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Discussion Starter · #1 ·
After installing my rear KW's saturday, I realized there wasnt a tutorial for fooling the 4C. There are multiple threads with instructions but no pictures. If you are like me, you are a picture based learner. So here is a quick tutorial for making the 4C buttons still work and making sure you dont get a message in the DIM. Useful for folks who are going with air ride suspension or coilovers. Works on 04-07 S60R / V70R.


Stuff you need:

old 4C struts

a 4 1/2" grinder with a cutting disc OR or sawzall with a metal blade (7 tpi is good)

electrical tape / shrink wrap

spring compressors

18 / 19mm offset wrench

T40 torx bit



step 1:

take out the old struts from your R. Pretty straight foward. 4 bolts in the rear, 5 bolts and remove the endlink for the front. Many people choose to disconnect the 4C plug, when i saw how hard it was to access the plugs, (especially the rear) I just cut the wire, and reconnected and soldered them.


step 2:

REAR SHOCKS INSTRUCTIONS

use your spring compressors and crank down the springs. I started with the rear shocks on my car. once the spring is clamped down, use a 19mm wrench and a T40 to remove the perch / spring seat. I bought a set of these at sears namely for this job, and they work like a charm:

craftsman_passthru by Gabriel Simutiu, on Flickr


take the spring off afterwards.

step 3:

take your grinder / sawzall and make a cut about 1/8" of an inch from the body of the strut like so

Kws by Gabriel Simutiu, on Flickr


once you see / smell oil, take the shock and push the shock up and down, to push all the oil out. about 8-10 oz. of oil will come out. I recomend to do it outside.

Kws by Gabriel Simutiu, on Flickr


step 3

cut through the rest of the body of the 4C inducer, till you have just this:

Kws by Gabriel Simutiu, on Flickr


step 4

with your grinder / sawzall, make two cuts on the side, opposite side from each other. you dont need to cut deep, maybe 1/8" of an inch. once you have made cuts on each side, use a hammer and chisel to seperate the halfs. Go gentle, the inducer is inside of it. Refer to photo in step 3 of front shock instructions.

Kws by Gabriel Simutiu, on Flickr


the result: the bare inducer!

Kws by Gabriel Simutiu, on Flickr


step 5


shrinkwrap or wrap the inducer in electrical tape, wrap it multiple times, to make a watertight seal. This is your end result

Kws by Gabriel Simutiu, on Flickr


now, plug the sensor back in if you traced the 4c all the way to the plug, or just strip and splice / solder the wires together. find an area to ziptie / secure the sensors to, and you are done with the rears!



FRONT SHOCK INSTRUCTIONS

step 1

make a cut roughly where you see the mark in this picture:

Kws by Gabriel Simutiu, on Flickr

step 2

cut around the inducer as shown

Kws by Gabriel Simutiu, on Flickr


Kws by Gabriel Simutiu, on Flickr


step 3

make two cuts again on opposite side of the inducer, and use a hammer and chisel to seperate the halves.

Kws by Gabriel Simutiu, on Flickr


step 4


again, wrap the inducer in electrical tape / shrinkwrap, reinstall. Then go ahead and install your airbag suspension / coilovers / bro truck 12" raise :)


Many thanks to VR420MAN for several of his pictures, as well as me. I hope this was of help to you!
 

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Nice, so how do you like the KW's and what mode are you driving your caR in now? If I were on stock style tune (IPD or equivalent), I would be in Advance all day long with the KW's... gotta love that throttle response.
 

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very nice!
 

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Discussion Starter · #4 ·
i still have 4C in the front, the pictures for the front struts are from VR420MAN. I forgot to order front strut bearings / spring seats, and i didnt want to do the job twice, so Ill be replacing the front 4c shocks with KW's saturday, so I still drive on the highway in comfort mode. but now that the suspension rake is gone and there is some rear camber, I get a lot more thumbs up on the highway ;)
 

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Excellent to see with pics..... Thanks man! :thumbup:
 

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I'm an idiot for throwing my old front shocks away. Definitely should have cut out the doohickeys just in case.
 

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Lol!
 

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Awesome!!

Sent from my SM-G900V using Tapatalk
 

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Couldn't you just attach a resistor to the lead wire to simulate the response from the sensor, instead of doing all this work?
 

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damper electrical load impedance = probably more inductance than resistance

Couldn't you just attach a resistor to the lead wire to simulate the response from the sensor, instead of doing all this work?
Something like that...

iirc, Dougy's (inadvertent missing bolt or other ferrous core?) experiment revealed that the inductance of the load is critical. Coils have inductance (which changes when an iron core is inserted inside the windings). The thing about inductors is that they have back-EMFs: when you run a (direct) current through a coil, a magnetic field is produced. When the current flow stops, the field collapses, inducing a backward current flow.

I'm still studying the SUM, but what I've leaned so far tells me that the output devices (they look like transistors but they're fancier...) are specially designed and built to witstand back-EMFs, making them ideal for driving PWM direct current through solenoids. I also know that each output channel of the SUM has what amounts to a built-in ammeter, so it can check current flow, though I don't know for sure that it's looking for (trying to measure) the reverse current flow that only an inductor would provide, but that seems likely...

In any event, there is nothing magical about what's inside a 4C variable damper, and any similar electrical load with a similar inductive component (like, say, a solenoid, or a bolt or ferrous torroid with the right geometry and armature wire wrapped around it, possibly in series with a resistor) will undoubtedly fool the SUM (...with less mess and hassle) equally well.
 

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Considering what's involved I should just set up a test rig to see what the circuit impedance is and make a plug in replacement to save people all the chop saw work, lol.
 

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Considering what's involved I should just set up a test rig to see what the circuit impedance is and make a plug in replacement to save people all the chop saw work, lol.
Kind of what I had in mind. Recreate the signal with a simple plug in device. I just don't have a front set of struts to work with. I bought my car with non 4c struts up front already. I'd like to fix that dash message and also prepare for when I have to replace the rear.
 

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I've been monkeying with it off and on. As I've mentioned before, I've used a speaker to trick the system. I'm trying to find something that's smaller and doesn't beep....
 

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Discussion Starter · #17 ·
I chose to go this route because:

i already had 4C struts

from start to finish it took me about 10 minutes to remove the sensors from both rear struts

i'm not a pansy when it comes to using power tools ;)
 

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Considering what's involved I should just set up a test rig to see what the circuit impedance is and make a plug in replacement to save people all the chop saw work, lol.

As I was putting my caR back together last week I measured the 4 dampers' DC resistance at the SUM: 4.7~4.9 ohms, which accounts for how/why a speaker('s voice coil) is in the ballpark...
 

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So uhhhh...anyone want to sell me their old 4c struts? :)
Well, I've got two front 4C struts sitting in the garage if you're interested. I live in WA State if that is of interest.
 
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