IS - 2nd Gen (2006-2013) Discussion about the 2006+ model IS models

So I took my 350 on a canyon-type road today

Old 07-02-14, 02:36 PM
  #46  
rawr2is250
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Originally Posted by redspencer
I agree 100%.

I had the exact same experience as you when I autocrossed against E46 M3s at autocross events. When I was running the full F-Sport suspension system (springs/shocks/sways/brace) and no LSD, I consistently finished within the same second as competing E46 M3s. When I also compared online review specs between the M3 and the Lexus IS equipped with the F-Sport Accessories package, I noticed that the skidpad and slalom figures were near identical. The M3 would have a better steering feel than the Lexus IS350 but that can be rectified with an IS-F Steering ECU.
Wow, good work
Old 07-02-14, 03:16 PM
  #47  
Re3iRtH
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True. But as far as comfort and luxury, its laughable to compare these two
Not to mention reliability.


Originally Posted by redspencer
I agree 100%.

I had the exact same experience as you when I autocrossed against E46 M3s at autocross events. When I was running the full F-Sport suspension system (springs/shocks/sways/brace) and no LSD, I consistently finished within the same second as competing E46 M3s. When I also compared online review specs between the M3 and the Lexus IS equipped with the F-Sport Accessories package, I noticed that the skidpad and slalom figures were near identical. The M3 would have a better steering feel than the Lexus IS350 but that can be rectified with an IS-F Steering ECU.
Old 07-03-14, 06:49 AM
  #48  
An2ny
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As far as AutoX; unless you are running a SCCA national competitive event; or a local event with some national competitive drivers and cars, you cannot really compare any data/ results…same goes for HPDE.
Old 07-03-14, 01:22 PM
  #49  
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What data / results are you referring to?


Originally Posted by An2ny
As far as AutoX; unless you are running a SCCA national competitive event; or a local event with some national competitive drivers and cars, you cannot really compare any data/ results…same goes for HPDE.
Old 07-03-14, 02:02 PM
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Originally Posted by Re3iRtH
May I ask the year and specs of your F, and how much you payed?

Only one used IS-F for sale in my state, its a '12 with around 12k miles,
and he wants about 52k$ with some bolt ons already installed.

I paid 41xxx for mine with 16k miles on it. I was just looking around the other day and found several F's ranging from 2008-2011 with under 20k miles.. all priced in the low 40s. I took a nice hit when i traded in the IS350... it was a great car but the F suits my style much better.
Old 07-03-14, 03:14 PM
  #51  
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Originally Posted by mike33
An isf steering ecu will not eliminate the "pedal dance". You would need to get an abs/skid control ecu from a 2007 or newer isx50. I purchased a used one on ebay for $110, and no more "pedal dance". The 2007+ would be part # 89540-53290 and will have a VT on the label. The 2006 is part # 89540-53251 and has a V5 or V9 on the label.
Good to know.

But sucks... now I have two things on my list to purchase.
Old 07-03-14, 05:46 PM
  #52  
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So it looks like you have to choose between an ECU that
will tighten up your steering vs one that will let you turn of
traction control easier, but not both.

Is there any problem with preprogrammed or remembered
things in the stock ECU, to go ahead and just switch out
for a different one?
Old 07-03-14, 10:32 PM
  #53  
sjgIS350
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I owned an 04 S2000 and took it on many twisting mountain type roads. Although a great design, the S2000 is/was a niche car. The IS is a mainstream car and thus sacrifices some of the characteristics of a car like the S2000.

Spend a ton of money on the IS trying to make it a canyon carver like the S2K..DNA is DNA. You can only do so much.

I really miss my S2K. Damn fun to drive. Just totally impractical as a daily driver.

Love my IS350 but for the same reasons the OP noted..but that same "WOW" factor that the S2000 has/had just isn't there…one of those tradeoffs we accept I guess.

Last edited by sjgIS350; 07-03-14 at 10:47 PM.
Old 07-04-14, 03:38 PM
  #54  
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Originally Posted by Re3iRtH
So it looks like you have to choose between an ECU that
will tighten up your steering vs one that will let you turn of
traction control easier, but not both.

Is there any problem with preprogrammed or remembered
things in the stock ECU, to go ahead and just switch out
for a different one?
I believe they're two different ECUs, so both are upgradeable.
Old 07-04-14, 05:19 PM
  #55  
Re3iRtH
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I thought cars had only one ecu, shows how much I know

Originally Posted by iNfectious
I believe they're two different ECUs, so both are upgradeable.
Old 07-05-14, 02:58 PM
  #56  
mike33
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Originally Posted by Re3iRtH
I thought cars had only one ecu, shows how much I know
There are multiple ecu(s), the steering ecu is located under the battery, the trac control/skid control ecu is under the glove box, and there are others... These are not to be confused with the ECM (engine control module)...
Old 07-05-14, 03:52 PM
  #57  
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Hey Re3iRtH

That sucks sorry that your s2k was totalled.. I used to have an ap1 myself and man I miss that car!
Yes s2k to Is350 is way different. You can put as many mods as you like but the characteristics of both cars are just night and day, one is a go cart stock and the other is an off the line beast. But I am a handling perfectionist so I don't care so much about off the line power as long as my handling is superb.

Yes definitely get the F/R sway bars, F/R struts, and cross body chassis braces and to top if of your coilovers. But looking over your previous post you want to stay with springs? So if you do that get some adjustable shocks to complement it. In addition I would recommend getting a LSD from an FR-S to get you the best handling ability to come even close to the s2000.

The Steering ECU, is just to make the steering feel more solid and is not necessary but it does make a difference on the feel. The f-sports have them as well but not as solid as the F's.
Old 07-05-14, 08:39 PM
  #58  
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Just curious, where would a rear strut bar go in this car, through the trunk?

I will install the rear sway and chassis brace this week. I didn't order a front sway, because I
read (can't find the post off hand) that the F-sport front sway only adds 5% stiffness over stock,
and the rear sway adds something like 150% more..

I am interested in F/R strut bars, which do you guys like?


Originally Posted by azfsprt
Hey Re3iRtH

That sucks sorry that your s2k was totalled.. I used to have an ap1 myself and man I miss that car!
Yes s2k to Is350 is way different. You can put as many mods as you like but the characteristics of both cars are just night and day, one is a go cart stock and the other is an off the line beast. But I am a handling perfectionist so I don't care so much about off the line power as long as my handling is superb.

Yes definitely get the F/R sway bars, F/R struts, and cross body chassis braces and to top if of your coilovers. But looking over your previous post you want to stay with springs? So if you do that get some adjustable shocks to complement it. In addition I would recommend getting a LSD from an FR-S to get you the best handling ability to come even close to the s2000.

The Steering ECU, is just to make the steering feel more solid and is not necessary but it does make a difference on the feel. The f-sports have them as well but not as solid as the F's.
Old 07-06-14, 06:24 AM
  #59  
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Originally Posted by Re3iRtH
I will install the rear sway and chassis brace this week. I didn't order a front sway, because I
read (can't find the post off hand) that the F-sport front sway only adds 5% stiffness over stock,
and the rear sway adds something like 150% more..
When the F-Sport accessories package first came out, Lexus initially posted that the F-Sport front sway bar added 6% stiffness over stock and the rear F-Sport sway bar added 151% stiffness over stock.

Lexus later revised the IS350 % stiffness of the F-Sport sway bars stating that the front F-Sport sway bar now provides a 42.8% stiffness improvement over stock while the rear F-sport sway bar remains the same at 151% stiffness improvement.

The change in the % stiffness has been a topic of discussion on CL for years as it is unknown whether or not the revision to the % stiffness change for the front was intentional (meaning the original statistics were incorrect) or not. It doesn't help that the IS250 and IS350 both have different % stiffness increases when the consensus here is that the OEM sway bars for both models are the same.

Those that did the rear sway bar mod first and then the front sway bar mod later down the road have all said that the F-Sport front sway bar has a noticeable improvement at improving initial turn-in and reducing body roll in the front but the F-Sport rear sway bar mod has a much more noticeable change to the vehicle dynamics.

As an owner that had previously driven with only the F-Sport rear sway bar for nearly a year and a half prior to finally getting the F-Sport front sway bar, I sincerely believe that the revision to the % stiffness over the front stock sway bar is more accurate at 42.8% as the oversteering issues that I previously had with using only the rear sway bar were now gone when the front sway bar was later installed, specifically at certain on-ramps and corners which I would use to analyze the car's handling characteristics. I noticed that the body roll that I used to have up in the front was greatly reduced and I'm fairly certain a 6% increase over stock wouldn't have a noticeable impact if that old statistic was still used and was accurate (The old 6% stiffness data is why forum members here continue to skip the purchase of the F-Sport front sway bar due to the belief that it has little to no improvement over stock [which is why I'm typing this long email response for added perspective]).

This previous thread may help provide an additional perspective to the whole F-Sport Front vs Rear Sway bar discussion: https://www.clublexus.com/forums/sus...-sway-bar.html

Hope this info helps.

Originally Posted by azfsprt
In addition I would recommend getting a LSD from an FR-S to get you the best handling ability to come even close to the s2000.
Unfortunately, the FR-S Torsen LSD is only compatible with the IS250 and not the IS350. When it comes to IS350 differential options, we only have a handful of vendors to choose from and most available LSDs are pricey (I definitely know this). >_<

Last edited by redspencer; 07-06-14 at 06:41 AM.
Old 07-06-14, 12:07 PM
  #60  
Re3iRtH
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Wish ya told me sooner.. I would have just ordered the front sway
as well (maybe save some $ bundling it too). Given that the rear sway
and brace give the most noticable improvement I don't feel so bad.

And I think it shouldn't be that hard to dig that info from corporate
Lexus why the initial stiffness % was posted then revised later.

Originally Posted by redspencer
When the F-Sport accessories package first came out, Lexus initially posted that the F-Sport front sway bar added 6% stiffness over stock and the rear F-Sport sway bar added 151% stiffness over stock.

Lexus later revised the IS350 % stiffness of the F-Sport sway bars stating that the front F-Sport sway bar now provides a 42.8% stiffness improvement over stock while the rear F-sport sway bar remains the same at 151% stiffness improvement.

The change in the % stiffness has been a topic of discussion on CL for years as it is unknown whether or not the revision to the % stiffness change for the front was intentional (meaning the original statistics were incorrect) or not. It doesn't help that the IS250 and IS350 both have different % stiffness increases when the consensus here is that the OEM sway bars for both models are the same.

Those that did the rear sway bar mod first and then the front sway bar mod later down the road have all said that the F-Sport front sway bar has a noticeable improvement at improving initial turn-in and reducing body roll in the front but the F-Sport rear sway bar mod has a much more noticeable change to the vehicle dynamics.

As an owner that had previously driven with only the F-Sport rear sway bar for nearly a year and a half prior to finally getting the F-Sport front sway bar, I sincerely believe that the revision to the % stiffness over the front stock sway bar is more accurate at 42.8% as the oversteering issues that I previously had with using only the rear sway bar were now gone when the front sway bar was later installed, specifically at certain on-ramps and corners which I would use to analyze the car's handling characteristics. I noticed that the body roll that I used to have up in the front was greatly reduced and I'm fairly certain a 6% increase over stock wouldn't have a noticeable impact if that old statistic was still used and was accurate (The old 6% stiffness data is why forum members here continue to skip the purchase of the F-Sport front sway bar due to the belief that it has little to no improvement over stock [which is why I'm typing this long email response for added perspective]).

This previous thread may help provide an additional perspective to the whole F-Sport Front vs Rear Sway bar discussion: https://www.clublexus.com/forums/sus...-sway-bar.html

Hope this info helps.



Unfortunately, the FR-S Torsen LSD is only compatible with the IS250 and not the IS350. When it comes to IS350 differential options, we only have a handful of vendors to choose from and most available LSDs are pricey (I definitely know this). >_<

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