Best mod I ever did since owning my GS430
03-29-09, 03:05 PM
#32
found it! but it wasn't brown, it was a blue box for me for some reason.
I drove around with the ECU unplugged and to be honest, I think it needs some tweaking. If you're used to the NA1, yeah it might work for you. But at 0-5mph range, it feels like you have NO power assist. Parking does require a lot more power. But once you're going, it's great. It doesn't handle any better but I think it does give the delusion of the car steering more directly.
If we can develop some sort of speed sensitive module or to turn it on once you go below 5mph, I think it'll be great.
I drove around with the ECU unplugged and to be honest, I think it needs some tweaking. If you're used to the NA1, yeah it might work for you. But at 0-5mph range, it feels like you have NO power assist. Parking does require a lot more power. But once you're going, it's great. It doesn't handle any better but I think it does give the delusion of the car steering more directly.
If we can develop some sort of speed sensitive module or to turn it on once you go below 5mph, I think it'll be great.
03-29-09, 05:04 PM
#34
I just got done installing my control arm bushings (caster only), and I already have the steering rack bushings. The steering is now smooth and tight. The problem is, it's been at least 3-4 years since I drove a BMW 330i so I already forgot how communicative it is. Hopefully the additional ECU disconnect mod brings me one step closer to that magical BMW steering 
03-29-09, 05:25 PM
#35
This mod will only add stress to the already weak lower ball joints guys! You are basically removing the power assist. That power assist will be needed come emergency maneuver time.. Basically, this mod can be done on any car with power steering. I would not do this mod at all if I were you guys..
03-29-09, 11:05 PM
#36
This mod will only add stress to the already weak lower ball joints guys! You are basically removing the power assist. That power assist will be needed come emergency maneuver time.. Basically, this mod can be done on any car with power steering. I would not do this mod at all if I were you guys..
I believe all this mod is doing is keeping the solenoid that controls hydraulic fluid to the steering racks reaction chamber to remain fully open, thus the increased steering effort. When the solenoid closes a little, it restricts fluid flow into this chamber thus lighter steering effort. I believe Lexus calls this their PSS, or as I have researched on google "Progressive Power Steering" and that is controlled via the steering ECU. From what I understand, the steering ECU receives VSS signals to know how fast the vehicle is traveling, and sends out the appropriate current to the steering rack solenoid. The faster the car is traveling, the lower the current, the more open the solenoid valve is, the more fluid goes to the reaction chamber, the more effort it takes to move the steering wheel. Disconnecting the ECU should just mean zero current being applied to the solenoid to maximize fluid in the reaction chamber. For the owner in my reference link below, this resulted in too heavy a steering feel. For me, its fine, but I like his idea of a variable resistor so he can fine tune the feel. An automatic electronic variable resistor control would be ideal though. In fact, that is what the power steering ECU really is. One could just modify the resistance in the steering ECU and basically have an L-Tuned ECU only with their own preferences. I may end up doing that myself.
Anyway, here is the link I used for my research.
http://autospeed.com/A_110778/cms/article.html
03-29-09, 11:55 PM
#38
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For those wondering about the above posts with causing excessive or any wear on the steering system, it is false.
The reason why it cannot cause any more wear or stress is simple.
This mod is still sending (from the rack) the same amount of pressure to the tie rods.which in turn move the knuckle/wheels .
The only effect is from the rack back to the steering wheel which now requires you to turn with more effort but the same amount of travel. By doing this it just increases the feedback /effort . If it were to wear anything it would be the steering wheel U joint under the dash from parking where the car is static.
BTW it is not the ball joints and control arms that are weak that i see so many people mentioning in this and other posts it is the strut bars which are dead and allowing too much movement to all the other componets thus causing them to wear from thrust pressue from being out of alignment.
The reason why it cannot cause any more wear or stress is simple.
This mod is still sending (from the rack) the same amount of pressure to the tie rods.which in turn move the knuckle/wheels .
The only effect is from the rack back to the steering wheel which now requires you to turn with more effort but the same amount of travel. By doing this it just increases the feedback /effort . If it were to wear anything it would be the steering wheel U joint under the dash from parking where the car is static.
BTW it is not the ball joints and control arms that are weak that i see so many people mentioning in this and other posts it is the strut bars which are dead and allowing too much movement to all the other componets thus causing them to wear from thrust pressue from being out of alignment.
03-30-09, 06:31 AM
#40
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Now, I do see that it may cause wear & tear on the rack & or pump but not the ball joints.
03-30-09, 10:10 AM
#42
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I just tried it at lunch with my 400 but I disconnected the 2 wire connector on the pump itself. I only drove it around a parking lot to test it out though. Its okay while your moving but it is stiff while parking or sitting still. It's not THAT stiff but it is too stiff for me. I was not able to turn the wheel with one finger and thumb. At least not while standing still.
Last edited by KiPod; 03-30-09 at 11:00 AM.
03-30-09, 10:27 AM
#43
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I installed the L-Tuned ECU years ago and it took out a lot of the sloppy steering without having to adjust the pre tensioner on the Rack. I didn't like the sloppy steering of the OEM ECU after having installed the L-tuned S/S.
03-30-09, 10:53 AM
#44
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I changed the Steering ECU in my 400 as well (I used a SportDesign ECU). The ECU does help a little. Leaving the ECU disconnected is on a completely different level than swapping ECU's.
