Project EP3 Civic Si: Suspension Upgrades with Whiteline!

So everyone into Hondas just about universally ignores or even hates the dumpy EP3 Civic. The EP3 represents, to most Honda fans, the generation of Civic where Honda lost their brand identity and started to make cookie cutter shitboxes.

Who can blame them; the much loved sixth generation EK was the peak of the Civic’s development. It was good looking, lightweight and featured excellent handling with 4 wheel, multi-link suspension.

The seventh generation EP was Honda’s first step to decontent the Civic to make it cheaper to produce and bigger. The EP was supposedly designed to appeal to a theoretical early 20’s, single, female, college graduate named “Buffy” who just got her first professional job. (Can you believe this is the BS the PR guys spouted at the cars intro?).

Well, it was obvious that Buffy was not a car enthusiast. The EP had dumpy, boring styling. McPherson struts took the place of the multi-links in the front suspension and flaccid handling and understeer was the name of the game. Honda Civic fans were heartbroken. To top it all off, the front steering geometry was designed for ease of fitting a steering column with no regard for bump steer.

As a result, the EP3 is the least desirable of all the Civics and probably why we got ours for so cheap. On the positive side, the EP is the least likely Civic to get stolen! One of the EP’s worst traits is its handling, and we will do our best to improve it.

Previously, we have paved the way for better suspension by upgrading our EP3 with RSX Type-S parts, a 5-lug conversion, and bigger brakes. Now we are going to install some Whiteline bits to give our cars handling a needed boost.

To read more about Project EP3 check here!

To help get the EP3’s large amount of body roll under control, we got a set of antisway bars from Whiteline.

The Whiteline bars are much larger in diameter than stock and add considerably to the overall roll stiffness. They also add more roll stiffness to the rear in proportion to the front to reduce understeer that the EP3 has in droves.


The front Whiteline bar is 24mm in diameter. This is one mm in diameter more than the stock 23 mm bar. This makes the Whiteline bar about 20% stiffer than stock.

The rear Whiteline bar is 24mm in diameter- up from the stock bar’s 15mm in diameter. This makes the rear bar about 5 times stiffer than the stock bar!

Both the front and rear Whiteline bars are 2-way adjustable. Going to the stiffer, inner position makes the bar about 20% stiffer than the soft position.

Although we are going to use a set of Fortune Auto coilovers on our car that have camber plates, we also wanted to install these Whiteline camber bolts to the struts.

The bolts allow for 1.5 degrees of camber adjustment. We like to use the camber plates to set the steering axis angle and adjust that to minimize the scrub radius, which is critical on an FWD car. This is especially important for one with a lot of bump steer like the EP3. Too much scrub makes bump steer feel worse.



  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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