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Discussion Starter #1
OK,

I saw that there is an existing thread about this, but I am starting a new one because the way I did it is not like any of the ways previously discussed. I will use the info that I supplied to a member who asked how I did it. Here you go, and I hope this helps. You will be able to retain CC but not IAC. I don't have any issues with IAC, my idle is a little hi so it's not really any issue for me even with the A/C on.

Basically, what you have to do is:
-Take the throttle body off.
-Take the 4 bolts off that hold the throttle cable assemby to the throttle body off and take it off.
-Look inside and you will see a cammed deal that the throttle assembly mechanical stop will hit and allow the throttle to open about 50%.
-If you clock the throttle assemby about 45 degrees, you will notice that you can almost put it back in and there will be no slack so that when you open the throttle with the pedal, it would open 100%.
-The only problem will be that there is a plastic mechanical stop that you will have to break/trim to make it all go back together as discribed (I wish I had pics of this because I'm going from memory right now). I think when you take it apart, you will see exactly what I'm talking about.
-After you trim/shave the mechanical stop, you will be able to put the throttle cable assebly back together with it clocked up at about 45 degees.
-Now the bolts will not match up obviously. The two bolts holes in the 3 o'clock and 9 o'clock position will line up with the sides of the throttle cable assembly.
-You will have to use 2 washers and the original bolts in the 3 and 9 o'clock position to sandwhich the sides of the throttle cable assembly to the throttle body.
-You will only be able to use 2 of the 4 original bolts but 2 is plenty (I've run mine like this for about 5K miles with no issues).
-Now you will see that the original cable is too long. You will have to trim it to fit and terminate it with a barrel tip kit. I got this from Autozone (I don't know what you have in the D/R, but I could send you some if you need (they are pretty cheap).
-The kit comes with various sizes and one is perfect to fit the throttle cable assembly. You will have to cut a few of the strands off the tip so that it will fit in the hole or you can open the hole up some.
-The barrel tip has a jamb screw that keeps the cable from slipping out. Make sure this is tight
-When you get it all back together, have someone open the throttle with the gas pedal to make sure the throttle plate opens 100%.
-You should be done now and you will notice that there is no slack when giving it gas and that your throttle response is much quicker! Blipping the throttle is a breeze with the DBW bypassed.
-Make sure you re-connect the DBW cable so that your cruise will still work and you're done. Enjoy. Here are some pics.





__________________
Red IS300 w/Boostlogic Turbo Kit, Built Aristo block (CPs, Carrillo H-beams, SPS Carr bolts) TEC3, Innovate Wideband, Rays Versus wheels, Eibach springs, B&M Shifter, etc, etc, etc. (R154 and MKIII Supra LSD in the works ;-).

408HP 411TRQ @ 14psi 93 pump & 5800RPM

F/S Aristo GTE or Built blocks available
 

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nice post. I like to say I learn something new everyday on this site, but that just isnt the case.
 

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i wouldn't even have the balls to attempt that for the first time, unless i had a bunch of throttle bodies.
 

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Wow, I might try to do this and see what happens. -B
 

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Discussion Starter #8

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Just did mine, followed the instructions, 100% correct.

Throttle response is 10X better, specially with the turbo, the car now breaks the tires loose HARD in the 1-2 shift unlike before due to the lag when I shifted, not any more.

I believe that my car since day one was not opening the throttle 100%, Id say maybe 95% because now the car pulls harder up top on all gears, which has nothing to do with DBW lag. So guys with Haltechs, CHECK THAT BUTTERFLY.

Idle right now is a little low, I need to screw the small allen to get the revs a little higher or just tight a little more the throttle cable.

Im getting the limp mode sympton where the gas pedal goes dead but I believe it has to due with the TPS plug which is a little toasted from the heat. Ill fix that and see if I get rid of the limp mode which comes on and off.

AWESOME MOD. A must of your turbo with a manual tranny. +rep
 

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how much slack is left of the throttle cable when the throttle assembly is clocked?
i dont like the idea of snipping off a piece of the throttle cable
ill take a look at it and try it out w/o cutting the throttle cable
 

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Discussion Starter #12
how much slack is left of the throttle cable when the throttle assembly is clocked?
i dont like the idea of snipping off a piece of the throttle cable
ill take a look at it and try it out w/o cutting the throttle cable
There is no way to make it work without cutting the cable. There is too much slack for it to work. If you cut the cable and need to go back to stock, you would have to purchase a new cable. I have no idea how much, but once you go without the DBW, you probably will not want to go back anyway.
 

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Discussion Starter #13
can u do this with out a ems? or does the stock ecu freak
I have no idea. You would have to try it and see. I do know that the CC still works so the stock ECU must be atleast somewhat OK with it ;)
 

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Anybody have any suggestions on what bare minimum EMS that could be used with a cable throttlebody setup?(on an NA motor)
pick your choice of any standalone fuel and ignition system.
 

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This is my number one complaint about the IS. It drives me crazy when I heel toe down shift and the vacuum to the brake booster goes away because Lexus thinks I need help driving and hangs the throttle open for what seems like eternity. In the meantime I just twiddle my thumbs waiting for my brakes to get their vacuum boost back... then about the time the DBW releases the throttle and I get vacuum it is time for another downshift and the whole cycle starts again.

This is my theory anyways on why the IS brakes so inconsistently when rev matching under braking. None of my non-DBW cars have ever felt this way when rev matching.

I am running the stock ECU so I need to find a reversible way to do this mod just in case the stock ECU wigs out.

I was just about to buy a spare T/B that I could hack up somehow in hopes of disabling DBW. This thread gives me hope.

Thanks htekwo!!

+rep
 

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noob question, what does dbw stand for?

drive by wire?
DBW = Drive By Wire.

On older cars there is a cable that physically connects the gas pedal to the throttle. Today auto manufactures do away with the cable and replace it with a sensor on the gas pedal that the ECU monitors. When you press the gas the ECU sends a signal over a "wire" to a stepping motor that is connected to the throttle body. They are mainly doing this to make traction control and cruise control work better but unfortunately they are also doing stupid stuff like smoothing out spikes in pedal application, not letting you press the gas and brake pedal at the same time (trail braking ; thank god the IS doesn't do this) and the most aggravating thing which the IS is real bad at is holding the throttle open even though you have completely let off the pedal. They do this for people who drive manual tranys so when you up shift the revs drop slower giving you more time to upshift without the revs dropping bellow the next gear. My right foot is fully capable of doing this.. I don't need the car to do this for me. People like Honda do this better. Honda drops the revs just enough for the next gear and then hangs there.. if you don't let the clutch out the revs will then fall off rapidly. The IS just drops the revs all the way to idle at a very very slow pace. It feels like it has a 300lbs flywheel. :)

Anyway.. that is DBW in a nutshell.

BTW, some people (car salesmen :)) will argue that the IS isn't DBW because it still has a cable running from the pedal to the throttle body. Toyota just put the sensor on the throttle body instead of putting it directly on the gas pedal.
 

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Discussion Starter #19
DBW = Drive By Wire.

On older cars there is a cable that physically connects the gas pedal to the throttle. Today auto manufactures do away with the cable and replace it with a sensor on the gas pedal that the ECU monitors. When you press the gas the ECU sends a signal over a "wire" to a stepping motor that is connected to the throttle body. They are mainly doing this to make traction control and cruise control work better but unfortunately they are also doing stupid stuff like smoothing out spikes in pedal application, not letting you press the gas and brake pedal at the same time (trail braking ; thank god the IS doesn't do this) and the most aggravating thing which the IS is real bad at is holding the throttle open even though you have completely let off the pedal. They do this for people who drive manual tranys so when you up shift the revs drop slower giving you more time to upshift without the revs dropping bellow the next gear. My right foot is fully capable of doing this.. I don't need the car to do this for me. People like Honda do this better. Honda drops the revs just enough for the next gear and then hangs there.. if you don't let the clutch out the revs will then fall off rapidly. The IS just drops the revs all the way to idle at a very very slow pace. It feels like it has a 300lbs flywheel. :)

Anyway.. that is DBW in a nutshell.

BTW, some people (car salesmen :)) will argue that the IS isn't DBW because it still has a cable running from the pedal to the throttle body. Toyota just put the sensor on the throttle body instead of putting it directly on the gas pedal.
With the DBW disabled, the revs drop almost too fast! If you don't engage the next gear, you sometimes have to re-rev to match the gear! I was just thinking yesterday that it almost feels like a light flywheel, but I didn't use one.
 

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With the DBW disabled, the revs drop almost too fast! If you don't engage the next gear, you sometimes have to re-rev to match the gear! I was just thinking yesterday that it almost feels like a light flywheel, but I didn't use one.
Great.. this is what I have been wanting. I have an Integra with a 9lbs flywheel so I am used to the revs dropping like a ton of bricks. :)
 
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