Roadworthy

Two weeks ago the car's front suspension was a mess with massive toe and a 4x4 stance.  I am happy to report the car is home now with a sporty ride height and good alignment thanks to shorter Swift springs and hard work from Yawsport.

We bailed on the original plan to use Todd's camber plates because of suspension travel and tie rod issues.  Utilizing Todd's trick design gives alot of caster and camber, but the strut mounted tie rods run out of adjustment well before the camber plates limits are met.  Custom length tie rods would solve all the alignment issues but are not allowed per the ST* rules.  Top mount camber plates are on the design board, but in the meantime a semi-custom bottom mount setup adds over an inch of strut travel while still maintaining similar alignment parameters available with Todd's plates.

The current front ride height is conservative until I can run a few autox laps and determine range of travel and bump stop clearance.  If and when the front suspension ride height is lowered it should change the tie rod angle in a good way that could allow more camber/caster at the current toe.  Right now the front camber is about -3* with 1/4"+ total toe out. Rear camber is -1.5* with 1/8" total toe in.

Feels like a new car with the firm suspension and all new front bushings and motor mounts. Thrashed the car on some twisty roads for the drive home and it is much more confident, precise, and agile.  Drove it hard enough to stink up the brakes or clutch.  Ride is very firm, but not nearly as jarring as I expected, well at least not on the current spring rates and damper valving.  Initial impression is that the rear shocks may be under damped.  Got some funky rear dynamic toe / bump steer too.

Below, the left picture shows the SPC upper rear camber arm and Bilstein ASN shock with Swift springs. Also visible is the 27mm Hotchkis swaybar.  The right picture is the 'before' variation of the front strut.

          

At The Shop

Shock and strut assembly and install has begun.

Rear shocks are Bilstein ASN with 70mm 6" Swift main springs and Swift helper springs.  Swift thrust sheets are utilized at all the spring contact points.  A simple adapter keeps the upper spring seated and centered within the oem top mounts and heim spacers for the lower eye mount complete the basic install.  With a race ready ride height, rear suspension travel and range of adjustability appear to be very good.

Front struts are Bilstein B8 with 2.5" ID Swift springs and Swift thrust sheets with planned use of tender or helper springs. The struts are oem length and Todd's camber plates mount to the underside of the strut towers which creates a problem with ride height and suspension travel.  Just over an inch was removed from the internal strut bump stops, but the assembly is still too long for the ride height I am trying to achieve.

There are a few ways to solve this problem.  One is to shorten the internal strut and strut housing, which is an expensive and complicated procedure.  Two is to machine the strut stem to eliminate the 'step' and allow the strut to rise higher into the top mount.  Third is to use alternate camber plates that mount to the top of the strut tower instead of below it.  The least expensive and most simple current solution is to use option number three which could gain up to 2" of travel over the current configuration.  Will that be enough?  Maybe a combination of option 2 & 3?

Of course there is another option; buy 8611 DA Koni inserts and start over.  If the internet chat rooms are to be believed, the 'race' koni strut inserts are short enough to use Todd's camber plates and maintain a low ride height.  Major drawback is the strut tower prevents top strut adjustment when set at max caster.

Todd's camber plates are preferred because they give alot of caster which relates to great dynamic camber, but because they need to mount underneath you lose valuable travel unless the struts are very short or a stock ride height is preferred.

The Hotchkis camber plates are a top mount design no longer in production and difficult to find. The range of adjustment is not as good as Todd's, but suspension travel will be gained.  Custom camber plates on the menu if used parts are not found.

Toe is also a major concern.  Due to the steering arm location on the strut housing, maximum camber and caster settings at the strut tower can result in toe changes that cannot be corrected by using the standard tie rod ends. A delicate combination of ride height and top strut alignment settings can get toe back to zero.  One or two pairs or camber bolts at the strut mounts can help the alignment issues without affecting toe.

On the lift, Yawsport installs new Mugen compliance bushings and Hardrace front control arm bushings.  New NAPA lower ball joints are replaced too. Mugen also supplied upgraded motor mounts for the left, right, and front locations.

Debut Autox

Our local region hosts a championship autox event the weekend after SCCA Solo Nationals and my MX5 is not home yet so I throw the Hotchkis rear sway bar and some tools into the car and head to Qualcomm Stadium.  Tires are very old 225/45-17 BFG Rivals on 17x7 Kosei wheels taken from my Mazda.  Two tires were already blistered so I put those on the back.  50 psi front, 35 psi rear.

The swaybar bracket holes are slotted bigger than I think they should be and I did not have new bolts or any washers .  After my runs I discovered that the bolts were barely loose with one being backed out about 1/4".  This may be one reason why the car slightly tightened up during my runs.  I re-torqued all the bolts and two days later everything seems fine - no stripped nuts or damaged threads.  A future trip to the hardware store will get me some new bolts and large washers. Also gonna keep my eye on the bushings and brackets as I think the left one is looser than it should be - replacements are $20 / pair.  I positioned the endlinks on the soft outer setting for today's adventure.  Stock swaybar weight is 6.75 lbs.

The stereo subwoofer is unique for the Type-S and is secured in the spare tire with one long bolt. I removed it all to save weight.  The subwoofer can be installed without the wheel/tire but is much more solid when assembled as designed.  With the factory supplied hardware, the spare tire cannot be properly secured without the subwoofer.  The spare is reported to weigh 28.5 lbs. and the subwoofer is reported to weigh 6.5 lbs.

The driving experience was better than I thought.  The course had a few long straights and fast kinks with a couple slow sweepers and a small slalom.  I was able to stretch the legs of the K20 engine and it pulled hard and smooth all the way to rev limit. The brakes worked fine for what I assume is OE equivalent pads and old brake fluid.  ABS is too intrusive and something that I will have to adapt to.  With positive front camber and practically zero caster, the handling is what I expected - pushy - and as mentioned above an 'active' rear swaybar probably did not help.  The old tires certainly did not help as the fronts blistered, peeled, and corded about half way through our session.  

Hood open between autox runs to help cool the engine I notice oily fluid sprayed beneath the power steering reservoir.  Might be a leak at the lower non-pressurized hose but I cannot find a problem.  Fluid is full and PS works fine. Engine oil is full also; no leaks.  After my third run I notice the engine note has changed and minor vibrations can be felt through the gas pedal.  I press on with uncertainty fearing the worst and complete my runs and park it in the pits to cool down.  Post event bench racing with the hood up we notice the engine side (passenger) motor mount is damaged - the oily mess is from the fluid filled mount and the vibrations are from the busted mount being metal-to-metal.  Such a relief to know it was nothing worse.

Suspension Pieces

 
   I am teaming up with YawSport to help with the suspension fabrication and setup.  Front Bilstein struts, originally designed for a Civic SI will have the steering arm reworked to accommodate the RSX tie-rod taper and stock oem spring perches will be cut off and replaced with threaded coilover sleeves.  The strut inserts will be sent to Bilstein for revalving.  11.20 lbs each as pictured.

Here is what Todd's camber / caster plates look like.  These are daVinci Designs Version 1. Allows maximum 7* caster without slotting or cutting the strut tower.  Each plate weighs 3.25 lbs.

Version 2 is a much more simple design with fixed maximum caster, but I got these V1 plates used for a good price.  The upper spring perches are for 2.5" springs.  The shoulder nuts pictured are sized for the 14mm PSS9 shaft instead of the 12x1.25mm shaft on my B8 Bilstein struts and new replacement parts are not available at this time.  We may need to custom machine new parts.  Also need to sleeve the upper  perches to precisely fit the strut shaft.


Keeping an eye on the classified section at ClubRSX and I scored a used Hotchkis rear swaybar.  No longer in production and originally priced at a whopping $400, this one is 27mm diameter hollow with two adjustment holes on each arm and room to drill another stiffer hole if required. Weight 7 lbs with brackets and urethane bushings.

Offset

18Racing via Ebay delivered my new wheels yesterday.  15x7.5" 5x114.3 Rota Slipstream.  Advertised and sold as a +40 offset but they are actually boxed, stamped, and stickered as a +35 offset. Backspace measures 5 5/8" or 34.9mm.  Weight 13.45 lbs.

This could be a good thing because front brake caliper clearance is a concern. And depending on ride height, camber, and tire size, the lower offset could also cause problems with outer fender clearance.

Test fit without tires or any suspension modifications and all is good with plenty of clearance everywhere.  Just about a quarter inch clearance at the front brake caliper.  Due to the curve of the spokes it is difficult to tell if the +40 offset wheel would hit the caliper or not.  With a planned moderate drop in ride height and a much shorter tire than stock I do not anticipate any tire to fender rubbing with the +35 offset, although if needed fender lip rolling is allowed.

Fix It

I took the RSX to Rocky at Miatomotive to see what the exhaust leak was all about.  Only happened under load so I assumed it was the 'donut' between the oem header and cat midpipe.  Correct diagnosis and the car is now quiet again.

Here are some random pictures while the car was on the lift.  California car, one-owner, unmolested.

And while I was putzing around I changed out the stock wheels for some Kosei K1-TS 17x7 +50 wheels form my MX5.  The 16x6.5 OEM Acura wheels look fine and the tires are decent, but I will not deal with Honda's stupid convex or ball lug seat and required lug nuts.  With the amount of wheel changes I will be doing I need to stick with one design.

And a couple more pictures of the stock suspension.

My First Honda

Today, I bring home a 2002 RSX Type-S.  Desert Silver exterior color with a tan leather interior.  162K miles.  All original, accident free, one owner, and dealer serviced. A few items of concern; the original clutch engagement point is rather high and there is a minor exhaust leak under load between the manifold and cat mid-pipe.

Twelve years old and this car is solid and well built with quality materials and good fit and finish.  Drives beautifully and everything works.  Dare I say it is too nice to hack up for autox.

Here is another tire gearing calculator that I found.  This one does not have a 'fudge factor' so use the data wisely.  MFactoryCalculator