Project Budget Integra - Tech

One major complaint of the fantastic Integra chassis is the street car flex in the rear suspension that accounts for unwanted toe change. We replaced the aged stock trailing arm bushing with a new one as it offers the best balance of flex, ride quality, and serviceability. The toe and camber (not seen here) link were replaced with pieces from SPC Performance. These links do not carry the weight of the car, so we could afford to use stiffer parts with less slop and less free play friction while still not transferring significant vibrations.

One major complaint of the fantastic Integra chassis is the street car flex in the rear su

Less Toe Slop
While stock durometer OEM rubber bushings are great for NVH and compliance, their use can be a double-edged sword. The compliance they offer in the vertical axis for ride comfort has the disadvantage of lateral compliance. This basically means the rubber bushing can also move side to side, which causes unwanted toe change, making precise cornering a little less predictable. On the front suspension, toe is controlled with the steering tie rods, which have little slop except in the ball joint connecting the steering rack to the hubs. In the rear, toe change is constrained by a toe link at the front of the rear-trailing arm. The cost saving stock link, while plenty strong, still uses rubber bushing inserts that soak up vibrations, but inherently have a little slop.

We replaced these with SPC Performance rear toe links (PN: 69450). We really didn't need the additional length adjustment on top of the slotted OEM toe adjustment, but the aluminum heim-joint links have essentially no slop or deflection since it uses metal spherical bushings. We can also adjust toe more precisely with the link length (even though tool clearances are limited) instead of monkeying with the stock slotted adjustment. While heim joints are more prone to wear and transmit more vibration, these links are oriented so that there is little movement as the suspension travels, so wear is not as severe as in a control-arm bushing or pillow-ball upper mount. The links also role play very little in transmission of vibration due to its role in how the rear suspension articulates. SPC also offers a single heim joint version of the toe kit (PN: 69250) that uses a solid mount on the slotted chassis mounting side of the link, but we chose the 69450 since our softer street car suspension requires more stroke and thus has more trailing arm and toe link articulation.

The SPC Performance adjustable camber link allows us to change the rear camber since there are no factory adjustments. We dialed it in for -1.0 degrees at static height, which is near what the stock suspension sits at once lowered. Our car was lowered minimally for street use, but dumped cars will need this to increase static camber back to a reasonable range.

The SPC Performance adjustable camber link allows us to change the rear camber since there

Rear camber also got the same treatment with SPC's rear camber link (PN: 67030.) The EZ Arm XR adjustable camber link doesn't use heim-joints, but does have thinner hard rubber bushings than stock that don't deflect as much. Now we can adjust rear camber for our slightly lower ride height, which the factory doesn't offer. For now, we left the link at roughly stock length since the car was only slightly lowered (more on this later) which increased static camber just enough for our purposes. The main point of the camber link was again to degrease slop.

In the front, we opted for a complete adjustable upper A-arm from SPC (PN: 72150.) The forged aluminum arm replaces the entire stock upper arm for a slight bit of weight savings, but more importantly hard rubber inboard bushings and a polyurethane ball-joint bushing that can adjust for between -2.50 to +3.50 degrees of camber and -1.25 to +1.25 degrees of caster. The single point adjustment design is pretty ingenious. Camber is controlled by sliding the ball joint inboard or outboard in the slot and caster is adjusted by rotating the offset mounted ball joint in detented increments of 45 degrees to increase or decrease the swing angle of the front hubs. During installation, it's important to check the sweep of these arms to see if it will contact any sheet metal seams in the upper wheelwell. Our kit cleared without any plastic trimming or hammering.

Our front upper control arms were replaced with SPC Performance's forged aluminum arms. These arms are stronger and lighter while offering more camber, as well as castor adjustment for the front wheels.

Our front upper control arms were replaced with SPC Performance's forged aluminum arms. Th

For now the SPC control arm is a slight bit of overkill, since we don't need quite that much camber adjustment for our ride height, but the caster adjustment will come in handy later as we adjust for castor steer and compensate for the torque steer that will come with the jump in torque we're anticipating (hint, hint).

Coilovers For The Masses
Our first project Integra followed the trend and technology for the times. It came on lowering springs and a set of high performance replacement dampers. In all reality, the right combination of spring rate, spring height, stroke, and damping characteristics is more than enough for a street car.