Project Trackday

A few minor things going on the last week.  I decided to lower the car a little bit to reduce the amount of wheel gap and lower the ride height by switching the perch settings on the koni sports.  Both front and rear shocks were set on the middle perches, resulting in a ride height of 13.5″ front, 14.0″ rear.

Top: Middle perch setting, Bottom: Lower perch setting

For the front I was able to get the spring compressor on without removing the shock from the car, however due to space constraints in the rear (namely the upper A-arm and drive axle) I had to remove the rear shocks to get the rear adjusted.  Current ride height is 12.875″ front, 13.75″ rear, though I do expect the rear height to still settle a bit more.  I’d like for the rears to sit at about 13.5″ but I’m not confident it will get there..

Also took the opportunity to change out the front brakes as they were just about at the end of their usefulness.

One shot front pad...

Going with vented blank rotors from a national chain auto parts store ($40 for two) and replaced the front pads with a set of new Carbotech XP10 pads I purchased from NASAforums ($75).  The A/C parts were also sold off (-$50) so the running total for the season is now at $750.

Was a little concerned initially about the brake bias difference between running the Carbotech XP10 in the front and keeping the EBC Yellowstuffs in the rear, but after doing some brake testing it seems to be very well balanced under braking.  Will get a better idea of how good these Carbotechs stand up when I head back to Gingerman next week.

A few more items off the checklist and a first chance to test out the new shocks this weekend.  Changed the diff oil with some Mobil1 75W90 GL5 diff fluid ($7) and flushed the brake system.  Fresh ATE Super Blue (extra inventory from 2009) in to get ready for the trackday in less than 1 month.

Sunday was IndySCCA’s first solo event of the year, starting out with a ‘fun event’ (i.e. no points awarded) at 16th Street/Bush Stadium in Indianapolis.  Was extra cautious in the first run because I did not know what to expect, but the car felt quite well balanced right off the bat (35psi front, 36psi rear with all shocks set to full stiff), just some minor oversteer.  Turned the rear shocks back a half turn and the car settled to be very nice to drive.  For the first time today I also ran in the STS class although the car still needs a lot of work in order to be competitive in the class.  Beats not having anyone to run against at least.

…and of course, here’s the video of the final run (now available in 720p HD!).  Clocked in at 0:40.505, which put me in 2nd place for STS:

As I am keeping track of event entry costs, this one is the first of the season and costs $20.

Got the front shocks in today.  Took about 2hrs to get both of them installed as the front install is very similar to the rear.  I went with the ‘Andy Hollis’ method found in the tutorial from miata.net again.

First things first, place the car on jackstands and remove the wheels.  The aftermarket intake was blocking the upper shock mount so I needed to first unbolt the holding bracket for the intake to move it out of the way.

Intake blocks the upper shock mount

Just like on the rear shocks you need to first loosen the center shock bolt (17mm) and then remove the upper shock mount bolts (14mm).

Loosen center bolt and remove upper shock mount bolts

The next step is to disconnect the front sway bar at the end link (14mm socket + wrench).  With all of these bolts keep notice on their orientation when you remove them so you can install them in the correct orientation afterwards.

Disconnect sway bar at end link

Followed by removing the lower shock mount bolt (17mm)

Lower shock mount bolt

In order to disconnect the upper A-arm to remove the shock you will need to back out the sway bar mounting bolts a bit.

Back out the sway bar mount bolts to make room for the upper A-arm bolt

Now the big one, the 21mm upper A-arm bolt.  Requires a 21mm socket and a 21mm wrench holding the nut on the other end to get this one.  Once its off you can slide it back to disconnect the upper A-arm and make enough room to remove the shock.  Make sure not to stress that brake line as the hub will be slack when the upper A-arm is disconnected.

Upper A-arm bolt (21mm)

With the shock removed (keep that white plastic piece for when you replace the shock back into the car!) it is time to compress the spring and then remove the upper mount.

Old shocks look tired...

Drill out the upper shock mount and the bump stop plate to 12mm.  Once again an unibit drill makes this cakewalk.

Both the upper shock mount and the bump stop plate need to be drilled out

Reassemble and decompress the spring, making sure to line up the spring and upper shock mount in its old orientation (mine were marked with a yellow dot on the upper shock mount and red dot on the spring).

Spring ready for decompression

Koni sport shock ready to install

With everything together, reassemble (remember to replace that plastic piece on top of the shock mount.  You may need to rotate the spring/perch/upper shock mount after the lower shock mount bolt is in to make sure the upper shock mount lines up with the bolt holes.

May need to rotate the upper shock mount and perch/spring to make sure the upper shock monut bolts line up to the hole

Bolt everything (except the sway bar) in reverse order but do not torque to spec just yet.  Now do the same on the other side…  The reason for this is to keep the sway bar out of the way when working on the other side.  With the other shock installed connect the sway bar on both sides.  I actually had to loosen the lower end link bolt in order to get the sway bar to reconnect.

The next step is to jack up the hub to take the load of the corner before torquing the bolts to spec.  The jack I used was a piece of shit and couldn’t get enough jacking height so I had to use some wood blocks to get the necessary height.  This is NOT recommended, but I was limited on resources.

Left fornt jacked up to hold weight of LF corner

The same goes for the other side, jack and torque to spec.  Replace the wheels and torque lugs to spec, remove jackstands.  I’ve scheduled an alignment job for tomorrow to get the car ready.  Remaining on the checklist is to redesign the camera mount, flush the brake fluid and to check the trans and diff fluid.

Initial impressions of the Koni Sport shocks.  On the softest setting they feel a bit smoother than the stock shocks though the placebo effect makes me think the car handles a slight bit more responsively too.  When the shocks are turned to full stiff it is pretty uncomfortable on public roads, but the car is definitely more responsive to steering inputs.  One main problem right now is the intake blocks adjustment on the front left shock, so I will need to fabricate something that will allow adjustment of that shock without having to detach the mounting frame for the intake tube.

Overall the ride height has increased by 0.5″ in the front and 0.875″ in the rear on the middle perch setting.  I will measure in a week to see if the ride height settles down any, though jacking up each corner before torquing should have eliminated making the ride height temporarily higher…

Decided to attempt the install of the Koni Sport Single-Adjustable shocks today, but it took much longer than I expected (first time!) so I only got the rears done.  I’ll finish off the install on the fronts this upcoming week and get the car into the shop to get an alignment before the weekend.

I had planned on taking pictures for the install process, however the camera ran out of battery almost immediately at the start.  I’ll make sure to get more pictures for the front install.  First of all I want to state that I used the extremely useful guide from miata.net.  The instructions are very clear so I’ll just skip going over them and just go over some of my opinions and views on the process.

When loosening the upper shock mount bolt and removing them it is probably best to make sure that you have the right tools.  14mm deep socket is better as it gives more clearance over the trunk floor.  On the left side you will need to work around the fuel fill lines and I found that having the wrench under the fill line worked best for me.

Loosen upper shock mount bolt (do not remove) and remove both bolts that hold the shock to the body

When working on the lower shock mount, upper A-arm bolt and the sway bar it is a good idea to hit them up with some penetrant or anti-seize the day before so they break easily.  The lower shock mount bolt is just a bolt that goes into the frame (no nut on the other side to remove), so only a 17mm wrench needed for this.  Remove the lower shock mount bolt, then use a jack to lift the lower A-arm up a bit to reduce the load on the upper A-arm bolt, this makes removing the upper A-arm bolt a bit easier.

Old bolts can be a bit stubborn. Use anti-seize or rust penetrant and plenty of elbow grease

Compress the spring on the old shocks once it is off the car and then transfer the compressed spring directly onto the new shock to assemble.  Do not decompress the spring until you have bolted back on the upper mount to the new shocks (the free length of the spring is probably like 12 inches and takes forever to compress by hand). [note:  the camera is dead by this point, so no more pix.  Sorry!]  The upper shock mount and the metal washer attached to the bumpstop need to be drilled out to 12mm in order to accommodate the Koni shocks.  A uni-bit drill piece is HIGHLY recommended and makes the task much easier!

When reassembling, attach the lower shock mount bolt first but do not tighten, then the upper shock mount bolts.  Once that is done use the jack to lift the lower A-arm a bit so it is easy to slide in the upper A-arm bolt.  Jack up the hub until it is lifting the entire corner load (i.e. that side of the car is off the jack stand) and then torque all bolts to specs.  The upper shock mount bolts for the stock shocks are 17mm, however the bolts for the Konis are 19mm and will require a deep socket in order to clear the adjustment tab.

First shock took just about 3 hours because I didn’t disassemble the spring compressor apart to attach it onto the spring and compressed the spring against the lower perch of the stock shock.  This resulted in having to decompress the spring to its free length (!) and then re-compress to get it around the Koni shocks.  The second shock took just about 1 hour, though a large amount of that time was trying to get the lower shock mount bolt to loosen and to line the bolt up properly when reinstalling the new shock.

I think the fronts will be much easier now that I have gotten the rears done.  More to follow later on this week.

The weather is finally starting to improve here and the car was pulled out of storage on 3/17/10 (special thanks to Tom W. for letting me keep the car in his garage over the winter!).  A fresh oil change (Mobil1 5W-30 Full Synthetic, M1-110 oil filter) today is the first step in preparations for the 2010 season.  I will flush the brake fluid next week (weather permitting) and check the brake pads/rotors for wear.

Koni Sport (Single adjustable) shocks to replace OEM shocks

The plan is to also get the newly acquired Koni Sport shocks on the car and a new alignment before the auto-x season opener on 4/11/10.  Currently it looks like I will be sticking with the stock springs for at least the first half of the season, though upgrades to the sway bars may be in order.

A quick summary of the first season: The goal was to buy and prep a car for the track in under $4000, and I’m glad to say mission accomplished. The final total was $3,822! To top it off I received the 1st place trophy in E-Stock from the Indianapolis Region SCCA:

Now to look forward to 2010!

For this second season (2010) I’m setting myself a budget of $1,000 for upgrades/maintenance and repairs. The shocks will need to be replaced as the front right was starting to show signs of leakage. I am also going to need a new set of tires and brakes at some point during the season, and if there are sufficient funds remaining I would like to do something about the large body roll on the track (sway bar or stiffer springs).  I will also be keeping track of entry fees, membership fees and registration fees to events this season to give an idea of how much it costs to run a car per season.

Just a recap of what has been going on since the last post of 2009…  The broken rear finish panel was replaced and the broken taillight was replaced with a set of OEM taillights (never did like the Altezzas anyways).  A generous friend (Tom) provided some garage space to stow the car away in winter and it has been sitting there since late November.  Once the weather warms up a bit the car will be brought back out and the frantic work on it will begin.  New parts to go on and fresh fluids (brakes, engine, etc) will be the first things on the menu.  The condition of the tires will be determined at the first auto-x of the season, though the plan is to upgrade to the Dunlop Direzza Z1 Star Spec which is now offered in a 14″ size for the first time.

Bring on 2010!