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Of all the many reports I've read, none of it discuss how the new IS350/250 chassis is xx% stiffer then the predecesor. Many automakers love to promote this to journalist when they introduce a new model. But I haven't read this about the new IS

I conclude that to mean the new IS chassis is not as stiff torsionally or measured in whatever other means. Which makes sense since most of the reports now say it is less of a 3 series fighter, but more of a baby GS. Meaning it is moving further away from a true sports sedan. That's too bad for us enthusiasts. Yes, the 300+ horsepower is nice, but the handling dyanimics is really lacking and that kills the car as a package.

Regarding VDIM, for better cornening capability, you better defeat VDIM before you go spending money on suspension goodies. I'm certain VDIM can be defeated. These systems have so many sensors, the minute one of the sensors gets an erroneous signal, the entire system shuts down, potentially turning off ABS, TCS, Brake Assist, and of course VDIM. Reset the sensor for raining or snowy days and you have toyota engineers patroling your every move again to prevent a spin out and withholding you from too much fun. Get the service manual, study the schematic, its pretty easy to figure out how to defeat it.

Perhaps Toyota control freaks will wake up and give us a defeat button. Naa. I doubt it. One of Toyota's utopian goal is to build car which can prevent 100% accidents. I'm not kidding, this was written up on a automotive trade magazine. The other goal is to build cars with 0 enviromental impact. Nice goals, but in practice it means we'll all be passengers being chaufered around in computer controlled cars made from 100% recycled materials. No thanks!
 

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Not enough info to be basing such a strong opinion or theory on the new IS.

Have any empirical data or anything to back up your claim? 6 months ago, there was no indication of what kind of power the IS350 was going to have, so should we conclude the IS350 has no significant power increase?

Just because you haven't read it doesn't mean it doesn't or won't exist. And the cars haven't even come out yet, so give tuners time before they figure out VDIM.

Oh, and finally, this isn't some pre-OBD1 setup here, defeating VDIM I will gaurantee won't be done by jumping some wires here and splicing some wires there. There will need to be significant research that won't be shown in basic repair manual schematics.

Shit, the taillight failure sensor on the current IS300 isn't even drawn up on repair manual schematics, i had to draw the circuit myself. And then, after that, all their IC's are proprietary to Denso, and they will not release info about the components they design and manufacture EVEN FOR EDUCATIONAL RESEARCH PURPOSES.

It always seems easier than it is...
 

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I would love for my car to drive itself or have the option to. Driving can suck a lot of the times since other humans are on the road and are idiots.
 

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Discussion Starter #7
Inspar, your points are well made.

I'm sure lexus marketing would be really quick to point out a stiffer chassis if that was the case. Most manufactures point that out. Lexus isn't talking about it. We can draw our own conclusions.

In regards to defeating VDIM, it can be done at the cost of having idiot lights coming on. In addition to the schematic, you'll need to study the diagonstic portion of the manual and do some trial and error to understand their control strategy. Yes, toyota has secondary sensors which check their primary sensor are operating properly or they have check routines built into their ECU to ensure the sensor are active and operating within range. The entire system is always under close supervision courtesy of Toyota engineers. I've spent too much time studing their strategy and algothrim when I defeated some of their systems. And I agree it is not as easy as jumping a wire.

VDIM is a good thing. What's missing is the ability to defeat it or have different levels of threshold to select from such as those found in the C6 Corvette. What is the point of having 255/18 inches rear tires and "Performance Suspension" when VDIM stops the fun at 0.80 Gs and 61-62 mph slalom speed (Oct issue of Road and Track). A 2001 IS tested by Road and Track back in 2001 blows that away on skinny 215/17 tires, which cornerned at 0.90 G and Salom at 64-65mph. It is not progress if VDIM harness the car true capabilities. Lexus mind as well put on skinny 205mm/16 tires to achieve those poor lateral acceleration and slalom speeds.
 

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Rob L said:
I would love for my car to drive itself or have the option to. Driving can suck a lot of the times since other humans are on the road and are idiots.
Hmmm....this is sounding like a scene from Minority Report. ;)
 

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SilverF16 said:
I conclude that to mean the new IS chassis is not as stiff torsionally or measured in whatever other means. Which makes sense since most of the reports now say it is less of a 3 series fighter, but more of a baby GS. Meaning it is moving further away from a true sports sedan. That's too bad for us enthusiasts. Yes, the 300+ horsepower is nice, but the handling dyanimics is really lacking and that kills the car as a package.

Regarding VDIM, for better cornening capability, you better defeat VDIM before you go spending money on suspension goodies. I'm certain VDIM can be defeated. These systems have so many sensors, the minute one of the sensors gets an erroneous signal, the entire system shuts down, potentially turning off ABS, TCS, Brake Assist, and of course VDIM. Reset the sensor for raining or snowy days and you have toyota engineers patroling your every move again to prevent a spin out and withholding you from too much fun. Get the service manual, study the schematic, its pretty easy to figure out how to defeat it.
I think Toyota have in mind to have the best structural rigidity for the new IS350. Remember that Lexus is the benchmark in NVH. They need to achieve high torsional stiffness in order for them to be the leader in NVH.

In terms of driving dynamics, the only problem that sets back the new IS compared against the new 3series is the undefeatable VDIM and lacked of manual tranny.

Also, I don't think Toyota engineers designed the VDIM to completely fail if one sensor malfunctioned or broke. That'll be catasthropic. Think about it.
 

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SilverF16 said:
Of all the many reports I've read, none of it discuss how the new IS350/250 chassis is xx% stiffer then the predecesor. Many automakers love to promote this to journalist when they introduce a new model. But I haven't read this about the new IS

I conclude that to mean the new IS chassis is not as stiff torsionally or measured in whatever other means. Which makes sense since most of the reports now say it is less of a 3 series fighter, but more of a baby GS. Meaning it is moving further away from a true sports sedan. That's too bad for us enthusiasts. Yes, the 300+ horsepower is nice, but the handling dyanimics is really lacking and that kills the car as a package.

They did as a matter of fact, at the press event @ Tarrytown we attended.
I need to look for it, I know I wrote it down somewhere, and made a comment to jruhi4 about it. I recall something about 30 and 10 percent increase in torsional and something else...
 

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SilverF16 said:
Of all the many reports I've read, none of it discuss how the new IS350/250 chassis is xx% stiffer then the predecesor. Many automakers love to promote this to journalist when they introduce a new model. But I haven't read this about the new IS

I conclude that to mean the new IS chassis is not as stiff torsionally or measured in whatever other means.
Unfortunately everything you read isn't exactly what's necessarily true about the vehicle. Like Meteoro, I was able to drive the New IS at the Irvine event a few weeks prior to when the East Coast guys got their turn. There is a definite increase in structural ridigity. You can definitely tell this by driving over the railroad tracks and various types of pavement we drove on during our 2.5 hour drive with the car. I don't recall what the % was but it's quite considerable when you go over broken pavement and railroad tracks and you hear nothing but the rubber tires hitting these surfaces. No creaking, rattle or groaning. After our drive with the New IS, we drove about the same route to get back on the freeway with our own IS300's, the difference is night and day.
 

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could it be also that Lexus is reserving things like a manual tranny, defeatable VDIM and whatnot for a performance version of ther IS350

I like to hang on to thhis idea... LOL!
 

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Inspar8r said:
could it be also that Lexus is reserving things like a manual tranny, defeatable VDIM and whatnot for a performance version of ther IS350

I like to hang on to thhis idea... LOL!
Lexus has said that they want to continually update their car line-up throughout their lifespan.
 

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Oooooooooooooops!
 

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Because lexus/toyota isn't actively pushing frame stiffness means it's less than the current model?

How can you make assumptions like that?
There's really very little logic behind that.
 

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I bet there a YAW sensor that if you removed would kill VDIM, just a guess.

the is300 platform was designed to be a sports car, the is350 is based on the gs300 which was not.
 

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GutterMouth said:
Maybe he is refering to the 350?....
My mistake... I misinterpreted the post. For some reason I read "You lost all that horsepower..."
 
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