Project EP3 Civic Si: Suspension Upgrades with Whiteline!


Whiteline also provided us with an assortment of their high-quality polyurethane bushings so we could get rid of the compliance caused by squishy rubber, adjust the rear camber and improve the geometry of the front suspension.

This cool bushing is for the front of the front lower control arm. It has a solid middle to resist excessive moment under cornering and braking but has cutouts allowing the control arm to pivot and articulate without binding like some solid bushings will.

The coolest feature is the metal insert that is offset to the inside. This will cant the lower control arm forward increasing positive caster by 0.5 degrees. This helps straight line stability, gives the numb Honda electro-hydraulic steering some more much-needed feel and makes the outer tire have more negative camber under cornering helping to reduce understeer.


The front urethane bushing has a molded-in insert of slippery plastic, making the bushing much less likely to squeak. Squeaking bushings is an issue that all urethane bushings fight and Whiteline has done a great job of reducing this. The insert also reduces static friction which improves the ride.

The upper rear suspension link will use this Whiteline bushing with an eccentric inner sleeve. This will allow the camber to be adjusted.

These bushings will replace the soft rubber inner link bushings that are located in the rear knuckle.



  1. I installed the Whiteline RSB this weekend. WOW, I did not expect the dramatic difference in balance it would make. It really improved the car’s handling on the old stock suspension with +135k miles on it. Greatly reduced the plowing effect and the car will actually rotate now when pushed hard! Also seems to have fixed the weak rebound I was experiencing in the rear [but didn’t notice until now]. I love it!

    One question, the instructions from Whiteline said to sandwich washers between the bar and the endlink inner nut and locknut. Did you guys also do this? I’m using Hardrace rear endlinks and with washers in place the bolt is barely long enough to clear the width of the locknut, full thread engagement on the nut, but no extra threads left sticking out. I understand not having the nuts eat into the RSB, maybe I just need thinner washers?

  2. 2005 Honda Civic Si project. I want to upgrade the suspension on my 05 Honda to improve handling using the parts on your webpage. Can u provide a list of the items I will need to do the upgrade. Can I come in to pick up the parts for purchase? I would like to get the parts asap and come in to get them. I live locally in SoCal. Please advise.

  3. Reference EP3 Suspension Project. 30:41 video. WOW, I’m blown away! Not super mechanically inclined, but after spending a good amount of time researching, still can’t figure out whiteline special? bushing part numbers for the 12:06 time in the video (2 items), and 12:08 time (4 items) ? PLEASE PLEASE assist.
    Thank You for helping ALL the EP3 enthusuiasts ! You are the BEST ! Thank You Mike Kojima and the team! HUGE support for us Yes, I’m doing the majority of this project ! Super Excited

    1. At 12:06, those are the KCA424 bushings –
      At 12:08, those are the W63381 bushings. They only seem to be in stock on the UK website -

      Maybe because these chassis are not the most popular, it seems that Whiteline might not have the stock like they did when the Moto IQ video was made. It might be worth contacting someone at Whiteline to see what their actual availability on these parts is.

      Just purchased an EP2 here in Europe after owning an EM2 in the US and hope to make some of these improvements myself.

  4. Charles, the W63381 bushing is for the rear lateral arm the video has some photo discrepancies. I think David was looking for the 2 bushings being pointed a few seconds earlier in the video. If that is the case then I believe he is looking for the 2 front lower control arm bushings. He’ll have to confirm for us that’s what hes after.

    As for W63381 being sold out I think the main reason they are possibly discontinued is the abundance affordable aftermarket arms that replace the thin oem arms like these

  5. read the whole article on this website, and have watched the video several times over. i purchased the whiteline camber bolts for my front suspension on my 2005 honda civc si. per the whiteline doc that came with the bolts i installed them on the upper strut damper bolt. and put the apex of the lobe pointing to the inside of the engine bay for a `A` camber effect.

    is this how yall installed the bolts? i did not see any video footage in the youtube video of the bolts installed and their orientation nor did i see any pictures of the bolts within this 7 page article. look forward to your response.

  6. hey Mike, if I farm out this project to a local mechanic, how many hours of labor roughly speaking do you think all of this requires? and roughly the cost of parts?

  7. Good day
    In regards to the trailing arm bushings, it was mentioned that they used the OEM rubber trailing arm bushings, but what about the harden rubber trailing arm bushings from hard race or the powerflex trailing arm bushings

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