Project EF Civic Racecar: Fixing the Front Suspension

So far we’ve only been picking at the edges of our 1991 Honda Civic Improved Touring racecar.  It has been fun to autocross but before we take it to the track we need to go through it much more thoroughly than we did last summer.  This is a multi-piece installment as we will be going through the front and rear suspension, the brakes, the cooling system, the exhaust, the interior, and cover lots of other small details.  This car is now 34 years old, has 182,000 miles on the clock, and has been a racecar for two decades.  It was built on a budget and it’s time to give it the attention it deserves.  Along the way we will do lots of old car maintenance, improve the suspension and brakes, and make sure as many failure points are addressed before we take to the track.  Let’s dig in!

Project EF Civic Racecar's old front suspension. Everything is rusty, worn and old looking
Here is our old front suspension. Aside from the Ground Control Advance Design coilovers, it is entirely stock. The balljoints, tie rods, wheel bearings, studs, and control arms are all factory and are at least as old as the original build. Improved Touring is a fairly restrictive class: we must use factory arms and links. Dampers and swaybars are unregulated (though they must mount in factory locations if available). We can replace rubber bushings with bushings of any material, or spherical bearings where applicable. There are also some allowances for adding alignment capabilities in links or arms that do not have that adjustment. This means we need to be careful when shopping for parts as a lot of the popular aftermarket parts are not usable for us.
Front suspension gutted aside from the axles, coilovers, and tie rods
In an afternoon we had the entire front end out: uprights, control arms, tension rods, sway bar, brakes, tie rods, and front subframe. Yes I know you can see the tie rods here but it was getting dark and I wanted to get a photo before I lost the light. We will be reusing the swaybar and coilovers. Replacing coilovers is out of the budget for this year and unfortunately these are so old, Ground Control no longer services them. They’re not leaking so they should be OK for another year. The only better option for a front bar is from the CRX HF which is smaller and hollow so it’s softer than the DX bar this car has. Finding one isn’t easy though and we gave up after a few weeks of searching. All of the adjustable bars we could find on the market are bigger and that isn’t the direction we want to go right now.
Old front lower control arms. Rubber bushings are worn and split.
These are our original lower control arms. The EF Civic uses a unique version of Honda’s double wishbone front suspension. The front lower control arms use a single bushed arm and radius rod that goes to the front subframe. Later Civics and Integras used a more conventional single piece wishbone.
Kingpin Machine Outlaw front lower control arm. Shiny, gorgeous, and the spacers for the spherical bearings are held in with zip ties
We sent our old lower arms to Kingpin Machine to be converted to their Outlaw Lower Control Arm. Kingpin removes the old bushings, then has the arms bead blasted, shot peened, and zinc plated. Finally, they machine the bores for press fit sleeves and aircraft grade NMB spherical bearings. The finished pieces are works of art. These will remove all of the slop in our lower arms.
More detail of the Kingpin machine Outlaw control arm
Kingpin Machine’s arms offer a number of benefits over their competitors: first, they only use OEM Honda arms meaning you have the same shape and alloy Honda designed into the arm. Next, zinc plating will last longer than the paint most competitors choose. Third, aerospace grade bearings will last up to three times longer on the track than the lower quality bearings the competition uses. Additionally the shot peening process will greatly strengthen our arms making them durable enough for even the most abusive of track sessions. Finally, Kingpin blueprints each and every bearing they ship so you’ll have silky smooth suspension movement with zero stiction. Our old Project S2000 used Kingpin control arms. Grassroots Motorsport’s One Lap CRX has been using the same Kingpin arms for a decade of autocrossing, track days, tire testing, and street driving. There’s no better endorsement for durability than that.
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4 comments

  2. I absolutely loved the Kingpin spherical bearing setup on Project S2000. All that suspension work is going to transform the car. What can you do to stiffen the chassis within the rules?

    Reply

    1. Well it’s already got a rollcage and front strut tower brace. We can add a few more per the rules. I would like to add to the cage as it is very basic. Could use some extra diagonals.

      Reply

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