Fine Tuning & Stuff

  Dyno tuning at MakSpeed in Temecula.  We focused on a safe A/F tune and also picked up some power and torque.  The base tune was a conservative Hondata file so additional gains were expected.

Static rear toe and rear camber.  At the current race height, approx 1.5" lower than stock and with 3.5* camber, the rear toe goes positive, or inward, as the ride height is lowered.  Rough estimate with toe plates is a 3/16" gain per inch of shock/spring travel (.590 motion ratio).  Previous rear suspension camber adjustments tell me that negative toe (toe out) is gained as negative camber is increased.

From looking at the forward mounted rear LCA oem bushings and reading Honda's press materials, I believe the dynamic rear toe goes negative (out) as the suspension compresses.

Honda News Release - - 2002 Acura RSX - - Chassis

During the El Toro Pro Solo I experienced oil loss back through the intake manifold during long hard left hand corners.  This resulted in brief power reduction and billowing smoke out the tailpipe.  I bought a cheap ebay oil catch can to help solve the problem.  The PCV should be to blame as it is located relatively low near the front of the engine and connected to the intake manifold via a small 4" hose.  I simply looped the catch can hose between the two fittings and mounted the can above the battery.

  So I got my hands on some Hotchkis camber plates for the RSX/EP3.  These are no longer produced and hard to find.  The design uses a bonded rubber bushing with a metal sleeve and does not change caster when installed per the instructions.  However, they can be 'flipped' to achieve an angled adjustment giving a combination of camber and caster, similar to the ebay plates I am currently using.  Unfortunately, the Hotchkis bushing design is not as precise as a spherical bearing and the unique bushing is a non-serviceable part and no longer available - the pictured bushings below had significant play. The plates do mount to the top side of the strut tower which does not take away valuable strut travel.  A good camber plate when new or if the price is right, but not what I need for the STF Acura.

  With $17 worth of 3/8" aluminum plate and some generic pillowball bearings, I work on fabricating my own front upper strut mounts, or camber/caster plates.  The basic design will be mounted above the strut tower with a simple fixed bearing mount and not adjustable.  Due to the limited tie-rod  adjustment and the strut mounted steering arm, I am going to set as much caster as I can get and then tweak camber based on available toe.  Strut articulation and upper spring perch clearance within the 80mm strut tower hole will be my limiting factor.  Version one may be slotted or re-drilled until I find the best alignment combination and then a final version should be fixed for maximum strength and to limit slipping.  Top mount design uses an 1/8" steel supporting ring below the tower and standoffs above the tower will give much needed bump travel.   M12 studs and full circumference spacers can reduce stress in this high load area.

Speedway

  The new front swaybar has finally been attached to the car.  It is a Speedway center with 3" offset aluminum arms.  Mounts are generic urethane with stamped steel brackets and the endlinks are from Blox.  One-piece collars from Ebay keep the bar centered.  Drop-down spacers are scrap aluminum bar cut and drilled to fit.

Currently only using the 1" spacers and the bar has about 1/8" clearance from the OBX header.  I have an assortment of thin spacers to drop the bar down more if needed.  As is, there is almost 4" of ground clearance at the lowest point with the ~24" tall tires.

 At near full steering lock there is tire interference with the arms at the center portion of the offset.  This is with the 24" tall tires and 50 offset wheels with which I daily drive.  I assume the shorter 23" race tires may clear due to the smaller diameter and lower offset wheels, however full steering lock is something not generally needed for autox competition.

The arms are nearly parallel or level with the ground and go under the front lower control arm.  The oem swaybar angled upward and set above the LCA but with the new bar's lower mounting location and straight arm configuration I feel it will function more efficiently and be easier on the endlinks if I stay below or even with the LCA.  This level arm setting uses the stock A-arm endlink mounting point with a 2.5" long endlink.  More adjustment holes can be drilled into the arms as desired.  Alternate custom endlink mounting tabs on the A-arms could provide more adjustment range and offer better ground clearance.

I don't expect this bar to do much and ultimately I may chose to remove it completely, but for now it fixes the binding issues with the EM2 Civic swaybar and still gives some roll control and adjustability while I fine tune the car's handling balance.