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I just got my IS, would like to know if anyone with a stock or NA removed their CDD and what the 1/4 ET difference was. Ran a search and found what needs to be done, but no actual testaments as to what the removal of that damned choking device yields. It is quite annoying that my car will make me lower my rpm to 3200 or so in order for me to up-shift. I got my manual to gain control, not to push a stick around. Very dumb move on the part of lexus imo :pissed: .
 

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187g....I think you are missing the purpose of the CDD. The CDD don't force you to get to 3700 rpms to upshift. I upshift at 4000+ rpms all the time from 5-4 or 4-3, as long as you rev match you will be fine. Redline or someone else who is more mechancially inclined please chime in if I get anything wrong...but the CDD was developed so that when you shift hard the car tries to still provide a relatively smooth shift so it provides a more "lexus feel" by engaging the clutch semi-slowly rather then letting it slam down all at once. Removing your CDD will probably have minimal if any affect on your 1/4 time. Hardlining or gutting the CDD will only remove the pressure sensitivity during hard shifts....but then again this is all hearsay..I haven't done mine yet either.
 

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Well, the CDD effects my time in major ways, but only when launching, if I attempt to launch over 2 grand in my car right now, I will spin all through first, then when I switch to second, my clutch will stick, and burn, which is caused by the CDD, it attempts to move the chance of any major spin out or loss of control, but it really just focks up your launching. I think my first and second gear are starting to slip a little on my stock clutch because of the CDD kicking in in those gears in the past, I will get it taken out soon. I will probably try it myself and switch to synthetic.
 

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the clutch dampning device does not shift for you, or lock you out of shifting unless you are below a certain rpm

what it does do is modulate how hard/quickly a change in hydraulic pressure is applied to the slave cylinder/pressure plate. which in turn modulates how much shock can be transfered to the driveline in a given time period

-gte




187g said:
I just got my IS, would like to know if anyone with a stock or NA removed their CDD and what the 1/4 ET difference was. Ran a search and found what needs to be done, but no actual testaments as to what the removal of that damned choking device yields. It is quite annoying that my car will make me lower my rpm to 3200 or so in order for me to up-shift. I got my manual to gain control, not to push a stick around. Very dumb move on the part of lexus imo :pissed: .
 

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pmergler said:
187g....I think you are missing the purpose of the CDD. The CDD don't force you to get to 3700 rpms to upshift. I upshift at 4000+ rpms all the time from 5-4 or 4-3, as long as you rev match you will be fine. Redline or someone else who is more mechancially inclined please chime in if I get anything wrong...but the CDD was developed so that when you shift hard the car tries to still provide a relatively smooth shift so it provides a more "lexus feel" by engaging the clutch semi-slowly rather then letting it slam down all at once. Removing your CDD will probably have minimal if any affect on your 1/4 time. Hardlining or gutting the CDD will only remove the pressure sensitivity during hard shifts....but then again this is all hearsay..I haven't done mine yet either.
Yup...right on! Many dots for you.

I have had my CDD removed for a loooooong time now. No problems have stemed from it. Except a bit more tire wear :lol:
 

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redline814 said:
pmergler said:
187g....I think you are missing the purpose of the CDD. The CDD don't force you to get to 3700 rpms to upshift. I upshift at 4000+ rpms all the time from 5-4 or 4-3, as long as you rev match you will be fine. Redline or someone else who is more mechancially inclined please chime in if I get anything wrong...but the CDD was developed so that when you shift hard the car tries to still provide a relatively smooth shift so it provides a more "lexus feel" by engaging the clutch semi-slowly rather then letting it slam down all at once. Removing your CDD will probably have minimal if any affect on your 1/4 time. Hardlining or gutting the CDD will only remove the pressure sensitivity during hard shifts....but then again this is all hearsay..I haven't done mine yet either.
Yup...right on! Many dots for you.

I have had my CDD removed for a loooooong time now. No problems have stemed from it. Except a bit more tire wear :lol:
Thanks bro....but you couldn't spare more with 619k of them....damn dot hog :lol: :lol:
 

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187g said:
VVTIS, so how much faster would ur 1/4 be if u got a better launch off the line?
Not sure, I would not accelerate through second at all, so if you take that into account, I would guess a .5 to .7 faster, but I am running a SC as well. First I spun all through the gate, shift to second, clutch stays in, revs to 6 grand, switch, clutch stays in till I let of the gas, all the time burning the clutch, so basically, the CDD will kick in as long as you are launching at high, or in my case, over 2500 RPM.
 

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the clutch sticking seems to be a problem with the clutch...not the CDD. removing the CDD seems to correct it, but there are other ways too. i had that problem since i got the car, and it caused my clutch to burn out around 20k miles. so i went into lexus and complained, and they gave me a new clutch and flywheel for free. they also replaced the slave cylinder, which they said was the part that was causing the problem. now after i got the new clutch, i can actually launch my car without the clutch sticking and burning through all the gears...and i found out that we can actually chirp our tires in second gear
 

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WiLz said:
we can actually chirp our tires in second gear
Love the second gear chirp....have been doing it since I've had the car 8)

VVTIS said:
187g said:
VVTIS, so how much faster would ur 1/4 be if u got a better launch off the line?
Not sure, I would not accelerate through second at all, so if you take that into account, I would guess a .5 to .7 faster, but I am running a SC as well.
I would be interested and I am not saying that VVTIS's claim isn't accurate...but on a stock IS I wouldn't expect much change in your 1/4 time...definitely not more then a half second.
 

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pmergler said:
WiLz said:
we can actually chirp our tires in second gear
Love the second gear chirp....have been doing it since I've had the car 8)

VVTIS said:
187g said:
VVTIS, so how much faster would ur 1/4 be if u got a better launch off the line?
Not sure, I would not accelerate through second at all, so if you take that into account, I would guess a .5 to .7 faster, but I am running a SC as well.
I would be interested and I am not saying that VVTIS's claim isn't accurate...but on a stock IS I wouldn't expect much change in your 1/4 time...definitely not more then a half second.
Yea, that is why I put in the claim of mine being supercharged, but I dont think the CDD effects stock cars as much because the wheels are not "as" prone to spin out as with the high hp cars. My CDD never kicked in as much as when I was stock, only when launching about 3500 or so, then it would stick.
 

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WiLz said:
the clutch sticking seems to be a problem with the clutch...not the CDD. removing the CDD seems to correct it, but there are other ways too. i had that problem since i got the car, and it caused my clutch to burn out around 20k miles. so i went into lexus and complained, and they gave me a new clutch and flywheel for free. they also replaced the slave cylinder, which they said was the part that was causing the problem. now after i got the new clutch, i can actually launch my car without the clutch sticking and burning through all the gears...and i found out that we can actually chirp our tires in second gear
We can get 3rd stock too, second is easy, but third takes some precise shifting for me.
 

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1/2 a second :eek:

they'd be lucky to see a 10th improvement on a stock car. you can launch the car with the cdd device, i cut a 1.9 sixty foot with that device on the car

-gte



pmergler said:
WiLz said:
we can actually chirp our tires in second gear
Love the second gear chirp....have been doing it since I've had the car 8)

VVTIS said:
187g said:
VVTIS, so how much faster would ur 1/4 be if u got a better launch off the line?
Not sure, I would not accelerate through second at all, so if you take that into account, I would guess a .5 to .7 faster, but I am running a SC as well.
I would be interested and I am not saying that VVTIS's claim isn't accurate...but on a stock IS I wouldn't expect much change in your 1/4 time...definitely not more then a half second.
 

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IS300GTE said:
1/2 a second :eek:

they'd be lucky to see a 10th improvement on a stock car. you can launch the car with the cdd device, i cut a 1.9 sixty foot with that device on the car

-gte



pmergler said:
WiLz said:
we can actually chirp our tires in second gear
Love the second gear chirp....have been doing it since I've had the car 8)

VVTIS said:
187g said:
VVTIS, so how much faster would ur 1/4 be if u got a better launch off the line?
Not sure, I would not accelerate through second at all, so if you take that into account, I would guess a .5 to .7 faster, but I am running a SC as well.
I would be interested and I am not saying that VVTIS's claim isn't accurate...but on a stock IS I wouldn't expect much change in your 1/4 time...definitely not more then a half second.
My 60 foot was a 2.5 with the CDD kicking in, a half a second may be modest, but basically it was sticking in the end of first, all of second and in 3rd till I let off a bit. So, in my experience, with my crappy run, I think it could be .5 sec. But then again, my 19s were not granting much traction either, which may have provoked the problem of the CDD kicking in.
 

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that would have to be due to your wheels, or your driving style, like i said, you had the same CD device that i had on my car, they are mechanical so they are identical in how they operate

i would bet that you could cut better sixty foots by changing your style of driving ... you cannot ride the clutch at all with that device, you have to dump the clutch at the "sweet spot"

-gte



VVTIS said:
IS300GTE said:
1/2 a second :eek:

they'd be lucky to see a 10th improvement on a stock car. you can launch the car with the cdd device, i cut a 1.9 sixty foot with that device on the car

-gte



pmergler said:
WiLz said:
we can actually chirp our tires in second gear
Love the second gear chirp....have been doing it since I've had the car 8)

VVTIS said:
187g said:
VVTIS, so how much faster would ur 1/4 be if u got a better launch off the line?
Not sure, I would not accelerate through second at all, so if you take that into account, I would guess a .5 to .7 faster, but I am running a SC as well.
I would be interested and I am not saying that VVTIS's claim isn't accurate...but on a stock IS I wouldn't expect much change in your 1/4 time...definitely not more then a half second.
My 60 foot was a 2.5 with the CDD kicking in, a half a second may be modest, but basically it was sticking in the end of first, all of second and in 3rd till I let off a bit. So, in my experience, with my crappy run, I think it could be .5 sec. But then again, my 19s were not granting much traction either, which may have provoked the problem of the CDD kicking in.
 

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IS300GTE said:
that would have to be due to your wheels, or your driving style, like i said, you had the same CD device that i had on my car, they are mechanical so they are identical in how they operate

i would bet that you could cut better sixty foots by changing your style of driving ... you cannot ride the clutch at all with that device, you have to dump the clutch at the "sweet spot"

-gte



VVTIS said:
IS300GTE said:
1/2 a second :eek:

they'd be lucky to see a 10th improvement on a stock car. you can launch the car with the cdd device, i cut a 1.9 sixty foot with that device on the car

-gte



pmergler said:
WiLz said:
we can actually chirp our tires in second gear
Love the second gear chirp....have been doing it since I've had the car 8)

VVTIS said:
187g said:
VVTIS, so how much faster would ur 1/4 be if u got a better launch off the line?
Not sure, I would not accelerate through second at all, so if you take that into account, I would guess a .5 to .7 faster, but I am running a SC as well.
I would be interested and I am not saying that VVTIS's claim isn't accurate...but on a stock IS I wouldn't expect much change in your 1/4 time...definitely not more then a half second.
My 60 foot was a 2.5 with the CDD kicking in, a half a second may be modest, but basically it was sticking in the end of first, all of second and in 3rd till I let off a bit. So, in my experience, with my crappy run, I think it could be .5 sec. But then again, my 19s were not granting much traction either, which may have provoked the problem of the CDD kicking in.
True, either way, I need to go back to the track with the CDD off and my 17s on with the car tuned.
 
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