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!
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.
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…
Just playing a bit of catch up on the posts for the blog. A couple of weeks ago I ran in Tom’s ’99 Miata Sport for the IndySCCA points event #2 and came in 3rd again, though I am struggling to come to grips (no pun intended!) with the way the slicks behave in the dry. The car feels less responsive than my NA partly due to the suspension setup and additional weight, but mostly the width of the tires that Tom runs on the car (225 tread width). I will have to adjust my driving style to compensate for that in following rounds. I may have to try and force myself to turn earlier than I think I need to in order for the car to transition correctly when I actually want it to. For those keeping track of season entry fee costs, the auto-x adds another $20 to the tally. Adding in the cost of running the trackday at Putnam Park ($245), the season cost so far is already at $355.
IndySCCA Points Event #2 in Tom's '99 Sport
I also found someone to trade turn signals with on my car, opting to go back to a stock look. The turn signal inlets are gone, replaced with some stock indicators from a 94M Miata, with the daytime running lights modification.
New turn signal indicators replacing the turn signal inlets
As for upcoming events: The next one will be a trackday at Autobahn Country Club (Joliet, IL) with 10/10ths Motorsports on 6/19/10. The daytime will be run on the North course (1.50mi), with evening running on the full 3.51mi track. I will need to finish up some work on the brakes and remove the A/C system before then.
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.
Just a quick progress report since the last post. At the Grissom AFB auto-x the ambient temps were down in the low-mid 50s and although the car felt fine I did notice that there was an overall lack of grip. Also the previous 33/34psi setup did not work very well (possibly due to the high grip on the surface), causing some rolling beyond the wear bars on the tires. I upped the pressure to 35/36psi and it prevented roll on the sidewalls. There may be some issues with running these tires in such cold conditions without any chance to warm them up, hopefully at a trackday this won’t be as much of a problem.
Had some nice weather this weekend so I took the opportunity to finish off some of the work I had planned on doing to the car. This included a valve cover gasket change and an oil change. Used some Mobil1 5W-30 as it has worked well up till now, and went with a longer M1-110 oil filter (stock is M1-108) as per recommendations from a lot of the Miata forums community. Unfortunately I spaced out a bit and completely forgot to take a camera for pics. The only thing left to do is schedule an alignment job and get the pre-inspection sheet filled out before the trackday. Can’t wait, but hope that it’s a bit warmer than 50F out there…
I think I’ve finally found a good setup on the tire pressures for the Azenis. Started out running 32psi all around on a damp track but was getting a LOT of understeer + some excessive tire rolling onto the sidewalls. For the remaining runs I bumped the pressures up a bit, and ran the staggered pressure setup of +1psi in the rears to counteract the understeer, and settled on 33psi front, 34psi rear. This resulted in very neutral handling and exactly what I was looking for.
As for results for the day.. Finally had another car in the E-Stock class to go up against (a 2007 Honda Civic Si, which I now know was misclassed and should have been running in GS). With a damp and drying track it was definitely difficult to account for the level of grip changing for each run, however I managed to win the ES class again, and on the way also set the fastest novice PAX time of the day. Of course the weather had a lot to do with it (earlier run groups ran in wetter conditions), but I’m happy with setting a 43.xxx second time as my goal was to break 45s.
Double trophy day, and a good baseline for setup. I’ll need to work on some maintenance before the next event (valve cover gasket replacement), and then next time out I need to focus more on improving my driving.
Got to test out the new tires today at the IndySCCA Auto-X in Indianapolis, however the day did not go without its problems. With a strict time constraint on the location we were only given 4 runs each, and I wasted 3 runs because it turns out the tire pressure gauge I was using was reading pressures 8psi too low (i.e. 44psi showed as 36psi on the gauge!). So for 3 runs I was running pressures in the low/mid 40s (psi) front and rear, resulting in quite a significant loss of grip. Even with the tire pressures way off the summer tires offer a significant improvement on grip levels and response.
Final run, tire pressures set to at least the right ballpark
On the final run I borrowed an accurate pressure gauge, set the pressures to 35psi front, 36psi rear and went for it, basically not really having any baseline setting except previous auto-x where I have had more luck running slightly lower front pressures (albeit on different tires). The car suffered from some oversteer on the final run, however I was still able to shave over a full second off the time from run #3. Looks like I need to invest in a better tire gauge… Best run today: 32.871. With a few more runs and some tweaking of the tire pressures I believe I could have cracked into the 31 second range.
Once again there were no other E-Stock cars running, so I ended up on the day with the trophy for the ES class. Hopefully more to come with some competition next time.
My first trophy (considering I didn't claim the trophy at the last event)
Thanks to Justin for grabbing pics of the car in motion. Hopefully you’ll run your WRX next time around!
Edit: Instead of posting a track map I found a video posted from a E46 M3 driver on his run: http://vimeo.com/6143126
Got around to cleaning the car today and took some pictures, now the Current Specifications page has up-to-date pictures of the car in its current spec. Now with the rollbar + summer tires on the car:
