for your info.

So we can estimate spring rates and assume the alignment hasnt been changed to much. Unless we can find more up to date specs.

How can we set the toe to 3? Im confused here.

I think that toe in GT is 0.1 = 1mm in real life

So for rear toe at 3mm, in GT it can be set as 0.3. I do think this is a bit excessive as these alignment specs are for daily road use, so it'll be quite biased towards understeer.

I've also found that the IS-F in GT already has a LSD installed as stock. I'm guessing it is for simulating the VDIM in the IS-F that acts as a electronic LSD.

 

[iCyCo]

Seems like you both have done your research. Greatly appreciated.

I've run the car on Fuji now, ran Stock '07 first then chased ghost with '11, was trailing until Sector 3 where I passed and completed the lap ahead buy a few tenths. Car really came in to it's own in sector 3

@SuperMelon
Going to take a stab at a tune and post it up? Stock Tires (Sports Hard)

 

[jeremy_craig]

Which fuji speedway do they use? The gt or not??

 

[iCyCo]

The one with the chicane

 

[jeremy_craig]

Seems like you both have done your research. Greatly appreciated.

I've run the car on Fuji now, ran Stock '07 first then chased ghost with '11, was trailing until Sector 3 where I passed and completed the lap ahead buy a few tenths. Car really came in to it's own in sector 3

@SuperMelon
Going to take a stab at a tune and post it up? Stock Tires (Sports Hard)

I updated the tune with sport hard tires and it's more accurate to the real settings I believe from the info we have. I ran a 1:57.946 on Fuji with it so I guess it's faster than the 2011 now.

 

[Supermelon]

Seems like you both have done your research. Greatly appreciated.

I've run the car on Fuji now, ran Stock '07 first then chased ghost with '11, was trailing until Sector 3 where I passed and completed the lap ahead buy a few tenths. Car really came in to it's own in sector 3

@SuperMelon
Going to take a stab at a tune and post it up? Stock Tires (Sports Hard)

lol I generally do a little bit of suspension tweaks here and there, but I don't consider myself good at tuning.
I also tend to avoid Full Customizable suspension as there is too many variables for my brain to handle. I prefer to use the height-adjustable suspension more often.

I'll try to see what I can do with the height adjustable suspension for the IS-F. Will report back when I have some results.


Edit:

I updated the tune with sport hard tires and it's more accurate to the real settings I believe from the info we have. I ran a 1:57.946 on Fuji with it so I guess it's faster than the 2011 now.

I've just tried this tune out and I will say it feels quite nice. Especially in section 3 with all the uphill hairpins and off camber corners. I was able to turn in better than the stock car and accelerating out of a corner was also easier. Performance in the other sections were similar to the stock car, however midway in the 100R corner it felt like grip was reduced very slightly. Overall this is a good tune, I was able to reduce laptimes by about 0.2 seconds and reached the 55 second range.
Stock IS-F ran Fuji F in about 1:56.1xx
Tuned IS-F in about 1:55.9xx