Project Trackday

Turn 10 at Putnam park

I don’t know where I got this target benchmark of 1:30.x for my time at Putnam Park.  I believe it was a time I read off James’ laptimer when he did some chase-cam footage for me last time I was there.  So with that in mind, my goal for the weekend on the new wheels and tires was to beat a 1:30.x lap.  I have to apologize for the lack of photos/video from this weekend as my camera battery died early on in the day, resulting in only half a session being recorded.

With it being the first time out on new wheels and tires I was back to square one in terms of setup.  I started out with 34psi (cold) all around and set off to my first session at 9:30am, ambient temperature in the high 60s.  Immediately it was clear that the Star Spec tires had a lot more grip than the Azenis they replaced, as I could comfortably carry more speed in the corners.

I had an instructor ride along in the second session to give me some pointers around the track and to pick up some speed.  Gained lots of useful advice on how to approach some of the tricky corners, especially corner 2, 4, 8 and 9 (thanks Aaron!), then jumped in a spec suspension’d Miata for a ridealong to watch and learn.  I experimented with allowing the car to slide out towards the track out kerb instead of driving towards them.  This allowed for much higher corner exit speeds.  Lowering the tire pressure resulted in better cornering, allowing me to turn the wheel less and scrubbing less speed off in the corners (especially turn 2).  I can still go faster through some of the corners if I trail brake into them to start the car rotating, something I will need to keep practicing.

For the 3rd session I lowered the tire pressures to 32psi in each corner and set off.  The turn in and cornering grip felt even better and I was able to further reduce the steering angles to accomplish the desired line.  Marla was on board and timing my laps with a stopwatch and clocked several laps ranging between 1:29.7 and 1:30.4 in a row, only interrupted when I approached traffic.  Onboard footage for the first half of the session below:

I had beaten the previous benchmark of 1:30.x, but only barely. I also started to experiment with carrying more speed into the corners and minimizing braking.  During the 5th session I missed the turn in for corner 4 by a split second but decided to just ride out out without lifting the throttle anyways, ended up dropping the rear right wheel beyond the track out kerb and spun it around, across the track, ending up on the inside of turn 4 after a full 360.  Surprisingly calm feeling after spinning the car, just wish I had it on video to review…

On the subject of video review…  I was a bit displeased with my lap times as I felt I was going much faster but only managed high 1:28s, but after reviewing the old footage from Putnam (on the Azenis and old wheels) I realized that I was running 1:34s before, so a 5-6second/lap improvement is definitely something I am happy with!  There is still much more room for improvement but I’m sure it will come with more seat time.

Putnam is notoriously hard on tires but the Star Specs do extremely well...

Just a few other observations on the new tires… When I tried out running lower tire pressures (lower than 32psi cold) the car would have a tendency to hop in the corners a bit.  Although this was the only way to use the entire contact patch (based on visual inspection of the tread wear), it resulted in less than ideal feel and worse grip than when I had higher tire pressures.  I will need to get more negative camber in the alignment to use the tires properly!  Overall, I think 32-33psi cold felt just about right.  The tire squeal is a much lower pitched than the Azenis, instead of a high-pitched squeal it is more of a low howl.

New wheels got plenty dirty and picked up lots of rubber bits

So I set myself a season budget of $1000 for maintenance and upgrades earlier this year, but like many drivers before me I was bitten by the speed bug and couldn’t resist spending more to make the car faster…

TRMotorsport C1 15x7.5 on 205/50R15 Dunlop Direzza Z1 Star Spec

I caved and got a set of TRMotorsport C1 wheels in 15×7.5 ET42 wrapped in a set of Dunlop Direzza Z1 Star Spec tires.  The tires are 10mm wider than the 195/60R14 Azenis that they are replacing.  Going with a much wider wheel (50.8mm) with only a 10mm wider tire tread should result in more responsiveness.   I will get to test out the new tires/wheels this weekend at Putnam Park.

New (wider) shoes for the miata.

So how much is the damage?  The total for the wheels/tires (including mounting, balancing and lugnuts) was $820, putting the season total way past the $1000 budget limit to $1570.  Oops.

Thanks a million to DL, Nathan and George for driving across the country to deliver these tires!

Can you spot the change?

More to come…

Another fun test’n'tune event at Gingerman Raceway yesterday.  I got the opportunity to try out the new front brake pads and also experiment a bit with my line at the 2.21mi 2010 layout course.  Firstly I have to say that I am very happy with the performance of the Carbotech XP10.  With the Yellowstuffs I was finding that I had to press harder on the brake pedal as the pads got up to temperature, but on the Carbotechs the bite feels a lot more consistent between cold and hot.  Overall the braking power between both compounds is hard to judge because it feels like there is now too much front bias as the XP10s have more bite than the EBCs.  That’s not to say they have more stopping power, but just that the brake balance is a bit off.  I will either need to change the rear pads/rotors to Carbotech XP8/XP10 or consider getting a brake proportioning valve installed.

No open-wheel cars showed up, therefore the 3hr test’n'tune was split amongst two run groups, with 1.5hrs of track time per group.  As for the event, there were a few drivers in the novice group that had never been to Gingerman before so the first session was run under full-course yellow (no passing).  I went out on track first but by lap 3-4 was catching up to the back of the group so I decided to pull in and request some open track space.  Back out again and a further 2-3 laps into the session I’m back stuck behind again.  With no point-bys and basically getting 1 lap of running between warm-up and cool-down laps I decided to scrap the session.

After the run the course director suggested that I try running with the intermediate group to see if that would get me some more open track.  Obviously I was slower but at least I could point-by the faster guys and focus on my own driving.  I tried different lines and shifting during the session, setting several 2:04.7s laps (about 4 laps timed at 2:04.7 during the session).  That’s a slight bit slower than the times I estimated from reviewing video footage from the last time at Gingerman (2:02 +/- 1s) but the track and ambient temperature was also about 15F cooler, and the Azenis are probably closing in on the end of their usefulness.  All in all I feel like I was driving pretty hard on the tires so I’m not sure where the discrepancy is in the timing, though I will review the on-board footage in more detail later.

(note:  after reviewing the previous footage it looks like I was running a low 2:07 last time around, so a 3 second lap improvement this time around is a pretty productive day!)

At least I wasn't being easy on the tires...

On-board footage from session 2 of 3 with the intermediate group:

$60 entry fee for the test’n'tune (not bad for 1.5hrs of track time!) puts the season entry fee total to $815.

Driving Tom's '99 Sport

IndySCCA points event 5 today, my fourth run in CS for the season in Tom’s ’99 Miata Sport.  Unfortunately Tom was feeling a bit under the weather today so I had to lead the charge against 3 other drivers in the class.  Was able to best both drivers in the NC Miata, but lost out to the Pontiac Solstice by a considerable margin.  The 2nd place result now puts me in 1pt behind 2nd place in the Indy region C-Stock season standings, though 12 points behind 1st place.

Not a class win, but a decent drive for 2nd place today

I’m starting to find my rhythm running on the Hoosier A6s, setting the car up with significantly stiffer settings on the rear shocks and the fronts on full soft. At least I am starting to extract some of the potential that the tires have to offer, even though there is still a lot to learn about them.

Another $20 to the season entry costs, putting the total up to $755. Will be heading up to run another Test’n'tune Tuesday evening in my own car, can’t wait…

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.

Got to run at Gingerman Raceway for the first time yesterday afternoon for their mid-week test’n'tune.  The sessions were run on the newly revisied 2.21mi circuit.  Test’n'tunes are run Tue/Wed/Thurs from 5:30pm-8:30pm with the track time split amongst three run groups.  Overall a really great way to spend an afternoon, just a shame its so far away otherwise I’d probably go much more often!

The newly paved section and some of the new patches of surface are a bit slippery but I’m sure this will improve over time.  I found that the course had a few challenging corners, especially turns 5-6 and the 7-8-9 sequence with some high speed transitions, but this is what makes this track so much fun.

The cost for the test’n'tune was $60, putting the season running cost up to $735.  The front brake pads are probably near finished at this point so I will need to check on them and decide if I need to replace them soon.

Here is some on-board footage from session 3 of the day:

Quick update on the progress for the 2010 season.  Ran another auto-x in Tom’s CS ’99 Miata and came in 3rd place, losing out to the RX-8 in 2nd by 0.022 seconds.  Still not happy with my driving on the Hoosier A6 tires but I’ve at least picked up on a few things to work on in the next events.  Season entry costs now up to $675.

As for the ProjectTrackday Miata, the cost of an oil change ($30) plus some other various bits (power steering depower plug, $20) was offset by the sale of the power steering pump and belt, so the season total still stands at $685.

Gingerman Raceway Track Map

Up next is a test’n'tune at Gingerman Raceway (South Haven, MI) tomorrow evening.  Its another new track for me so I’ll be reviewing youtube videos to try and learn the track in the meantime.  Video + writeup to come after the test’n'tune…

Photos in the current specifications page are now up-to-date.